MAX-C/ExoMars, Dual NASA/ESA rovers slated for 2018 launch Options

[peter59]

Isn't the martian atmosphere of such low density that not even the strongest storms will move anything more substantial than dust?

The answer is in this picture.

[AndyG]

I can't help thinking that a panel which can flap a bit would be a positive benefit on a solar-powered rover in a dusty environment.

[djellison]

The answer is in this picture.

And did the arrays get blown off, did they drop of, was it actually a problem?

No.

Your concern is totally and utterly unwarranted, and the inference that engineers would be so dumb as to build solar panels that would be 'totally destroyed' by a dust storm is frankly, insulting.

Have you forgotten just how thin the Martian atmosphere is?

[hendric]

Another nice advantage is the additional space on the deck when you have the solar panels out of the way, and also less shadows on the panel from objects on the deck.

Although panels as large as shown would probably dictate some special rules for tilt, otherwise they might hit the ground.

[ElkGroveDan]

The answer is in this picture.

The wings on a 747 do that.

[elakdawalla]

Edited the topic title to be more general.

[JohnVV]

and the inference that engineers would be so

well things have been known to happen .Just look at the "Tacoma narrows bridge "
or the first passenger jet the de Havilland "Comet " the pressuring and square windows caused metal fatigue - the whole top of the aircraft came off IN FLIGHT
or the Apollo #1 fire
the issue of 100% o2 at sea level pressure was a known problem but....
so things do happen

[ElkGroveDan]

Those are ridiculous examples John. Doug's point wasn't that engineers don't make errors. His point was that engineers designing a Mars Rover would not be so stupid as to design one where the solar panels were so faulty as to fail under known and foreseeable conditions, which is what Peter was implying:

Firstly, I can not imagine riding in a very rocky terrain. Secondly, in the case of strong wind (dust devils, dust storms) forces acting on the panels will be huge and can easily destroy them.

It's not as if people sit around a bar dreaming these things up and sketching out the final blueprints on a cocktail napkin, or for that matter by chatting with their keyboards on a discussion forum. There are extensive and rigorous years-long planning stages, drafting, simulations, testing, and more and more and more testing involving hundreds of people's expertise and input along the way. In fact far more eventualities and potentially destructive factors are taken into account than most of us ever imagine. The fragile craft Peter is imagining wouldn't make it past the first round of launch vibration tests.

[eoincampbell]

Is it conceivable that MAX-C could land at, MSL's "outstanding samples" site ?

[Hungry4info]

Wikipedia mentions something about that being a possibility. Take that for what it's worth.

[Drkskywxlt]

Based on Jim Green's presentation to the PSS, MAX-C and ExoMars will be combined into one rover. Still will use skycrane for descent and landing, still will cache samples for return and the goal is to drill below the surface.

[monitorlizard]

FWIW, issue 145 (Feb 2011),page 81 of ESA Bulletin has the following to say about ExoMars:


"NASA/JPL announced an architecture review for the 2018 mission that will consider two main approaches. One approach is to land two Rovers individually mounted on a platform...The other approach being considered by JPL is a single Rover landing with separation into two vehicles after landing. This architecture maximises the use of the NASA/JPL Mars Science Laboratory designs...but may require ESA to adapt significantly to the new approach."

I'm having a hard time visualizing how one rover can separate into two. If it's two rovers, isn't it essentially the same approach both ways?

[nprev]

Not from the perspective of systems interfacing. I'd call this significantly more complex than having two independent rovers on the same landing system; you've added a whole extra level of interfacing if you had two landers that were supposed to separate post landing. (Of course, we're reading into a top-level report; no idea what the detailed concepts--if there are any at this point--may have in mind.)

EDIT: Upon a bit more consideration, I think that defining the requirements of each rover is of paramount importance. If you want two rovers with essentially identical capabilites, then "twinning" them would make more sense. However, if you want two vehicles with complemetary (and different) capabilities, then you're just adding a lot of risk via the twinning approach.

But again, we don't know what's going on here very well in terms of mission concept. If one of them is minimally capable and is designed solely to be a paparazzi in order to document the science payload's adventures, then it's a lot less difficult.

[Paolo]

the goal is to drill below the surface.

I find it rather funny that the drill will be a derivative of the Italian DeeDrill that was under study for the Mars Surveyor 2003 sample return. I worked on that for my thesis in 1999, and it now seems that it will eventually fly... in 2018!

[Drkskywxlt]

NASA's contribution to this is $1.2B plus launch vehicle according to Jim Green. I hope this "one rover splitting into two" was a pre-Decadal idea, because it sounds awfully complicated, compex and expensive. Based on the budget reality and the experience with massive cost overrruns with MSL, I don't think the powers that be won't be as accommodating to cost overrruns and we could end up without a mission completely.