Philae's Lost Seven Months Were Completely Unnecessary

StartsWithABang writes: This past weekend, the Philae lander reawakened after seven dormant months, the best outcome that mission scientists could've hoped for with the way the mission unfolded. But the first probe to softly land on a comet ever would never have needed to hibernate at all if we had simply built it with the nuclear power capabilities it should've had. The seven months of lost data were completely unnecessary, and resulted solely from the world's nuclear fears.

Comments

But how would it hug the comet...

[Rinikusu]

With nuclear arms?

Re:But how would it hug the comet...

[Nidi62]

With nuclear arms?

That warm soft glow isn't radiation, it's love!

Re:But how would it hug the comet...

[CreatureComfort]

With nuclear arms?

That warm soft glow isn't radiation, it's love!

If it was an ice comet it wouldn't glow, it would melt. Defeating the purpose of sending a probe there.

How many probes does it take to get to the center of a 67P/Churyumov-Gerasimenko?

Re:But how would it hug the comet...

[zeugma-amp]

How many probes does it take to get to the center of a 67P/Churyumov-Gerasimenko?

The world will never know.

Obligatory reading

[rodrigoandrade]

https://en.wikipedia.org/wiki/Nuclear_power_in_space

Re:Obligatory reading

[Shatrat]

Have there been? 10,000 people die in Japan from a tsunami and everyone is still shitting their pants over a nuclear reactor that didn't kill anyone. People fear what they don't understand, and most of us aren't physicists.

Re:Obligatory reading

[Drethon]

Right, because the number of fatalities due to nuclear power have been horrific! http://www.the9billion.com/201...

Re:Obligatory reading

[serviscope_minor]

And people go "oh no they can detect the radiation IN CALIFORNIA ITS LIKE THE TITANIC BUT WITH BEARS EVERYBODY PANIC!!11111ONE!11ONEoneleven1!11"

Which is actually a testament to the astonishing sensitivity of modern equipment. The level of radation in california is 8 disintegrations per cubic meter per second. That's 8 whole atoms per second in a tonne of water. That's 8 out of 100000000000000000000000000 atoms (that's actually the right number of zeros give or take).

It's also about an order of magnitude below the background radiation from naturally occuring stuff in the water, never mind the incoming cosmic rays and stuff from the ground and food.

Another fun fact: the Super-K detector can pick up the signature from relatively nearby nuclear submarines that aren't leaking any ionising radiation at all.

Instruments are sensitive.

Re:Obligatory reading

[x0ra]

Easy, just avoid going in the contaminated zone, and everything will be fine.

Re:Obligatory reading

[whathappenedtomonday]

While it is true that people are not dropping dead in the thousands due to Fukushima, I'll leave this to consider:

Estimate of Consequences from the Fukushima Disaster, Jirina Vitazkova and Errico Cazzoli, Nordic PSA Conference (nuclear utilities in Finland and Sweden), September 2011 (emphasis added): The results with respect to health effects show that within 80 years the number of victims of the Fukushima disaster can be expected to be AT LEAST in the range of 10,000 to 300,000 people in terms of deaths due to infectious diseases, cardiovascular diseases, genetic diseases, and cancers; and about the same number of sicknesses/syndromes needing prolonged hospitalization and health care are expected to occur. This estimates accounts only for the population already living at the time of the accident. A comparable number of excess deaths and sicknesses may be expected in the population that will be born in the period. In addition to these, more than 100,000 excess still-births and a comparable or larger number of excess children born with genetic deformations (e.g. Down syndrome) are expected [...]

Whether the estimate is correct or not, it will take decades before it's safe to say "a nuclear reactor that didn't kill anyone". The actual outcome will also largely depend on how well the Japanese authorities will handle the cleanup. Judge for yourself whether they've done a good job so far.

Re:Obligatory reading

[Applehu Akbar]

After Chernobyl we heard the same predictions, initially of "millions of excess deaths." Exactly the sort of handwavy pseudo-statistics the flat-earth lobby outgasses when it doesn't have any real science. But after all those yaers, the Chernobyl death toll remains stubbornly at 51.

