Slashdot Mirror
NEAR to Fly Once More
david.given writes "Yes, those loons at APL just will not leave the spacecraft in peace. The latest plans are to attempt to fire the thrusters again on Feb 14, 1900UTC (1400EST) and lift off the surface of EROS. If the thrusters work, and the trajectory is correct, and the camera is undamaged, and the communications system holds up, they reckon that they should get some more pictures from about 400m up. What's next? They're going to bring it home?"
I believe it's QNX or a flavor thereof.
...phil
...phil
"For a list of the ways which technology has failed to improve our quality of life, press 3."
No, they're going to DISNEY LAND!
"Pinky, you've left the lens cap of your mind on again." - P&TB
"I can see my house from here!" - ST:
Well, since the camera can't focus on anything inside of 500 yards (it's designed for longer range viewing), maybe it would be nice to get this thing up and flying for a few days more, some more close-in pictures.
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
NASA is going to do all future space exploration with NEAR.
NASA: Can we please have funding for another mission? We could build this great space craft and...
Congress: What's wrong with NEAR? Can't you keep using that?
NASA: We used NEAR last time. We put it on EROS and then we found there wasn't anything to do with it once it was there, so we took it back off. Can't we have one with more toys on it?
Congress: No, go away. Can't you see we're busy?
Because they couldn't make up the data fast enough.
----
lake effect weblog
{Network engineer in Chicago--looking for work!}
I thought TCP had some design limitations that cause it to fail when the signal delay exceeds some threshold. If so, that puts a limit on the distance TCP can function.
I have discovered a truly marvelous sig, unfortunately the sig limit is too small to contain i
There was some talk very early on in the mission that they would try to touchdown and then leave the asteroid again. Recently they've only been talking about the touchdown (controlled crash landing?) because of the high risk of damaging the probe. Now that that's sucessful and they can apparently send a new program to the device, it's time to finish the show.
I can't wait to see a picture of the mark they made on the surface of Eros. Way to go, APL! This is going out in style.
I have discovered a truly marvelous sig, unfortunately the sig limit is too small to contain i
I don't think that's correct. Breaking free of Eros gravity would still leave it in orbit around the Sun. There's a minimum delta v necessary to get it on a trajectory where it would cross Earth's path when the Earth was there and an additional delta v necessary to get it in orbit around Earth.
It's all academic at this point, the burn won't take place and if it had, it would not have placed the craft in orbit areound Eros, just landed it elsewhere. See this press release from JHUAPL.
I have discovered a truly marvelous sig, unfortunately the sig limit is too small to contain i
There isn't enough propellant to get it back to Earth.
I have discovered a truly marvelous sig, unfortunately the sig limit is too small to contain i
SPACE HACKER 1: Cool.. Um, let's land it again!!
SPACE HACKER 2: yeah! I bet I can get it right in that big crater.
SPACE HACKER 1: Let's see how low an orbit we can keep it in without it hitting!
SPACE HACKER 2: Let's take it reeeally far out, then turn it around and ram the asteroid!
Kevin Fox
Kevin Fox
Instead, **Two** probes goes out, one lands, takes samples, and launches samples back into orbit where probe two rendezvous with the payload, and heads back Earthwards.
Samples are then picked up, later, in Earth Orbit by the shuttle, or another probe, preferably a re-useable one, that would return it to the shuttle or the ISS. . . .
A stable orbit is impossible around a body like Eros -- its irregular shape perturbs the circular orbit so that the spacecraft would eventually crash into the surface. Lunar orbits decay over a manner of weeks for the same reason.
Just landing on the surface has limited scientific use, any lander which wants to really investigate primordial bodies such as asteroids and comets need to be somewhat more firmly attached. Look at the Rosetta site for an idea of some of the problems that landing on and doing science with a comet can cause.
--
Actually it is rocket science...
Can they get it inserted into a stable orbit around the rock again?
:-)
Possibly, but why would they want too? They have exhausted the possibilities of that anyway, thats why the decided to land (ok, it was more complex than that, it has a lot to do with budgets as well as science).
Can they escape the gravity of the rock entirely?
Again, possibly, but why? All the instruments are designed to look at an asteroid from close up. There are probably too low on fuel anyway, and I doubt there is enough budget to do anything useable.
Can they skitter across the landscape, trying for more landing sites and near-ground imaging?
Which is probably what they are doing, taking more and more risks each time, because the are only going to have very very limited amounts of access left on the DSN [1]. Probably so long as the press is interested NASA will find them time on it though.
Footnote [1] Initially typed as DNS...<sigh> I need to get out more
--
Actually it is rocket science...
