NASA Moves Ahead With Robotic Plane to Take Mars Exploration to the Skies

They need to make it more efficient, maybe instead of jets they could you electric motors. And maybe solar panels to give some more time.

It would be a great achievement however, in its current iteration, it would be a bit of a waste.

As stated above, why not include a motor that is solar/battery powered that could extend its flight for another hour?

Why not include a compressed helium canister that could inflate a balloon and extend its flight for another hour and could allow for a soft landing in a location where it could perform more experiments. The solar/battery could add ground mission capabilities in an inaccessible location.

We are a little too technologically advanced to simply send a plane all the way to another planet just to fly for an hour and then crash it.

I agree with all4it. Why not launch a plane that lands safely and recharges. Or land a rover and a plane. The rover serves as a refueling station. 10 visits of helium. The balloon takes off, flys around and then when it needs to land, it glides back to the rover spilling the helium.

I'm afraid i have to dash the above ideas. At first glance you think yourselves correct, and I would agree with you, an electric plane would last a lot longer and enable the mission to yeild more reults.

Except we're on Mars.

On Mars, the gravity is a bit over 1/3 of earths. However the Atmospheric pressure is under 15pounds per square foot.

For reference, Earth's atmospheric pressure is about 15psi (pounds per square inch) or about 150 times as much as on Mars.

I hope I don't need to explain how airplanes fly, so suffice it to say that without rockets, you can't fly anything. Balloons only work via bouyancy, and there is a lot less pressue. Jets work on combusting fuel with oxygen from the air (none of that there). Propellors apply work on the atmosphere to generate forward thrust, which doesn't yeild enough of a result in that thin of an atmosphere.

In Short, you can't fly there with any airplane from Earth. The atmosphere is too thin to fly in conventionally. As a rule of thumb, if the answer is so obviously simple to you, NASA/scientists involved probably discarded that answer it for an equally simple reason you overlooked.

And I apologize profusely for the misspellings and typos above. I accidentally copied the unedited version of my post into the box.

Brian144 is completely correct. You can't presume that Earth-based aerodynamics will work the same on a different planet with a different atmosphere. And if the people at NASA didn't include it in their plan, it's probably not a feasible solution. Their budget is getting axed, so they are making the best plans they can with the decreasing amount of money they have.

Actually I believe what you stated is not technically accurate.

I believe the air density is the technical challenge that leads to a low lift to weight ratio and thrust from a propeller. Earth's air density at STP is only about 80 times that of Mars and the gravity, as stated above, is about 1/3. While the density is a function of pressure, the air pressure does not create the lift.

General Equation:

L = 1/2 * C * p * V^2 * A

Where:
L = Lift
C = Lift Coefficient
p = Air Density
V = Wind Velocity
A = Wing Area

Note that pressure is not in this equation.

So in general terms you would use this for you lift of the wing but can also be applied to the thrust of the propeller as it is simply a rotating wing. There are other factors in producing thrust from a propeller but this a generalization.

So a propeller needs to be able to create lift, termed "thrust" to overcome the drag on the fuselage created by the atm. Since the atm is less dense there is also less drag therefore requiring less thrust.

While these are technical challenges I don't see them as insurmountable. I am sure a plane that has less weight (no pilot), large wings, large high pitch propellers, high speed servo motors, and sleek low drag fuselage is very easy to design.

Consider a glider. While it does not move as fast as an airplane, it still generates enough lift to stay in the air for a considerable amount of time. Why? It has no propellers or jets yet it does not fall out of the sky like a rock. It's huge wing span creates a high lift at low speeds.

Based on these issues I would have to conclude that the bigger technical issue is having the space on board the launch vehicle to transport the plane with a wingspan and propeller large enough for flight in this low density atm.

A rocket and wing body design is just easier to work with.

Just my 2 cents.

As a side note that's pretty offensive for you to assume that just because someone works for NASA they are automatically smarter then someone who doesn't.

Sometimes when people are always working on complex problems they sometimes seek complex answers and overlook the simple ones. It never hurts to ask.

Why not a glider?

@mike041
The rocket scientists over at NASA are smarter than you.

The NASA scientists may be smart, but the ones working on this "Aerial Regional-Scale Environmental Surveyor" are a bunch of ARSES.

