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Unmanned Spaceflight.com _ Exploration Strategy _ Discovery Mission Competition 2021 selection

Posted by: vjkane Feb 13 2020, 06:58 PM

With the announcement of the down selected missions a few hours away for the final selection in spring 2021, it seemed time for a new thread.

Once with know the semi-finalists, this would be a good place to post links and news the the proposed missions.

Here's my list of known and possible proposals:


Concepts with ? have been presented in last year or two, appear to be the right scope for a Discovery mission, but weren't presented as Discovery missions

Asteroids - MANTIS

Centaurs - Centarus, Chiron, SW 1
Centaurs - Chimera SW 1 orbiter

Jupiter, Io - Io Volcano Explorer
Jupiter, Callisto - MAGIC orbiter


Luna - Compass Lunar Rover
Luna - Moon Diver
Luna - ISOCHRON sample return
Luna - Luna Volatile Orbiter ?
Luna - NanoSWARM

Mars - COMPASS climate orbiter
Mars - Ice Breaker polar lander

Neptune, Tritan - Trident

Venus - Veritas mapping orbiter
Venus - DaVinci+ atmospheric probe
Venus - HOVER hyperspectrol observer
Venus - Thalassa orbiter explore ocean loss ?


Posted by: JRehling Feb 13 2020, 09:13 PM

And the semifinalists are:

Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging Plus
Io Volcano Observer
Trident (to Triton)
VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy)

All sound great. If the two Venus missions are chosen, it would be, in a sense, Venus finally getting its Viking.

These are the four I am personally most excited about.

We'll either get the first U.S. mission (at least one) to Venus since Magellan, or an exciting pair of missions to deserving outer satellites.

Posted by: volcanopele Feb 13 2020, 10:35 PM

I still haven't come down yet (I'm on the IVO proposal).

So we have nine months to complete a phase A mission study and send that off to NASA. Final selection of one or (hopefully) two missions will be in May 2021.

Posted by: antipode Feb 14 2020, 02:25 AM

As someone who desperately longs for an Ice Giant mission or two I cant believe I'm saying this, but Venus' time has come (I hope).

If flybys are all that's financially possible for Ice Giant missions in the foreseeable future then surely there should always be a TNO or two selected as a secondary target?

P

Posted by: JRehling Feb 14 2020, 03:36 AM

Best wishes to Jason and those others who have a professional stake in this. I wish that all four missions were starting their science phase tomorrow (well, that might cause downlink problems) and I hope that whichever of these four don't fly this time get the nod in the next round. Whichever of them do, the results will be phenomenal. I've had my mind more on Venus lately (in fact, I just took a photo of it), but the others are also long overdue.

I know this is not the basis for evaluation, but they are also three of the largest worlds with (likely) current active volcanism.

Posted by: Explorer1 Feb 14 2020, 04:12 AM

I would love to see all four too, but that's probably not going to happened. Even getting two will be good.
I only worry that if TRIDENT were selected, it would make the incentive for a dedicated flagship mission to Neptune go down.
And of course, Venus and Io are so much closer and (relatively) faster to reach.

Posted by: JRehling Feb 14 2020, 04:54 AM

I mean getting all four soon – two now and two in the next round.

Posted by: Steve G Feb 15 2020, 01:09 AM

The nice thing about Venus, is it's close enough to see it in my (remaining) lifetime.

Posted by: JRehling Feb 15 2020, 01:44 PM

QUOTE (Steve G @ Feb 14 2020, 06:09 PM) *
The nice thing about Venus, is it's close enough to see it in my (remaining) lifetime.


Venus definitely has an advantage over any other solar system target, excepting the Moon.

The years when these four missions might conclude seems to be about 2028 for either Venus mission, 2035 for IVO, and 2038 for Trident. However, if two are launched, whichever goes second will be delayed by a couple of years, and the trajectory may be time-sensitive for the outer missions. Perhaps even one or both of them can't make use of the second launch window? Those details should come out eventually. Venus, naturally, is available every 19 months; there's a possible synergy that Veritas could help select Davinci+'s entry location if they launched in that order, although given the operational dynamics, I'm sure that the Davinci+ team will state that they can select an entry/landing location just fine with existing knowledge of Venus (and ~half of Davinci+'s goals are absolutely independent of entry location).

