GOLDEN,
Colorado -- UP Aerospace has fully analyzed the mishap that led to the failure
last September of its SpaceLoft XL suborbital rocket - the inaugural launch
from New Mexico's Spaceport America. Corrective actions have been taken, with
design changes to the vehicle now incorporated as the firm targets an April
return to flight of the rocket.
Lifting
off on its September 25 flight from Spaceport America, the SpaceLoft XL -- a
20-foot (6 meters) tall, single-stage solid-fuel rocket -- experienced problems
that led to the vehicle corkscrewing in the air, then crashed into desert
landscape after 90 seconds of flight.
UP
Aerospace, Inc. conducted a two-month anomaly-investigation process that
spanned structural mechanics, aerodynamic analyses, on-board flight systems,
radar tracking data, optical tracking data, and a comprehensive study of the
vehicle after it landed.
Tale of the tail
Full
investigation of the mishap both internal to the company and through outside
independent expertise has centered on the rocket's fixed in place, three fin
tail section, explained Jerry Larson, President of UP Aerospace, Inc., with its
primary business office in Highlands Ranch, Colorado.
Larson
said that the launch mishap has boiled down to two things: an aerodynamic
stability margin in the rocket that was too low, coupled with the vehicle
incorrectly designed not to spin fast enough on its ascent.
"We
thought we had plenty of margin," Larson said, but the investigation into the
rocket's flight, he said, showed a far less stable vehicle than had been
predicted pre-launch.
"There
were no fins that fell off. The vehicle actually remained structurally intact
throughout the entire flight...down to the ground," Larson said. The rocket's
less than adequate spin rate, he added, meant that the rocket could not correct
for thrust-induced moments typical for a fixed-fin vehicle nosing to higher
altitudes and reaching higher speeds.
All
these factors coupled as the rocket reached about mach 4 - four times the speed
of 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
The
SpaceLoft XL's return to flight will feature a fourth tail fin and an increased
spin rate, Larson said. The four fins are larger in size and shaped differently
in response to the mishap findings from the first flight.
"The
new design is robust and can handle very large deviations...so we have built in a
lot of margin in the new design," Larson explained. From a return to flight
hardware status, the next SpaceLoft XL is ready to go, he said, and will carry
customer hardware into suborbital space.
Larson
said that the next flight will also carry a comprehensive data sensor suite -
built by New Mexico State University -- to gather information about the
correction actions taken in SpaceLoft XL's return to flight.
The
SpaceLoft XL vehicle can launch up to 110 pounds (50 kilograms) of scientific,
educational, and entrepreneurial payloads into space, with an altitude capability
of up to 140 miles (225 kilometers).
UP
Aerospace is working with the Federal Aviation Administration's Office of
Commercial Space Transportation to obtain, perhaps by early March, a return to
flight go-ahead and approval for flying the vehicle throughout 2007, Larson
said. In addition, UP Aerospace is working on a multi-year lease agreement with
New Mexico Spaceport America officials.
Regarding
last year's mishap at Spaceport America outside Las Cruces, New Mexico, Larson
remained upbeat: "It is part of the business and goes with the territory. We're
in it for the long haul. It's a tough business. You can't get into the launch
vehicle business with rose colored glasses."
advertisement
