Comet Probe Philae To Deploy Drill As Battery Life Wanes

An anonymous reader writes With less than a day of battery life left, The European Space Agency's Philae probe will begin to drill for samples even though the drilling may dislodge it. From the article: "Philae is sitting in the shadow of a cliff, and will not get enough sunlight to work beyond Saturday. Friday night's radio contact with the orbiting Rosetta satellite will be the last that engineers have a reasonable confidence will work. The team is still not sure where on the surface the probe came to rest after bouncing upon landing on Wednesday. Scientists have been examining radio transmissions between the orbiter and the lander to see if they can triangulate a position. This work has now produced a 'circle of uncertainty' within which Philae almost certainly lies."

Comments

Drill

[Anonymous Coward]

Drill baby, drill!

Re:Drill

[zeroryoko1974]

Your drill is the drill that will pierce the Heavens!

Re:Drill

[Anonymous Coward]

Back to work! I’m now drilling into the surface of #67P #CometLanding @Philae2014

Re:Drill

[Anonymous Coward]

Ask #shirtstorm guy, I'm sure he know!

Re:Drill

[Anonymous Coward]

Fracking rock!

Re:Drill

[Anonymous Coward]

And it STINKS, too!!!

Can't trust robots

[Anonymous Coward]

A man has to get there and do all the hardwork himself.

Re:Can't trust robots

[Eunuchswear]

What state would the man be in after 10 years in space?

How big would the initial launch have had to be to keep a man alive for 10 years in space?

Re:Can't trust robots

[Lumpy]

About the same as a typical video gamer.

Re:Can't trust robots

[morgauxo]

What an insulting thing to say about the astronaut!

Re:Can't trust robots

[Anonymous Coward]

Still more capable than a useless arduino in a shoebox that cost a billion euros.

And when something doesn't go as planned, as inevitably happens at some scale, we get to listen to people complaining about the useless person stuck there that costs 100 billion euros. An the question shouldn't be if a person is more capable than a $1 billion euro robot if the person would cost way more to get there, the question should be if a person would be more capable than 100 $1 billion euro robots. For quite a lot of science work, that is a hard sell, even if a significant fraction of the robots failed, because then we could send them to many different comets and adapt and do different things with them in ways that a person couldn't even do if they were there (e.g. new instruments that require more than just duct taping together parts a person would have).

Re:Can't trust robots

[Anonymous Coward]

That's a strange assumption. Whence did it come?

I did intend to say maybe 10-100 billion, but went with the higher end because of how expensive it is to get people just considering how expensive it is to get people to near-earth orbit and inflation adjusted prices for the Apollo program. It could easily cost a lot more than that, but even if you take the lower bound of $10 billion, that still can buy a lot robots for ten times the price, especially since a large fraction of the cost is development costs. With few exceptions, space agencies seem to focus on using money to develop new and better probes instead of producing a few of the same type, even though that is an option.

Probably yes.

And from someone complaining about assumptions. It really comes down to what science goals you are trying to achieve. If your goal is to move manned flight ahead, then of course you need to do things with more people, although don't need to disguise it as being done to improve success rate of missions like this. If your purpose is to do composition analysis of materials, and measure mass distribution in comets and asteroids, especially in some sort of comparative sense, then a boring probe would be great at doing repetitive scans.

At this price and success rate, hardly.

Seriously, are you dense enough to think that a sample size of one is a great estimate of success rate? Which is also not perfect for manned missions either? And also think that we could send a person for the same cost as a single unmanned mission, and couldn't send multiple unmanned missions for the price of a single manned mission?

I wasn't specifically asking for you to go, there are quite a few people who have more skills than being able to duct tape.

I only design and build high resolution spectrometers for a living, including ones that get used in laser induced breakdown spectroscopy. The issue is not that I only know how to use duct tape, but that I know exactly how much equipment and tooling is needed to build such instruments, considering I've built them from scratch in a machine shop myself. Once constructed, a lot of instruments will have very limited flexibility to be changed with portable tools. They won't have a full machine shop there, and even then a lot of specialized components can't be made in a normal machine shop and require a lot of other special tools and services. A person could still tweek something in situ. But considering even a robot mission like this has over a dozen different instruments, it isn't just about knowledge of how to service all of them, but also time. It is bad enough screwing around with alignment on an optical device for a whole day because of a spec change or design fault when you have a nice open lab and that is the only instrument you are working on at the moment. At some level, regardless of the skills of the person, they're options will be limited to banging on something a few times before moving on to something else with less risk of eating up too much time.

But as you said, I guess I don't have enough skills to have an opinion on such things, and am sure that you aren't making any assumptions or superficial judgements despite the lack of content in your post.

Re:Can't trust robots

[beelsebob]

That's a strange assumption. Whence did it come?

Well, a mannad mission to mars is estimated to need roughly 800 Mg of equipment lifted into space, and then slung out onto a mars intercept orbit. The orbit required for this comet intercept is thankfully pretty similar (it needs only to get around mars to do a gravity assist back to earth, for a few more gravity assists to get out to jupiter). But a mission to mars would take only 2 years, this requires 10. That means 5 times as much food, and I'd bet a bunch more equipment. So lets conservatively guess at 1.6Gg of stuff that needs to be lifted into space.

Meanwhile, the launch mass for the robotic longer was a mere 100kg. So, even if you assume that you can scale the amount of fuel needed to get all the stuff up there linearly (which you can't), you're looking at 16000 times the cost, i.e. $1.6 trillion.

To me, it appears that the above poster underestimated quite a lot, not overestimated as you'd like to believe.

Re:Can't trust robots

[HairyNevus]

What, everything didn't go 100% according to plan in a groundbreaking attempt to land a probe on a comet? Quick, let's easily write off the whole endeavor to seem cool!

Re:Can't trust robots

[Anonymous Coward]

And yes, I notice now that "they're" is used instead of "their", but sometimes one doesn't expect proofreading to be worth the effort around here, as half the time the person being argued with doesn't read the posts they respond to anyway.

Re:Can't trust robots

[Anonymous Coward]

Launch mass of Rosetta was 3000kg (3Mg). The lander mass is 100kg. Only counting the mass of the lander and not counting the mass of the Rosetta craft that got it there is like only counting the mass of the astronaut and not the mass of the ship. You still have a large multiple, but 30 times less than you calculated.

Re:Can't trust robots

[Anonymous Coward]

"when we talk about those,"

Like now, considering the Philae lander has three different spectrometers on it? Or how every Mars rover going back to Sojourner had various types too? Seems pretty relevant for discussing what kind of science work is done on these missions. What type of equipment experience do you have that is relevant to the equipment these missions actually use?

Re:Can't trust robots

[Waffle Iron]

What state would the man be in after 10 years in space?

With adequate life support, as good as new,

Hardly. Cosmonauts returning from Mir after only one year in space could barely function once they returned to earth. I kind of doubt that anybody would physically survive 10 years in zero-G, even assuming they've survived the long-shot odds of no fatal spacecraft malfunctions in 10 years.

Not to mention that they would gone bat-shit insane by that time, after they realized that they've sat in a tiny tin can eating stale cat food and being blasted by cosmic rays for over a decade just so they get a sample of some crappy small-time comet; a job that could be easily done by a robot.

Re:Can't trust robots

[Anonymous Coward]

So apparently you're suggesting the discussing capabilities of space missions should only be done by those not knowing about the things they actually do?

Re:Can't trust robots

[Anonymous Coward]

You are completely neglecting the science advancements we'd gain simply by building the necessary components to send the man there in the first place! SCBA ring any bells?

Re:Can't trust robots

[rjstanford]

Launch mass of Rosetta was 3000kg (3Mg). The lander mass is 100kg. Only counting the mass of the lander and not counting the mass of the Rosetta craft that got it there is like only counting the mass of the astronaut and not the mass of the ship. You still have a large multiple, but 30 times less than you calculated.

So only 500X? Oh, well then. Let's get going tomorrow!

Re:Can't trust robots

[f3rret]

...I kind of doubt that anybody would physically survive 10 years in zero-G, even assuming they've survived the long-shot odds of no fatal spacecraft malfunctions in 10 years.

