Weather permitting, NASA today is testing a giant, inflatable flying saucer that's designed to crash. Yes, crash. The Low Density Supersonic Decelerator (LDSD) is designed to slow down a vehicle in atmospheric re-entry so the vehicle can crash at acceptable speeds. This is an important step if we're ever going to put people on Mars.
Here's the issue: Mars has a thinner atmosphere than Earth. Up until now, when we've landed rovers on Mars, we've had them deploy parachutes (as we've done for 50 years) and possibly some air bags or retrorockets (depending on the mission) so that we create a controlled crash on the surface. It isn't a fun way to land, and as objects get more massive the parachutes can't slow down vehicles enough in the thin atmosphere.
Right now, we can land about a ton on Mars safely. That's fine for a rover, but it isn't enough if we're landing people. The parachutes required to do that on Earth are already gigantic. And retro rockets (like the ones we used to land on the moon) are practical, but very heavy, especially when you need to reserve fuel for leaving again, too.
[ NASA is working on making research cheaper right here in low Earth orbit. Read NASA, CASIS Show How Your Company's Space Strategy Can Work. ]
Instead, NASA is planning on a lander which expands in surface area using air bags. By expanding the surface area, the airbags slow the descent, which means parachutes can be used to slow the rest of the descent. They based the design on the puffer fish.
What you get basically looks like a 1950s B-movie flying saucer.
Today's is the second test of the LDSD. The first one worked flawlessly from the point of view of the airbags expanding and slowing down the ship. Sadly, the parachutes that were supposed to be able to slow it down from there shredded. NASA went back to the drawing board, and believes it has a better parachute.
The second test will possibly take place on Friday, June 5. (Thursday's launch was cancelled, so check here for updates and details.) It should be a pretty cool show. A balloon will take the LDSD up to 120,000 feet, where the air is thinner. Then the LDSD will use rockets to get itself up to the edge of our atmosphere, where the air is as thin as the Martian atmosphere. It will drop and accelerate to Mach 3 before puffing up and slowing its descent enough to deploy the parachutes to go the rest of the way safely. If all goes according to plan, it will land off the coast of Hawaii and get scooped up.
The whole thing will be available on live video as it happens. "You get to see all the same video I do, at the same time I do," said Mark Adler, project manager for LDSD at NASA's Jet Propulsion Laboratory in Pasadena, Calif., in a NASA press release.
It should be a great show, and it is a major step toward putting people on Mars.