OK - I'm totally freaked out now. I did a calculation in my head based on your reasoning and came up with an answer: NEAR would need an infinite amount of fuel to get there and back. I need to go to bed now...
--- Hot Shot City is particularly good.
I just don't understand this NASA / JHUAPL team. You'd think that crashing into an astroid would be enough, BUT NO, these guys need a second time. Just get it right the first time. You're giving us space-probe-obituary writers from getting ulcers.
<serious>This is quite impressive.</serious>
Given one hour to live, the student replied: "I'd spend it with professor FP who can make an hour seem like a lifetime."
And then send Bruce Willis up after it.
I wouldn't imagine that anyone would consider an asteroid landing an obvious extention of a lunar landing.
All your events are belong to us.
One of the less-well known subtleties of slashdot is how to link to a comment in an archived story.
http://slashdot.org/science/01/01/22/1710234.shtml #23
All your events are belong to us.
What's the Ring? This is a hard one.
Someone you trust is one of us.
There's no reason not to see what else this thing can do. It's completed it's mission, it's set to become nothing but space flotsam, why not fire it up and blow a few doughnuts?
From this last picture taken before landing, you can see that some sentient being intentionally commandeered the spacecraft's controls.
This is probably to blind us from realizing that it's re-launching to invade packed with micro-organisms intent on feasting on human flesh
- passion
If it's been this easy, why haven't they just sent a rover out that can return asteroid samples? I mean, if they can set a craft down that wasn't even supposed to land, how much harder is it to make one that is?
anacron
Am I the only one who thinks it is a little suspicious that NEAR, which was "not designed" to land on the asteroid, and had only a 1 in 100 chance of survival. The craft is now planning to take off and land again. I think the designers may have actually had some capability of landing in mind from the start, but didn't talk about it.
I heard someplace that most of the recent probes run VxWorks. I'm pretty sure Mars Pathfinder did. If it's not VxWorks then it's some other similar real time OS.
Go Badgers! -- #include "std/disclaimer.h"
Of course they would never let us direct our tax dollars. First that would mean they would have to tell us where "THEY" are spending our money now, which ain't going to happen. Second, no one would want to pay for all those nasty little Police Actions we've been involved with in the last 20 years. Then where would all those Arms Dealers, OOPS, I mean Defense Contractors be.
Jesus died for sombodies sins, but not mine.
"Our products just aren't engineered for security,"
-Brian Valentine,VP in charge of MS Windows Development
But in order to get to your bed, first you have to get half way to your bed.
And once you get half way, you'll have to go half of the distance remaining, and you'll still be only 3/4 of the way to your bed.
But once you get 3/4 of the way to your bed, you'll have to go half of the remaining distance again, and then only be 7/8 of the way...
I feel bad for you... you'll need an infinite amount of time to get to your bed.
Slashdot is jumping the shark. I'm just driving the boat.
They should set up an arcade-style coin-op outside and let people play with NEAR for $10,000 a shot. That way, they can generate enough cash for the next mission!
"Whoa triple point-score! I just got NEAR to do a combo-move!"
--
Wooden armaments to battle your imaginary foes!
I can see it now:
Geez...
I am NOT saying that I think this happened at all. I am just saying that we have no way of verifying that this is true.
Well I dont want to start any conspiracy theories, I just thought others might find this possability interesting.
A slashdotter who didn't build his own computer is like a Jedi who didn't build his own lightsaber.
::NASA engineer comes in the room::
NASA Engineer: "Say guys, how many inches of height does the thing have to break to reach escape velocity?"
APL Tech: "What the HELL did you just say??"
Men believe what they want. - Caesar
200 years from now that asteroid will be a floating museum piece that people will pass by on their tour of the solar system. Leaving it there will be a reminder of what we went through to get that thing there.
"Beware of he who would deny you access to information, for in his heart, he dreams himself your master."
Is a shame that they didn't pack enough fuel to just give it one good shove back towards earth orbit. Might be nice to grab it on a flyby with a shuttle, and see if NEAR managed to keep any dust along for the trip. Sure, it wasn't designed to take samples...but it wasn't designed to land and take off again either
Scientist 1 to Scientist 2: Stop hogging Lunar Lander! You got past level 1, now I want to play!
Set yer phasers to stun. The Linux Pimp
--It's Pimptastic!--
Scientists admit that the surface of Eros was not as interesting up close as it had been from wider views. "We definitely had 'space goggles' on," explained Farquhar.
NEAR stayed on the asteroid for a few hours, made breakfast and idle chit-chat. But after a while, he could tell that it was his time to go. Firing its reverse-thrusters, NEAR left the surface never to return. NASA engineers excitedly noted that the landing and take-off have prepared the asteroid for future landings.