Oh, I think they'd survive just fine (appart from the numerous radiation induced cancers, natch), it'd be the whole 'returning to Earth' that'd cause problems.

plan directly from ESA

[Anonymous Coward]

SD2 got an opportunity: plan is to operate soon in very risky conditions to serve @Philae_COSAC and possibly @Philae_Ptolemy on @Philae2014

#esahangout

[Anonymous Coward]

We'll be hosting an #esahangout on #cometlanding from ESOC today at 13:00 GMT/14:00 CET, details shortly plus.google.com

Re:#esahangout

[Anonymous Coward]

Join us at 2 for #cometlanding briefing with @ESA_Rosetta and @Philae2014 experts from @esa @DLR_en @CNES @NASA

Re:#esahangout

[Anonymous Coward]

The hangout was already over when you posted on Slashdot. Watch the replay.

no harpoon use

[Anonymous Coward]

In the end, I won’t be firing my harpoons, just in case. Safety comes first! @Philae2014 #CometLanding

Re:no harpoon use

[Anonymous Coward]

Now that I’m safely on the ground, here is what my new home #67P looks like from where I am. #CometLanding pic.twitter.com/gFmt8Ldvpa

Re:no harpoon use

[Anonymous Coward]

Back to work! I’m now drilling into the surface of #67P I’ll give you updates as soon as I can! #CometLanding

Re:no harpoon use

[Anonymous Coward]

Another stunning image of my new home taken by ROLIS during #CometLanding yesterday, when I was just 40 m from #67P pic.twitter.com/I8OZ5kXjXA

Huh

[koan]

It seems to me the design and/or planning of this mission were poorly thought out, it's obvious the comet has a rough surface, they knew there would be shadows.
Why can't it back off and take another run at it?

All that distance to be screwed by being askew.

Re:Huh

[Anonymous Coward]

@ESA_Rosetta I was quite a bit away from you, wasn’t I? http://ow.ly/Ed3Dc #CometLanding

Re:Huh

[jandrese]

Part of the problem is that some of the systems intended to help the probe land properly aren't working, like the thruster on top.

Some of it seems like just poor planning though. How hard would it have been to install a bright LED on the top that Rosetta could see from a few km away? LEDs don't weigh much and you only have to run it while Rosetta is taking the picture so the power budget would be nominal. It seems better than not being able to find the lander because it is in shadow.

Re:Huh

[Eunuchswear]

Because Philae does't have any manouvering capability (appart from some springs).

And even if it had, with a 2x28 minute round trip time who would give the orders?

Re:Huh

[Scottingham]

"It seems to me the design and/or planning of this mission were poorly thought out"

Is the funniest fucking thing I've heard all day. Do you have any idea how well thought out this mission was? FFS look at the trajectory it took 10 YEARS(!) to get to the comet. And you think they overlooked the fact that the comet is craggly?

Jesus-Dunning-Kruger-Christ.

http://www.esa.int/esatv/Video...

Re:Huh

[Anonymous Coward]

All hail the armchair asteroid mission planning experts. Why they keep hiring professionals to do these jobs is beyond me.

Re:Huh

[gstoddart]

It seems to me the design and/or planning of this mission were poorly thought out, it's obvious the comet has a rough surface, they knew there would be shadows.

I think that's pretty unfair.

It was launched 10 years ago, and has been spiraling around the solar system doing fly-bys to get going fast enough to match speed ... and then it got close enough to land, even though it wasn't perfect.

I'm more inclined to think this is a demonstration of just how damned hard something like this is, and that no matter how much you try to plan for stuff, you can't know everything until after it's happened.

I think a bunch of whiny nerds saying this was poorly thought out is some pretty lame arm chair quarterbacking.

Tell you what, when your probe lands on a comet, we'll all line up to tell you what a shitty job you've done.

Oh, wait, you don't have a probe and wouldn't know how to make one, right?

Re:Huh

[Anonymous Coward]

This is Slashdot, where the ramblings of a neckbeard who hardly passed high school Rocks for Jocks is held in higher esteem than the thoughts of real scientists because of a low UID.

Re:Huh

[wonkey_monkey]

No, the design and planning were rigorously thought out - certainly rigorously enough to withstand five minutes of bewildered pondering from a Slashdotter after the fact.

The actual problem here is that landing on a comet is really hard.

Why can't it back off and take another run at it?

Ask the guys at ESA. They could probably explain in great detail exactly what the probe is and isn't capable of and why they took the decisions they did after years of planning and cost-benefit analyses. They probably even have graphs.

Re:Huh

[Anonymous Coward]

Come one, clearly some dude on Slashdot is better at landing on a comet than those people.

He's done it like twice in KSP.

Re:Huh

[Anonymous Coward]

Exact. What's with a washing machine? They should have sent an armchair. And a dressing gown.

Re:Huh

[pla]

Y'know, I realize that all the self-righteous "Papa knows best" crowd recently learned the term "Dunning Kruger", but casually tossing it out as a way to instantly shut down any discussion works about as well as complaining about "privilege".

More importantly - For all you know, koan works for the Mars Rover program, and has a legitimate right to mock the ESA's lack of foresight.

On a purely practical level - Yes, more instruments means more weight. But to have no maneuvering capabilities, not even the ability to flip itself over if it landed on its side, or make short hops around the surface - Keep in mind the gravity here - A tiny piston slightly off-center on each side of the cube would have added a few hundred grams and meant a billion dollar mission wouldn't die later today because of shadows, of all things.

Re:Huh

[Lord Crc]

Time to audit the books to see who pocketed the money a more robust design would have addressed.

I think you guys should play some Kerbal Space Program and see just how much more fuel you need at every stage just to put an extra kg of equipment on that lander.

Re:Huh

[Anonymous Coward]

Isn't the whole problem that they assumed a softer (ice) surface?

Re:Huh

[Anonymous Coward]

Time to audit the books to see who pocketed the money a more robust design would have addressed.

Yeah... because that is how such projects work, where they get a blank check and can make changes to the fundamental mission specs and pocket the money difference. It is not like there is extensive cost-benefit analysis done before the main part of such projects get funded, spelling out the costs and risks of different sets of capabilities, with a line drawn by the administrators when a final budget and schedule is worked out.

Re:Huh

[Dr. Evil]

"How hard would it have been to install a bright LED on the top that Rosetta could see from a few km away?"

If you were to drop the LED frequency into the radio spectrum you could reduce the power requirement further.

Re:Huh

[Anonymous Coward]

"If I don't understand it, it must be easy."

Re:Huh

[Anonymous Coward]

It's true that the landing was a phenomenal accomplishment, however ALL of the systems designed to secure the probe failed, and these failures had nothing to do with the nature of the comet surface. I wouldn't say this was poor planning. It was a failed engineering design.

Re:Huh

[gstoddart]

Isn't the whole problem that they assumed a softer (ice) surface?

Look, unless you're a friggin' rocket scientist, or believe they had additional information they didn't use ... summarizing anything as "the whole problem" is kind of childish.

Based on your vast experience of landing on comets after a 10 year journey, do you think you have a better sense of what the assumptions about the hardness of the ice should have been? Maybe you should have shared that with them.

Lots of smart people worked on this, took all they knew and could surmise, and made choices with the best available information, and using the technology and money available to them.

I'm sure as heck not going to say "well, if only they'd done this it would have worked". I know I'm not qualified to do that, and I'm quite certain most of us on Slashdot aren't either. In fact, I'm betting the people who are qualified are all thinking this was a monumentally difficult task. NASA isn't sitting around going "Ha ha!"

To me, even what they did is some pretty mind-boggling engineering. But in interviews I heard over the last few weeks, they still knew there were risks and uncertainties.

It sucks, but unless you're more qualified than the entire team who did this, you have to realize this is still an incredible feat.

I won't even claim this to be an accurate analogy: But this is kind of like hitting a target in China from New York, using a home made gun, in the dark, and while both you and the target are moving.

Me, I'll applaud the ESA and everyone involved. Success for this kind of engineering includes all of the stuff that got you there. Getting far enough to have a failed landing is still a huge undertaking.

Re:Huh

[Anonymous Coward]

Oh, wait, you don't have a probe and wouldn't know how to make one, right?

You know koan works on the Mars Rover project, right?

Re:Huh

[Anonymous Coward]

That's why they gave it batteries that last long enough to fulfill the primary objectives of the lander.

The solar panels were for the icing on the cake. Or rather the icing on the icing of the cake - most of the scientific relevant data is collected by the orbiter.

GP is right - there's no other place where the gap between actual and imagined capabilities is so dramatic as on Slashdot. I really wonder where this overestimation of the own capabilities coupled with an uncalled-for arrogance comes from.

Re:Huh

[butalearner]

"It seems to me the design and/or planning of this mission were poorly thought out"

Is the funniest fucking thing I've heard all day. Do you have any idea how well thought out this mission was? FFS look at the trajectory it took 10 YEARS(!) to get to the comet. And you think they overlooked the fact that the comet is craggly?

Jesus-Dunning-Kruger-Christ.

http://www.esa.int/esatv/Video...

And Philae bounced twice, finally settling in two hours after first touching the comet, which is enough time for the comet to rotate almost 60 degrees. The two systems meant to prevent bouncing - the thruster and the harpoons - failed, so it ended up some kilometer away from the carefully chosen site. That we are getting any science at all after that potentially mission-killing news is just fantastic.

