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Philae Lander: “It’s time for me to say goodbye”

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Re: Philae Lander: “It’s time for me to say goodbye”

#31

Post by Alupis »

calgoo wrote: post #28
WhoBeI wrote: post #22

Earlier quoted context omitted.

True, you don't really want that stuff to fall into the wrong hands. NASA seem to like RTG's though and used them for New Horizons and a few others. Apparently they share since it's used in Cassini as well.

There is not enough light to power probes after a certain distance. That's why they have to use the RTG's in mission like New Horizons. There was also a shortage of the Radioactive material to make the RTGs, but that seams to be solved with NASA producing its own material.

> There was also a shortage of the Radioactive material to make the RTGs

From my understanding, this shortage is caused by the lack of nuclear power facilities in the USA - which supports the GGP's point about negative political/public reactions to anything nuclear.

Re: Philae Lander: “It’s time for me to say goodbye”

#33

Post by voidz »

coldtea wrote: post #12
aaron695 wrote: post #6

If only science not religious anti-science sediment ruled the earth then they would have just used a nuclear battery instead.

Well, science also gave us Josef Mengele. He was done with puny religious and moral concerns too.

https://upload.wikimedia.org/wikipedia/en/e/e0/Steve_Urkel.j...

Re: Philae Lander: “It’s time for me to say goodbye”

#35

Post by pavlov »

throwaway049 wrote: post #20
pavlov wrote: post #11

Earlier quoted context omitted.

Here's a source specifically for the EU portion of the ESA budget: http://www.esa.int/About_Us/Welcome_to_ESA/ESA_and_the_EU "Some 20 per cent of the funds managed by ESA now originate from the EU budget." I'm not disagreeing with you, but it seems unlikely that UK just won't participate in that 20% of ESA activities anymore. So they'll have to renegotiate the membership fee to account for that.

It might not need a renegotiation as such, just a direct payment of the same amount as previously went via the EU account.

Britain can't unilaterally decide to do that. So, a renegotiation is needed.

That's a big problem with Brexit. Some highly visible supporters promoted the idea that Britain will simply be able to dictate new and more favourable terms for everything that happens through the EU framework currently.

It's essentially the same as what Trump is saying -- "I'll deal with China. I know how to make deals. I'll make a great deal" -- With no specifics on what the deal would be and why the other side would accept it.

Re: Philae Lander: “It’s time for me to say goodbye”

#38

Post by mikeash »

lmm wrote: post #25
ralfd wrote: post #16

Earlier quoted context omitted.

Sure, but for what purpose? The mission was done, nothing to see here anymore. So the ESA would have traded the (very small, but not zero) risk of radioactive contamination from a launch failure for not enough additional research gain.

AIUI the lander (Philae) is believed to have failed because it landed in a valley where its solar panels couldn't collect enough energy. Had the lander used an RTG it would likely have worked, returning valuable science data.

It also would have been a lot heavier. There is certainly an excessive fear of nuclear stuff that pushes for space missions to use solar when RTGs would be more suitable (Juno may be an example of this) but this does not seem to be one of those cases.

Re: Philae Lander: “It’s time for me to say goodbye”

#39

Post by talideon »

bhrgunatha wrote: post #4

I wonder how much impact the UK's withdrawal from the EU will have on the ESA and future missions.

Very, very little direct effect. While the EU might part-fund the ESA, it's not an EU body.

The effect will be indirect, mainly due to reduced funding to UK science and less collaboration between scientists in the UK and those in the EU.

Re: Philae Lander: “It’s time for me to say goodbye”

#40

Post by mikeash »

Alupis wrote: post #31
calgoo wrote: post #28

Earlier quoted context omitted.

There is not enough light to power probes after a certain distance. That's why they have to use the RTG's in mission like New Horizons. There was also a shortage of the Radioactive material to make the RTGs, but that seams to be solved with NASA producing its own material.

> There was also a shortage of the Radioactive material to make the RTGs From my understanding, this shortage is caused by the lack of nuclear power facilities in the USA - which supports the GGP's point about negative political/public reactions to anything nuclear.

We have a lot of nuclear power plants. There hasn't been much new construction, but there hasn't been much decommissioning either. It makes up about 20% of our total electrical generating capacity.

The problem is that turning nuclear reactors into Pu238 requires a lot of extra work and equipment. They produce small amounts, but separating it out is tough. You can make more by irradiating other waste products, but that's not easy either. Apparently some stuff used for making nuclear weapons can be used for this purpose (note that nuclear weapons use Pu239, not 238) and the shortage happened because those facilities were closed.

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