GOLDEN, Colorado -- UP Aerospace has fully analyzed the mishap that led to the failurelast September of its SpaceLoft XL suborbital rocket - the inaugural launchfrom New Mexico's Spaceport America. Corrective actions have been taken, withdesign changes to the vehicle now incorporated as the firm targets an Aprilreturn to flight of the rocket.
Liftingoff on its September 25 flight from Spaceport America, the SpaceLoft XL -- a20-foot (6 meters) tall, single-stage solid-fuel rocket -- experienced problemsthat led to the vehicle corkscrewing in the air, then crashed into desertlandscape after 90 seconds of flight.
UPAerospace, Inc. conducted a two-month anomaly-investigation process thatspanned structural mechanics, aerodynamic analyses, on-board flight systems,radar tracking data, optical tracking data, and a comprehensive study of thevehicle after it landed.
Tale of the tail
Fullinvestigation of the mishap both internal to the company and through outsideindependent expertise has centered on the rocket's fixed in place, three fintail section, explained Jerry Larson, President of UP Aerospace, Inc., with itsprimary business office in Highlands Ranch, Colorado.
Larsonsaid that the launch mishap has boiled down to two things: an aerodynamicstability margin in the rocket that was too low, coupled with the vehicleincorrectly designed not to spin fast enough on its ascent.
"Wethought we had plenty of margin," Larson said, but the investigation into therocket's flight, he said, showed a far less stable vehicle than had beenpredicted pre-launch.
"Therewere no fins that fell off. The vehicle actually remained structurally intactthroughout the entire flight...down to the ground," Larson said. The rocket'sless than adequate spin rate, he added, meant that the rocket could not correctfor thrust-induced moments typical for a fixed-fin vehicle nosing to higheraltitudes and reaching higher speeds.
Allthese factors coupled as the rocket reached about mach 4 - four times the speedof sound. The rocket's short flight prevented deployment of parachutes.
"Essentially,it's all isolated to the fin section of the vehicle," Larson told SPACE.com.
Design changes
TheSpaceLoft XL's return to flight will feature a fourth tail fin and an increasedspin rate, Larson said. The four fins are larger in size and shaped differentlyin response to the mishap findings from the first flight.
"Thenew design is robust and can handle very large deviations...so we have built in alot of margin in the new design," Larson explained. From a return to flighthardware status, the next SpaceLoft XL is ready to go, he said, and will carrycustomer hardware into suborbital space.
Larsonsaid that the next flight will also carry a comprehensive data sensor suite -built by New Mexico State University -- to gather information about thecorrection actions taken in SpaceLoft XL's return to flight.
TheSpaceLoft XL vehicle can launch up to 110 pounds (50 kilograms) of scientific,educational, and entrepreneurial payloads into space, with an altitude capabilityof up to 140 miles (225 kilometers).
UPAerospace is working with the Federal Aviation Administration's Office ofCommercial Space Transportation to obtain, perhaps by early March, a return toflight go-ahead and approval for flying the vehicle throughout 2007, Larsonsaid. In addition, UP Aerospace is working on a multi-year lease agreement withNew Mexico Spaceport America officials.
Regardinglast year's mishap at Spaceport America outside Las Cruces, New Mexico, Larsonremained upbeat: "It is part of the business and goes with the territory. We'rein it for the long haul. It's a tough business. You can't get into the launchvehicle business with rose colored glasses."
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