OCO Press Conference Notes: Fairing Did Not Separate

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As Ian reported earlier this morning, NASA’s Orbiting Carbon Observatory satellite failed to reach orbit after its 4:55 a.m. EST liftoff Tuesday from California’s Vandenberg Air Force Base. At a press conference, officials said preliminary indications are that the fairing on the Taurus XL launch vehicle failed to separate about three minutes into the flight. The fairing, or nosecone, is a clamshell structure that covers the satellite as it travels through the atmosphere. “The fairing has considerable weight, and when it separates off you get a jump in acceleration,” said John Brunschwyler from Orbital Sciences Corporation, the rocket’s manufacturer. “We did not have that jump of acceleration and as a direct result of carrying that extra weight, we could not make orbit. And so, the initial indications are that the vehicle did not have enough Delta V to reach orbit, and landed just short of Antarctica in the ocean.”

Brunschwyler added, “Our whole team, at a very personal level, is disappointed in the events of this morning….Certainly for the science community it’s a huge disappointment. It’s taken so long to get here.”

Watch the launch video below:


A mishap investigation board has convened, and will endeavor to determine the cause of the failure. “We need to come to a most probably cause for this failure,” said NASA’s Expendable Launch Vehicle launch director Chuck Dovale. “Our goal will be to find a root cause, and we won’t fly the Glory mission until we have that data known to us.” Glory is the next Earth science mission, set to launch in June of 2009, and will collect data on aerosols and black carbon in the Earth’s atmosphere and climate system.

Orbiting Carbon Observatory (OCO) was intended to help target the key locations on our planet’s surface where CO2 is being emitted and absorbed. The project has been in the works for eight years.

NASA’s Expendable Launch Vehicle launch director Chuck Dovale said the countdown proceeded normally. “Stage zero ignition occurred at 1:55:31. All indications were nominal. The motor burned for 1 minute 24 seconds, then the first stage ignited. That proceeded normally, and burned 2 minutes and 43 seconds. Stage 1 separation occured five seconds later, and allowed second stage to ignite. At that point we expected to see fairing separate. We got indications that the sequence was sent, but shortly after that we started getting indication that the fairing did not separate.”

Brunschwyler explained how the fairing separates and what indications the team received about the anomaly.

“The fairing separates by a sequence of electrical pulses,” he said, “and the clamshell fairing is a two piece device that separates with four pulses from an electrical box, two primary pulses and two redundant pulses, which separate the longitudinal fairing rails, or the vertical part of the fairing. About 80 milliseconds later, the base joint is severed in a similar fashion. We have confirmation that correct sequence was sent. We had good power, and also healthy indications from electronics box that sent the signal. Three minutes into the flight, we had observed various pieces of telemetry, which we tried to correlate. When the fairing comes off, we have wires that break to give indication it has separated, but those indications did not change.”

There are also temperature sensors, but Brunschywler said the most significant data was no jump in acceleration from less weight if the fairing had properly separated.

“We constantly take altitude and velocity measurements. The vehicle didn’t fly over any land and all indications are it landed just short of Antarctica,” he said. “We’ll know a more accurate location tomorrow.” Brunschyler said since all the stages had burned, there shouldn’t be much, if any, hazardous hydrazine fuel left on board the rocket.

“OCO was an important mission to measure critical elements of the carbon cycle,” said Michael Freilich, director of NASA’s Earth Science Division. “Over the next several days, weeks and months we will carefully evaluate how to move forward and advance science, given our evaluations of the assets that are on orbit now, assets from our international partners and the existence of flight spares, in order to thoughtfully put together flight program, to as rapidly as possible to pick up where OCO left off and advance Earth systems science.”