But to stay on topic: supposedly the reason Philae did not have a radioisotope generator is that these are rather large, roughly the size and mass of a person. This would have been more useful for a long-endurance version of the Rosetta itself than a small lander probe.

Re:Obligatory reading

[kbonin]

Are you sure its radiation hasn't killed anyone? I've seen several "news" articles that claim a death toll of over 10,000 spread across the pacific, including thousands in California.

Sarcasm aside (and the above is true, in that those "articles" are floating out among fringe "environmentalist" sites), a HUGE part of the problem is in domestic nuclear industry that isn't replacing plants far past their operational lifetime with the newer and MUCH safer designs, since that would cost real money and the stockholders want that to be reexamined next quarter, after they sell. And short. Greed and stupidity on both sides...

Re:Obligatory reading

[drinkypoo]

But after all those yaers, the Chernobyl death toll remains stubbornly at 51.

Right, there's no way to accurately count the people who succumbed to various illnesses which wouldn't have killed them if not for its influence, so it's never going to be incremented substantially, but it will also never accurately reflect the impact of the Cherbobyl disaster.

Re:Obligatory reading

[whathappenedtomonday]

After Chernobyl we heard the same predictions

I already said that "whether the estimate is correct or not, it will take decades" because of "the long latency period for some cancers. WHO said in 2005: "The total number of deaths already attributable to Chernobyl or expected in the future over the lifetime of emergency workers and local residents in the most contaminated areas is estimated to be about 4000." Again, the numbers do not matter, or that they only look at the "most contaminated areas" in their estimate. All I was saying was that it is too soon to talk about the death toll, because it will take decades of science to say anything meaningful. The OP argument was like "I locked up 10 people in an airtight room and they were all ok when I checked on them a minute later."

Re:Obligatory reading

[fermion]

this is an engineering problem, and incompetent people should have nothing to say about it. One of the primary ways that we can identify incompetence is when someone say if we would have done this then the problem would have been solved. Engineering problems are complex, especially in space travel, and there is no way to know that, for example, a nuclear power source designed for a soft landing would have survived a hard landing. That is, in fact, the engineering problem on which the mistake was made after all.

To answer this specific engineering problem, plutonium is simply too dangerous and costly to use in space. The reason is that plutonium is actually very safe to humans except when breathed in as small particles, such as what might be generated when a launch vehicles catastrophically explodes on launch. In this case, the small particles will tend to be inhaled by animals, pass through the lungs, and pretty permanently become part of the body. The plutonium will then go though the 24,000 half life, which means over the lifespan of the contaminated human almost no Pu will decay. It will radiate and cause health issue for a lifetime.

Again, this is an engineering problem with very smart people working it. All engineering problem result in an engineering solution, and an engineering solution is always a compromise between competing factors, some technical, some emotional.

In hind sight it is always easy to poo poo an engineering solution. People who do nothing but push paper, like the readers or forbes, are the most likely candidate is simply say 'why did we do this'. They can ask that question because they have never created a practical device in their lives, therefore never have been part of the engineering process and therefore have never understood that the result is always a less than perfect but usually quite acceptable solution.

While the nuclear power proponents want us to believe that nuclear power is the solution to everything, history tells us otherwise. Even though nuclear power is very mature technology, there is little private funding for it. In the US Nuclear power plants are not being build because bankers know there is no profit in it, and government should no more subsidize a nuclear power plant than a coal fired plant. Both are mature enough to stand on their own.

Nuclear power cannot stand on it's own because it cannot generate enough profit. For instance, BP generates enough profits so that when the Deep Horizon rig failed it could cover the 13 billion dollar clean up. Fukushima is going to cost 10 times that much to clean up. Who is going to pay for that. They taxpayer. The US taxpayer for contamination that reaches US land and water. It is true that the readers of Forbes loves to make profits at taxpayer expense, but I don't think that it is a good idea. It is only free if you are not the one impacted.

