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Future Venus Missions
JRehling
post Mar 24 2019, 04:19 PM
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A nice summary! I've seen other write-ups of the specs and it's a phenomenal instrument design for a specific case of interest.

Now the pity would be if the Indian mission is the only planned Venus orbiter that doesn't include it and ends up being the first to fly, which it could be by a margin of years. If we have to wait ~15 years to get this data back, it will be a pity when it could easily be done within 4 years if Venus were a higher priority.
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Steve5304
post Apr 3 2019, 03:33 AM
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Just read the Russians gave agreen light and will send a new lander before 2023. Hoping to use some experimental tech to allow the probe to operate in extreme temperatures. Nasa is interested in helping develop this technology

I know roscosmos says alot and doesnt follow through. But Venus is definitely something they are capable of.
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Paolo
post Apr 3 2019, 05:26 AM
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QUOTE (Steve5304 @ Apr 3 2019, 05:33 AM) *
Venus is definitely something they are capable of.


or at least they were capable of. I doubt that almost 35 years after the most recent successful Russian planetary mission they are retaining any of the know how
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bobik
post Apr 3 2019, 08:35 AM
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The Phase II Report of the Venera-D Joint Science Definition Team calls for a launch in 2026 at the earliest.
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Steve5304
post Apr 3 2019, 07:38 PM
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QUOTE (bobik @ Apr 3 2019, 09:35 AM) *



thanks for that. Glad I can count on this place to be accurate.

Yahoo later corrected the article to 2026. mad.gif

QUOTE
or at least they were capable of. I doubt that almost 35 years after the most recent successful Russian planetary mission they are retaining any of the know how


Man Russia needs a win so bad. The last somewhat successful interplanetary mission was....what ? ..Phobos II....somebody?
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Paolo
post Jun 5 2019, 04:41 PM
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in today's Nature:
Venus is Earth’s evil twin — and space agencies can no longer resist its pull
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atomoid
post Jul 3 2019, 09:50 PM
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QUOTE (Steve5304 @ Apr 3 2019, 11:38 AM) *
Man Russia needs a win so bad. The last somewhat successful interplanetary mission was....what ? ..Phobos II....somebody?


Phobos2 though unfortunately not fully successful, did get some great images, yet it seems to be the most recent Russian exploration mission to at least make it beyond Earth orbit. The most recent success seems to be Vega which after a couple of as-yet unmatched firsts in deploying landers and balloons to Venus, continued another first visiting Halley in 1986 according to this wikipedia page. After the breakup of the USSR, other than the Russian's fine and clockwork Soyuz activities and contribution to ISS, its unfortunately been crickets as far as exploration is concerned. It looks like Luna25 in 2021 is their next hope in a long line of false starts, found this article on the space review.
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atomoid
post Oct 24 2019, 11:41 PM
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new Wired article on the LLISSE is interesting once you bat away all the adverts.
The 20cm cube is designed to stay operational for 60 days capturing day/night transition, but likely have no camera, is hoping to hitch a ride on Venera-D.
Also found an old PDF and another older? paper mentioning a possible wind-powered battery option for demonstration in 2023. Wind speeds are so fast at altitude it speeds the planets rotation by 2 minutes per day, wind slows at the surface to apparently a few km/hr so seems workable, solar cells should be considerably less mass but im not sure what the status is now though ive also heard due to high albedo Venus actually receives less energy at the surface than Mars does.. here's more fun.
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tanjent
post Nov 20 2019, 06:15 PM
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https://www.space.com/possible-nasa-venus-f...ip-mission.html

This article discusses the possibility of a flagship-class mission to Venus sometime after 2023.
One may argue that recent Venus proposals have failed because they are too cautious, so perhaps a multifaceted
approach on the scale of Cassini would stand a better chance of success.
Mentioned are multiple orbiters, long and short-term landers, and a balloon-based aerial platform with, (sic) a seismometer.
Despite its ambitious nature, the proposal strategy seeks to be cheap relative to other flagship-class contenders.
I guess that means we'll have to wait a few more decades for a sample return.
,
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JRehling
post Nov 21 2019, 04:05 AM
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Interesting timing, given that three Discovery proposals aimed at Venus are now being evaluated with an announcement of selection for Step 1 targeted for January 2020, only weeks from now. Any of those three would satisfy the flagship aims partially, so the proposal of a flagship mission puts some (more) people/programs at cross purposes, and the community has to have a lot of overlap; there can't be very many people who would be investigators for the flagship mission who aren't involved with some of those Discovery proposals.

Orbital studies of the surface and orbital/descent studies of the atmosphere are both addressed by the Discovery proposals, in addition to the descent imaging of tessera terrain. The flagship mission includes a lot more in situ surface focus.

The timing feels off unless the people proposing the flagship mission have a strong sense that the Discovery proposals are all going to be rejected. Otherwise, the flagship goals could descope and focus with the satisfaction of some of those goals.
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tanjent
post Nov 21 2019, 10:26 AM
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I don't recall any precedent for gathering together several discovery-scale proposals with the same destination and consolidating into a single flagship-scale mission. But there could be some efficiencies in launch, data return, shared infrastructure. Politically it would be difficult to persuade the individual would-be PI's to report to a single overall head, but I suppose they might be willing to settle for a piece of the action with high probability, in place of a low-probability shot at being the sole focus.

