It looks like SpaceX's Falcon 9 rocket failed to deliver a secondary payload to its intended orbit during an otherwise successful Oct. 7 mission. The payload -- Orbcomm's prototype OG2 communications satellite -- was launched aboard NASA's first Cargo Re-Supply Services (CRS-1) mission, which sent the SpaceX Dragon cargo capsule on its way to service the International Space Station (ISS).
The launch, which took place Sunday evening at 8:35 pm EST from Cape Canaveral, Fla., marks the fourth flight of Falcon 9.
Although SpaceX deemed the CRS-1 launch a success, the Hawthorne, Calif.-based company says an engine anomaly occurred approximately one minute and 19 seconds into the mission. Initial data suggests that one of the rocket's nine Merlin engines, Engine 1, lost pressure suddenly and an engine shutdown command was issued.
Orbcomm says its OG2 satellite separated from the Falcon 9 launch vehicle at approximately 9:00 pm EST, but due to the engine anomaly, the rocket was prevented from performing a second burn for safety reasons associated with its primary mission.
"For this reason, the OG2 prototype satellite was deployed into an orbit that was lower than intended," Orbcomm said in an Oct. 8 statement. Orbcomm says the company and OG2 prime contractor Sierra Nevada Corp. are in contact with the spacecraft, and are assessing whether OG2's orbit can be raised using its on-board propulsion system.
In the meantime, Orbcomm says it still plans to launch 17 more OG2 satellites aboard two Falcon 9 missions in mid-2013 and 2014. The OG2 satellites "will be the primary payload on both of these two planned launches to directly insert the OG2 satellites into the operational orbit."
SpaceX, which addressed the engine anomaly in an Oct. 8 mission update, has so far said nothing about Orbcomm.
“We know the engine did not explode, because we continued to receive data from it. Panels designed to relieve pressure within the engine bay were ejected to protect the stage and other engines,” SpaceX said in the statement. “Our review of flight data indicates that neither the rocket stage nor any of the other eight engines were negatively affected by this event.”
SpaceX says the onboard flight computer did exactly what it was designed to do, which is recompute a new ascent profile in real time to ensure Dragon's entry into orbit.
“This was achieved, and there was no effect on Dragon or the cargo resupply mission,” the statement reads. “Falcon 9 is designed to handle an engine out situation and still complete its mission. No other rocket currently flying has this ability.”
Great news, though not necessarily for Orbcomm.
According to Jonathan's Space Report, a website that reports on space launches, OG2 was ejected at 0137 UTC into a 203x323 km orbit, instead of its planned 350x750 km insertion orbit.
“Orbcomm will not be able to get to its operational 750x750 km orbit but there's a chance they'll get a few month's of system tests out of it,” the report says, adding “a further small debris object has been cataloged in low orbit.”
It is worth noting that this is not the first time Falcon 9 has experienced an engine anomaly. During a Dec. 8, 2010 launch that orbited a Dragon qualification unit for NASA's Commercial Orbital Transportation Services (COTS) program, one of the rocket's engines experienced an "oxygen-rich shutdown," according to Ken Bowersox, a retired NASA astronaut and former SpaceX vice president for astronaut safety and mission assurance. Bowersox revealed the anomaly in a September 2011 interview with Space News shortly before leaving the company.
Falcon 9 also suffered an anomaly during its inaugural flight June 4, 2010, though flight data from the mission was never made public. The rocket appears to have experienced a slight roll at liftoff, visible in a video of the launch. And in a post-launch interview I did for Space News, SpaceX founder, CEO and CTO Elon Musk said he was surprised by a pronounced roll that occurred following the rocket's upper stage firing.
“We didn't expect the roll," Musk said, adding that it did not affect the payload's insertion vector and had no adverse impact on the mission.
It is also worth noting that next year SpaceX plans to fly an upgrade to the Falcon 9 rocket that will effectively replace the existing launch vehicle. They've cleverly dubbed it Falcon 9 v1.1, a name that suggests only minor modifications to the current version. But the upgrade will feature a new engine -- the Merlin 1D -- to be arranged in an octagonal, rather than the current tic-tac-toe configuration. The rocket will also be longer, to accommodate stretched fuel tanks, and incorporate a wider payload fairing, meaning v1.1 will bear little resemblance to the Falcon 9 of today.