Re:Obligatory reading

[fafaforza]

That's a statistic I'd find hard to believe. And besides, immediate death is just a small part of it. There are a few hundred people that were in the Russian army at the time and had to respond to the disaster who have either died of various cancers or are suffering from them now. There are kids in Ukraine that are born with many genetic defects, like holes in their hearts, presumably because their parents were affected.

I wouldn't count this out as a negative effect. And these are obvious effects. How many people there suffer from lesser ilnesses that might or might not be attributed to Chernobyl, like stroke, cancers, etc.

I'm not opposed to nuclear. I think it needs to be a viable option if we are to stop producing CO2, but I won't pretend that it's harmless, either. Even if we get to a 100% safety record, there's still the matter of storage, and transporting that waste to the storage areas. How many TEPCOs do we need to realize many of these companies entrusted with the task can be very incompetent and borderline criminal in ignoring safety lapses pointed out by inspectors.

Re:Obligatory reading

[fizzup]

the 24,000 [year] half life

TFA refers to Pu238, which is quite active. It has a half life of about 88 years. It is an energetic alpha emitter, which is not dangerous outside the body because the skin absorbs the emission and you can wash Pu238 off pretty easily. However, once it's inside you, virtually all of the alpha emissions will be absorbed by your body unless/until you can excrete it. A good fraction of any amount ingested will eventually emit energetic radiation that you will absorb. A disaster could be bad.

Having said all that, including Pu238 in a spacecraft is a problem we have solved before, so it's not all that crazy.

Re:Obligatory reading

[BevanFindlay]

Not necessarily. Time won't solve basic physical limits. Chemical batteries, as most will know, have very limited lifetimes. The RTG on Voyager 1 has been going for more than 37 years. If you rule out radioactivity or nuclear power, then your only options in space are chemical or something like solar. Solar has problems, as Philae has demonstrated. The issue with chemical is that there are hard limits on how much energy you can store in the bonds between atoms - even if we invent a wonderful new rocket fuel or battery type, the maximum limits can still be worked out and they will never exceed that (there's a reason why we use ion engines for space probes, and it has to do with "mass you have to carry" and "how much it can change your speed"). "More technology" will never overcome these problems, unless you come up with something really exotic (like zero-point energy). One that is easy to understand is solar on Earth: we can make it more and more efficient, but we can never exceed 1kW/m^2, as this is the total amount of solar radiation reaching the surface (and, I don't think we've got better than about 30% efficiency). It doesn't matter how wonderful your technology gets, it can never beat basic physics.

The only "high-yield, low launch risk" technology I could think of would be fusion (as deuterium isn't radioactive), but we are yet to get that viable. Apart from that, you're dreaming of magic, no matter how much time you wait.

Re:Obligatory reading

[BevanFindlay]

Love your explanation of why engineering problems are hard (everything is a compromise of something else, nothing is as simple as it first seems), although I disagree with you about nuclear power. Why should "how much money it makes" be the ruling metric? That's extremely foolish. Despite the high-profile cases, nuclear power is actually one of (if not the) safest forms of power generation. We are ruining people's health and the environment by using things like coal, so we need an alternative. So, nuclear power doesn't make lots of money - so what? If that's all we are measuring things by, then it explains why so many things are screwed up. Apply the same engineering thinking you explained to the performance metrics question: any single-metric performance measurement will be wrong ("good" overall is measured by a number of competing and sometimes conflicting factors; so, in your case "profitability" is a poor reason to say "nuclear isn't a solution").

The prevention and clean-up do need to be factored into the use of nuclear power, but we also need to drag the technology forward to safer designs, not keep limiting it to unsafe, inefficient forms that haven't changed in half a century.

Re:Obligatory reading

[tnk1]

I chalk up the deaths of Chernobyl less to nuclear power, and more to being the risks of living in a place like the Soviet Union. Yes, you can set off nuclear plants like that, but let's face it, Chernobyl was a triumph of Communist bureaucratic indifference at work.

Re:Wind is the answer!

[disposable60]

SOLAR Wind turbines!

