(USA Today) -- There won't be any little green men. But there really will be a flying saucer hurtling through the skies above Hawaii any day now.
As early as Thursday, NASA plans to send a giant, Frisbee-shaped aerial vehicle high into the stratosphere. It may seem straight out of a B-movie, but the space agency says the launch has a serious purpose: to test technology that will help land spacecraft and someday humans on Mars.
NASA still relies on some of the basic designs developed more than 40 years ago to land the Viking spacecraft on Mars, principal investigator Ian Clark of NASA's Jet Propulsion Laboratory said Monday.
"We've been using the same parachutes for several decades now," he said. "If we want to eventually land a human on the surface of Mars, we realized we need to develop new technologies."
The low-density supersonic decelerator, as it's officially known, will ascend into the skies dangling from a gargantuan balloon filled with helium. At 34 million cubic feet, the balloon would fill the Rose Bowl, encasing the helium in a skin made of a high-tech film as thin as sandwich wrap. Originally the launch from the Navy's Pacific Missile Range Facility on the Hawaiian island of Kauai was scheduled for Tuesday, but late Monday, the Jet Propulsion Laboratory announced that bad weather has forced a postponement until Thursday morning. The next opportunities after that will be June 7, 9, 11 or 14.
After the balloon and its load soar to roughly 23 miles high, the balloon will break away from the vehicle and drop to Earth, the cue for a rocket attached to the saucer to fire. The rocket will propel the saucer to four times the speed of sound, duplicating the rapid clip of a spacecraft bound for Mars.
If all goes according to plan, the saucer's inflatable ring, made of the same material as bulletproof vests, will pop up, expanding to some 3 feet high in a fraction of a second. The ring is designed to brake the vehicle as it speeds through the atmosphere. Finally a parachute much bigger than anything of its kind will cushion the saucer as it drifts down to an ocean landing.
NASA's latest rover on Mars, the Mars Science Laboratory, weighed about a ton. The new technology being tested would allow the landing of a load twice as heavy, and the use of multiple parachutes could mean even spacecraft of 20 to 30 tons could make a soft landing, Clark said.
At the test location high above the Earth, the air will be as thin as the wispy atmosphere around Mars, but it will be a lot easier to recover the saucer if things go wrong. The balloon could fail or the vehicle itself may prove balky, Clark said.
"We want to test them here — where it's a lot cheaper — before we we send them to Mars," said project manager Mark Adler, also of the Jet Propulsion Laboratory.