Quote from: Phil Stooke on 09/05/2017 09:11 pmIt's the next mission which is (probably) an automatic flagship. Although there is also the concern that discovering life slows exploration as people struggle with how to study it without messing it up.From my limited understanding of astrobiology, it's misleading for us to even be discussing "finding life," because that's not really how the science works. The more accurate--and annoying--way to look at this is "finding some evidence that might be life, or is consistent with life, but will probably require decades of discussion and arguing ad infinitum, along with even more data gathering that will cost a lot of money and may not even settle the issue."At a recent meeting of planetary scientists, somebody pointed out that there are still people arguing over the Viking findings, and it took over a decade to finally settle the Alan Hills meteorite argument in favor of it not being life.
It's the next mission which is (probably) an automatic flagship. Although there is also the concern that discovering life slows exploration as people struggle with how to study it without messing it up.
As far as Dragonfly goes, I think the level of complexity looks more like MSL than any $1 billion mission. New Horizons was RTG powered, and that bought a very simple spacecraft for $800 million or so. Dragonfly will cost a lot more than that or Juno or OSIRUS-REX. MSL did have a brief powered flight when it was being lowered from the skycrane. Dragonfly will weight a lot less, but it needs autonomous navigation capabilities that even MSL did not have and it operates in a much colder environment which will cause materials and component challenges. I think I remember something about MSL having trouble because the development of a low temperature electric motor failed. I don't think I can believe in anything less than $1.5 billion for Dragonfly cost, and $2.5 billion seems like a more likely number.
@Star One... There are a lot of features of this mission that make me worry about costs. RTG powered missions are normally very expensive and rarely come in at less than $1billion. Low temperature operation causes trouble because some materials become brittle. Infra-red telescopes cast far more per unit of area than visible light ones because of this. While we are on the subject of embrittlement, hydrogen can also cause problems and the Titan atmosphere has it.Flying vehicles are normally far more expensive than wheeled ones. Think of the cost difference between a car and a helicopter. While there is a lot of talk about advances in autonomous systems, why are they not being used to guide the next Mars rover to a pinpoint landing? Unlike Titan, we have high resolution imagery of Mars which could be used to train an autonomous system. Human pilots have always been able to find a runway using landmarks, which implies navigating with 10m precision. I'm not aware of an autonomous system that can reliably manage that feat.
Jeff Foust @jeff_foustNASA’s Jim Green: we’re in good stead for the next several decades regarding plutonium for RTG-powered future missions; won’t be limiting.6:35 pm · 13 Sep 2017
Jeff Foust @jeff_foustGreen appeared to confirm that there were missions to Enceladus and/or Titan proposed in latest New Frontiers round (not surprising).6:46 pm · 13 Sep 2017
QuoteJeff Foust @jeff_foustGreen appeared to confirm that there were missions to Enceladus and/or Titan proposed in latest New Frontiers round (not surprising).6:46 pm · 13 Sep 2017https://mobile.twitter.com/jeff_foust/status/908024205123432461
Quote from: Star One on 09/13/2017 07:15 pmQuoteJeff Foust @jeff_foustGreen appeared to confirm that there were missions to Enceladus and/or Titan proposed in latest New Frontiers round (not surprising).6:46 pm · 13 Sep 2017https://mobile.twitter.com/jeff_foust/status/908024205123432461I believe that he was only talking about what in the 12 submitted If that's correct, we could assume 2 out of the "3-ish" missions are Saturn themed with 1 non-Saturnian running mate. I hope Venus fared better than in Discovery.
I believe that Green was talking only about what is in the 12 submitted proposals. I don't believe he would give any hint about what the possible down selects will be. And considering that the announcement of the down selects are expected as a Christmas present, he may not know what those will be yet.
When I did my blog post on the New Frontiers proposals, there was one mystery proposal. Several people told me this was a late entry JPL Venus proposal, the Venus Origins eXplorer (VOX).This proposal takes a very different approach than either of the other two proposals which would use one or two entry probe-lander(s).VOX combines the ideas of the not selected (but found selectable) Discovery VERITAS orbiter along with what appears to be the CUPID high atmosphere probe. In submitting this proposal, JPL (which is also backing the VICI entry probe-proposal), is betting that a very different approach will be found acceptable. The entry probe-lander approach would provide much richer atmospheric measurements and richer surface composition measurements at an area on Venus that might be a couple of square meters in size. VOX would provide the key noble gas measurements along with less rich but global composition measurements. VOX would also provide high resolution radar mapping and higher resolution gravity measurements than previous missions did.The VOX team is hoping to pull a Juno. The original Decadal Survey requirement for the Jovian mission was an orbiter and multiple entry probes. The Juno mission accomplishes the goals of the entry probes via remote sensing instruments. The VOX team is proposing that for the solid planet measurements and proposing a much simpler atmospheric probe. Designing an entry probe-lander for Venus does have its challenges, although the Discovery DAVINCI entry probe from the same PI as for the VICI probe-lander was judged suitable for selection.As a geomorphology kind of guy, I do like the VOX proposal.