Nuclear Power Fears

[ZeroWaiteState]

People will stop fearing nuclear power when world leader stop making irresponsible remarks about nuking people when they are upset. Until then, anything with a rocket stage and a nuclear device in the payload will be taboo.

Re:Nuclear Power Fears

[jthill]

Well, yeah, if you pick a synthetic radioactive source with a half-life longer than humanity's been in existence.

Strangely enough, nobody's fucking idiot enough to do that.

Re:Nuclear Power Fears

[Coren22]

RTGs are deigned that even in the event of a rocket breakup (the rocket makes a big boom), or reentry (blast furnace for 30 or so seconds), that the RTG will not breach, and will frankly land (hit the ground pretty damn hard) without any possibility of damage. You are more likely to die from getting hit by the thing than any possibility of radiation from the thing, unless you disassemble it.

Re:Nuclear Power Fears

[Applehu Akbar]

Radioisotopes that last "longer than humankind has been in existence" are so weakly radioactive, and so small a part of a nuclear event, that we can ignore them. The most dangerous isotope in an accident is I-131, which has a half-life of eight days. That's a lot of energy it has to release in a short time.

HÃ?

[angel'o'sphere]

and resulted solely from the world's nuclear fears.

What bollocks is that? What has an RTG in space to do with a nuclear (fission) reactor on earth?

No one cares how you power your satellites, space probes.

I for my part have no back yard on a comet light minutes away.

Re:HÃ?

[sjames]

What bollocks is that? What has an RTG in space to do with a nuclear (fission) reactor on earth?

Nevertheless, a bunch of fearful and uninformed people vigorously protested Cassini and it's RTG. Sky is falling, something something we're all going to die!

Re:HÃ?

[jfengel]

Space probes do get started on earth, and have to go through a somewhat unreliable launch process to get to space. There is a fear that if the rocket were to blow up, radioactive material released into the atmosphere would be dangerous.

It almost certainly wouldn't be. Even in the worst-case scenario, that the RTG vaporized on reentry, it would be heavily dispersed. Still, NASA calculated for a similar case, there could be several thousand deaths (page 66). (Not that you could peg any one death to it, but rather thousands of additional cancers compared to not having an accident with an RTG launch failure.) Plus some land contamination with radioactive dust.

So it's not completely insane to be concerned. They figure your personal odds of dying because of it to be one in a trillion, which most of us would say is too low to think about. But I can understand why a few people might say that even one-in-a-trillion (especially since it's repeated for everybody on the planet) is worth considering. It's not as simple as having it millions of miles away in space.

Re:HÃ?

[Orgasmatron]

Yeah, that table is based on LNT, a "theory" with less supporting evidence than Santa Claus. Actually, that's not fair to Santa, since the evidence directly contradicts LNT. But LNT is mandated by law in many cases, which you should keep in mind the next time someone tells you that the left is pro-science.

LNT is "Linear, no threshold". According to that nonsense, a radiation dose expected to cause cancer in a person, but distributed over 7 billion people still causes 1 "extra" cancer in the world. This dose may not even be detectable, by the way, and would be far smaller than the ordinary background radiation levels.

In reality, people with occupational radiation doses have lower cancer rates than the general population.

Re:HÃ?

[brambus]

What bollocks is that? What has an RTG in space to do with a nuclear (fission) reactor on earth?

