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How Cassini Will Begin Its Date with Death on Saturn

64 points by my_first_acct 10y ago

joshlemer 10y ago
Pardon my ignorance, but what is the point in sending the Cassini probe to burn up in Saturn's atmosphere? Are there no more useful observations it can make, and if there isn't right now, can it not just be parked in orbit around Saturn until later? I mean, just the launch vehicle itself cost $422 million according to Wikipedia.
- rietta 10y ago
  Probably some sort of space protection treaty once they are done funding ground operations. I too am dismayed about crashing perfectly functioning science vehicles.
  - rietta 10y ago
    This looks like the principle "States shall avoid harmful contamination of space and celestial bodies." Presumably crashing into a gas giant is considered less harmful than polluting orbit. Source: http://www.unoosa.org/oosa/en/ourwork/spacelaw/treaties/introouterspacetreaty.html http://www.unoosa.org/oosa/en/ourwork/spacelaw/treaties/intr...
    - therein 10y ago
      How is having a vehicle that is hibernating and can be contacted with considered polluting the orbit? It's not like it is debris. I would see this as in fact the opposite, I would see it as the first step to colonization. Having autonomous outposts all around the solar system, orbiting various celestial bodies. Build a meshnet with them.
      - stouset 10y ago
        It's functional now. After 30 years in hibernation? Who knows. The potential science value of life on another body in our solar system is so great, it's not worth the risk. The science Cassini is capable of collecting will pale in comparison to whatever we'll have in orbit in 30 years anyway.
      - cbanek 10y ago
        One thing to remember is that any probe past Mars is almost certainly going to use an RTG over solar panels. This means that you will always have an exponentially decaying power supply (wattage goes down over time if you use it or not). This is how voyager was powered, and because of the power drain, they had to turn off more instruments as time goes on.
      - Sharlin 10y ago
        It's not like its orbit is stable in an environment like that. Eventually it's going to collide with something due to lack of fuel for maneuvering burns.
- kkylin 10y ago
  The article didn't say, but off-hand I would guess it's for the same reason they crashed Galileo into Jupiter (https://en.wikipedia.org/wiki/Galileo_(spacecraft) https://en.wikipedia.org/wiki/Galileo_(spacecraft)), namely to avoid any possibility of contaminating one of the moons (see https://en.wikipedia.org/wiki/Life_on_Titan https://en.wikipedia.org/wiki/Life_on_Titan) with life (e.g., bacteria) from Earth.
  - idlewords 10y ago
    This is correct, the probe was too large to sterilize, and they want to avoid any possibility of contaminating Enceladus. http://www.spacesafetymagazine.com/space-exploration/extraterrestrial-life/cassini-huygens-preventing-biological-contamination/ http://www.spacesafetymagazine.com/space-exploration/extrate...
  - Figs 10y ago
    That seems like a really poor reason for doing it seeing as Cassini carried Huygens with it -- which already landed on Titan over 10 years ago.
    - cgriswald 10y ago
      Flying a mission to intentionally study a moon is a bit different than accidentally contaminating it while getting no useful data. Titan isn't a likely candidate for contamination anyway and if we ever do find life there it is likely to be distinguishable from Earth life. Enceladus, on the other hand, is one of the likeliest places for Earth-like life in our solar system and much more succeptible to contamination. Since the orbiter is out of fuel and will eventually crash into something, Saturn makes the most sense.
  - myowncrapulence 10y ago
    Are we not actively trying to terraform Mars? Why is "life contamination" seen as a problem for our solar system rather than a goal?
    - noelwelsh 10y ago
- GFK_of_xmaspast 10y ago
  See: https://saturn.jpl.nasa.gov/mission/grand-finale/why-end-the-mission/ https://saturn.jpl.nasa.gov/mission/grand-finale/why-end-the... and https://en.wikipedia.org/wiki/Cassini–Huygens_retirement https://en.wikipedia.org/wiki/Cassini–Huygens_retirement
- noselasd 10y ago
  Cassini have used up almost all its fuel, so it cannot be controlled for much longer.
punnerud 10y ago
If you can't read: https://www.google.no/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwiK7sLIo8jQAhViLZoKHdPwCKAQqQIIHjAA&url=http%3A%2F%2Fwww.nytimes.com%2F2016%2F11%2F25%2Fscience%2Fcassini-saturn-rings.html&usg=AFQjCNGK77fbavJgWmyzg1XzJNIThj25_g https://www.google.no/url?sa=t&rct=j&q=&esrc=s&source=web&cd... (skip subscription by going through Google)
IndianAstronaut 10y ago
Cassini gave us so much amazing information. Lakes on Titan, giant geysers on Encaladus from an underground ocean, a moon that looks like the death star, our first lander on an object further than Mars, etc.
lucidguppy 10y ago
Doesn't Cassini have some nasty nuclear fuel? Probably best to put it where no one could get at it.

