UPDATE on 17 June: Due to continued unfavourable weather conditions, Nasa did not conduct the flight test of its LDSD vehicle from Hawaii during the designated launch period – 3-14 June. Nasa continues to look at options for a future launch window.
Nasa’s flying saucer-shaped test vehicle – the Low Density Supersonic Decelerator (LDSD) – is waiting patiently to take to the skies from the US Navy’s Pacific Missile Range Facility in Kauai, Hawaii, for its first engineering shakeout flight.
Nasa identified six potential dates for launch of the high-altitude balloon carrying the LDSD experiment: 3, 5, 7, 9, 11 and 14 June. Unfortunately, unfavourable weather conditions have now pushed the launch to Saturday, 14 June.
The test will be carried live on Nasa TV and streamed on the Ustream. The test vehicle itself carries several onboard cameras. It is expected that video of selected portions of the test, including the rocket-powered ascent, will be downlinked during the commentary.
The cutting-edge, rocket-powered LDSD test vehicle will gather data about landing heavy payloads on Mars and other planetary surfaces. The heavier planetary landers of tomorrow will require much larger drag devices than any now in use (such as the Viking parachute design used as recently as 2012 to deliver the Curiosity rover to Mars) to slow them down. Plus those next-generation drag devices will need to be deployed at higher supersonic speeds to safely land vehicle, crew and cargo. The LDSD Technology Demonstration Mission will conduct full-scale, stratospheric tests of these breakthrough technologies high above Earth to prove their value for future missions to Mars.
“The agency is moving forward and getting ready for Mars as part of Nasa’s Evolvable Mars campaign,” said Michael Gazarik, associate administrator for Space Technology at Nasa Headquarters in Washington. “We fly, we learn, we fly again. We have two more vehicles in the works for next year.”
“The success of this experimental test flight will be measured by the success of the test vehicle to launch and fly its flight profile as advertised. If our flying saucer hits its speed and altitude targets, it will be a great day,” said Mark Adler, project manager for the Low Density Supersonic Decelerator at Nasa’s Jet Propulsion Laboratory.
The way Nasa’s saucer climbs to test altitude is almost as distinctive as the test vehicle itself. A helium balloon will be used to left LDSD to 36 576 metres. “From there we drop it for about one and a half seconds. After that, it’s all about going higher and faster — and then it’s about putting on the brakes,” said Adler.
A fraction of a second after dropping from the balloon, and about a metre below it, four small rocket motors will fire to spin up and gyroscopically stabilise the saucer. A half second later, a Star 48B long-nozzle, solid-fuelled rocket engine will kick in and carry it to 54 864 metres, accelerating to Mach 4.
“This first test is a true experimental flight test,” said Ian Clark, the LDSD principal investigator from JPL. “Our goal is to get this first-of-its-kind test vehicle to operate correctly at very high speeds and very high altitudes.”
The project management team decided also to fly the two supersonic decelerator technologies that will be thoroughly tested during two LDSD flight tests next year. If this year’s test vehicle flies as expected, the LDSD team may get a treasure-trove of data on how the 6-metre supersonic inflatable aerodynamic decelerator (SIAD-R) and the supersonic parachute operate a full year ahead of schedule.
The SIAD-R, essentially an inflatable doughnut that increases the vehicle’s size and, as a result, its drag, is deployed at about Mach 3.8. It will quickly slow the vehicle to Mach 2.5 where the parachute, the largest supersonic parachute ever flown, first hits the supersonic flow. About 45 minutes later, the saucer is expected to make a controlled landing onto the Pacific Ocean off Hawaii.
Watch how Nasa and JPL test a supersonic parachute under Mars-like conditions:
JPL’s Mike Meacham explains how an inflatable decelerator will help larger spacecraft land on Mars: