I just published a piece on my blog describing nine of the twelve New Frontiers 4 proposals. (For two others we know only the destination, and one remains a mystery.)Link:http://futureplanets.blogspot.com/2017/08/proposed-new-frontiers-missions.htmlBriefly:Venus In Situ Explorer• Venus In situ Composition Investigations (VICI)• Venus In Situ Atmospheric and Geochemical Explorer (VISAGE)Lunar South Pole-Aitken Basin Sample Return• MoonriseComet Surface Sample Return• COmet Nucleus Dust and Organics Return (CONDOR)• COmet Rendezvous, Sample Acquisition, Investigation, and Return (CORSAIR)• A third mission, led by Stephen Squyres, reportedly has been proposedTrojan Tour and Rendezvous• I have not found any information on any proposed missions. Ocean Worlds (Titan and/or Enceladus)• Enceladus Life Finder• One paper gives the acronym for a 2nd Enceladus proposal, ELSAH • Oceanus Titan orbiter• Dragonfly Titan mobile landerSaturn Atmospheric Probe• Saturn PRobe Interior and aTmosphere Explorer (SPRITE)
Briefly:Venus In Situ Explorer• Venus In situ Composition Investigations (VICI)• Venus In Situ Atmospheric and Geochemical Explorer (VISAGE)Lunar South Pole-Aitken Basin Sample Return• MoonriseComet Surface Sample Return• COmet Nucleus Dust and Organics Return (CONDOR)• COmet Rendezvous, Sample Acquisition, Investigation, and Return (CORSAIR)• A third mission, led by Stephen Squyres, reportedly has been proposedTrojan Tour and Rendezvous• I have not found any information on any proposed missions. Ocean Worlds (Titan and/or Enceladus)• Enceladus Life Finder• One paper gives the acronym for a 2nd Enceladus proposal, ELSAH • Oceanus Titan orbiter• Dragonfly Titan mobile landerSaturn Atmospheric Probe• Saturn PRobe Interior and aTmosphere Explorer (SPRITE)
Quote from: vjkane on 08/05/2017 02:17 pmBriefly:Venus In Situ Explorer• Venus In situ Composition Investigations (VICI)• Venus In Situ Atmospheric and Geochemical Explorer (VISAGE)Lunar South Pole-Aitken Basin Sample Return• MoonriseComet Surface Sample Return• COmet Nucleus Dust and Organics Return (CONDOR)• COmet Rendezvous, Sample Acquisition, Investigation, and Return (CORSAIR)• A third mission, led by Stephen Squyres, reportedly has been proposedTrojan Tour and Rendezvous• I have not found any information on any proposed missions. Ocean Worlds (Titan and/or Enceladus)• Enceladus Life Finder• One paper gives the acronym for a 2nd Enceladus proposal, ELSAH • Oceanus Titan orbiter• Dragonfly Titan mobile landerSaturn Atmospheric Probe• Saturn PRobe Interior and aTmosphere Explorer (SPRITE)I just heard that NASA is holding 3 MMRTGs (in terms of fuel) for this competition. Which of the above missions would likely require an MMRTG? The comet, Trojan, and Enceladus missions are the only ones that I can think of. Saturn probe should be batteries, right? Is there any indication of these clearly needing an MMRTG?
Quote from: Blackstar on 08/15/2017 03:21 pmQuote from: vjkane on 08/05/2017 02:17 pmBriefly:Venus In Situ Explorer•Venus In situ Composition Investigations (VICI)•Venus In Situ Atmospheric and Geochemical Explorer (VISAGE)Lunar South Pole-Aitken Basin Sample Return•MoonriseComet Surface Sample Return•COmet Nucleus Dust and Organics Return (CONDOR)•COmet Rendezvous, Sample Acquisition, Investigation, and Return (CORSAIR)•A third mission, led by Stephen Squyres, reportedly has been proposedTrojan Tour and Rendezvous•I have not found any information on any proposed missions. Ocean Worlds (Titan and/or Enceladus)•Enceladus Life Finder•One paper gives the acronym for a 2nd Enceladus proposal, ELSAH •Oceanus Titan orbiter•Dragonfly Titan mobile landerSaturn Atmospheric Probe•Saturn PRobe Interior and aTmosphere Explorer (SPRITE)I just heard that NASA is holding 3 MMRTGs (in terms of fuel) for this competition. Which of the above missions would likely require an MMRTG? The comet, Trojan, and Enceladus missions are the only ones that I can think of. Saturn probe should be batteries, right? Is there any indication of these clearly needing an MMRTG?The Saturn atmospheric probe proposal has the use of an RTG to provide power on the carrier spacecraft. Of course, once released from the carrier, the probe would run on its batteries. The carrier would be on a flyby trajectory.