Having worked on this project, I can tell you that the team started with an open field of ideas, ranging from balloons to blimps to gliders to airplanes, and with all sorts of propulsion concepts. When you combine the needs of the science mission with the constraints of earth-launch, Martian entry, the limited payload/space in the launch vehicle, and the very difficult physics of flight on Mars, only one feasible solution emerges, and it's a rocket powered airplane. Even that has significant technical challenges and hurdles to overcome.

Propellors would not be feasible for propulsion for several reasons. Chief among them is that the airplane needs reliable, instantaneous power during the transonic pullout phase of atmospheric entry, where it transitions from a ballistic object to a flying aircraft. Propellors are not feasible in that flight regime. Second, and more fundamental, is the low atmospheric density, which affects both gross thrust and the Reynolds number (Re) at which the props (and wings) operate. The props would have to be unrealistically large to give the amount of thrust needed and to reach a desirable Re, and just don't make sense.

The low atmospheric density also drives the size and speed of the aircraft -- it needs to have enough wing area and fly fast enough to reach a stable flight condition. Combine that with constraints of launch size and the need to fold up inside an aeroshell, and you end up with the ARES configuration. I have no doubt there are other solutions and configurations that would work, but they won't be much different than this one for the given science mission.

Gliders would suffer the same issues as props, needing to be unrealistically large to generate lift at low speed and reach a reliable Reynolds number.

Thank you very much skier219 for clearing that up and restoring my faith in the brains at NASA. The budget might be getting axed but they still have some of the best minds in the country there.

This may or may not be related, but I was thinking that NASA should look into employing a bunch of those solar satellites that beam down solar energy (http://www.popsci.com/scitech/article/2009-09/japan-wants-power-300000-homes-wireless-power-space). It may not apply in this case as skier219 noted the amount of speed needed to generate lift. However, it would be a way to power slow moving simple devices... for example a large solar powered weather balloon that uses the IR beam from the satellite to not only heat the balloon for elevation, but power a small motor for minimal navigation at high altitude. With the solar satellite method the winters wont be as much an issue.

@mike041
Just because a variable isn't in an equation doesn't mean it isn't related. Gas density is a function of mass and volume OR temp, gas constant, and pressure.

It's all the same/related. You're both right on some parts. The nice thing about your equation you threw out is it shows why the plane has to be rocket powered and go 450mph.

To maintain the same lift as on Earth, it would need to go much faster than it would need to on Earth because the air is much less dense (pressure so low).

Traveling over 100 million miles and over six months to Mars for the self propelled airplane to cruise above the surface of the planet for just several hours, to me is a waste of money. They can do this much better with balloons that can last for over 100 days and cost a lot less.

Now it would make much more since if they called them drones and armed them because they spotted some Taliban on Mars trying to convert the local aliens to radical Islam.

friggin send me to mars with an inflatable 'biodome' greenhouse, some granola bars and a lifetime supply of arizona green tea. that's heavy, but man cannot live on water alone. oh and i'll need internets too, so i can torrent all the latest movies and music to mars, so i can curb the insanity of having an entire planet to myself.
idk how long it takes to get to mars, but once i get there and get a nice martian farm going, gonna need to ship me a ladyfriend so we can start a martian family.
mars is red, and contains lots of iron if i remember correctly. since it is red i would assume that this is oxidized iron, and maybe it would be possible via some chemical reaction to release oxygen from the red stuff in an emergency. i know i've turned a metal oxide back into the base metal before, using aspirin, sugar and heat. im not sure if one of those is not necessary. my reasoning behind using sugar was that c6H12O6 plus metal oxide = CO or CO2, water, and the metal. same with aspirin, C9H8O4. it worked. will try it with iron someday when i have a test tube again. i used copper oxide and ended up with a test tube with an internal metallic copper coating. i think i would want a nice solar panel-plated hut because i hear mars gets atmosphere destroying solar storms or something. and i will need some kudzu, which i will use to terraform mars.

How about some HD video ?
One of these centuries, I would like to see some smooth HD video from a Mars rover or a soon to be rocket UAV. Is it really that hard to install 'HD Hero' cam on one of those things ? All I'm asking for is some 720P-60fps Mars action. :)

@Jeditalian
thats all very nice and proper but, will it blend?