One document from the Trident team calls the 2026 launch opportunity "rare" so it might require that window; I wonder now if the IVO mission would be able to take the later window if it came to that.

As an unusual aside, Trident would flyby Venus and Io on the way to Neptune, so Venus will get at least a quick visit from three of the four missions, and Io from two of the four.

Posted by: antipode Feb 15 2020, 09:29 PM

Its kinda annoying that after all these decades we are still so energy constrained with spacecraft trajectories, and so reliant on interplanetary billiards.
Don't get me wrong, the trajectory gurus work miracles, but wouldn't it be nice to have a truly high energy upper stage? If you want to go to Neptune, then go to Neptune!
I know I know....

p.s. go Davinci+!

P

Posted by: Explorer1 Feb 16 2020, 12:17 AM

The trouble is that a fast, direct launch to Jupiter/Neptune is possible with a heavy lift vehicle, but an encounter would be at such speeds that an orbit insertion would be prohibitive in delta v terms.

Posted by: Holder of the Two Leashes Feb 16 2020, 07:55 PM

I'm not sure why a direct approach with a heavy lift vehicle would add any more velocity on arrival than using planetary billiards to ramp up speed?

Posted by: Explorer1 Feb 17 2020, 12:02 AM

Antipode was mentioning a high energy upper stage, presumably to shorten the travel time to the destination (like New Horizons), so that's what my reply was about.

Posted by: JRehling Feb 17 2020, 08:21 AM

Trident is a flyby, so orbital insertion is not a consideration. Cost, however, is.

Until/unless imparting delta-v becomes extremely cheap, elaborate trajectories will still be employed in order to permit missions with larger mass that allow more ambitious outcomes.

Posted by: vjkane Mar 21 2020, 03:42 PM

I listened the the virtual LPSC 2020 virtual NASA headquarters briefing. Lori Glaze, the Planetary Science Division director, discussed the challenges selecting two missions from the current Discovery competition semifinalists. Prior to the InSight mission, principal investigators were required to include the development of the spacecraft and instruments, the launch vehicle, and mission operations from their PI budget.

Under the rules for this current competition, the PI budget (which has grown somewhat over time), the PI budget now pays for only the spacecraft and instrument development. NASA separately pays for the launch vehicle and mission operations. As a result, the projected total costs of the Lucy and Psyche missions will be nearly double the cost of the Dawn mission (note, the chart attache from her talk shows real year dollars, so the Dawn mission's cost in current dollars would be higher than in this chart).

Glaze says that she really, really wants to pick two missions from the current semifinalists, but the potential cost of these missions may not make that possible.

Net in my assessment: Total mission cost to NASA may have a big influence on the mission(s) selected. This would seem to favor the Venus missions, which have shorter lifetimes, and hence possibly lower mission operation costs, than the two outer solar system moon missions. It's difficult to estimate launch vehicle cost differences since I've seen no information on the launch energy required by any of the proposals: DAVINCI+ and VERITAS launch toward Venus, IVO launches for a Mars Gravity Assist, and Trident launches for an Earth gravity assist with following Venus, Earth, and Jupiter gravity assists.

The same slide (slide 19) is in this headquarters update given to the Planetary Science Advisory Committee a couple of weeks ago: https://science.nasa.gov/files/science-red/s3fs-public/atoms/files/Glaze-PAC-March2020-FINAL.pdf

 

Posted by: vjkane Apr 29 2020, 02:48 PM

Here's a link to the LPSC 2020 DAVINCI+ ePoster

https://www.hou.usra.edu/meetings/lpsc2020/eposter/2599.pdf

Posted by: Phil Stooke Jun 18 2020, 03:00 AM

Here is a link to a presentation about the Io Volcano Observer, discussing fascinating add-on observations of small bodies:

https://www.lpi.usra.edu/sbag/meetings/jun2020/presentations/IVO-SBAG-2020-McEwen.pdf

From the recent Small Body Assessment Group meeting.

Phil

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