This Won't Hurt A Bit. We're Just Going To Shove This Probe Up Your Asteroid
Actually the fact that they could drop a probe onto Eros and maintain functionality brings an interesting idea to mind:
While the best method we have of cataloging asteroids is currently by using optical telescopes (a tedious and slow method for tracking their movement as well), why not make a series of miniprobes that will land on every asteroid as they're detected, so that their movements could be tracked with radio telescopes instead?
The benefits could be two-fold, one being that it would be easier to tell undetected asteroids apart from tagged ones, second being that any changes in path could be easily detected...
For those saying "What'll it cost?", well, what would it cost to rebuild after a smaller asteroid decimates several hundred square miles? Or worst, what would it cost to rebuild after a large one hits? A few hundred million to billion in disposable probes designed as a radio collar for stray asteroids beats trillions in damage if one slips through undetected...
Just because you can mod me down, doesn't mean you're right. Shoes for industry!
We'll find out in 2002 - there's a joint mission between NASA and the Japanese Institute of Space and Aeronautical Science called Muses-C that is due to try to collect and return samples from an Asteroid.
The whole idea of a government letting citizens direct their tax dollars is absolutely absurd. A government like that would collapse within 10-20 years. No government that has lasted long in history has let the citizens "Direct" their tax dollars. The United States was founded on the principle that the common citizens as a mass are absolute idiots, which I fully agree with them on. And supporting NASA is not a bad thing, all that "space age" crap in your SUV would not have occurred, if it weren't for NASA sponsored research.
Knowing NASA, they'll probably fire the thrusters and bring the whole asteriod home to Earth. Bean Bandit "Farewell Cruel World!"
But if you think this was great, just wait till you see what other missions JHUAPL has in store.
A number of these are excellent examples of the great, focussed science experiments that can be done under the faster-better-cheaper paradigm, and they're even competing for slots in the slightly more expensive Mid-Explorer program.
*It should be noted in fairness that NEAR itself had a glitch; in December 1998 they failed to make their planned orbit insertion, and had to circle the sun 14 months before another approach could be made. (At that time I'm sure many /. posters were blaming NASA for yet another failure! Indeed the faster-better-cheaper policy was being severely criticized.)
Dan
The latest plans are to attempt to fire the thrusters again on Feb 14..
Hey those are my plans too tomorrow if you know what I mean...
CNN is reporting that the project has been given another week of deep space network time to continue getting readings observations.
a nd ing.02/index.html
http://www.cnn.com/2001/TECH/space/02/13/near.l
Yeah, there's some comment in the Linux TCP stack along the lines of
/* delay timeout mandated by TCP spec, we'll have to use something else to talk to the University of Mars. */
"If ignorance is bliss, may I never be happy.
-- Veni, vidi, dormivi
A few quick articles from
The New Scientist
USA Today
An interview with Vince Cerf
I'm not sure what has been done lately if anyone has some more recent links let us know.
This space for rent. All reasonable inquiries will be entertained at proprietors discretion.
What's next?
I'll tell you what's next. They'll make their final log entries, clean the crud out of their desks, and get ready for the next assignment. Why? Their funding runs out tomorrow at midnight. It's a shame.
Heard on CNN:
The gravity is so weak that a 160 lb astronaut would "weigh" only about one ounce.
Given this, I was amazed that a 5 mph crash wasn't just a complete bounce. They're running out of fuel on the NEAR, so I don't know what their next choice will be.
Can they get it inserted into a stable orbit around the rock again?
Can they escape the gravity of the rock entirely?
Can they skitter across the landscape, trying for more landing sites and near-ground imaging?
Interesting thoughts on what to do with a now-disposable craft.
[
No! They're going to let it land again. They just want to get a few more pictures with the resources remaining. The probe itself might be solar powered, but the thrusters aren't.
By the way, does anybody else think the "official diagram" looks like legos?
"well thats it boys we have photed the entire rock what do we do now?"
SPACE HACKER1: lets try and land it!
SPACE HACKER2: COOL the next day
SPACE HACKER1: well that was fun whats next?"
________
Does anyone actually have a Java program designed to control air traffic, or for the operation of a nuclear facility?
We need to leave it there!!! How else will we know when Eros is about to hit Earth ??? It could kill your children!!!
"TONIGHT ON FOX.."
end communication
Budget cuts have often come with the simple reasoning that not enough comes out of the space program and individual missions rarely bring in value to exceed their cost.
The NEAR mission has been a total success beyond anyone's wildest dreams. They even recovered from almost certain tragedy when a mis-fire forced them a year off course. It has proven that sometimes the value of the mission does exceed the cost.
The global economy is a great thing until you feel it locally.
Does anyone know what OS their software is running on?
Vxworks, reportedly. It is a real-time OS.
