

NASA might put a drone on Mars - yawz
http://www.washingtonpost.com/news/speaking-of-science/wp/2015/01/26/nasa-might-put-a-drone-on-mars/?tid=sm_tw

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ggreer
An aircraft on Mars would be quite an engineering feat. The average
atmospheric pressure on the surface of Mars is 600 pascals, which corresponds
to an altitude of 35km on Earth. Since that's all carbon dioxide, oxygen-
consuming jets aren't usable. The only propulsion options are battery-powered
fans/propellers and rockets. And even with huge wings, any aircraft would have
to be going at hundreds of meters per second to generate lift. Looking at
altitude records[1], I see NASA's Helios UAV got up to 30km. Pressure at that
altitude is only twice that of Mars, so a battery-powered Mars aircraft seems
barely doable with current technology.

Edit: I was curious about higher altitudes on Mars, so I looked that up as
well. Pressure at the top of Olympus Mons is only 30 pascals. That corresponds
to 60km altitude on Earth. Good luck getting anything to fly up there. It's
effectively a low-grade vacuum.

1\.
[http://en.wikipedia.org/wiki/Flight_altitude_record](http://en.wikipedia.org/wiki/Flight_altitude_record)

2\.
[http://en.wikipedia.org/wiki/NASA_Helios](http://en.wikipedia.org/wiki/NASA_Helios)

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bhhaskin
I hate how drone has become synonyms with UAV. All UAVs are drones, not all
drones are UAVs.

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baddox
Assuming we're ignoring obviously separate definitions, like bees and sounds,
all drones _are_ UAVs. The word "drone" in the aviation context means "an
aircraft without a pilot on board." A few dictionaries throw in "autonomous"
as a criterion, but I'm not sure where that comes from, since "drone" referred
to remote controlled aircraft at least as far back as 1946. Also note that the
"drones" that became infamous in the American military were largely _not_
autonomous, but rather were remotely piloted (most American UAVs _can_ loiter
autonomously, but as far as I know attack missions are always remotely
controlled).

[http://www.etymonline.com/index.php?term=drone](http://www.etymonline.com/index.php?term=drone)

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vacri
A drone in robotics does not have to fly, it just means that primary direction
comes from elsewhere, whether or not the drone itself has any smarts. As
alex_duf mentions below, the rovers currently on Mars are drones. 'Drone' has
had this meaning long before Parrot and Predator drones existed (which seem to
be the things that popularised that meaning).

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baddox
I agree. I believe "drone" in this context was first used for aircraft (target
drones), but it has been further extended to any vehicle in robotics.

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IvyMike
Back in 2000, Austin Meyer simulated Mars in X-Plane, his physics-based sim.
(Nitpickers corner: some people don't like it, but it's good enough for this
kind of a thing)

His summary is kind of over-the-top but interesting nonetheless:

[http://www.x-plane.com/adventures/mars.html](http://www.x-plane.com/adventures/mars.html)

TL;DR: Flying on Mars is tough. He used a JATO to take off at 600 mph, a plane
similar to a U-2, and an arresting hook to stop.

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acadien
I wonder if this is meant to replace the ARES project which seems to have gone
nowhere.

[http://marsairplane.larc.nasa.gov/](http://marsairplane.larc.nasa.gov/)

I'm not familiar with the details of either project or why a drone might be
advantageous over a plane, although they have different applications. The ARES
project has been around for a while though so its a mystery to me why it
hasn't been implemented yet (the answer must be $$$).

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pj_mukh
I love this idea, I hope it comes to fruition and the science becomes public.
I don't quite understand the NASA project approval plan though. AFAIK, the
similar NASA Ares project was shelved? :(
[http://marsairplane.larc.nasa.gov/](http://marsairplane.larc.nasa.gov/)

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trhway
why not solar-powered blimp/airship? What NASA proposes here - land vehicle
with separable drone - looks more like future combat systems for Earth :)