So this would be a combination orbiter/entry probe-lander? I can understand the functions of an orbiter and atmospheric probe, but how would it obtain surface measurements...and more importantly by 'surface' are they implying gas or soil sampling? I understand Huygens did some surface science on Titan, mainly in the form of physical properties, otherwise its priority was atmospheric and camera imaging. Although I wouldn't think this particular mission would be as well-funded as Huygens, but it occurs to me that Huygens got some grand science about Titan in a time frame not unlike what a Venus probe might have: 2 hours.
Quote from: redliox on 09/26/2017 01:37 amSo this would be a combination orbiter/entry probe-lander? I can understand the functions of an orbiter and atmospheric probe, but how would it obtain surface measurements...and more importantly by 'surface' are they implying gas or soil sampling? I understand Huygens did some surface science on Titan, mainly in the form of physical properties, otherwise its priority was atmospheric and camera imaging. Although I wouldn't think this particular mission would be as well-funded as Huygens, but it occurs to me that Huygens got some grand science about Titan in a time frame not unlike what a Venus probe might have: 2 hours.More to come in a blog post I'm writing for publication probably this weekend.
Just published my blog post on the New Frontiers Venus Origins eXplorer proposalhttp://futureplanets.blogspot.com/2017/10/venus-origins-explorer-new-frontiers.html
The only justification for NASA to go back to Venus would be if it was a mission carrying something truly revolutionary like a long duration lander/rover as we’ve recently seen proposed in concept.
The Venus In Situ Explorer mission theme is focused on examining the physics and chemistry of Venus’s atmosphere and crust by characterizing variables that cannot be measured from orbit, including the detailed composition of the lower atmosphere, and the elemental and mineralogical composition of surface materials. The science objectives (listed without priority) of this mission theme are:• Understand the physics and chemistry of Venus’s atmosphere through measurement of its composition, especially the abundances of sulfur, trace gases, light stable isotopes, and noble-gas isotopes;• Constrain the coupling of thermochemical, photochemical, and dynamical processes in Venus’s atmosphere and between the surface and atmosphere to understand radiative balance, climate, dynamics, and chemical cycles;• Understand the physics and chemistry of Venus’s crust;• Understand the properties of Venus’s atmosphere down to the surface and improve understanding of Venus’s zonal cloud-level winds;• Understand the weathering environment of the crust of Venus in the context of the dynamics of the atmosphere of Venus and the composition and texture of its surface materials; and• Search for evidence of past hydrological cycles, oceans, and life and constraints on the evolution of Venus’s atmosphere.
Quote from: Star One on 10/01/2017 06:24 pmThe only justification for NASA to go back to Venus would be if it was a mission carrying something truly revolutionary like a long duration lander/rover as we’ve recently seen proposed in concept. That's not how NASA selects missions. The criteria for a Venus mission in this New Frontiers call are spelled out in the AO:QuoteThe Venus In Situ Explorer mission theme is focused on examining the physics and chemistry of Venus’s atmosphere and crust by characterizing variables that cannot be measured from orbit, including the detailed composition of the lower atmosphere, and the elemental and mineralogical composition of surface materials. The science objectives (listed without priority) of this mission theme are:• Understand the physics and chemistry of Venus’s atmosphere through measurement of its composition, especially the abundances of sulfur, trace gases, light stable isotopes, and noble-gas isotopes;• Constrain the coupling of thermochemical, photochemical, and dynamical processes in Venus’s atmosphere and between the surface and atmosphere to understand radiative balance, climate, dynamics, and chemical cycles;• Understand the physics and chemistry of Venus’s crust;• Understand the properties of Venus’s atmosphere down to the surface and improve understanding of Venus’s zonal cloud-level winds;• Understand the weathering environment of the crust of Venus in the context of the dynamics of the atmosphere of Venus and the composition and texture of its surface materials; and• Search for evidence of past hydrological cycles, oceans, and life and constraints on the evolution of Venus’s atmosphere.