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I noticed a post on the "Tallbloke's Talkshop" blog which comments on the fact that the European Space Agency (ESA) seems to have been compromised by its over-optimism in solar power technology for the Rosetta space mission that is monitoring and has recently landed a probe called Philae on comet 67P.
The traditional thinking by NASA is that solar power is not really adequate for "deep space missions", which are missions which go beyond the asteroid belt situated between Mars and Jupiter, and at these distances from the sun, RTGs or "nuclear batteries" should be used instead. The ESA position is that solar power is viable even in deep space, but in the case of 67P they seem to have been caught out by the the discovery that the comet is much more non-spherical and randomly shaped than they had expected (and that might be true for comets and asteroids in general), resulting in there being lots of well-shaded areas where use of solar power is compromised, and the Philae probe has now run out of electricity after only a day or so. Knowledge of the composition of the comet that might have been provided by Philae is potentially useful for the future of the human race, as it might offer clues on how to deal with comets that are on a collision course with Earth.
I remember this issue of whether you can use solar power in deep space came up back in the late 1990s in regard to the Cassini mission which landed a probe on Saturn's moon, Titan. Cassini was powered by nuclear batteries, and as might be expected, Green groups protested against its launch, as described in this letter from Greenpeace to the US President of the time, Bill Clinton (I had to use the "Wayback machine" to find this letter, as the Greenpeace press release link has now gone dead):
ESA designed the Huygens probe used in the Cassini mission, and Greenpeace noticed that the more politically correct ESA was claiming that solar power could be used for missions like Cassini, resulting in even more vociferous environmental protests. This article from Spiked in 2005, written just after the probe sent back spectacular pictures from Titan, gives some idea of the protests:
In addition to trying to disrupt the launch in 1997, where a group called "Grandmothers for Peace" was heavily involved as I remember it, the environmental protesters even tried to create a few panics after the launch when the Cassini space vehicle did a couple of "flybys" of Earth to pick up speed for the journey to Saturn, where the vehicle passed a few hundred miles from Earth.
I remember in the early 1970s at the time of the moon landing missions that it was assumed to be a mere formality that man would have landed on Mars by the end of the 20th century. But travelling to Mars in that timescale presumed that nuclear-powered rocket technology was going to be developed, which of course has never happened. If you look at the protests over the Cassini mission you can see why - if the Green movement makes that much fuss over a comparatively small nuclear battery going up into space, what fuss are they going make over a nuclear-powered rocket?
I've just noticed that there was an article trumpeting the supposed success of solar power in deep space written on "The Ecologist" magazine's website. This magazine had Zac Goldsmith as its editor until he joined David Cameron's "Vote Blue Go Green" project and became a Conservative MP. The article, called "Rosetta shows - we can keep space plutonium-free!", was written in August 2014 by Karl Grossman, who is a professor of journalism and probably the world's leading anti-nuclear power in space Green activist.
He seems to have been a bit premature in writing it a few months before the attempt to land the solar-powered Philae probe on the comet.
Grossman mentions that NASA is using solar power for the Juno mission to Jupiter that was launched in 2011, the first time NASA has adopted solar power for a deep space mission. However he doesn't mention a major setback to the plans of the Green Blob's space division in that NASA has now started to adopt nuclear power in the non-deep space zone as well, in the form of the RTG powered Curiosity rover vehicle which has been sending back pictures from Mars for about two years.
I believe that ESA are tring to develop RTG technology themselves, but intend to use a more politically correct material, Americium 241 instead of Plutonium 238. Presumably the logic behind this is that Americium 241 is used in smoke alarms, and as the Greenies don't currently complain about that, then they won't complain about its use, albeit in larger quantities, on a space mission. My prediction is that when you try to launch a spacecraft with radioactive americium material onboard, there will still be environmental protests.
I noticed a recent article about the Philae probe where it looks like ESA made another over-optimistic assumption about the comet. At the time of the comet landing, the harpoon anchorage system for the lander failed, and this was given as the main reason by the mainstream media for the landing mission not being a complete success - failure to anchor to the comet's surface at the first impact resulted in the probe bouncing about on the surface and settling in a well-shaded location where the illumination was too weak to recharge the solar-powered batteries.
According to the Rosetta mission scientist Matt Taylor (most well-known for being attacked by feminist activists for wearing what they regarded as an inappropriate shirt at the mission's press conferences), the comet's surface was much harder than expected, and the harpoons might have failed to embed in the surface material at all if the system had actually worked, resulting in an unintentional extra recoil force which might have sent the probe completely back into space rather than just experiencing a high first bounce.
There seems to be a strange working culture operating in this European Space Agency. In most industries, you tend to make pessimistic assumptions when dealing with the unknown. This lot seem to think that when you deal with the unknown all you have to do is follow whatever are the text book assumptions, and if that doesn't work, you were unlucky. So the text book assumption is that a comet is a 'dirty snowball' in composition that you should be able to grab at the first impact with some harpoon anchoring system. The text book assumption is that comets will have a nice round shape rather than having some irregular shape even though nobody has actually seen one close up.
The ESA organisation is a very strange beast indeed and probably not susceptible to normal argument. I have to work under their edicts on a daily basis and they often seem irrational to me.
On this subject of space missions being compromised by Green technology, there was a news story today about a NASA satellite orbiting Mars managing to locate the ill-fated British space probe "Beagle 2" on the surface of Mars. Beagle 2, which was designed to look for signs of life on Mars, landed in December 2003, and was assumed to have been effectively destroyed in the landing operation (as I remember it, the man in charge of Beagle 2, the late Colin Pillinger, claimed they had been caught out by a 'Martian heatwave' making the atmospheric conditions a bit different from what had been designed for).
It turns out that the probe did land in an intact state rather than being destroyed, and landed within 5 km of the centre of its target location, but it appears that it failed half-way through the operation of unfolding its arrangement of disk-mounted solar panels, possibly due to the discs being excessively deformed by the landing. The solar panel arrangement had to unfold completely before it could contact Earth, and it was then going to send a signal to Earth composed by British pop group Blur as I remember it. Basically, as far as I can see, the mission seems to have failed because the probe was designed to use solar power - if it had been using a robust and reliable power source like an RTG, the mission would probably have been a success.
If the Green lobby had never existed, then in my opinion RTGs would probably be used routinely to power spacecraft that are designed to land on planets, moons, comets, etc. But due to the influence of this lobby, solar power has to be the first choice for these landing missions, with RTGs only allowed in unusual situations that have to be justified.