I'm hoping they make some last-ditch effort to have Philae try to jump over to another part of the comet to get more sunlight, though I'm not sure what kind of resources they have to try it. Can they command the drill and/or the legs to jab downward relatively quickly? Command the harpoons to fire? I don't know, but you can bet this will be part of the design on future missions. I actually did some work on this, which made hopping around a key part of the mission.

Re:Huh

[Anonymous Coward]

>Y'know, I realize that all the self-righteous "Papa knows best" crowd recently learned the term "Dunning Kruger"

Are you stupid? The term was not recently learned. The realization was that Slashdot has become Slashderp because of all the clueless people who think they're smart because they lack the ability to self-assess. Do you have a better term for that than Dunning-Kruger?

Re:Huh

[tnk1]

I doubt that anyone who worked in any serious capacity for the Mars Rover program would mock these folks. They know everything that could go wrong in ten years of space travel.

Re:Huh

[Anonymous Coward]

I agree it was still a very impressive achievement. I just know there are some who have been questioning the "dirty snowball" theory of comets. Anyway, this AC claims it was not due to assumptions regarding the surface:
http://tech.slashdot.org/comments.pl?sid=6057825&cid=48385797

Re:Huh

[tnk1]

You're right. For a billion dollars, they could have built and launched an Iowa-class battleship, which totally would have landed robustly on any comet or planet that you'd like. And at 58,000 tons, could easily have stuck to the surface of any silly comet.

Because obviously, the only consideration in launching missions like these is robustness of the package.

Re:Huh

[meta-monkey]

To be honest, the trajectory calculations aren't that difficult. It's fairly cut and dry math and there have been computer programs to calculate this stuff for decades. It's cool, don't get me wrong, and the margin for error is a lot smaller than trying to hit Jupiter, but it ain't exactly rocket science.

Wait...

Re:Huh

[Anonymous Coward]

As a janitor.

Re:Huh

[Savage-Rabbit]

"It seems to me the design and/or planning of this mission were poorly thought out"

Is the funniest fucking thing I've heard all day. Do you have any idea how well thought out this mission was? FFS look at the trajectory it took 10 YEARS(!) to get to the comet. And you think they overlooked the fact that the comet is craggly?

Jesus-Dunning-Kruger-Christ.

http://www.esa.int/esatv/Video...

True, it's easy to throw snide comments at the people who designed this mission but until now nobody really even knew any details of what the surface of a comet looks like. Furthermore landing on Mars is difficult enough, the success rate for landings on the Martian surface is something like 30%. Getting a probe to rendezvous with a comet and land on the surface is a way bigger achievement. Finally I'm not exactly surprised that some systems failed after almost a decade in space. I just hope they manage to milk the maximum amount of data out of this probe.

Re:Huh

[Anonymous Coward]

Everyone knows you use Yamato-class battleships for interstellar travel!

Re:Huh

[pla]

They know everything that could go wrong in ten years of space travel.

...Except landing in a shadow in the most important 30 seconds of the mission?


Though overall, I agree, and offer the ESA a hearty congratulations - Well done! Just somewhat disappointing that the coolest part of the whole mission, while "technically" successful, won't get to do anything more than drill a few small holes.

Re:Huh

[jandersen]

It seems to me the design and/or planning of this mission were poorly thought out, it's obvious the comet has a rough surface, they knew there would be shadows.

The planning for this mission was started 30 years ago - in 1984; 5 years before the Berlin Wall came down, 7 years before the Soviet Union was dissolved, 3 years after the first IBM PC was released. This mission has been compared to "throwing a hammer from London and hitting a nail in New Delhi".

Imagine that - the IBM PC with its 16 KB of RAM was advanced, for gods' sakes! It may be that it is easy to sit in front of your top-of-the-bloody-range games PC and imagine that 'it can't be that hard', but the fact is that it would be very hard even today, and the fact that we actually have anything man-made touching the surface of an actual comet at this moment is mindblowing. It was only really designed to run a few measurements on its main battery, and even that was considered beyond what we could reasonably expect; the secondary battery and solarpanels were more of a "you never know, we might get lucky". This mission has already been a huge success.

Re:Huh

[Remus Shepherd]

The legs are 'springy' and can be used to hop the lander off the surface. The problem is that they can't tell the orientation of the lander. If it's in a cave, the legs might hop it deeper into shadow.

Re:Huh

[Scottingham]

Time out! Are you saying I'm in the 'Papa knows best' crowd proudly displaying my new knowledge of the D-K and using it as such to shut down discussion? I feel like there's some irony somewhere in there...perhaps the D-K effect doesn't mean what you think it means? I do like the idea of a self-proclaimed D-K expert though, deliciously recursive. If anything I'd say it is a gauntlet-throw to put up some actual citations or evidence or get off the lawn.

If Koan had a modicum of expertise I'm sure he would have cited it prominently. Then again, he also probably wouldn't have said anything knowing that every cubic cm and milliwatt was accounted for.

I realize that it is frustrating seeing such a badass feat of astrophysics be humbled by a shadow...but...

If wishes and buts were clusters of nuts, we'd all have a bowl of granola!
(Jellineck, Geoffrey et al 2000)

Re:Huh

[Anonymous Coward]

They should have just used the transfer to object, and landing assist in their MechJeb. Or did they forget to add it before launch, I've done that before. Oh sorry, too much Kerbal.

Re:Huh

[jandrese]

Only if the Rosetta spacecraft has a camera tuned to that frequency. Lower frequencies add more uncertainty to the measurements too.

Re:Huh

[nick357]

I know!! Its so simple: just land a little craft on a comet as it flies through our system! Come on people: its not rocket science!

Re:Huh

[tnk1]

I think JSA is holding out to use Yamato on a mission where it's Wave Motion Gun could have maximum effect.

Re:Huh

[bluefoxlucid]

Well, apparently they planned to launch with the gravity assists and eddies needed, and to intercept the comet's trajectory. That's macro-scale planning: "I'm going to go grocery shopping at Big K-Mart".

They apparently didn't plan back-ups for parts failure (thruster on top), landing anomalies (bounces around), losing track of the probe, or landing in shadow (couldn't make it mobile enough to move to a lighter place). They also didn't consider the cost in delivering a payload, versus the cost in delivering a slightly larger payload--two probes, which is less than two probes and two launchers and two fuel loads. That's micro-scale planning: "I need to carry a second credit card in my wallet in case I run low on cash or the first has a mag strip failure".

It's certainly easier to plan a mission that can get there and do its work if all goes well compared to if things go wrong. Realizing that something can be done and drawing up the plans to point-and-shoot isn't "well thought-out"; risks and contingencies are what make a plan well thought-out.

Re:Huh

[butalearner]

The legs are 'springy' and can be used to hop the lander off the surface. The problem is that they can't tell the orientation of the lander. If it's in a cave, the legs might hop it deeper into shadow.

I understand why they haven't tried it yet, but if it's about to run out of juice anyway, there's no reason not to give it a shot.

Re:Huh

[bluefoxlucid]

It's a potential opportunity risk analysis problem: the panel was added to take advantage of the opportunity of greatly increasing your ROI by having a long-term operable probe.

Applying the small costs additional to add tracking or mobility so the probe can recover from landing somewhere unfavorable (there is an entire dark side of the comet) potentially has huge returns in additional scientific data gathered: even absolutely minor, unique data is data you can't get without funneling billions of dollars and years of space travel into a comet excavation mission, so any additional data gathered is billions of dollars cheaper than it otherwise would be.

If the probe turns out like the mars rovers--able to operate for months or years on solar power, possibly occasionally powering down for a few days or weeks to let the batteries recharge for laborious drilling and analysis--then your small additional investment pays enormous dividends. If the probe is simply able to gather more data than predicted, but the data is good and interesting, your small investment is still paying off. If the probe simply fails, the small additional investment costs you little compared to the vast base cost of the mission itself.

This type of analysis tells you when to capitalize on risk opportunities. If you can turn a 10% likelihood of gathering 1% additional ROI into a 95% likelihood by adding 0.001% to the cost, you do that. You should look at all risks and combine as much mitigation as you can to minimize the discrete cost of each and maximize the total opportunity exploitation and total risk mitigation, and then add contingencies (alternate plans) which take effect at possible cost (maybe you can do X and Y, and it's expensive to be able to do BOTH, but you can implement the capability to do EITHER and sacrifice the other for cheap), but only when the threat or opportunity presents itself in earnest.

Re:Huh

[Anonymous Coward]

Yes, if only they had detailed mapping images of a comet nucleus before they sent a mission to orbit and map the surface of a comet nucleus in detail for the first time.