64 points by my_first_acct 10y ago

Pardon my ignorance, but what is the point in sending the Cassini probe to burn up in Saturn's atmosphere? Are there no more useful observations it can make, and if there isn't right now, can it not just be parked in orbit around Saturn until later? I mean, just the launch vehicle itself cost $422 million according to Wikipedia.

rietta 10y ago
Probably some sort of space protection treaty once they are done funding ground operations. I too am dismayed about crashing perfectly functioning science vehicles.
- rietta 10y ago
  This looks like the principle "States shall avoid harmful contamination of space and celestial bodies." Presumably crashing into a gas giant is considered less harmful than polluting orbit. Source: http://www.unoosa.org/oosa/en/ourwork/spacelaw/treaties/introouterspacetreaty.html http://www.unoosa.org/oosa/en/ourwork/spacelaw/treaties/intr...
  - therein 10y ago
    How is having a vehicle that is hibernating and can be contacted with considered polluting the orbit? It's not like it is debris. I would see this as in fact the opposite, I would see it as the first step to colonization. Having autonomous outposts all around the solar system, orbiting various celestial bodies. Build a meshnet with them.
    - stouset 10y ago
      It's functional now. After 30 years in hibernation? Who knows. The potential science value of life on another body in our solar system is so great, it's not worth the risk. The science Cassini is capable of collecting will pale in comparison to whatever we'll have in orbit in 30 years anyway.
    - cbanek 10y ago
      One thing to remember is that any probe past Mars is almost certainly going to use an RTG over solar panels. This means that you will always have an exponentially decaying power supply (wattage goes down over time if you use it or not). This is how voyager was powered, and because of the power drain, they had to turn off more instruments as time goes on.
    - Sharlin 10y ago
      It's not like its orbit is stable in an environment like that. Eventually it's going to collide with something due to lack of fuel for maneuvering burns.
kkylin 10y ago
The article didn't say, but off-hand I would guess it's for the same reason they crashed Galileo into Jupiter (https://en.wikipedia.org/wiki/Galileo_(spacecraft) https://en.wikipedia.org/wiki/Galileo_(spacecraft)), namely to avoid any possibility of contaminating one of the moons (see https://en.wikipedia.org/wiki/Life_on_Titan https://en.wikipedia.org/wiki/Life_on_Titan) with life (e.g., bacteria) from Earth.
- idlewords 10y ago
  This is correct, the probe was too large to sterilize, and they want to avoid any possibility of contaminating Enceladus. http://www.spacesafetymagazine.com/space-exploration/extraterrestrial-life/cassini-huygens-preventing-biological-contamination/ http://www.spacesafetymagazine.com/space-exploration/extrate...
- Figs 10y ago
  That seems like a really poor reason for doing it seeing as Cassini carried Huygens with it -- which already landed on Titan over 10 years ago.
  - cgriswald 10y ago
    Flying a mission to intentionally study a moon is a bit different than accidentally contaminating it while getting no useful data. Titan isn't a likely candidate for contamination anyway and if we ever do find life there it is likely to be distinguishable from Earth life. Enceladus, on the other hand, is one of the likeliest places for Earth-like life in our solar system and much more succeptible to contamination. Since the orbiter is out of fuel and will eventually crash into something, Saturn makes the most sense.
- myowncrapulence 10y ago
  Are we not actively trying to terraform Mars? Why is "life contamination" seen as a problem for our solar system rather than a goal?
  - noelwelsh 10y ago
GFK_of_xmaspast 10y ago
See: https://saturn.jpl.nasa.gov/mission/grand-finale/why-end-the-mission/ https://saturn.jpl.nasa.gov/mission/grand-finale/why-end-the... and https://en.wikipedia.org/wiki/Cassini–Huygens_retirement https://en.wikipedia.org/wiki/Cassini–Huygens_retirement
noselasd 10y ago
Cassini have used up almost all its fuel, so it cannot be controlled for much longer.

punnerud 10y ago

If you can't read: https://www.google.no/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwiK7sLIo8jQAhViLZoKHdPwCKAQqQIIHjAA&url=http%3A%2F%2Fwww.nytimes.com%2F2016%2F11%2F25%2Fscience%2Fcassini-saturn-rings.html&usg=AFQjCNGK77fbavJgWmyzg1XzJNIThj25_g https://www.google.no/url?sa=t&rct=j&q=&esrc=s&source=web&cd... (skip subscription by going through Google)

IndianAstronaut 10y ago

Cassini gave us so much amazing information. Lakes on Titan, giant geysers on Encaladus from an underground ocean, a moon that looks like the death star, our first lander on an object further than Mars, etc.

lucidguppy 10y ago

Doesn't Cassini have some nasty nuclear fuel? Probably best to put it where no one could get at it.