Author Topic: New Frontiers 4  (Read 98193 times)

Offline JH

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Re: New Frontiers 4
« Reply #120 on: 08/10/2017 08:54 pm »
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.html

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
•   Moonrise

Comet 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 proposed

Trojan 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 lander

Saturn Atmospheric Probe
•   Saturn PRobe Interior and aTmosphere Explorer (SPRITE)

The final one is a third Venus proposal.

Offline Blackstar

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Re: New Frontiers 4
« Reply #121 on: 08/15/2017 03:21 pm »
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
•   Moonrise

Comet 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 proposed

Trojan 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 lander

Saturn 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?


Offline whitelancer64

Re: New Frontiers 4
« Reply #122 on: 08/15/2017 03:50 pm »
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
•   Moonrise

Comet 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 proposed

Trojan 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 lander

Saturn 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.
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Offline Star One

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Re: New Frontiers 4
« Reply #123 on: 08/15/2017 03:57 pm »
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
•Moonrise

Comet 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 proposed

Trojan 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 lander

Saturn 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.

Wouldn't the Titan orbiter need one, or even the lander mission?

Offline vjkane

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Re: New Frontiers 4
« Reply #124 on: 08/15/2017 04:35 pm »
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
•   Moonrise

Comet 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 proposed

Trojan 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 lander

Saturn 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?
In the last several years, proposing teams (which means the engineers on those teams) have become comfortable with using solar power as far out at Saturn.  The ELF, Oceanus, and SPRITE missions are stated to be solar powered.  Dragonfly requires and MMRTG since Titan's haze diminishes sunlight and the craft would need power during 8 Earth day long Titan nights.

For the rest of the missions, solar power appears sufficient.  The CONDOR and CORSAIR comet sample return missions are stated to use solar power, and I cannot think of a reason why the Moonrise or any of the three Venus missions would not use solar power.  It's possible that the ELSAH Enceladus or the third comet mission might use an MMRTG, but the additional financial burdens that using a radioisotope power supply would seem to put these missions at a disadvantage.

It may be that review panels will conclude that solar power at Saturn is too risky, but I would be surprised.  There have been several Discovery and ESA medium class missions proposed for solar power.  If this was a deal killer, the engineering community should know this by now.

So it seems that MMRTGs are now needed for missions where 1) the spacecraft will operate beyond Saturn, 2) there's a location specific feature that makes solar infeasible (long-lived Venus or Titan landers or the permanently shadowed craters on the moon), or the size of the solar panels would make design impracticable (larger Mars rover like Curiosity, although there were versions shows with large solar panels).

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.

Offline Star One

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Re: New Frontiers 4
« Reply #125 on: 08/15/2017 04:49 pm »
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.
« Last Edit: 08/15/2017 05:17 pm by gongora »

Offline Jim

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Re: New Frontiers 4
« Reply #126 on: 08/15/2017 05:08 pm »

Surely fuel stocks would have been replenished by 2030s to allow the manufacture of more.

With what production?

Offline Star One

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Re: New Frontiers 4
« Reply #127 on: 08/15/2017 05:40 pm »

Surely fuel stocks would have been replenished by 2030s to allow the manufacture of more.

With what production?

They've restarted production I thought.

Offline vjkane

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Re: New Frontiers 4
« Reply #128 on: 08/15/2017 05:45 pm »

Surely 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!

Offline Blackstar

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Re: New Frontiers 4
« Reply #129 on: 08/15/2017 05:53 pm »

Surely 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.


Offline Star One

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Re: New Frontiers 4
« Reply #130 on: 08/15/2017 05:57 pm »

Surely 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.

Does this also depend on if Neptune or Uranus is chosen? Is one more demanding in this area than the other?
« Last Edit: 08/15/2017 05:57 pm by Star One »

Offline Blackstar

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Re: New Frontiers 4
« Reply #131 on: 08/15/2017 06:11 pm »
They've restarted production I thought.

They have, but not full scale. They got something like 100 grams, but it will not be until 2019 that they will be able to produce 1.5 kg per year.

Pu-238 production gets complicated fast. There's the existing stockpile, then there is the older, depleted material that became available around 2013. And then there is new production. Think of the older depleted stuff kinda like adding water to a stew--you get a soup and you can feed more people, but at lower density. So they can stretch out the supply a bit.

I was curious, and I raised this issue, because if an MMRTG is not required for NF4, then of course the existing supply can be stretched out longer. But that's not necessarily a good thing in terms of programmatics. We've been kicking the can down the road for decades now, and I'd rather not give anybody an excuse to not produce new Pu-238.

Offline redliox

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Re: New Frontiers 4
« Reply #132 on: 08/15/2017 06:21 pm »
Does 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.

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?
« Last Edit: 08/15/2017 06:22 pm by redliox »
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Offline vjkane

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Re: New Frontiers 4
« Reply #133 on: 08/15/2017 06:26 pm »
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?
It appears that only Dragonfly would need MMRTGs.

Offline Blackstar

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Re: New Frontiers 4
« Reply #134 on: 08/15/2017 06:35 pm »
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.

I dug around for the SPRITE Saturn probe mission and couldn't find anything about a mission architecture. Do you know if they proposed using an RTG?

I assumed/thought that the Saturn probe mission can use solar all the way and use batteries on the probe itself. I would think that they would want to avoid putting an RTG into that mission because of cost.

Offline Star One

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Re: New Frontiers 4
« Reply #135 on: 08/15/2017 06:37 pm »
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?
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.

Offline Blackstar

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Re: New Frontiers 4
« Reply #136 on: 08/15/2017 06:53 pm »
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?
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.

Complexity counts against every cost-capped mission.

Offline mnauprsk

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Re: New Frontiers 4
« Reply #137 on: 08/15/2017 07:38 pm »
What about planned Mars Sample Return sample caching rover? It is now decided whether it will use solar panel or RTG?

Offline vjkane

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Re: New Frontiers 4
« Reply #138 on: 08/15/2017 07:46 pm »
What 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.

Offline Blackstar

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Re: New Frontiers 4
« Reply #139 on: 08/15/2017 07:52 pm »
What 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.

Yeah. It's a medium-size vehicle at best, only solar. I do think that they are considering a bit more than "minimal instruments." But that's all in the trades. It doesn't need RTGs. And really, if you were going to dedicate plutonium to that mission, the best place to spend it is keeping the ascent vehicle warm, not powering the rover.

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