NASA's flying saucers hopefully won't be a smash hit
This artist's concept shows the test vehicle for NASA's Low-Density Supersonic Decelerator (LDSD), designed to test landing technologies for future Mars missions. A balloon will lift the vehicle to high altitudes, where a rocket will take it even higher, to the top of the stratosphere, at several times the speed of sound.
NASA may, weather permitting, launch what’s playfully being called a flying saucer.
It does look like a flying saucer, but it’s really more like landing gear...for Mars. NASA has ambitious plans for what it wants to send to the Red Planet – like people, habitats, and rockets for return journeys back to earth. This would involve payloads of 20, 30, or perhaps even 40 tons – dwarfing the one ton Curiosity Rover that touched down on Mars two years ago.
To land said gigantic saucers on Mars – which, by the way, travel at four times the speed of sound (Mach 4, 3,044 miles per hour, or 0.8 miles per second) -- you need to slow them down first.
“It’s difficult to land things on Mars versus Earth because the atmosphere is very thin, just one percent of Earth’s,” explains Mark Adler, program manager for the Low-Density Supersonic Decelerator (LDSD) project.
Parachutes alone won’t do, and rockets would require more fuel than anyone would like to carry all the way to Mars. “So we need large decelerators, to slow things down.”
That's where the “flying saucer” comes in. It’s a disc shaped payload that has, among other things, two experimental technologies to slow down vastly massive payloads.
The first is a “supersonic inflatable aerodynamic decelerator”: a doughnut shaped airbag that will make the payload a little more fat and less dense, slowing it down from four times the speed of sound to a mere two times the speed of sound.
The second is a large 100-foot supersonic parachute.
Together, they will be taken up to 120,000 feet by helium balloon, and then launched up to 180,000 feet where the atmosphere resembles that of Mars, reaching Mach 4.
Keith Cowing, editor of NASAWatch, says the technology is “probably one of the most cost-effective things one can imagine,” compared to using rockets to brake a rocket’s fall.
Cost effective doesn’t mean cheap, of course. This program costs $200 million dollars, of which $150 million has already been spent. It's one of the reasons NASA can't privatize the project like it does with cargo flights to the space station.
“You know, landing on Mars so far doesn’t seem to be very profitable,” says Michael Lopez Alegria, president of the Commercial Space Flight Federation. While he foresees a day when private companies will take up the slack, governments will have to open the frontier to Mars.
For now, that means not crashing into the surface of Mars at 3,000 miles per hour.