Pu238 is produced in reactors here on Earth. Due to all the restrictions and red-tape put up by (supposedly) anti-nuclear activists, it's difficult and very costly to keep producing it, so everybody who had been producing it, simply shut down.
Now to be honest though, this is a poorly constructed argument. Strict regulation of nuclear materials isn't in itself a bad thing and besides, the lack of Pu238 is mainly due to the shutdown of the nuclear weapons industry, not the power industry (which never produced it anyway). Moreover, Philae was a low-value part of the mission to begin with and an RTG wasn't really necessary (needless to say that it can weigh quite a bit, potentially sacrificing other experiments that could be carried in its stead). Regardless, the comet was scheduled to make a close pass by the Sun regardless, so there was always the possibility of getting more power later on in the mission. Where the RTG argument *can* make sense is in missions like Juno. Juno had to go to some pretty serious compromises to be able to explore Jupiter without an RTG, such as having oversized solar panels for its relatively meager scientific payload. Had Juno had an RTG, it would likely have been able to pack a lot more equipment that is also more power-hungry, allowing us to get more out of the mission. Anything beyond the orbit of Jupiter without an RTG is an outright non-starter using solar power, as the scientific return quickly diminishes to zero simply due to the lack of power. Even Mars missions without RTGs were compromised (one of the principal reasons Curiosity got an RTG was so that we could get more power-hungry experiments on it, cause being able to snap pretty pictures only gets you so far).
Overall, it's a soapbox article and sadly, it starts out with the wrong premise.

Re:HÃ?

[sjames]

Actually, the RTG would have survived had the launch vehicle exploded. It also wouldn't be the first RTG to re-enter the atmosphere.

meanwhile, they missed the boat on the launch, so they protested the Earth slingshot maneuver instead.

Re:HÃ?

[Applehu Akbar]

In fact, there is NO valid example of a LNT toxin in nature. If you reduce the concentration of any toxin in, say, water, there is always a point at which its medical impact drops to zero while there is still some toxin present. This is because natural selection ensures that we can survive the amount of that toxin that we normally find in the environment. This includes the constant drizzle of background radiation that we live in.

In fact, the scientific term for belief in LNT in chemistry is "homeopathy."

Not nuclear fear

[edxwelch]

Firstly, what caused the problem was not "Nuclear fear", but failure of the harpoon to hold Philea down. The solar panels would have worked fine otherwise.
Secoundly, Plutonium-238 is simply no longer available - nobody makes it anymore. The reason why is because it is created using a dangerous and expensive process by irradiation of neptunium-237.

Re:Not nuclear fear

[Anonymous Coward]

Thirdly, the lander was "bonus", an "extra" and had to meet very tough weight limits. There was simply not enough mass available on the rocket to put anything but light weight solar.

Why is this even being brought up anyway? They couldn't launch with an RTG because rocket didn't have enough capacity.

Re:Not nuclear fear

[alexhs]

Plutonium-238 is simply no longer available - nobody makes it anymore.

That's pretty much what's in the article. The summary is inflammatory (on Slashdot ? Who would have guessed ?).
The meat of the argument is this :

1. All previous deep space probes have used RTGs [Radio-isotope Thermoelectric Generator], but the ESA has not developed RTG technology. They couldn’t get it from NASA (who wouldn’t provide it) or Roscosmos (which would violate the ITAR treaty).
2. We are literally running out of our Pu-238 supply for deep space missions. We are no longer making more, although we could be easily doing so for scientific purposes. It just costs a little bit of money.

So : side effects of nuclear regulations, and lack of material.
By the way, weight was not a reason, RTG weighting about the same as solar panels (12kg).

Re:Not nuclear fear

[hey!]

Still doesn't mean the solar panels aren't cheaper and more effective for the mission, at the cost of some additional risk. That's how engineering works: you don't get unlimited budget to drive risk to zero.

The important thing to realize here is that events have actually validated the engineers' choice to use solar. Had the interesting stuff been happening out at 5+ AU where you'd only be getting only 5% as much solar radiation as Philae is getting now, then failure to orient the lander ideally would have meant mission failure. But that's not the case. The interesting stuff is happening *now* around perihelion, where there's boatloads of solar radiation available even if the solar panels aren't pointed just so. There is not very much if anything substantive lost by the interim inactivity of the lander, other than a few years life expectancy for the program managers.

Given that we now know that the nitrocellulose powering the harpoon system is unreliable after ten years in a vacuum, you wouldn't design the lander the same way today. You might even choose to use an RTG; I don't know. But this result certain bears out the engineers' assessments of the net prior probabilities; in fact the current outcome was no doubt one of the possible scenarios the engineers considered and put in the success column.

