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

[Guest_BruceMoomaw_*]

The main justification for simplifying a Venus lander is that it can enable you to launch more than one at one time. Larry Esposito's "SAGE" concept -- which, from what little I know about it, apparently DID have both an airlock and a GCMS atmospheric analyzer -- neverthless consisted of two or three landers on one mission.

[AndyG]

Given that the surface is so hot and so highly pressured, why not take a leaf from the early explorers of the ocean bottoms? Dredge for rocks!

Picture a balloon flying in Venusian atmosphere at about the 32km level. This height is good since it's below the bulk of the cloud cover, giving you the ability to view the surface. Pressure is around 8bar and the temperature is around 200C. Not really a problem for well-designed electronics & balloon materials. Water doesn't automatically boil at this pressure/temp, so may be useful for radiators.

A thin titanium wire, with a basic end effector, could be winched down from a balloon at this height to pick up suitable rocks for analysis back within the balloon. A wire some 1.32 mm across, tapering to around 1mm at the bottom, would in total mass about 160kg, and enable a load of about 20kg to be lifted, assuming some 5kg mass for a grabber/hardened camera, etc.

100kg of lift in a CO2 atmosphere could be provided with just under 8 cubic metres of H2 in the balloon, so the size of the bag could be really quite trivial.

Andy G

[Bob Shaw]

As there are some fairly well-described outline designs for RTG-powered refrigerated landers, I find myself wondering whether the waste heat from the refrigeration system could be used to produce lift in a hot-air balloon. An almost mechanically inert (in terms of externals - obviously, there's pumps and whatnots beavering away inside!) lander could drift around the landscape, rising from time to time then falling once more. Think of a Galilean Thermomoter, and the way the glass spheres bob up and down...

You'd get:

Multiple ground-truth sites
Aerial imaging
Meteorology

And probably a few other goodies, too!