Aerospace Engineering FTW !!!

@Skier219 - thanks for the insightful post. It's always nice to see people with the first hand experience comment on the challenges they have to overcome when working on complex problems.

@No More Heroes - Very insightful post. You intellect shines through your ability to communicate ideas and concepts through writing. I am sure everyone here had to step back and consider the magnitude of your contribution to this discussion. Nice troll.

@johnt007871 - Thanks for the comment but please re-read my second paragraph. I recognize that density if a function of temp and press, hence the abbr STP which stands for "Standard Temperature and Pressure". I also make reference to the relationship of density and pressure in my last sentence stating "While the density is a function of pressure, the air pressure does not create the lift."

@rlb2: it's important to measure the relevance and success of a mission by the amount and quality of data it collects and the amount of information obtained, not by the time duration of the mission. ARES will collect massive amounts of high quality, high fidelity data over a long distance, and it will be the type of data we have never obtained on Mars before. It has the potential to totally redefine our understanding of that planet. In two short hours, ARES has the potential to obtain more valuable data than some missions take months or years to accumulate.

You could make the opposite complaint against rovers or landers, because they take so long while obtaining a trickle of data, or because they don't cover much ground, but I don't think anyone will say that our lander/rover missions were a "waste of money". In fact, some of those slow-paced missions only made a few key discoveries, but boy were they huge discoveries. Each mission has a particular focus and value, and you need to step back and think about the big picture. Whether it takes two hours or two years, and whether the mission measures distance traveled in cm or km, is not really so important. It's what you learn in the process.

Balloons have some potential for studying Mars, but again we run into a size issue in many cases, just to be able to create buoyancy in the Martian atmosphere. In this particular case, a balloon is not a good choice for an ARES-type mission because you can't really control where it goes. Many types of data/science require us to fly a specific flight path/pattern, and we need to have the capability to dictate and control where we go and react to winds and atmospheric patterns. A powered airplane gives us that capability.

When exploring an 'unknown' environment such as Mars, with the purpose of collecting data about the composition of its atmosphere, soil etc. is it such a great idea to blast around spraying rocket exhaust gases and particles all over everything?

Just askin'...

Yea but, immense amount of data in such a short time, there is nothing in orbit to record and beam that amount of data back to earth in such a small 2 hour window. The only way to do that is record the data from ARES flight then parachute the recorded information to the surface of Mars before it crashes and slowly beam all that data back to earth. Because of the thin Martian atmosphere anything parachuted to the surface of mars needs a lot of mass to help land safely which would be too much mass for ARES to carry. Another way is to place in orbit a special device to receive the transmitted data then beam it back to earth as time will allow, we should have learned our lesson from the Cassini / Huygens mission trying something similar -- a lot of data was lost. You're in luck, "The Skyclimber," can parachute a load to Mars with much less mass and cost using only parachutes and a recoil device, see here:

www.shineinnovations.com/5512.html

Here is my favorite balloon type mission to mars, "The Martian Windsurfer," that would last 100 days and travel as much as 1,500 kilometers over the Martian surface gathering data from the surface and the atmosphere. The ballast of the balloon, the rover, tether would be cut to let the balloon circumnavigate the entire planet while the rover gathers more data on the surface, see here:

www.shineinnovations.com/5812.html

Ron Bennett

NICE!!! They need to fund NASA more!

lets go 100 million miles for a 2 hour flight to gather a bunch of data that will never get beamed back to earth because there inst enough bandwidth.
congratulations NASA you created the stupidest idea ever.

why cant we use that old mission we were planning i think it was called MAP and it used a bunch of balloons. makes much more sense since you can probably upload 1 picture every 15 mins with the available bandwidth.

http://www.buzzle.com/editorials/7-16-2004-56697.asp
ALL HAIL THE COMMON SENSE

Flight on two planets, it's like the Wright Brothers all over again except this time only one actual test is done however and it isn't at Kitty Hawk.

Waffles? I think you mean carrots.

why not send a rover geared for longdistance travel and loaded with little drones that come back to the rover every once in a while to recharge