Of course, in reality they spent the last couple of months mapping before launching Philae, and picked a nice, smooth spot that they hit just about perfectly. And they spent about a decade before that of planning, including the possibility the surface would be rough. And they designed the lander with shock-absorbing legs to deal with an irregular surface. Oh, and they were guessing maybe ~75% chance they'd land successfully given the tremendous uncertainties.

It landed, bounced three times, and survived intact to take pictures and run almost all the experiments despite not attaching to the surface. I'm marking that in the "success" column.

Re:Huh

[CaptainLard]

Back off and take another run? Think outside the box man. The obvious thing to do now that we have an orbiter circling the comet at 10km and can see it in exponentially more detail than we could have ever hoped to from earth.. EVER...is use the time machine to send that information back to the early 90's when they started designing the lander.

Seriously, have you seen the earth observations? They're like 8 pixels.

Re:Huh

[Anonymous Coward]

More importantly - For all you know, koan works for the Mars Rover program, and has a legitimate right to mock the ESA's lack of foresight.

Regardless of one's background, one should be able to realize that if they put just an opinion and not much actual content to explain and backup their point, or even lack much of a specific point in the first place, no one will be able to tell the difference between what they said and what some armchair expert pulled out of their rear. The statement becomes nearly useless even if great insight and experience went into making it.

Re:Huh

[Anonymous Coward]

They apparently didn't plan back-ups for parts failure (thruster on top), landing anomalies (bounces around), losing track of the probe, or landing in shadow (couldn't make it mobile enough to move to a lighter place).

They actually did plan for back-ups for part failures, like the thruster on top, and for the possibility of bouncing. What they didn't plan for was failure of several backups (harpoons, thruster, and possibly screws). They also planned knowing the possibility of landing in a shadow, and this was considered an acceptable risk versus the cost and complexity of adding more maneuverability.

They also didn't consider the cost in delivering a payload, versus the cost in delivering a slightly larger payload--two probes, which is less than two probes and two launchers and two fuel loads.

Multiple landers was considered when going back to at least the stage when it was still NASA's CRAF project that was to use a penetrator. Considering there was a lot of risks that would not be mitigated by two landers and a lot of the big science questions were being done by the orbiter, the thoughts were that the lander was more of a quick landing test that could be used to help plan for a future mission with more emphasis on the lander.

risks and contingencies are what make a plan well thought-out.

A well thought out plan does not necessarily mean having a contingency for every risk though. The evolution of this project went through several cut backs as budget was an issue. At some point, there are acceptable risks, especially ones that still allow for the bulk of science work to be done but cut things short.

Re:Huh

[andydouble07]

In that case they should have just edited the save file. I mean it's in JSON and everything.

Re:Huh

[Anonymous Coward]

"How hard would it have been to install a bright LED on the top that Rosetta could see from a few km away?"

How about impossible?

"2006 The first light-emitting diodes with 100 lumens per watt are produced. This efficiency can be outmatched only by gas discharge lamps."

http://www.osram.com/osram_com/news-and-knowledge/led-home/professional-knowledge/led-basics/led-history/index.jsp

Re:Huh

[Anonymous Coward]

More importantly - For all you know, koan works for the Mars Rover program, and has a legitimate right to mock the ESA's lack of foresight.

No, he doesn't, ya blithering fool! If koan actually worked for the Mars Rover program he would understand just how technically difficult this comet rendezvous actually was. Both the science and the engineering aspects of this mission were truly ground-breaking. Apart from the fact that the batteries on the lander are about to give out, this mission went about as well as anyone could have hoped for. Hell, even with the batteries about to give out, this mission was a spectacular success! Seriously, the people criticising this mission come across as a bunch of know-nothing teenagers. Do you know how many probes sent to Mars ended in failure? Venus? Space exploration is high risk. But it's OK, kid. With a bit more age will come some perspective.

Re:Huh

[Anonymous Coward]

If you can turn a 10% likelihood of gathering 1% additional ROI into a 95% likelihood by adding 0.001% to the cost, you do that.

First off, it is easy when you can just make up numbers. Second, a lot of the mission objectives for the probe would not be improved by greatly extending the life of it on the surface. Instruments designed to look at the composition underneath the probe quickly run into diminishing returns from time. There are times when working space probes and satellites are cut off, not because they break, but because the cost of staff is considered more expensive than the returns from running it for more time. And in this case the cost benefit analysis, considering one of the main goals was to study the composition of the comet, suggested decreasing the payload on the probe, because several aspects of those goals could be better achieved by instruments on the orbiter, which capable of getting measurements from multiple locations. The mission originally started as a sample return mission, and continually got scaled back and changed due to both budget problems and because they worked out how to best get objectives with an orbiter.

Re:Huh

[Anonymous Coward]

Lower frequencies add more uncertainty to the measurements too.

The narrow angle camera on Rosetta is diffraction limited, so there is not additional uncertainty from going to longer wavelengths, and in fact such cameras tend to be more sensitive to light in the near-IR part of the spectrum.

Re:Huh

[HBI]

In 1984 no one bought an IBM PC with 16k of RAM. 256K was normal, larger sizes less so, but not entirely unheard of. 640K was growing common within a couple of years, but the great RAM price spike of the late 80s (something like $1k a meg) put a little bit of a damper on that.

Re:Huh

[Anonymous Coward]

Oh, wait, you don't have a probe and wouldn't know how to make one, right?

You know koan works on the Mars Rover project, right?

He does? Really? Seriously? And he is still this clueless?

Re:Huh

[petermgreen]

The planning for this mission was started 30 years ago - in 1984;

Do you have a source for that claim? googling Philae 1984 doesn't seem to turn up anything relavent.

Imagine that - the IBM PC with its 16 KB of RAM was advanced

The XT which came with 64K as standard and supported 256KB on the motherboard (and 640K through add-in cards) was released in 1983.

Re:Huh

[Anonymous Coward]

"The narrow angle camera on Rosetta is NOT diffraction limited," Left out an important word...

Re:Huh

[rahvin112]

The battery life is good enough for the primary mission which is to plunge a drill into the comet. After they've accomplished the mission they will probably try something, but give them time to analyze things and accomplish the primary goal before they try.

Keep in mind they try to jump and they might jump into deep space.

Re:Huh

[Anonymous Coward]

Heh, I can't do this reliably in Kerbal Space Program, never mind real life..

Re:Huh

[R3d M3rcury]

While I'm not sure how many football fans are here on Slashdot, there are always plenty of Monday morning quarterbacks.

Re:Huh

[Agent0013]

"It seems to me the design and/or planning of this mission were poorly thought out"

Is the funniest fucking thing I've heard all day. Do you have any idea how well thought out this mission was? FFS look at the trajectory it took 10 YEARS(!) to get to the comet. And you think they overlooked the fact that the comet is craggly?

If they knew it was craggly, then why were they surprised at how irregularly shaped it was. I remember them saying how they suspected comets would be much more smooth than this was and they had a tricky time trying to find good places to land.

Re:Huh

[Agent0013]

They originally thought there would be no shadows because comets are very smooth and round. It wasn't until the Rosetta probe came close that they saw what it actually looked like.

Re:Huh

[blackomegax]

Because that's all science ever is, some scam to get money. Understanding the universe better is just an annoying side effect that they don't give a shit about.

Re:Huh

[Agent0013]

This mission has been compared to "throwing a hammer from London and hitting a nail in New Delhi".

Why do all the comparisons involve a non-powered ballistic object like a bullet or in this case a hammer. The Rosetta probe does have thrusters on it and can adjust it's trajectory to hit the comet. It would be more like a heat seeking missile shot at a flare.

Re:Huh

[Anonymous Coward]

googling Philae 1984 doesn't seem to turn up anything relavent.

Philae wasn't named until 2004, and even documents created after that still sometimes referred to the "Rosetta lander" and not using its name. I'm not sure when the exact start date can be pinned down, as the history is kind of messy, with roots originally in the NASA Comet Rendezvous Asteroid Flyby project with a ESA follow-up, that then started morphing when NASA dropped their project. But by the time the Giotto mission visited Halley's comet in 86, there was definitely already talk of doing another mission.

Re:Huh

[Anonymous Coward]

They knew there was a chance of big shadows, as even pictures from the Giotto project in 1986, the project that inspired this project, showed irregular shapes that could create large shadowed areas depending on orientation.

Re:Huh

[fafaforza]

I would attribute it to not realizing one has taken their glasses off and become ... Captain Hindsight. Everything is easy to see after the fact.

Re:Huh

[skastrik]

In August 2015 the comet will be at its closest to the sun, it would be neat if the lander could just go to sleep until then ...

