4 ms·

Yes, basically slowing down enough to orbit Pluto would have required too much extra launch weight, although the difference isn't enormous. The best candidate,

Yes, basically slowing down enough to orbit Pluto would have required too much extra launch weight, although the difference isn't enormous. The best candidate, a nuclear-electric propulsion system, would have approximately doubled the spacecraft's mass. This Stack Exchange question has more information: http://space.stackexchange.com/questions/9851/requirements-to-orbit-pluto http://space.stackexchange.com/questions/9851/requirements-t...

rootbear 11y ago
Nice discussion, thanks for posting.
jkachmar 11y ago
Additionally, from the linked paper [1], it would have required a 15 year transfer phase and a more capable launcher than the Atlas V. The report proposed using a then-unavailable Ariane 5 variant, which would have delayed the launch to 2016 (to line up the gravity assist with Jupiter) and put the final encounter with Pluto at June 2033. [1] http://www.esa.int/gsp/ACT/doc/PRO/ACT-RPR-PRO-ISTS2004-Pluto.pdf http://www.esa.int/gsp/ACT/doc/PRO/ACT-RPR-PRO-ISTS2004-Plut...
- yellowapple 11y ago
  So basically, if we can build a new probe within the next year and a half, and if this new Arianne variant is now available, we might have a chance of sending an orbiter to reach Pluto by 2033? That sounds like an opportunity that's too good to pass up if we can pull it off. I mean, the flyby's awesome, and it's bound to give us all sorts of new insights on the formation of the Solar System, but having a permanent orbiter there would let us continually study Pluto (and its moons), giving us that degree of information on a continuous basis.
  - smeyer 11y ago
    >if we can build a new probe within the next year and a half The amount of cost and level of precision and robustness required tends to mean that these probes take years to plan, design, build, and test. It's also far from clear that the value of the science of sending an orbiter to Pluto would outweigh other potential missions (that also wouldn't have the same timing constraints.)
    - yellowapple 11y ago
      Sure, though it sounds like the ESA's been planning such a probe for quite some time already. The linked report even has specifics on instrumentation payload and the mass thereof, and includes a rendering and parts list for the proposed "POP" probe. We'd just need to do the "build" and "test" parts, and while that likely would normally take a couple years, I reckon we could cram that into a year and a half with enough effort.
danieltillett 11y ago
I am wondering if you could use some sort of atmosphere breaking? The equivalent of a large parachute?
- ars 11y ago
  Until this mission (and perhaps even now) we did not/do not have enough information about the atmosphere of Pluto to design the parachute.
  - danieltillett 11y ago
    I think we knew there was an atmosphere on pluto before this, but I was more thinking about a new mission.
    - ars 11y ago
      Knowing there is an atmosphere is not the same as knowing the exact makeup, in particular density and pressure.
simonh 11y ago
Looks like a great proposal, but I don't see the point of preparing such a mission before we get all the data back from New Horizons. Once we have the latest data, then we'll have a much better idea about the kinds of questions that we would like an orbiter probe to answer. Already even with just about 2% of the NH data back, it turns out Pluto is radically different than most planetary scientists predicted. On the basis of the full data set, we'll have a much better idea of the types of instruments we'd need an orbiter to have in order to help solve these mysteries. So while the linked paper is a very useful proof of concept for an orbiter mission, and was in no way a waste of effort, actually building and committing to it and a launch in 2016 would have been a mistake.

rootbear 11y ago

Nice discussion, thanks for posting.

jkachmar 11y ago

Additionally, from the linked paper [1], it would have required a 15 year transfer phase and a more capable launcher than the Atlas V. The report proposed using a then-unavailable Ariane 5 variant, which would have delayed the launch to 2016 (to line up the gravity assist with Jupiter) and put the final encounter with Pluto at June 2033. [1] http://www.esa.int/gsp/ACT/doc/PRO/ACT-RPR-PRO-ISTS2004-Pluto.pdf http://www.esa.int/gsp/ACT/doc/PRO/ACT-RPR-PRO-ISTS2004-Plut...

yellowapple 11y ago
So basically, if we can build a new probe within the next year and a half, and if this new Arianne variant is now available, we might have a chance of sending an orbiter to reach Pluto by 2033? That sounds like an opportunity that's too good to pass up if we can pull it off. I mean, the flyby's awesome, and it's bound to give us all sorts of new insights on the formation of the Solar System, but having a permanent orbiter there would let us continually study Pluto (and its moons), giving us that degree of information on a continuous basis.
- smeyer 11y ago
  >if we can build a new probe within the next year and a half The amount of cost and level of precision and robustness required tends to mean that these probes take years to plan, design, build, and test. It's also far from clear that the value of the science of sending an orbiter to Pluto would outweigh other potential missions (that also wouldn't have the same timing constraints.)
  - yellowapple 11y ago
    Sure, though it sounds like the ESA's been planning such a probe for quite some time already. The linked report even has specifics on instrumentation payload and the mass thereof, and includes a rendering and parts list for the proposed "POP" probe. We'd just need to do the "build" and "test" parts, and while that likely would normally take a couple years, I reckon we could cram that into a year and a half with enough effort.

danieltillett 11y ago

I am wondering if you could use some sort of atmosphere breaking? The equivalent of a large parachute?

ars 11y ago
Until this mission (and perhaps even now) we did not/do not have enough information about the atmosphere of Pluto to design the parachute.
- danieltillett 11y ago
  I think we knew there was an atmosphere on pluto before this, but I was more thinking about a new mission.
  - ars 11y ago
    Knowing there is an atmosphere is not the same as knowing the exact makeup, in particular density and pressure.

simonh 11y ago

Looks like a great proposal, but I don't see the point of preparing such a mission before we get all the data back from New Horizons. Once we have the latest data, then we'll have a much better idea about the kinds of questions that we would like an orbiter probe to answer. Already even with just about 2% of the NH data back, it turns out Pluto is radically different than most planetary scientists predicted. On the basis of the full data set, we'll have a much better idea of the types of instruments we'd need an orbiter to have in order to help solve these mysteries. So while the linked paper is a very useful proof of concept for an orbiter mission, and was in no way a waste of effort, actually building and committing to it and a launch in 2016 would have been a mistake.