Venus Express Options

[remcook]

well...there's still orbit insertion.
but hopefully that will all go well. in the meantime: hooray!

[edstrick]

"....well...there's still orbit insertion...."

Mars Observer, lost during orbit insertion preparation.
Mars Climate Orbiter, lost in atmosphere during unsurvivable accidental areo-CAPTURE attempt.
Mars-4 and Nozomi both could not attempt orbit insertion burn.

85% is probably a fair arm-waving assessment of the risk fraction for an orbiter mission.

[Rakhir]

- First star tracker switched on.
- Reaction wheels switched on.
- Venus Express achieved Normal Mode indicating full 3 axis stabilised conditions and full control through ground operations.

http://sci.esa.int/science-e/www/object/in...fobjectid=38250

Rakhir

[RNeuhaus]

What I meant was, sometimes the answer is in the FAQ.   

Maybe, nobody will be able to answer it for forever....! That is a big question that its original axis has turned down or maybe it started so on the contrary to the rest of planets.

Rodolfo

[The Messenger]

"....well...there's still orbit insertion...."

Mars Observer, lost during orbit insertion preparation.
Mars Climate Orbiter, lost in atmosphere during unsurvivable accidental areo-CAPTURE attempt.
Mars-4 and  Nozomi both could not attempt orbit insertion burn.

85% is probably a fair arm-waving assessment of the risk fraction for an orbiter mission.

The upper atmosphere of Venus SEEMS to be less fickle, and there is a little less mission time delay - so there are some minor odds movers. The big intangable is solar flare-ups - some of those burps look like they could eat Messinger or Express.

[Rakhir]

The upper atmosphere of Venus SEEMS to be less fickle.

Anyway, the atmosphere should not be a problem because VE will not use aero-capture... unless a huge navigational error or unit of measure conversion error like it was for MCO

Rakhir

[JRehling]

And Public won't see any data till August.
Ya  ya I know I'm bad.

But ESA will claim important new discoveries sooner than that.

It's sad, but my elation over the purpose of the mission is so moderated by the fact that it's ESA doing the data release. I think we just need to psychologically prepare ourselves as though this were a 2008 mission and be happy to see the results trickle in eventually.

[Guest_BruceMoomaw_*]

Venus' upper atmosphere is MUCH more stable, density-wise, than Mars' -- simply because Mars' total atmosphere is so thin that the heating from dust storms can cause the atmosphere as a whole to dramatically warm, and thus balloon upwards in Mars' weak gravity. In fact, it was stated by a speaker at the COMPLEX meeting that this is the one piece of new environmental engineering measurements we absolutely MUST have for near-future Mars missions even of the unmanned variety: a satellite to monitor Martian weather and its correlation with upper-atmospheric density fluctuations in much more detail than has yet been done. We came within a hair of losing the Spirit rover even BEFORE it also ran into those high-speed near-surface winds (which, by the way, are less important for a throttled-rocket soft lander), because Mars' upper air density was 10% less than even the worst-case prediction based on obsevations the week before the landing, and so the vehicle was braked much less during entry than expected.

[Guest_Sedna_*]

But ESA will claim important new discoveries sooner than that.

It's sad, but my elation over the purpose of the mission is so moderated by the fact that it's ESA doing the data release. I think we just need to psychologically prepare ourselves as though this were a 2008 mission and be happy to see the results trickle in eventually.

Are you meaning that ESA's data policy is not the right one? Maybe JAXA's is better...

[The Messenger]

We came within a hair of losing the Spirit rover even BEFORE it also ran into those high-speed near-surface winds (which, by the way, are less important for a throttled-rocket soft lander), because Mars' upper air density was 10% less than even the worst-case prediction based on obsevations the week before the landing, and so the vehicle was braked much less during entry than expected.

Where do you get all this stuff? I have been looking for the descent profiles for Spirit and Opportunity for a year now!

[djellison]

Are you meaning that ESA's data policy is not the right one?

It's certainly not good enough - that is without doubt.

Doug

[tedstryk]

I am looking forward to the great discovery of the fact that the visible imaging channels can't see through to the surface.

[Guest_BruceMoomaw_*]

Where do you get all this stuff? I have been looking for the descent profiles for Spirit and Opportunity for a year now!

I got that from Jay Bergstralh's talk on the problem at COMPLEX -- but there have been some notes scattered around previously on the Web on the subject, though I'd have to track them down. (Bergstralh obligingly included a graph, which I'd never seen before, of the precise degree to which MER-A's air-density readings were below the 12-27-03 estimate -- the zone giving most of the trouble was 20-50 km, and at one point the density was fully 12% below the worst-case prediction. MER-A came down so much faster than predicted that had it popped its chute 3 seconds later, it would have crashed.)

[djellison]

The EDL data is on the PDS - but it's a bit awkward to use - the derived stuff is in there, I'll see if I can put Pathfinder, Spirit and Oppy pressure profiles together.

Doug

[The Messenger]

The EDL data is on the PDS - but it's a bit awkward to use - the derived stuff is in there, I'll see if I can put Pathfinder, Spirit and Oppy pressure profiles together.

Doug

Thanks Bruce and Doug - I guess I need to bite the bullet and figure out how to extract from the PDS, but doesn't look friendly, and it would be easy to spend days, and still not have confidence I had extracted the right data.

I'm looking forward to the day when the ESA is sitting on so much embargoed data, that they loose track of the release dates and open the floodgates. An ESA-PDS?