Re:Huh

[Anonymous Coward]

I am not an armchair asteroid mission planner. I have extensive Kerbal Space Program experience. I wonder how many of these so called "professionals" have even got to Mün and back.

Re:Huh

[msobkow]

That's a little misleading. It's not like they would have locked down the design to use components in 1984. That's just when they started talking about the project. The design likely wasn't locked down until 5 years before launch or so.

Re:Huh

[Anonymous Coward]

Look, I appreciate the point you are trying to make. But don't carry on about how this mission started in 1984, that adds nothing to the conversation. Nothing at all. It's not relevant now and it wasn't relevant in 1984.

The relevant and important constraints are issues like the amount of money in the budget, the weight constraints, the power envelope, and things known or those that can reasonably be surmised about the mission environment. Most of that wasn't so dramatically different in 1984 that we cannot even understand their decisions today.

Re:Huh

[Anonymous Coward]

The flight to get there was great.

The probe landing wasn't a complete disaster. But the harpoon and jet system both failed and the probe landed on its side leaving its solar panels without enough sunlight and it unable to complete the main part of its mission.

The whole point of the mission is to study the chemical composition of the comet body and hence the early solar system. If the mission doesn't produce and good quality data on that then they have spent E2,000,000,000 and a decade to get a few minutes coverage in the 24 hour news cycle. So hopefully the data from instruments on board Rosetta is good.

Re: Huh

[Anonymous Coward]

You made it back?! NASA, hire this man right now.

Re:Huh

[f3rret]

Oh, wait, you don't have a probe and wouldn't know how to make one, right?

Take a Rasberry Pi, a big ass Lithium Ion battery and some solar panels, attach that stuff to each other, then attach rockets to the bundle, point it at space and ignite.

I'm the best at space.

Re:Huh

[f3rret]

Isn't the whole problem that they assumed a softer (ice) surface?

Look, unless you're a friggin' rocket scientist, or believe they had additional information they didn't use ... summarizing anything as "the whole problem" is kind of childish.

Based on your vast experience of landing on comets after a 10 year journey, do you think you have a better sense of what the assumptions about the hardness of the ice should have been? Maybe you should have shared that with them.

Lots of smart people worked on this, took all they knew and could surmise, and made choices with the best available information, and using the technology and money available to them.

I'm sure as heck not going to say "well, if only they'd done this it would have worked". I know I'm not qualified to do that, and I'm quite certain most of us on Slashdot aren't either. In fact, I'm betting the people who are qualified are all thinking this was a monumentally difficult task. NASA isn't sitting around going "Ha ha!"

To me, even what they did is some pretty mind-boggling engineering. But in interviews I heard over the last few weeks, they still knew there were risks and uncertainties.

It sucks, but unless you're more qualified than the entire team who did this, you have to realize this is still an incredible feat.

I won't even claim this to be an accurate analogy: But this is kind of like hitting a target in China from New York, using a home made gun, in the dark, and while both you and the target are moving.

Me, I'll applaud the ESA and everyone involved. Success for this kind of engineering includes all of the stuff that got you there. Getting far enough to have a failed landing is still a huge undertaking.

Well, I think the whole problem was that they did not have a wizard on staff to solve every problem with magic.
Also, far as I know, their graviton phasor array had decohered somewhere along the journey.

Re:Huh

[uninformedLuddite]

I don't think he made them up. I have heard of those numbers before.

Re:Huh

[uninformedLuddite]

If no one has told you yet today(which is doubtful) - FUCK OFF

Re:Huh

[uninformedLuddite]

I have heard that the ice in deep space is extremely soft

Re:Huh

[akozakie]

I fully agree except for the wording of the last sentence. How is this a failed landing? Not as good as we hoped for, sure, but the lander is not damaged, the basic scientific programme was completed, data sent. Now they could perhaps do more with the additional solar energy, but the landing was not good enough to do that. Yes, it could have gone even better, much better, but sying it's a "failure" is far too negative.

Re:Huh

[uninformedLuddite]

If they don't have it on powerpoint im not interested

Re:Huh

[stoatwblr]

"To be honest, the trajectory calculations aren't that difficult"

First order calculations aren't hard. It's the myriad perturbations to both comet and probe trajectories caused by gravitational influences of various bodies which adds to the fun.

Space science is easy. Space ENGINEERING is bloody hard, and the environment is harsh on a scale which even people who work on these things have trouble comprehending (Disclosure: I work for a space lab with one of the best-regarded instrument engineering facilities in the world and we do have devices on the orbiter)

There are a number of ways the lander could have been built - all of which would probably have added more launch mass/operational complexity and reduced the science payload. This won't be the last comet lander and as a first one, it's informed a lot more than it's frustrated. As long as we're tied to making things as lightweight as possible there will always be compromises, especially when each probe is a one-off handbuilt design (even the "mass produced" birds are heavily customised)

Re:Huh

[stoatwblr]

With the best will in the world, by August 2015 the probe would be completely baked even in its current location.

Solar cells were a life-extension measure. The probe was designed to get all the essential science done in the lifetime of the batteries and the hope was to keep going for a few months after that.

At least the Iron Chicken didn't steal its legs for nesting material.

Re:Huh

[stoatwblr]

"The design likely wasn't locked down until 5 years before launch or so."

Which was around 2000-2001 - and space-rated semiconductors tend to lag terrestrial development by about a decade, more so for stuff which doesn't have the advantage of the earth's magnetosphere for protection.

We were still launching rad-hardened P90s in 2006. Many sub 200nm circuit elements would end up being destroyed (not just disturbed) by an errant cosmic ray (most often a near-light-speed proton or neutron, not a photon), which limits what's available, given that shielding from such things is virtually impossible in the allowable mass budgets.

Re:Huh

[jandersen]

Do you have a source for that claim?

Nothing more precise than the news broadcasts on BBC4 on the morning when the probe actually landed. Lots of talk about how many of the scientists involved had been involved from the very beginning, 30 years ago. You should be able to get more precise answers if you email BBC4's newsteam, there are quite good at responding.

Re:Huh

[jandersen]

Why do all the comparisons involve a non-powered ballistic object like a bullet or in this case a hammer.

Because it is a rather good comparison. Although the Rosetta has thrusters, for most of the 10 years it has taken to get to the comet, it was not moving under power, and in fact, unlike throwing a hammer from London to New Delhi, its trajectory was nothing as simple as a ballistic curve; apparently it passed by the Earth twice, and the 'nail' it was supposed to hit, was moving rather fast. Perhaps a better comaprison would have been playing billiars on an enormous table that wasn't flat, where all the bumps and valleys moved around and the target roaring across at the far end. The chances of ending up a million miles away from the target were significant.

Solar?

[rolfwind]

Why was this designed to use mainly solar instead of a radioisotope thermoelectric generator like the voyager probes?

A comet's trajectory out of the solar system would have been interesting thing to ride on, but then solar wouldn't be a viable option.

Re:Solar?

[Anonymous Coward]

Lander had to be as light as possible to make it out there with their expected launch volumes. The lander only weighs ~20kg.

Re:Solar?

[gman003]

Mass.

An RTG is heavy. Solar panels are much lighter, and the comet is currently on a sun approach.

Re:Solar?

[Anonymous Coward]

ESA doesn't have access to RTG's.

Re:Solar?

[ShanghaiBill]

An RTG is heavy. Solar panels are much lighter.

Also: An RTG is expensive. Solar panels are much cheaper.
RTGs are expensive to make, expensive to handle, and expensive to launch.
An RTG would have likely doubled the cost of the mission.
So if the budget is fixed, that means half as many missions, which is the same as a 50% failure rate, which is worse than solar panels.
Also: RTGs generate political opposition. Solar panels don't. If this was an American mission, that wouldn't matter so much, but this mission is from nuke-o-phobic Europe.

Re:Solar?

[Anonymous Coward]

A comet's trajectory out of the solar system would have been interesting thing to ride on, but then solar wouldn't be a viable option.

Sweet Jeebus, complete physics fail.

A comet "to ride on" doesn't help you at all if you want to leave the solar system. Either you manage to get into such an orbit - or not.

And by the way this comet is in the Jupiter family it does not leave the solar system.

Re:Solar?

[idji]

Europe wouldn't allow research and dev on such nuclear tech. (they asked this question in a Google hangout today)

Re:Solar?

[tomhath]

It's comical how many times we see this suggestion - that somehow hopping onto a comet or asteroid will "carry" a spacecraft.

Re:Solar?

[Charliemopps]

Europe wouldn't allow research and dev on such nuclear tech. (they asked this question in a Google hangout today)

Basically the leftists version of the rights stem cell research insanity.
Remember: No matter what your political beliefs are, you can always use them to be stupid.

Re:Solar?