Re:Not nuclear fear

[dryeo]

For a space launch, the RTG needs to be protected in case of launch failure and will weigh more then 12 kg. The ones currently used weigh 57 kg compared to Philae's 21 kg.
I also question whether putting a heat source (300+ watts of heat to equal the required 32 watts) on an ice ball would be smart

Re:Not nuclear fear

[hey!]

RTFA.

I did. I was not impressed.

We have NO idea whether anything "interesting" was happening during that time.

Well, like what, for example? What were you expecting to happen?

Your definition of "success" is "Well, it works now, because we got half-lucky on the landing."

My definition of success in this case is collecting the data which were used to cost-justify the mission. Do you have a better definition of "success"?

For whatever reason, you choose to disregard the fact that using an RTG would have eliminated that risk altogether, *and* it would have eliminated that seven month blackout period.

Because the mission will be successful according to my definition of "success" (see above). You seem to have a "cost is no object" mindset. Since the ESA does not have any of its own RTG technology it would have to buy it from the Russians or Americans, and then build in the necessary safeguards required by the mission profile's three near-Earth fly-bys. Since solar panels are cheap, simplify the mission, and the ESA has access to high-efficiency solar technology that can do the job, it makes sense to use them.

Your definition considers total mission failure, from a less lucky missed landing, an acceptable risk.

Of course it's an acceptable risk. If total mission failure were not an acceptable risk, then the mission would be too expensive to conduct.

Why oppose nuclear powered satelittes?

[140Mandak262Jamuna]

The amount of nuclear fuel they carry is not much, even if they are not on such missions as in comet landing, even if they eventually end up re-entering the atmosphere of planet earth, they can be designed to burn up and disperse. It is not going to add any more radioactive pollution than coal fired power plants. These coal plants burn so many thousands of tons, even trace radioactive elements measured in parts per billion eventually adds up to some serious numbers. Some burnt satellite is not going be significant.

Re:If it was political, that is sad

[oh_my_080980980]

It wasn't. This is a troll piece. People need to stopped be suckered by ass-holes and doe some god damn research before continuing the troll machine.

Re:This is an Opinion/Editorial piece

[MozeeToby]

Worse, it's not even informed opinion. You can't just "slap an RTG" on a probe and hope for the best. There are engineering, cost, and benefits considerations to make.

I really feel like people forget that the lander was an afterthought. The primary science of the mission was and is being performed by the Rosetta spacecraft. It was a "nice to have" that everyone was thrilled to see work as well as it did but wasn't critical for the success of the mission. Furthermore, it performed the vast majority if it's planned science activities during the 60 hour battery period after initial landing.

Yes, obviously, probes and landers can and do outperform their initial program goals. But treating the lander like a failure when it was anything but is dishonest. Using it as a soapbox to push your agenda (whether it's one I agree with or not) is insulting to the 2000+ people who worked to make the mission the fabulous success that it is and was.

Re:This is an Opinion/Editorial piece

[GNious]

You can't just "slap an RTG" on a probe and hope for the best. There are engineering, cost, and benefits considerations to make.

I've tested this extensively in KSP - you can, in fact, just "slap an RTG" on probes quite trivially!

Complete Hogwash

[Anonymous Coward]

It would have been totally ludicrous to equip Philae with a RTG. This would have meant a dramatically increased cost for probably little gain. The main mission is the orbiter - it works fine with solar panels. The lander had an estimated failure probability of 50%, and that was an optimistic estimation. In the case it lands, the lander was equipped with a battery for the prime scientific objective. For the icing on the cake cheap solar panels were added.

So this guy suggests to spend hundreds(?) of thousand Euros just for the totally unlikely event that a) the lander lands correctly and b) the lander bounces and c) the lander lands again in a shadow for d) the icing on the cake? He does not seem to understand how budgeting works.

Use RTGs for deep space missions, where they are needed.

How can this ignorant (or simly troll?) be a "NASA columnist"?

