Future Venus Missions Options

[Phil Stooke]

Oh well, might as well start that new topic since it's already well advanced in the Juno area...

My perspective on landers is as follows. All the landers we've had so far were dropped blind onto an essentially unknown surface. Any future landers can be targeted for specific terrains. It really is not true that we have had representative landings. Even a descent image or two, a panoramic photo plus a bit of surface composition, from a simple Venera-class lander just updated a bit, would be useful if we could put several down at well chosen targets. My choices would be:

Examples of the main plains units (smooth, fractured, ridged)

tesserae

high elevation radar-bright tesserae

large fresh lava flow unit ('fluctus')

crater dark parabola

crater ejecta outflow unit

dunes area.

And I have always assumed, rightly or wrongly, that it would be relatively easy to put these down, so they ought to be fairly inexpensive as planetary landers go.

Phil

[vjkane]

Presentations from the last VEXAG meeting are now posted: http://www.lpi.usra.edu/vexag/may2008/presentations/

I found the presentation on the Japanese Venus Climate Orbiter and the Flagship mission analysis particularly interesting. The former is an imaging mission that will use a near equatorial orbit to achieve semi-synchronous coverage of the atmospheric rotation of the atmosphere.

The flagship report details the analysis for a possible 2020's (or so hoped) mission. As reported in the press, the proposal would include an orbiter (high resolution radar seems to be the key instrument), two landers with atmospheric composition capabilities and balloon ascent following sample acquisition, and two mid-altitude balloon platforms. Total cost is ~$3B (presumably in today's dollars).

Some thoughts on the flagship proposal:

The proposal seems to knock the legs out from under the New Frontiers VISE proposal, or any similar New Frontiers proposal. (This involved two short lived landers without balloon ascent.) This scale of mission receives the lowest science score. Yet for the price of two of VEXAG's short-lived landers (with balloon ascent), 4-6 VIS landers could be implemented.

The orbiter is actually fairly cheap, almost Discovery class, and would probably fit within that budget with some modest international participation. There's no claim in the presentation that there is much advantage to flying the orbiter with the other Flagship elements.

All medium altitude balloon options seem to cost ~$2B, as do the short-lived landers with balloon ascent.

VEXAG appears to be going to the full monty with a Flagship proposal. Yet, at best, Venus would be third in line after an outer planets flagship and a Mars sample return. Never hurts to make your request. But I would have two requests outstanding -- a high priority Discovery and a New Frontiers mission (fly something in the next decade) and a follow on flagship that might fly in the 2020s, and more likely (in my opinion) in the 2030s.