[Anonymous Coward]

It's like the Europeans built up an advanced civilization only to fall on the sword to hand it over to Muslims; which BTW want's nothing to do with such philosophical advancement of mankind. "Be it the will of Allah as to what happens".

There's no honor in cultural suicide; yet, here we are.

Re:Solar?

[Solandri]

An RTG is heavy. Solar panels are much lighter, and the comet is currently on a sun approach.

According to Wikipedia, Philae's power system weighs 12.2 kg and generates 32 Watts @ 3 AU (approximately halfway between perihelion and aphelion).

A SNAP-19 (1970s-era RTG) weighs 13-15 kg and generates a constant 40+ Watts electrical.

The comet's perihelion is 1.2 AU, aphelion 5.7 AU. Generally, Mars (~1.5 AU) is about the point where solar ceases to be cost-effective. Orbiters sent to Mars are solar powered. But landers (which have to deal with longer nights) have used RTGs when possible (Viking landers, Curiosity rover), with solar powered landers having a life expectancy of weeks to years.

Given they were landing on a tumbling comet ((the comet has a 12.4h rotational period so the lander would experience a relatively lengthy "night"), and the perihelion being somewhere between Earth and Mars, this was probably a good candidate for a RTG. I suspect they weren't expecting the lander to survive past perihelion however (13 Aug 2015), which could have tipped it in favor of solar.

Re:Solar?

[Solandri]

The science payload is ~25 kg. The lander itself (including frame, power systems, communications array, electronics, stabilizers, descent systems, etc) is about 100 kg.

Re:Solar?

[Anonymous Coward]

As one of the scientists involved put it this morning (not a direct quote), it's a combination of not having the expertise in Europe to make RTGs, and politics, which largely determines why Europe doesn't have the expertise to make them or the ability to exercise that expertise.

Re:Solar?

[Anonymous Coward]

generates 32 Watts @ 3 AU

That is just what the solar panels produce, and not necessarily what the peak power demand is because there are batteries. I haven't seen what those numbers might be, other than some of the instruments individually can need more than 20 W at a time.

Philae's power system weighs 12.2 kg

This includes components more than just producing raw power too, although the batteries take up most of that mass. Getting an RTG in the space and mass budget as is would still be tight, and not necessarily some huge improvement.

Considering that most of the instruments on the lander would not benefit as much from extended life, it might not have been that great of an option even if it was much cheaper. The mission as a whole with the orbiter is only scheduled to be another year longer too.

Re:Solar?

[Tailhook]

That's the closest thing to honesty I've heard on this matter. That scientist has no future at all in government work.

In fact, I don't believe that actually happened. Got a link?

Re:Solar?

[sysrammer]

Remember: No matter what your political beliefs are, you can always use them to be stupid.

Truth.

Re:Solar?

[Anonymous Coward]

Mission was launched 10 years ago, and Europe did not have the technology available at that time. NASA had it however, for a long time...
Now, they're doing their best to get as much as they can from what has been built years ago.

lander back in touch

[Anonymous Coward]

Good morning, Earth! It’s been a busy night at #67P! Now that I’m back in touch with my team, I’ll tell you all about it! #CometLanding

Solar?

[Anonymous Coward]

Because nukes are environmental hazardous. Remember, this thing was designed in Europe.

ground penetrator used!

[Anonymous Coward]

Last night MUPUS hammered the penetrator into the ground. APXS also got to work! My team is currently checking how they did #CometLanding

Re:ground penetrator used!

[Scottingham]

My penetrator always hammers the MUPUS. Wait, what?

Re:ground penetrator used!

[Anonymous Coward]

Drilling in progress into surface of #67P @Philae2014

Re:ground penetrator used!

[aaron4801]

MUPUS from Space!

It landed YAY!

[Tyr07]

but it's running out of power...shit.

Re:It landed YAY!

[DahGhostfacedFiddlah]

But it came with a free frogurt!

Permanent problem?

[mooingyak]

Is the shadow a permanent problem? Or will it potentially get back into the sunlight at some point as the comet reaches a different part of its orbit?

Re:Permanent problem?

[Anonymous Coward]

The current resting place gets about half the sunlight that the original landing target does. It's not that the lander gets no sunlight, but the current levels are too low to maintain the battery for long.
It is possible that the obstructing crags will melt/shatter in a beneficial way as the comet approaches the sun, but that's like saying that a category 5 hurricane might finally clear up that unsightly tree in the neighbor's yard.

Re:Permanent problem?

[sjames]

They really aren't exactly sure where it is or what the surrounding terrain is like. It is quite likely that by the time the lander gets direct sunlight it will have failed due to prolonged cold.

BUT, the gravity is extremely low and it's not tightly anchored to the ground, so it could (accidentally or on purpose) throw itself into a new location that might work better. They want to accomplish as many objectives as possible first because it could also face plant.

Re:Permanent problem?

[Bongo]

By that time the panels may be covered in dust anyway, I think they mentioned.

Re:Permanent problem?

[oyenamit]

No, it does not seem permanent. As per the original plan, the secondary batteries were expected to receive about 7 hrs of sunlight each 12.4 hr comet day. Now it is expected to be only 1.5 hrs. This will definitely impact experiments that need to continuously run for long periods of time.

Re:Permanent problem?

[Anonymous Coward]

Of the ten instruments, only 3 of them have long term plans, and none of which need to run continuously, although one, the magnetometer, would be better off running without gaps in data. The bigger issue is that once power gets too low, it can't keep the probe warm enough and the whole thing will just shut down and likely not come back.

I know it!

[marcello_dl]

> What state would the man be in after 10 years in space?
The "Bored" state.

Re:I know it!

[DahGhostfacedFiddlah]

That puts him in the same state as the comet, assuming all goes well.

Re:I know it!

[codeButcher]

A man has to get there and do all the hardwork himself.

Pity they didn't send Bruce Willis with. What with all his previous experience. Would have been a win-win.

Re:I know it!

[BarbaraHudson]

Pity they didn't send Bruce Willis with. What with all his previous experience. Would have been a win-win.

I nominate Justin Bieber instead. The last 10 years out of sight, one-way mission ... now that's a win-win. Throw in the Kardashians, and we could probably crowd-fund it.

Philae's Drill

[Anonymous Coward]

Philae's drill is the drill that will pierce the heavens! FIGHT DA POWAH!

RTGs not feasible for small probes

[Anonymous Coward]

Radioisotope thermoelectric generators (RTGs) are big, heavy, and emit radiation that screws up some of the instruments.
The ones on Voyager are about the size of Philae. from Wikipedia: The GPHS-RTG has an overall diameter of 0.422 m and a length of 1.14 m.[1] Each GPHS-RTG has a mass of about 57 kg and generates about 300 Watts of electrical power.

Philae:
Launch mass 100 kg (220 lb)[1]
Payload mass 21 kg (46 lb)[1]
Dimensions 1 Ãf-- 1 Ãf-- 0.8 m (3.3 Ãf-- 3.3 Ãf-- 2.6 ft)[1]
Power 32 watts at 3 AU[2]

Unfortunately, RTGs don't come in multiple sizes, so you can't get a 1/10th scale RTG that weighs 6kg and is 15 liters in volume.

I don't know if ESA has access to RTGs in the first place, or if public policy would allow launching with a radiation source. The Cassini RTGs causes a huge public relations problem when it was launched in 1998.

There's also limited Pu240 available to make the RTGs.

Re:RTGs not feasible for small probes

[rolfwind]

I know Nasa anticipated smaller RTGs in the mid-90s for probe Missions to Pluto and beyond, just wasn't sure if that wish ever went anywhere.

Re:RTGs not feasible for small probes

[Puff_Of_Hot_Air]

Unfortunately, RTGs don't come in multiple sizes, so you can't get a 1/10th scale RTG that weighs 6kg and is 15 liters in volume.

What do you mean RTGs don't come in multiple sizes? How'd they fit them into pacemakers then?

Re:RTGs not feasible for small probes

[ColdWetDog]

Iron Man is not a documentary ....

Re:RTGs not feasible for small probes

[Anonymous Coward]

Pacemakers don't use RTGs, they use non-thermal radioisotope generators, like betavoltaics that harvest the current created by escaping beta particles.

Re:RTGs not feasible for small probes

[the_other_chewey]

Pacemakers don't use RTGs, they use non-thermal radioisotope generators, like betavoltaics that harvest the current created by escaping beta particles.

That's only true for the Promethium-powered ones with a Betacel unit. I think the number of
actual thermoelectric ones still "in the wild" using Plutonium is about the same.

Re:RTGs not feasible for small probes

[Puff_Of_Hot_Air]

Your signature contains more than a trace irony. If only stupidity hurt.

Re:RTGs not feasible for small probes

[uninformedLuddite]

It's like the TARDIS

In other Astronomy news...

