Mars Flier Prototype

SEWilco writes "BBC News reports that a full-scale prototype of a Mars flier will be built. The ARES glider will unfold in midair for a mission which may cover 850 km (528 miles). I wonder if its huge wings would allow it to be tossed back in the air by a storm in that thin air, although probably not by "winds of a few m/sec"."

Comments

What it can do

[Gortbusters.org]

• Simultaneous, in-situ, regional-scale measurement of the Mars atmosphere, surface, and interior
• Bridges critical scale and resolution measurement gaps of remote sensing and surface exploration
• Scout for future sample return and surface mission site selection
• Magnetic survey with spatial resolution two orders of magnitude higher than provided by Mars Global Surveyor, with ability to resolve the crustal magnetism source structure
• High-resolution measurements that cannot be achieved from orbit
• Geologic diversity from regional-scale coverage that cannot be achieved by surface missions
• In-situ atmospheric science
• Ability to traverse terrain inaccessible to surface vehicles
• Ability to precisely target science features
• Ability to execute a controlled, pre-planned aerial survey pattern
• Measurement of vertical surface structure not visible from orbit
• Robust performance with regard to atmospheric uncertainties

Can't wait to see the pics...

[Anonymous Coward]

when this thing lands and G.W. Bush, in full combat flight suit, steps off to greet the smiling Martian press...

using air currents to regain altitude

[Anonymous Coward]

I very much doubt that it would be able to use rising current to stay up in the air for a couple of reasons. First the aerodynamics. The wings would have to have a much larger aspect ratio, or span vs. chord length, since that govers much of your aerodynamic efficiency. you need to be very efficient to use air currents to gain altitude. Modern gliders, which are able to use rising currents, are able to do that because they very high aspect ratios compared to most airplanes, including this one. They probably can't increase the wing span a lot because you still have to pack this thing up in a rocket, plus I'm sure there are design (weight?) constraints for spring to deploy the wings. Don't want to make them too soft, since you have some aerodynamic loads that you may need to overcome during deployment, but not too stiff to minimize the weight and you don't want the wings to unfold too fast and snap off if you don't beef up the structure, ie more weight.

Second problem and a major one, is the control system. Developing algorythms to read atmospheric conditions to find sources of rising air would be very difficult to say the least. That's why we don't have cars that drive themselves. it's hard to design the control and sensing algorythms. You'd have to use thermals or ridge lift to gain altitude. I doubt you could use storms due to the dangerous, highly nonlinear environment.

Re:using air currents to regain altitude

[KrispyKringle]

Aside from the obvious comment that NASA surely knows what they are doing (more of a conversation stopper than anything), I think you miss a few points.

First, in reference to your comments on structural and weight limitations, the actual force born by the wings is far less, since there is far less gravity. In addition, while the thinner air is certainly a hindrance to how much lift can be acheived with the same area, it also means that the stresses that must be absorbed from turbulence and the like are probably a lot less.

In reference to unfolding wings, these have, I recall, been tested on Earth, so if they work in our dense air and stronger gravity, they should be fine on Mars. If I knew a link I'd post it; you can probably find more with google.

Finally, you talk a lot about control system algorithms. However, there are a number of reasons that Unmanned Autonomous Vehicles are simpler when flying than when driving. There are a couple of relevent articles in this month's Popular Science, as well as a very good one in the New York Times magazine from a few weeks ago that I just finished reading. If you think about it, the amount of leeway available in the air is far greater than that on the ground; whereas a car driver must maintain precision navigation within a few feet on a road and avoid obstacles and the like, a pilot can, during cruise, simply trim out the plane's elevators, maintain a proper heading, and get by without even an autopilot. If he drifts off by a few hundred feet altitude or a few degrees heading, it doesn't really matter. This is why we already have numerous UAV's in the air in the military (such as the well-known Predator drone) and why Boeing 777s and the new Airbus 330 (isn't that it?) both can supposedly fly without even needing a pilot, in an emergency.

In comparison, DARPA is working with a few contractors to develop UAV ground vehicles, but is really nowhere near production stage.

My knowledge about gliders specifically is limited, my personal experience being limited to powered planes, but I would imagine that with a fair level of accuracy, finding thermals and gaining altitude should not be all that difficult, since most of the control software already exists in some form or another.

Incidentally, X-plane.org

[torpor]

... has some Mars models (fliable) available here in case anyone wants to try and get a feel for the flight dynamics of this sort of trip.

Pretty interesting, though I don't suppose there's an ARES model for X-plane yet, I wouldn't be surprised if there wasn't one soon ...

Re:tiptoe advancements

[KrispyKringle]

Obviously we've all heard in general the debate on manned vs. unmanned expeditions. I may as well point out the obvious, that the money put into a project like this is pretty much a drop in the bucket compared to the amount needed for a manned mission.

More pertinant to this particular mission, though, and intersting in regard to the general debate, is the point that in this instance, we are looking at an unmanned mission with capabilities in fact different, not just lesser, than those of a manned mission. Certainly there is much valuable information to be gained from a manned mission that a glider will not provide, but by the same token, this mission will provide greater mobility and a larger sampling of the planet than any traditional manned (or unmanned) missions can.

While we all want to see manned missions, at the same time we must realize that pragmatically, unmanned missions often have not only more for the money, but more in and of themselves to contribute.

Mission Duration.

[uberdave]

This seems like an bad idea. The Mars Flier is a glider, which means it will have a very limited time aloft. 90 minutes from drop to landing in Earth's thick atmosphere - How long in Mars's thin atmosphere? I hope they train the on board computer to catch a few thermals here and there, otherwise this is a waste. A better idea would be a balloon or dirigible. These can stay aloft for days, weeks even. (Ultra long duration balloons could carry a lot more intstumentation than a glider. Theoretically, a balloon could even land, sample, and relaunch.

Nasa really needs to have another stunningly successful mission, like the pathfinder mission. Spending million of taxpayer dollars for a 90 minute glider mission will make them look bad.