4 ms·

You're blaming this on Europe being nuke averse, but Europe is not a homogenous area. While some European countries may be nuke averse, others have adopted nucl

You're blaming this on Europe being nuke averse, but Europe is not a homogenous area. While some European countries may be nuke averse, others have adopted nuclear power to a huge extent. There are other reasons why an RTG might not have been appropriate for Philae. They're pretty heavy, and the lander is pretty light. Also, it is wasteful to use an RTG that could last many years when the mission is only expected to last several months.

delinka 11y ago
Perhaps you have your causation backward: perhaps the mission was planned to last only months due to power limitations.
- dempseye 11y ago
  I was under the impression that they thought the lander would be blown off the comet when it starts to shed ice and debris in large amounts around perihelion.
- arrrg 11y ago
  Philae is a tiny little 100kg add on … 29 times heavier Rosetta (the orbiter) is the main course, Philae is this tiny little and quite experimental (though admittedly extremely cool – mostly because of exactly its novel mission) little hitchhiker. RTGs are heavy and consequently have pretty much only been used on much heavier spacecraft and even then mostly only when being solar powered just wasn’t an option. For Philae, besides it being very lightweight, being solar powered was and is an option and the only reason it didn’t work out is because things went wrong during the landing … How in the hell do you even get the idea that Nasa would have used an RTG in ESA’s place here?! They are not psychic. They couldn’t have predicted things going wrong during the landing … and why then put an RTG on this when that’s something Nasa themselves does only very, very rarely and only for very different missions with much more demanding payloads?! What is this insanity? Why the need to get onto this political pulpit and spew out some unrelated political propaganda because you feel like what? What’s the point of this deliberate and pointless provocation?! Huh? I’m confused and angry at this abundance of irrationality.
  - tdicola 11y ago
    RTGs don't have to be heavy and big. Sure one to power a car sized rover like Curiosity with large motors, science equipment, lasers, etc will be big. But one to power a little probe with 24 watts would be tiny. In the 70s there were actually nuclear powered pace makers implanted inside people, so the technology can definitely scale down: https://www.orau.org/ptp/collection/Miscellaneous/pacemaker.htm https://www.orau.org/ptp/collection/Miscellaneous/pacemaker....
    - deleted 11y ago
      [deleted]
    - arrrg 11y ago
      So why doesn’t Nasa use them all the time?
      - AnkhMorporkian 11y ago
        Two reasons. One, in a lot of situations solar power is essentially guaranteed, and when there's no chance that there won't be sun solar panels are a hell of a lot cheaper. Second, there's a plutonium shortage in the US at the moment [1] making it really hard to secure an RTG. [1] http://www.wired.com/2013/09/plutonium-238-problem/ http://www.wired.com/2013/09/plutonium-238-problem/
CydeWeys 11y ago
You're right that Europe isn't homogenous, but it's not like every country in Europe has its own independent space agency. They have the ESA, which is nuke-averse. I was using "Europe" as a linguistic short-cut for the European space efforts, which are unified. Per someone else's comment, RTGs don't have to be heavy. Wikipedia lists one as light as 2.1 kg: https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator#Models https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge... Keep in mind that RTGs replace not just the solar panel and electricity generating systems but also a lot of the heating system as well. You can see the breakdown on Philae here: https://en.wikipedia.org/wiki/Philae_(spacecraft)#Design https://en.wikipedia.org/wiki/Philae_(spacecraft)#Design It uses about 16 kg total between the power system and thermal control system. You could fit in an RTG with the same or higher power output as the solar panels for the same mass. Philae in total is around 98 kg, which is definitely above the size threshold of craft that could be powered with an RTG.
- DasIch 11y ago
  Not every country has it's own but quite a few do, like Germany for example.
- truthsayer1980 11y ago
  "You could fit in an RTG with the same or higher power output as the solar panels for the same mass." As an expert you should go work for ESA. I'm sure they need you. Oops, armchair space engineer, I forgot. If you need to look in Wikipedia, you have no clue about the subject matter.
deleted 11y ago
[deleted]

delinka 11y ago

Perhaps you have your causation backward: perhaps the mission was planned to last only months due to power limitations.

dempseye 11y ago
I was under the impression that they thought the lander would be blown off the comet when it starts to shed ice and debris in large amounts around perihelion.
arrrg 11y ago
Philae is a tiny little 100kg add on … 29 times heavier Rosetta (the orbiter) is the main course, Philae is this tiny little and quite experimental (though admittedly extremely cool – mostly because of exactly its novel mission) little hitchhiker. RTGs are heavy and consequently have pretty much only been used on much heavier spacecraft and even then mostly only when being solar powered just wasn’t an option. For Philae, besides it being very lightweight, being solar powered was and is an option and the only reason it didn’t work out is because things went wrong during the landing … How in the hell do you even get the idea that Nasa would have used an RTG in ESA’s place here?! They are not psychic. They couldn’t have predicted things going wrong during the landing … and why then put an RTG on this when that’s something Nasa themselves does only very, very rarely and only for very different missions with much more demanding payloads?! What is this insanity? Why the need to get onto this political pulpit and spew out some unrelated political propaganda because you feel like what? What’s the point of this deliberate and pointless provocation?! Huh? I’m confused and angry at this abundance of irrationality.
- tdicola 11y ago
  RTGs don't have to be heavy and big. Sure one to power a car sized rover like Curiosity with large motors, science equipment, lasers, etc will be big. But one to power a little probe with 24 watts would be tiny. In the 70s there were actually nuclear powered pace makers implanted inside people, so the technology can definitely scale down: https://www.orau.org/ptp/collection/Miscellaneous/pacemaker.htm https://www.orau.org/ptp/collection/Miscellaneous/pacemaker....
  - deleted 11y ago
    [deleted]
  - arrrg 11y ago
    So why doesn’t Nasa use them all the time?
    - AnkhMorporkian 11y ago
      Two reasons. One, in a lot of situations solar power is essentially guaranteed, and when there's no chance that there won't be sun solar panels are a hell of a lot cheaper. Second, there's a plutonium shortage in the US at the moment [1] making it really hard to secure an RTG. [1] http://www.wired.com/2013/09/plutonium-238-problem/ http://www.wired.com/2013/09/plutonium-238-problem/

CydeWeys 11y ago

You're right that Europe isn't homogenous, but it's not like every country in Europe has its own independent space agency. They have the ESA, which is nuke-averse. I was using "Europe" as a linguistic short-cut for the European space efforts, which are unified. Per someone else's comment, RTGs don't have to be heavy. Wikipedia lists one as light as 2.1 kg: https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator#Models https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge... Keep in mind that RTGs replace not just the solar panel and electricity generating systems but also a lot of the heating system as well. You can see the breakdown on Philae here: https://en.wikipedia.org/wiki/Philae_(spacecraft)#Design https://en.wikipedia.org/wiki/Philae_(spacecraft)#Design It uses about 16 kg total between the power system and thermal control system. You could fit in an RTG with the same or higher power output as the solar panels for the same mass. Philae in total is around 98 kg, which is definitely above the size threshold of craft that could be powered with an RTG.

DasIch 11y ago
Not every country has it's own but quite a few do, like Germany for example.
truthsayer1980 11y ago
"You could fit in an RTG with the same or higher power output as the solar panels for the same mass." As an expert you should go work for ESA. I'm sure they need you. Oops, armchair space engineer, I forgot. If you need to look in Wikipedia, you have no clue about the subject matter.

deleted 11y ago

[deleted]