The Americans pulled out

[Bluefirebird]

First of all, the Rosetta mission was a joint NASA-ESA mission, where NASA was in charge of providing the power supply. However, the US Congress pulled the funding on the mission and ESA had to do it alone. This was after most of the spacecraft was already designed.

Second, ESA never developed nuclear-powered spacecraft. Even though it is a policy choice due to the fears of blowing up nuclear material in the atmosphere, it is also reflection of a space agency created specifically for non-military purposes. While NASA is also a civilian agency, it has a strong connection with the US military and access to materials such as plutonium.

Third, different Nuclear Power sources in Space (NPS) have to be developed in order to guarantee the availability of the raw material. There is no point in developing a long-term programme based on rare or very hard to obtain nuclear materials.

Re:Pu-238 was available when it launced

[MozeeToby]

I think you are nitpicking the definition of "available". Yes, the fuel existed at the time, that doesn't mean the fuel was available for this mission. A high risk, relatively low reward, limited life lander almost certainly doesn't merit using 1/10th of the available reserves.

Don't think it was high risk? The lander failed in multiple different ways on deployment and was able to do science by little more than dumb luck (not discounting their success, dumb luck plays in important part in everything and it was their engineering and planning that allowed the landing to succeed despite those issues). Don't think it was low reward? Most of the science the lander was designed for was completed on batteries during the 60 hour window after landing. Don't think it's limited life? In a few months, the comet is going to start out gassing and the lander will almost certainly be disabled.

If Pu-238 were still in production the math works out differently. If the lander had been a more central part of the mission it might be different. If the comet were on it's way out of the system instead of in that could change things too (though then Rosetta would also need an RTG). The point is: it's not binary. It's not "the fuel is right there lets use it". There's a cost, and a benefit to using it in this probe rather than the next one.

Re:Whose nuclear fears?

[prefec2]

The claim of the political reason is without reference. However, the article correctly states that ESA does not have RTG technology and no one was selling RTGs at that time.

Re:Not fear but precaution

[kellymcdonald78]

RTGs have a perfect safety record, including cases there the rocket exploded, the RTG fished out of the ocean and used on a subsequent. We're talking about a few kg of PU-239 in an armored casing.

Re:Obligatory raidiating

[kellymcdonald78]

RTG's ARE containers designed to survive catastrophic launch failures. We're not talking about nuclear reactors here

Unnecessary

[ThePhilips]

The seven months of lost data were completely unnecessary,

A dangerous proposition. Some might counter it by questioning just how much the Philae's mission was really "necessary", and not just huge waste of funds and resources.

and resulted solely from the world's nuclear fears.

Or probably because world wants to push scientists to find alternatives?

Anyway. Nuclear power is one of those "not in my backyard" things. It's good - as long you live far enough from it. You do not "fear" it, unless it actually hits you. (And I am saying this as a person who as a child actually lived in the ex-USSR's area mildly affected by disaster of Chernobyl.)

Re:Not even that...

[Vihai]

A Thorium molten salt reactor would be able to produce Pu-238 without any considerable proliferation risk.

Re:Not fear but precaution

[Rei]

The article's understanding of things is no better.

The reason we don't use Pu238 more as a primary power source isn't NIMBYs - it's because we're almost out of it and it's absurdly expensive. Pu-238 isn't a "waste product" (except as mixed in with other isotopes and costing a fortune to isolate), it's a manufactured product - and with all transmutation, that means "slow" and "taking up neutronicity that could otherwise be going towards generating power". The plutonium to fuel Philae would have not only cost us a lot but also robbed us of the potential of an outer planets mission until our work to increase plutonium production catch up to our consumption.. It's just not worth it.

I agree with the author about heaters - sort of - but that's really a rather minor point compared to the bigger picture. As it stands, no, they should not have powered Philae with an RTG. And be freaking patient, Philae got to observe the surface when it was cold and is now getting to observe it hotter than we ever thought we'd get the chance to observe. And more to the point, you can't shut off an RTG or a radiothermal heater. Meaning if Philae had been nuclear, it'd be overheating today.