SpaceX was quick to acknowledge the first-stage engine anomaly that occurred when a sudden pressure loss without an explosion led to a shutdown command about 79 sec. into the nearly 10-min. ascent to orbit. But with Dragon speeding toward the ISS, SpaceX sought to accent the positive.
“Like the Saturn V [which experienced engine loss on two flights] and modern airliners, Falcon 9 is designed to handle an engine-out situation and still complete its mission,” SpaceX said on its website Oct. 8. “No other rocket currently flying has this ability.”
Notably absent from SpaceX's assessment of the launch mishap was any mention of OG2. But Nelson said Orbcomm knew the risks when it signed on for the Falcon 9 mission.
“Orbcomm requested that SpaceX carry one of their small satellites [weighing a few hundred pounds versus Dragon at over 12,000 pounds] on this flight so that they could gather test data before we launch their full constellation next year,” Nelson said Oct. 11. “The higher the orbit, the more test data they can gather, so they requested that we attempt to restart and raise altitude. NASA agreed to allow that, but only on condition that there be substantial propellant reserves, since the orbit would be close to the space station.”
Nelson said Orbcomm understood the orbit-raising maneuver was tentative. “SpaceX would not have agreed to fly their satellite otherwise, since this was not part of the core mission and there was a known, material risk of no altitude raise,” she said.
Whether there was a material risk of losing the spacecraft entirely just days after launch is unclear. Orbcomm did not return telephone queries by press time.
Shortly after the launch, Orbcomm said it was working with prime contractor Sierra Nevada Corp. to raise OG2's orbit using onboard propulsion, a workaround that probably would have depleted fuel reserves and potentially limited the spacecraft's service life to weeks. Following the spacecraft's deorbit, Orbcomm said it had “verified various functionality checkouts,” including power, attitude-control, thermal and data-handling, as well as the satellite's unique communications payload, which incorporates a highly reprogrammable software radio with common hardware. Orbcomm says the data will allow it to focus on completing and launching the OG2 satellites as the primary mission payloads on two planned Falcon 9 launches—the first in mid-2013 and the second in 2014—directly into their operational orbit.
“Had Orbcomm been the primary payload on this mission, as planned for the upcoming launches, we believe the OG2 prototype would have reached the desired orbit,” Orbcomm said in its Oct. 11 statement.
Under the terms of its $46.6 million agreement with SpaceX, Orbcomm planned to launch its 18 next-generation spacecraft atop six now-defunct Falcon 1e rockets, an enhanced version of the Falcon 1 light-launcher that suffered three failures before delivering Malaysia's RazakSat to low Earth orbit in July 2009.
When SpaceX shelved plans to continue operating the small-class Falcon 1e, OG2 payloads were shifted to the Falcon 9 manifest. Given the Falcon 9's advertised price of around $59 million per launch, Orbcomm is getting a bargain, despite the loss of OG2.