[SternisheFan]

Astronomers Discover Planet Identical To Earth With Orbital Space Mirror http://www.theonion.com/articl...

Circle of uncertainty

[Anonymous Coward]

Is 'circle of uncertainty' like 'cone of shame'?

Re:Circle of uncertainty

[ColdWetDog]

Is 'circle of uncertainty' like 'cone of shame'?

Maybe you should see if you can pass the Turing test before posting.

two bounces

[Thagg]

Philae bounced twice, the first bounce was about two hours, the second one 7 minutes. If the gravity on the comet is 1/200,000th that on earth (a reasonable estimate, it varies around the comet because it's *way* not round) then the first bounce was about 1,000 feet off the surface, but the second one was only about three feet. Seven minutes to fly up and down three feet; that's almost impossible to imagine.

Re:two bounces

[Anonymous Coward]

Hello! An update on life on #67P - Yesterday was exhausting! I actually performed 3 landings,15:33, 17:26 & 17:33 UTC. Stay tuned for more @Philae2014

Re:two bounces

[amicusNYCL]

The first bounce is pretty crazy to think about too. It landed, went 4cm into the surface, and bounced back up. It took an hour for it to stop moving away from the comet and start falling back down, and in that hour it only managed to travel about a kilometer. The entire thing is so otherworldly. Check out this picture, it might be my favorite so far. It's from 10km up and looks across the surface, and you can see a haze of some gas or dust plus the stars in the background. I've never seen anything that looks like that, it's just amazing.

Re:two bounces

[Qbertino]

Seven minutes to fly up and down three feet; that's almost impossible to imagine.

Yepp. You could probalby jump beyond it's gravitational pull.
One sneeze and your away for the day.
*Aaaachoooh!* ... oh noes! Help, I'm flying.

Re:two bounces

[Thagg]

It is fascinating that you can see stars and the comet surface at the same time; it shows how far from the sun they are. In no pictures from the moon can you see any stars.

Right now the spacecraft is about 3x as far from the sun as the moon is from the sun, so the sun is only 1/9th as bright there. I suppose the cameras might have a bit more dynamic range than the film cameras of the late 60's. The comet nucleus might also be quite dark, but the moon is very dark as well (about 10% albedo.)

Re:two bounces

[Savage-Rabbit]

Philae bounced twice, the first bounce was about two hours, the second one 7 minutes. If the gravity on the comet is 1/200,000th that on earth (a reasonable estimate, it varies around the comet because it's *way* not round) then the first bounce was about 1,000 feet off the surface, but the second one was only about three feet. Seven minutes to fly up and down three feet; that's almost impossible to imagine.

I've been watching this mission with a certain degree of anticipation for a while but I'm no space/physics nerd so I have two questions for those who are:

1) How likely is it that anything will come of the drilling now that the harpoons that were supposed to hold the probe down have failed given the low gravity?
2) Will the comet ever again come into a position that might cause the probe to get enough sunlight to do any worthwhile science?

Re:two bounces

[c]

Seven minutes to fly up and down three feet; that's almost impossible to imagine.

Insert union labour joke here

Re:two bounces

[SternisheFan]

This blog pic shows just how far that bounce was... http://blog.wolfspelz.de/2014/...

Re:two bounces

[Thagg]

1) There is/was a significant risk that drilling would push Philae off the comet again. Still, it's a risk worth taking; without the solar recharging ESA has only until Saturday before the batteries run out.
2) The challenge is that either the lander is on its side, so the solar panels can't see the sun; or that the lander is up against a wall blocking the sun most of the time. They are considering possible ways of reorienting Philae; but it doesn't seem too likely. Also, without the harpoons or ice screws, it's likely that Philae will be pushed into space by gasses escaping the comet as it gets closer to the sun; so the extra sunlight is a double-edged sword.

Re:two bounces

[sootman]

That pic is amazing. And I still get my ass kicked by Lunar Lander at anything but the easiest settings.

Re:two bounces

[Anonymous Coward]

Someone on reddit pointed out that it's not stars. It's just censor noise.

I can't find the post but if you zoom in you can see some "stars" on/in front of the actual comet so it's just noise, possibly caused by radiation or charged particles.

Re:two bounces

[Anonymous Coward]

Those aren't necessarily stars, could be noise due to eg cosmic rays hitting the camera. I'm not sure how they differentiate.

Re:two bounces

[Anonymous Coward]

The comet has the albedo of a lump of coal. Facsinating

http://www.bbc.co.uk/news/science-environment-29525157

Re:two bounces

[K. S. Kyosuke]

Doesn't sound too difficult. Stars would form fixed patterns that would move and rotate throughout pictures but wouldn't change shape.

Spoiled

[robstout]

I think we've been spoiled by the various Mars missions, and having rovers lasting well beyond the expected lifetime. We should not assume that all missions will be like that. We should revel in the fact that the probe is working at all after 10 years in space, and that it wa sable to land on the comet at all.

Re:Spoiled

[volmtech]

And where those rovers made?

Re:Spoiled

[itzly]

We had plenty of failed Mars missions too, but people tend to forget about those.

Re:Spoiled

[allsorts46]

Where those rovers made what?

Re:Spoiled

[Anonymous Coward]

green cheese?

Re:Spoiled

[Anonymous Coward]

>We had plenty of failed Mars missions too

kilometers .ne. miles

Re:Spoiled

[stoatwblr]

Which parts? I can think of 3 items on each (including the cameras) which were made in Europe.

Re:Spoiled

[volmtech]

Fortunately they refused my offers to help program them.

Why the negation?

[Anonymous Coward]

a 'circle of uncertainty' within which Philae almost certainly lies.

Do we also say a 'place of unwork' and an 'unparking spot'?

Live and learn

[Anonymous Coward]

Putting probes down on Mars as proved to be a difficult learning experience. This probe is demonstrating that landing on a comet or any similar body with very little gravitational attraction has its own set of issues.

My hunch is that landing on them will require a craft versatile enough to guide itself into a carefully controlled landing. It''ll have to approach slowly, maneuvering to find a level place and touch down very gently to prevent a bounce. Then rockets will need to fire allowing anchors to set into place. Maybe, just maybe, a chemical "superglue" type attachment might be better than a mechanical one, at least as a preliminary measure.

Unfortunately, a decade was lost with this particular learning experience. The next will have to be carefully researched and tested, so it works first time and every time.

Re:Live and learn

[stoatwblr]

"It''ll have to approach slowly, maneuvering to find a level place and touch down very gently to prevent a bounce"

This is a classic application for ion thrusters. The problem is that the exhaust for anything pointing "downwards" (chemical or ion) will contaminate the ground you want to sample, making the whole mission pointless.

This is why the landing thruster was a cold gas (nitrogen) device pointing upwards (away from the comet). It was intended to hold the thing on the ground whilst the harpoons fired and the legscrews locked it down. After that failed, the odds of Philae staying where it first arrived were greatly diminished but given a choice of "not bothering" or "may as well try anyway" I know which option I'd have taken.

For the naysayers: If you think you can do better then by all means come up with the funding to do it.

space USB

[Anonymous Coward]

Why aren't/weren't space probes and rovers equipped with external port for charging their internal batteries and accessing its computer for maintenance? That would allow future missions to easily revive old equipment and put it to new exploration tasks. Perhaps some space agency should develop "mobile mechanic" robotic platform to be deployed on Moon, Mars (Spirit, Opportunity) and, should something go wrong with Philae, on Comet 67P/Churyumov-Gerasimenko.

Show it that guy's t-shirt

[Anonymous Coward]

It'll be drilling in no time. You know the shirt I'm talking about. It got the feminists' leg hair all riled up.

Re:Show it that guy's t-shirt

[Anonymous Coward]

Not really. Link.

Re:Show it that guy's t-shirt

[Anonymous Coward]

Not really. Link.

#shirtstorm

drill and harpoon

[PW2]

Drilling and have it become dislodged for an hour or two, hopefully landing in a better place sounds like a feature -- I hope they fire the harpoons a few hours before the batteries are discharged to take the chance of repositioning it in an open area

#shirtstorm

[Anonymous Coward]

But how will #shirtstorm effect this?

Armageddon

[Anonymous Coward]

Where are the oil drillers when you need them?

Philae To Deploy Drill As Battery Life Wanes. . .

[Idou]

I only hope my final moments can be so bold. . .

Troll

[Anonymous Coward]

Nice troll, but no.

Kinda Sad

[Anonymous Coward]

I'm reminded of Short Circuit 2 where Johnny 5 is beat down and dying. I can imagine the probe drilling while the low battery light blinks at a increasing rate, While Bonnie Tyler's - I Need a Hero is playing in the background.