Anyway, I am just imagining that; the article mentions no such consolidation. It seems to describe a top-down effort by someone who wants to design the whole venture from scratch.
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rlorenz
post Nov 24 2019, 03:29 AM
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<personal opinion only>
Despite being a proponent of Venus exploration (I am associated with one present Discovery proposal, as well as having involvement in international missions)
I find the case for a Venus flagship somewhat uncompelling : I wonder if it essentially was the result of the architecture of the Decadal Survey
(i.e. the (non-Mars) terrestrial planets could get one Flagship into consideration, and that's what popped out)

There is definitely a need for higher-resolution radar observations (Magellan's stated purpose was to map Venus as well as Mariner 9 mapped
Mars, so there's a little catching up to do...) with an emphasis on change detection (e.g. multiple revisits, interferometry etc.) and for in-situ measurements on and near the surface.

The synergy of combining these into a single mission (for which there are surely *some* advantages) is IMHO less strong than at more remote targets (I led the
science definition team for the first Titan Flagship study in 2007, which advocated a lander, a balloon and an orbiter - at the large Titan-Earth distance, the
orbiter really improved the data return from the in-situ elements) - the data relay enhancement of return from a lander is not so critical for non-mobile
landers which develop new information at a much lower rate than rovers/balloons etc., and for the smaller Earth-Venus distance.

The capability for near-surface in-situ missions (high P,T) used to be within the purview of the USA and USSR. It isn't clear that Russia today really has that capability, so
I'd expect the USA to be the lead behind any future lander.
(Balloons etc near the 1-bar cloud tops are less demanding : although the entry challenges are non-trivial, they are comparable with Earth entry, that
ESA, China, Japan etc. can handle)
Unless surface mobility, multiple (>2) landers, or sustained longevity is introduced, near-surface in-situ measurements are within Discovery/New Frontiers scope

Beyond their propulsive demands, orbiters require attentive thermal design, but are otherwise not terribly different from Earth orbiters. So the pool of countries /agencies
that could 'bite off' the radar/gravity/near-IR mapping job is not small. We have already seen promise that India may enter this arena (although I am skeptical that the
downlink bandwidth will allow an Indian mission - if anything like MOM - to do justice to radar mapping)

If an Indian mission happens (even just an orbiter with a range of payloads), and a 'proper' radar mission (ESA's Envision and/or a US Discovery class like VERITAS) and
an in-situ mission (e.g. Discovery or New Frontiers and/or Venera-D [but Im not holding my breath on that, V-D's been nothing more than vugraphs for about a decade now]
start development in the next few years, then Venus science in the next decade will be in decent shape. In which case I'd find it hard to argue for a Flagship, and I'd suggest that
such a 'coalition' of smaller missions is more likely to happen than a Flagship.

If India+Envision only, that'd be good, but there are some major questions still not being answered (surface/atmosphere chemistry for one, probably the noble gas abundances)
If only one of those, it amounts to 'life support' for Venus science at best. The Venera/VEGA/Pioneer Venus generation are basically all retired, the Magellan generation (i.e. those
professionally active while the mission was in operation) still has a reasonable fraction of people in the field that can offer direct experience to missions developed and launched
in the 2020s, but if it takes until 2030 to go back, much of the intellectual heritage of the earlier missions and questions will be lost.

There are doubtless aspects of the Venus climate whose understanding can be refined, but IMHO (see my book 'Exploring Planetary Climate') the basics were pretty well figured-out by Pioneer Venus and the Veneras. There is
new appreciation of time variability from VEx and Akatsuki, but again, good traction of much of that science can be made from smaller missions. I just don't see a Flagship.

Akatsuki is great (but its near-IR cameras ceased operation after a year in orbit, so it's just doing UV, thermal IR, lighting/airglow and radio occultations). The Bepi-Columbo
and Solar Probe flybys are cool and all, but don't provide a lot of data or answer any major questions.

</opinion>
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JRehling
post Nov 27 2019, 04:54 PM
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Your opinions are gold, Ralph – very informative.

One thought on the engineering side that you didn't mention: Obtaining circular orbits via aerobraking or otherwise. Magellan began with a relatively low-eccentricity orbit attained with chemical propulsion, then used aerobraking to circularize the orbit for the gravity mapping phase. Since then, three U.S. orbiters and one ESA orbiter have used aerobraking to obtain a circular orbit at Mars.

Veritas and Envision would be the first mission(s) to use aerobraking to attain a circular orbit around Venus for a spacecraft's primary mission.

What I wonder is whether other space programs would have the capability to achieve this or if this seems like USA/ESA capability only for the time being. I realize that the question is potentially speculative, but seeing as the USA and ESA missions plan on it and the Indian mission does not it seems like a potentially significant distinction between proposed orbital surveys of the planet's surface.

For atmospheric science, this seems much less significant as time variation is important and a wide perspective is not a bad tradeoff.
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antipode
post Nov 28 2019, 10:34 PM
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Ill second that, but...

...What would be the most cost effective way to get more information on the mysterious 'unknown UV absorber' in Venus' clouds?
Does this need in situ sampling, or can it be done remotely, and if the latter, is it in the reach of a larger cubesat?

(I'm assuming there wont be megabucks around for Venus missions in the near-mid term)

P
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scalbers
post Nov 29 2019, 12:51 AM
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What's the story with disulfur oxide as a possible UV absorber as in this publication? Then we have this thread.


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