Tuesday, September 18, 2012
Flying Above Mars
You think we have it tough flying here on Earth? Consider the problems of aviating above Mars.
This allows insects to take off, maneuver, hover and land vertically. If such techniques could be applied to a miniature Martian aerial rover, possibly by blowing air out the trailing edges of the wings, a much smaller flapping-wing aircraft, perhaps one meter in span, could take off, fly a reconnaissance mission, execute its photo mission and return to the mother ship without concern for the thinner air.
Of course, Mars' atmosphere is almost pure carbon dioxide with no oxygen, so any flying machine would need to bring along its own oxygen supply or use an alternate power source. The obvious alternatives would be solar or nuclear power. Most previous Mars ground rovers (especially the two most recent, Spirit and Opportunity) employed solar power, but were plagued with dust storms that covered the solar panels with sand and reduced charging capability to near zero.
Curiosity uses nuclear power, a radioisotope, thermoelectric, plutonium dioxide, that will be unaffected by dust storms and could provide energy for as long as 14 years. A similar system might be utilized by a Martian aircraft.
Another limiting factor on Mars might be the temperature. The average temperature on Mars is about -60 degrees C, though it may reach 20 degrees C during the day at the equator. At the poles, the temperature may drop to -120 degrees C. Such realities would demand very resilient operating systems plus a major heater to protect any form of aircraft.
Cosmic radiation also could be a problem, even for an unmanned robotic system, carrying nothing more than gas sensors, cameras and instrumentation. Shielding would be mandatory for any aircraft flying above the surface of the planet. Solar radiation could effectively fry critical systems of an aircraft flying above Mars.
Navigation above Mars would be a challenge, too. The planet has no magnetic field, so there would be no convenient way to determine north or any other direction. Without several satellites overhead, there would obviously be no GPS guidance, though a form of ADF provided by the mother ship might work. Another possible method of navigation might be a modified type of inertial guidance. Similarly, a downlink might be utilized from satellites orbiting overhead, commanding relative bearings toward a given destination.
General aviation rarely receives credit for all the missions it performs—cargo, air ambulance, firefighting, aerial survey, law enforcement, pipeline patrol, wildlife management and about a hundred other jobs. Wouldn't it be interesting if the first Martian Aerial Rover Reconnaissance vehicle turned out to be a descendant of the Skyhawk?
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