Johnny 5 beating

space USB

[Anonymous Coward]

The main issue isn't actually the lack of *power*. If it were, the probe could just sit in 'powered off' mode until the panels collected enough energy to recharge the battery, and then continue from there.

The main issue is that in the time that will take, the probe will have frozen to 'death'. A significant portion of the power budget for space probes is spent keeping the parts within operational temperatures.

Time Travel

[Anonymous Coward]

Anyone know how far back in time the probe is? I assume that since it's been traveling at ~ 30 000 kph for 10 years that time would be passing relatively slower for the probe than for us.

what a waste

[jehan60188]

they decided to be cheap, and not install any kind of guidance on the probe, so they get a few days of experimentation instead of the years they could have achieved if they landed in a sunny spot?
wasteful

Re:what a waste

[Pope Hagbard]

We're all glad you're here to share your wealth of experience in space probe design with us.

Re:what a waste

[Anonymous Coward]

instead of the years they could have achieved if they landed in a sunny spot?

The orbiter is not even planned to last that long, with the mission end being a little over a year from now (although there is room to extend it). Most of the instruments on the lander couldn't do anything more after a couple days too.

Re:what a waste

[uninformedLuddite]

Oh Fuck oFF

Life Lessons from Kerbal

[Yergle143]

Hey Kerbal has taught me a lot about this kind of thing
1) Solar panels everywhere..hates it when I run outta power
2) Put a protruding strut on the top of the lander just in case your lateral motion causes you to topple
3) To stick the landing a bit of mystery goo can me most efficacious.
4) Get some mods...Philae looks like it was crafted from Vanilla parts.

Great mission while it lasted

[Anonymous Coward]

It was a great mission, while it lasted. Never send a solar panel to to the work of a slug of Plutonium. I am less than impressed with the 'green' approach.

Gravity of the situation

[oyenamit]

Despite the glitches, the fact that there is a man-made object currently sitting on the surface of a comet and beaming back actual pictures is flippin' mindblowing !

Re:Gravity of the situation

[Stan92057]

Already been done on an asteroid. already collected comet dust and returned to earth

http://www.telegraph.co.uk/sci...

http://www.space.com/26832-sta...

lost science of the Ancients

[Thud457]

I'm sure that in 1985, plutonium is available in every corner drugstore.
D'OH!

Re:Philae To Deploy Drill As Battery Life Wanes. .

[Anonymous Coward]

I only hope my final moments can be so bold. . .

Who are you kidding? You are posting to /. My guess is that there is no woman out there that would allow you to "drill" no matter how desparate you are.

Water pipe sticking out of comet?

[SloWave]

Anyone know what the deal is with the pipe or rod looking object in the lower right hand side of this picture http://www.esa.int/var/esa/sto... />? It looks like it is embedded in the comet and is casting a shadow. I am suprised the tin hat people haven't taken off with this yet.

Re:Water pipe sticking out of comet?

[Anonymous Coward]

It's a lander leg, bonehead.

Re:Water pipe sticking out of comet?

[uninformedLuddite]

It's evidence that the comet is inhabited. Look for my new YouTube videos on the subject

Space is hard

[12WTF$]

Comets are now known to be hard as well and definitely not mushy.
THAT is the major finding so far.
Philae was expected to land gently on a frozen snow cone into which it would fire anchoring harpoons,
but it bounced a off a deep frozen ice mass (ouch) ascending 400m then touched down again
then bounced yet again until coming to rest in the shadow of a cliff. Awkward.

Scientists expected the comet’s surface to be powdery, allowing the lander to settle instead of rebounding back into space.

“It’s not a powder, it’s a rock, so it’s like a trampoline,
You go there and it ejects you immediately afterwards.”

The objectives of the science mission will probably be missed because hardware failure and reality trumping assumption.

Re:Space is hard

[Anonymous Coward]

In an interview yesterday, a person on the project said the exact opposite: that the comet was softer than expected. They knew bouncing was going to be an issue, which is why they had three different systems to help force the lander down, but at least two of those didn't work. They were expecting a bounce to be so hard the probe would not likely land again, instead a combination of the landing gear and the soft surface absorbed enough energy that it came back down some distance away. So maybe we need to wait a little while for them to get the story straight.

There were also people on the team expressing worry before the landing that the surface would be too powdery and that the harpoons and screws would not get enough of a grip, so it seems some expectation of powder has been there for a while.

Re:Space is hard

[12WTF$]

Nice more information is.

In an interview yesterday, a person on the project said the exact opposite: that the comet was softer than expected.

Don't leave us in a vacuum. A link [citation] would be nice.

Space may surprise us in being part powdery as well as being hard.

Re:Space is hard

[12WTF$]

BBC quote follows:
MUPUS the sensor package from the German space agency's Institute for Planetary Research deployed a thermometer on the end of a hammer.
It retrieved a number of temperature profiles but broke as it tried to burrow its way into the comet's subsurface.
Scientists say this shows the icy material underlying 67P's dust covering to be far harder than anyone anticipated - having the tensile strength of some rocks.
It also helps explain why Philae bounced so high on that first touchdown.
The 4km-wide comet has little gravity, so when key landing systems designed to hold the robot down failed at the crucial moment - the probe would have been relying on thick, soft, compressive layers to absorb its impact.
However much dust it did encounter at that moment, it clearly was not enough to prevent Philae making its giant rebound.
[end-quote]
http://www.bbc.com/news/scienc...

Rosetta to the rescue?

[Anonymous Coward]

I'm just wondering how reflective Rosetta's panels are and whether it would be feasible to angle them to reflect its excess sunlight to Philae.
Probably not enough to make a difference, but just a thought.

Nuclear battery

[Anonymous Coward]

I guess next time they need to include a 20 years nuclear battery for exploration craft.
can't depends on the sun !!

And..., battery's out of juice

[SternisheFan]

From www.latimes.com/science/sciencenow/la-sci-sn-philae-lander-data-20141114-htmlstory.html

Fifty-six hours after landing on the surface of a comet, Philae sent one more round of data about its new home across 310 million miles of space. Then, its power went out.

"@Rosetta, I'm feeling a bit tired, did you get all my data? I might take a nap..." read a message on the @philae2014 Twitter feed.

The Rosetta mission's twitter response: "You've done a great job Philae, something no spacecraft has ever done before."

All the experiments on board the lander had a chance to run and return information back to Earth. Philae's instruments scooped up material from the comet's surface, took its temperature, sent radio waves through its nucleus, and went hunting for hints of organic material. Cameras took the first panoramic images from the surface of a comet.

It has been a whirlwind ride for the lander, which was dropped onto the surface of the mountain-sized comet 67P/Churyumov-Gerasimenko on Wednesday morning. Two harpoons that were designed to tether it to the surface failed to fire, and scientists say the lander made two bounces before becoming stable. The first bounce caused the lander to go one-third of a mile into the air.

Friday morning, ESA officials expressed concern that the lander would not have enough battery power left to send back any more data from experiments it was conducting on its new, icy home.

When Philae landed on the comet on Wednesday, it had enough battery power for about 60 hours of work. Scientists initially hoped that it would continue to operate on solar power, but the lander seemed to have settled in a hole on the comet, where it was surrounded by rock-like structures that block the sun.

Stefan Ulamec, the lander manager from DLR, said the that one of the solar panels on the lander was getting about an hour and 20 minutes of sunlight a day. Two other panels got just 20 to 30 minutes a day, he said.

At a news conference Friday morning before the last signal was received, Ulamec said it was possible that scientists would not hear from the lander again.

"We are hoping to get contact again this evening, but it is not secured," he said. "Maybe the battery will be empty before it talks to us."

Happily, that turned out not to be the case. On Friday evening, ESA reported that all the science experiments had been deployed, and that the lander had been rotated 35 degrees in an attempt to get more sun on one of its larger solar panels.

There is a chance that as the comet flies closer to the sun, the increase in solar energy will allow ESA to communicate with Philae once again.

ESA officials say the odds of that happening are small, but with Philae, the little lander that could, anything is possible.

The actual reason...

[Anonymous Coward]

This question was asked via the Hangouts chat w/ the developers of Philae and Rosetta. The answer was pretty simple.

1. RTGs weren't well researched in the EU at that time for space use.
2. Politics prevent above research as well as prevented anyone from acquiring the needed plutonium.
3. Had 1 and 2 not been enough, ESA was hesitant to push plutonium in to space.

You can argue with my points but that's the synopsis of what the directors themselves said.
Source https://www.youtube.com/watch?v=7Xm6y0LzlLo

organik hit program

[Anonymous Coward]

http://www.bunuindir.net/download2.asp?git=dosya&id=39&cat_id=25&dosya-download-Organik-hit-programi-programini-indir.html

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