Quote from: vjkane on 08/05/2017 02:17 pmBriefly:Venus In Situ Explorer•Venus In situ Composition Investigations (VICI)•Venus In Situ Atmospheric and Geochemical Explorer (VISAGE)Lunar South Pole-Aitken Basin Sample Return•MoonriseComet Surface Sample Return•COmet Nucleus Dust and Organics Return (CONDOR)•COmet Rendezvous, Sample Acquisition, Investigation, and Return (CORSAIR)•A third mission, led by Stephen Squyres, reportedly has been proposedTrojan Tour and Rendezvous•I have not found any information on any proposed missions. Ocean Worlds (Titan and/or Enceladus)•Enceladus Life Finder•One paper gives the acronym for a 2nd Enceladus proposal, ELSAH •Oceanus Titan orbiter•Dragonfly Titan mobile landerSaturn Atmospheric Probe•Saturn PRobe Interior and aTmosphere Explorer (SPRITE)I just heard that NASA is holding 3 MMRTGs (in terms of fuel) for this competition. Which of the above missions would likely require an MMRTG? The comet, Trojan, and Enceladus missions are the only ones that I can think of. Saturn probe should be batteries, right? Is there any indication of these clearly needing an MMRTG?
Briefly:Venus In Situ Explorer•Venus In situ Composition Investigations (VICI)•Venus In Situ Atmospheric and Geochemical Explorer (VISAGE)Lunar South Pole-Aitken Basin Sample Return•MoonriseComet Surface Sample Return•COmet Nucleus Dust and Organics Return (CONDOR)•COmet Rendezvous, Sample Acquisition, Investigation, and Return (CORSAIR)•A third mission, led by Stephen Squyres, reportedly has been proposedTrojan Tour and Rendezvous•I have not found any information on any proposed missions. Ocean Worlds (Titan and/or Enceladus)•Enceladus Life Finder•One paper gives the acronym for a 2nd Enceladus proposal, ELSAH •Oceanus Titan orbiter•Dragonfly Titan mobile landerSaturn Atmospheric Probe•Saturn PRobe Interior and aTmosphere Explorer (SPRITE)
If NASA has fuel for three MMRTGs beyond the Mars 2020 rover, I'm not sure which missions are likely to be chosen in the coming decade to use up that supply. An ice giant orbiter would make a dent, but it wouldn't launch until the early 2030s.
Surely fuel stocks would have been replenished by 2030s to allow the manufacture of more.
Quote from: Star One on 08/15/2017 04:49 pmSurely fuel stocks would have been replenished by 2030s to allow the manufacture of more.With what production?
Quote from: Jim on 08/15/2017 05:08 pmQuote from: Star One on 08/15/2017 04:49 pmSurely fuel stocks would have been replenished by 2030s to allow the manufacture of more.With what production?NASA plans to be producing ~1.5 kg of Pu-238 per year by the early 2020s. With a single MMRTG using 4.8 kg of Pu238, this would allow NASA to produce around 3 new MMRTGs per decade. If NASA has sufficient Pu-238 on hand for 3 MMRTGs after the Mars 2020 rover, then by the end of the 2020s, it would have ~6 MMRTGs (or even better, the eMMRTGs). Most of the conceptual orbiter designs from the recent ice giants study used 5 eMMRTGs (same fuel requirement as MMRTGs). If the next Decadal Survey prioritizes an ice giant orbiter, this leaves something like 1 (this is rough calculations!) for a mission between now and then.Choose well, NASA!
