NASA Satellite Launch Fails

SAN FRANCISCO - NASA's first mission to monitor the effects of humanity's input of greenhouse gas-causing carbon dioxide was lost Feb. 24 when the payload fairing on its Taurus XL 3110 launcher apparently failed to open about 2 minutes and 55 seconds into the mission.

The Orbital Carbon Observatory (OCO) and four-stage, 93-foot tall Taurus solid rocket, both built by Orbital Sciences Corp., were proceeding nominally through an 11-minute launch sequence after a 1:55.31 a.m. PST liftoff from Vandenberg Air Force Base, Calif.

The first stage, which Orbital calls the "0 Stage," burned for a nominal 84 seconds after liftoff, as did the second stage (Orbital's "first stage"), and separation occurred at 2 minutes and 43 seconds, Launch Director Chuck Dovale said.

A 5-second coast was followed by a successful third stage ignition. The fairing is supposed to separate about 7 seconds after that ignition, but apparently didn't.

"For the science community, it's a huge disappointment," Taurus Program Manager John Brumschwyler said.

He said mission control got confirmation that four electrical impulses - two primary and two redundant - were correctly sequenced to initiate the separation and that there were "good power" readings.

But three minutes into the flight, telemetry gave two indications there was no separation: temperature readings were off and wires that should have broken with the separation didn't. The failure was confirmed when flight control did not notice a jump in acceleration in the third stage, which would have occurred had the heavy fairing properly separated, Brumschwyler said.

"The initial indication is that [the fairing] did not come off, at least partially," he said. The added weight of the fairing meant the vehicle could not achieve orbit and fell into the ocean "just short of Antarctica," Brumschwyler said.

Orbital Sciences also built the 972-pound satellite at its Dulles, Va., facility. The OCO mission cost was $273.4 million.

Orbital had a 6 for 7 launch rate for the Taurus XL going into the mission. Brumschwyler said Orbital has not previously had fairing problems with the rocket. It was NASA's first use of the Taurus.

The mission was set for a sun-synchronous orbit with a near-polar inclination at an altitude of 438 miles. OCO was to be placed at the head of five climate observing satellites from NASA and the French space agency CNES orbiting in the "Afternoon Constellation," or A-Train.

The mission would have been science's most complete attempt to precisely measure where the Earth stores carbon dioxide (CO2) in the oceans, land and atmosphere. Understanding their absorption and release mechanism is considered key to determining exactly how man's industrial activities contribute to global warming. There is no backup satellite (Aerospace DAILY, Jan. 30).

NASA Earth Science Division Director Michael Freilch said it will take several weeks to determine how the space agency will proceed. In the eight years that NASA has been developing OCO, improved sensor algorithms are allowing instruments on other spacecraft to advance CO2 studies as well.

The Japanese space agency JAXA launched the Greenhouse gases Observing Satellite (Gosat) in January and it is making atmospheric measurements, although its primary mission is to measure CO2 and methane sources, not their global distribution (Aerospace DAILY, Jan. 26). OCO was using an innovative instrument to do that at the molecular level.

"We will take a good, thoughtful look at the best way to advance" CO2 studies, Freilch said.

OCO payload fairing photo: NASA