From the NEAR FAQ
31. What kind of computer is on NEAR Shoemaker?
The computer is a 16-bit machine called a 1750A. Based on a military standard that is about 10 years old, it runs at 12 MHz and has 256 KB of storage. This is equivalent to the PCs produced in the mid-1980s.
I have discovered a truly marvelous sig, unfortunately the sig limit is too small to contain i
When this team gets finished with little NEAR, they need to be put in charge of a Mars Landing project.
Were Eros not moving relative Earth, were Eros not at a different distance from the Sun than Earth, were spacetime flat between Eros and Earth, then yes, all it would take would be a small amount of fuel to get from one to the other.
However:
You have to put in a substantial change in velocity (delta-v) to get from Eros to Earth with any hope of not becoming a crispy critter in a meteoric reentry. You have to change your potential energy from the Sun's gravitational field. You have to make the transit so that you end up relatively motionless to the Earth at the time when you are relatively close to the Earth.
So, it takes a LOT of fuel to get there. If you take enough fuel to get BACK, you have to take even more fuel to get THERE, because you have to move the fuel to get back. Then you need even more fuel to haul the fuel to haul the fuel, and then some fuel to haul the fuel to haul the fuel to haul the fuel....
www.eFax.com are spammers
Everyone knows that asteroids are the main source of killer bacteria that will hunt the human race and turn us into mutants. I don't want to become a mutant. Unless I get superpowers like the X-men that is. Then it would be cool and I welcome all those killer bacteria. But only if I get superpowers!
This type of tomfoolery is exactly why the government should be completely in control of space exploration.
If NASA had handled this like they did on Mars, that ship would have STAYED crashed.
From the NEAR page and mirrors "Spacecraft not to be relaunched from Eros The NEAR mission operations team disabled a redundant engine firing today that would have been activated if it became necessary to adjust the spacecraft's orientation in order to receive telemetry from the ground. But because NEAR Shoemaker landed with a favorable orientation, and telemetry has already been received, it is no longer necessary to move the spacecraft from its resting-place on the surface of Eros." http://near-mirror.boulder.swri.edu/news/flash/01f eb13_2.html
I don't know if this was posted before, but I assume that the pictures they take when this lifts off will look much the same as the ones that were taken on the landing as can be seen in this link: Landing Photos
http://www.codewolf.com - Just good stuff to waste time
When NASA try to land something, it crashes. When they try to crash it, it lands safely and can even take off again.
There's a pattern here. Can you see what it is yet?
Scientists in a final attempt to squeeze every dollar out the NEAR project are going to launch the tiny spacecraft into the Sun. The NEAR has already provided facinating data by landing on an astroid, by crashing into a moon crator, by dipping into the rings of Saturn, by plumitting into the deep oceans and being swallowed by a giant squid, and most recently by being used as a target during the latest anti-ballistic missle tests. Go little buddy! go!
Someone you trust is one of us.
Let's re-read this sentence a few times, shall we? I rest my case.
---
---
Slashdot: News For Zealots. Stuff That's Hypocritical.
"OW! Great Vrebzjneb, what the photon was THAT?"
"It sounded like something crashing into the surface. Zarbonn, I thought you said you'd fixed the problem!"
"I did, I did! Just let me go take a look...."
time passes
"...Aw, geez."
"Well, what was it?"
It's that stupid shiny box with wings. It crashed *again*, this time on the other side of the asteroid."
"What!? You mean they sent a second one?"
"No, no, it's the same one. It lifted off and crashed down again."
"How did it do that? I thought you said you'd broken all the electronic bits off!"
I said I'd broken the camera off so it couldn't see us. I didn't think it'd be able to lift off again after being beat up that bad in the first crash, so I left it alone. I figured the garbagemen would pick it up next Wurblesday anyhow, so I left it alone."
"Well, that's just great. Now I'm going to have to help you pick it up and carry it all the way to the other side of the rock so that they *do* pick it up."
"No, just relax, I'll give Zarkkel a call tomorrow afternoon and have him bring his tow rocket. He owes me a favor anyways."
"Well, go up and break all the rest of the bits off so that it doesn't go off a third time. The last thing we need is to have that thing crashing through our ceiling like those poor Martians did just last cycle."
"Already done. By the way, I thought I could swipe those solar cells and hook them up to the transmitter next weekend. If they provide enough extra power, we should be able to pick up the pay-per-view movie channel they're broadcasting from Titan."
"Great! Say, you don't think that shiny transmitter box could have come from Earth, do you?"
"I doubt it. After we buzzed their last box and made it crash into Mars instead of orbiting it, you'd think they'd have learned their lesson."
"You'd think. 'Intelligent life' my berizzekl."