Quote from: vjkane on 08/15/2017 05:45 pmQuote from: Jim on 08/15/2017 05:08 pmQuote from: Star One on 08/15/2017 04:49 pmSurely fuel stocks would have been replenished by 2030s to allow the manufacture of more.With what production?NASA plans to be producing ~1.5 kg of Pu-238 per year by the early 2020s. With a single MMRTG using 4.8 kg of Pu238, this would allow NASA to produce around 3 new MMRTGs per decade. If NASA has sufficient Pu-238 on hand for 3 MMRTGs after the Mars 2020 rover, then by the end of the 2020s, it would have ~6 MMRTGs (or even better, the eMMRTGs). Most of the conceptual orbiter designs from the recent ice giants study used 5 eMMRTGs (same fuel requirement as MMRTGs). If the next Decadal Survey prioritizes an ice giant orbiter, this leaves something like 1 (this is rough calculations!) for a mission between now and then.Choose well, NASA!I just saw (this morning) a chart that is probably public that shows Pu-238 production and demands. There's enough for Mars 2020 (already allocated) and enough for the NF4, assuming 3 MMRTGs, and then enough for one additional mission such as an ice giants mission, although that would start to tap into new production. I need to look at the slide again. They are blending in the newly-acquired "old" Pu-238 and this extends the current stock of "newer" Pu-238. And by 2019 they will be producing 1.5 kg of Pu-238 per year.So you are correct and the quick answer is that if they do Mars 2020, NF4, and an ice giants mission, they will then not have enough for any other missions until they get the new production Pu-238.
They've restarted production I thought.
Quote from: Star One on 08/15/2017 05:57 pmDoes this also depend on if Neptune or Uranus is chosen? Is one more demanding in this area than the other?I don't think it matters.
Does this also depend on if Neptune or Uranus is chosen? Is one more demanding in this area than the other?
Agreed, although it does mean once the choice is made it'll be probably a further decade before the other ice giant can be visited. This of course is more relevant to the ice giant thread.Out of the current NF choices, which actually requires RTGs? I assume the Saturn (and its moons) proposals, which are collectively 4, the possible Trojan mission, and I assume at least one of the comet missions?
The Saturn atmospheric probe proposal has the use of an RTG to provide power on the carrier spacecraft. Of course, once released from the carrier, the probe would run on its batteries. The carrier would be on a flyby trajectory.
Quote from: redliox on 08/15/2017 06:21 pmAgreed, although it does mean once the choice is made it'll be probably a further decade before the other ice giant can be visited. This of course is more relevant to the ice giant thread.Out of the current NF choices, which actually requires RTGs? I assume the Saturn (and its moons) proposals, which are collectively 4, the possible Trojan mission, and I assume at least one of the comet missions?It appears that only Dragonfly would need MMRTGs.
Quote from: vjkane on 08/15/2017 06:26 pmQuote from: redliox on 08/15/2017 06:21 pmAgreed, although it does mean once the choice is made it'll be probably a further decade before the other ice giant can be visited. This of course is more relevant to the ice giant thread.Out of the current NF choices, which actually requires RTGs? I assume the Saturn (and its moons) proposals, which are collectively 4, the possible Trojan mission, and I assume at least one of the comet missions?It appears that only Dragonfly would need MMRTGs.I wonder if that complexity of mission could count against it, even though it's the mission I'd most like to see happen.
What about planned Mars Sample Return sample caching rover? It is now decided whether it will use solar panel or RTG?
Quote from: mnauprsk on 08/15/2017 07:38 pmWhat about planned Mars Sample Return sample caching rover? It is now decided whether it will use solar panel or RTG?The engineering concept images I've seen all show solar power. The goal for that rover is speed with minimal instruments, perhaps only cameras, an arm to gather sample tubes, and a container for the tubes.