Oct. 8, 2012 at 2:45 PM ET
Although SpaceX's Falcon 9 rocket successfully sent its Dragon cargo capsule toward the International Space Station, an engine failure and a less-than-nominal satellite deployment suggest that the company has some technical issues to resolve for future flights.
The California-based rocket company acknowledged soon after Sunday night's launch that one of the nine Merlin engines on the Falcon's first stage shut down, but the onboard computer recalculated the data for the other eight engines to get the Dragon in orbit and save the resupply mission.
Some observers pointed to SpaceX's long-range video of the ascent and pointed to what they thought was debris from an explosion. Today, SpaceX issued a statement saying that the engine didn't explode — but that protective panels were ejected because of the pressure loss associated with the shutdown:
"Approximately one minute and 19 seconds into last night's launch, the Falcon 9 rocket detected an anomaly on one first-stage engine. Initial data suggests that one of the rocket's nine Merlin engines, Engine 1, lost pressure suddenly and an engine shutdown command was issued. 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. Our review of flight data indicates that neither the rocket stage nor any of the other eight engines were negatively affected by this event.
"As designed, the flight computer then recomputed a new ascent profile in real time to ensure Dragon's entry into orbit for subsequent rendezvous and berthing with the ISS. This was achieved, and there was no effect on Dragon or the cargo resupply mission.
"Falcon 9 did exactly what it was designed to do. 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. No other rocket currently flying has this ability.
"It is worth noting that Falcon 9 shuts down two of its engines to limit acceleration to 5 G's even on a fully nominal flight. The rocket could therefore have lost another engine and still completed its mission.
"We will continue to review all flight data in order to understand the cause of the anomaly, and will devote the resources necessary to identify the problem and apply those lessons to future flights. We will provide additional information as it becomes available.
"Dragon is expected to begin its approach to the station on October 10, where it will be grappled and berthed by Akihiko Hoshide of the Japan Aerospace Exploration Agency and Expedition 33 Commander Sunita Williams of NASA. Over the following weeks, the crew will unload Dragon's payload and reload it with cargo to be returned to Earth. Splashdown is targeted for October 28."
There's a lingering question about the engine anomaly: What caused the sudden pressure loss?
Satellite in wrong orbit
Another question has yet to be fully resolved: What will happen to the Orbcomm OG2 telecommunication satellite, which rode into orbit as a secondary payload on the Falcon 9's second stage? The prototype satellite was supposed to be put into a highly inclined orbit after a second-stage restart, and serve as the first piece of a new 18-satellite telecom constellation.
On Sunday night, SpaceX said the satellite was "successfully deployed" — but Orbcomm acknowledged in a statement today that the satellite was deployed into the wrong orbit because of the engine anomaly. Here's the relevant excerpt:
"... Due to an anomaly on one of the Falcon 9’s first-stage engines, the rocket did not comply with a pre-planned International Space Station (ISS) safety gate to allow it to execute the second burn. For this reason, the OG2 prototype satellite was deployed into an orbit that was lower than intended. Orbcomm and Sierra Nevada Corp. engineers have been in contact with the satellite and are working to determine if and the extent to which the orbit can be raised to an operational orbit using the satellite’s on-board propulsion system.
"In mid-2013, Orbcomm plans to launch an additional eight OG2 satellites on a Falcon 9, which will be placed into orbits that are optimized to deliver the best coverage for the enhanced OG2 messaging services. The remainder of the constellation of 18 OG2 satellites is expected to be launched on a Falcon 9 in 2014. Orbcomm’s OG2 satellites will be the primary payload on both of these two planned launches to directly insert the OG2 satellites into the operational orbit."
Orbcomm's statement came after satellite-watcher Jonathan McDowell called attention to the fact that the satellite showed up in the Space-Track database as having a 203-by-323-kilometer orbit rather than the planned 350-by-750-kilometer orbit.
Looking on the bright side
Going forward, SpaceX should follow through on its pledge to "apply lessons to future flights," as it said in its statement. And skeptics should keep in mind that this is rocket science, which is "super-frickin'-damn-hard," to use SpaceX founder Elon Musk's words. It's a tribute to Musk's design that the Dragon's mission was unaffected by the loss of one rocket engine. On Sunday night, he pointed out in an email to NASA Watch that few if any other existing launch vehicles could have weathered that kind of problem: "I believe F9 is the only rocket flying today that, like a modern airliner, is capable of completing a flight successfully even after losing an engine."
What do you think? Does the Dragon's rise represent Falcon's finest hour, or do the problems point to a chink in SpaceX's armor? Feel free to weigh in with your comments below.
Update for 4:15 p.m. ET: I've updated SpaceX's previous update (which referred to an engine fairing) with the current update (which pointed to protective panels instead).
Update for 6:30 p.m. ET: I've added a link to the Orbcomm statement confirming that its OG2 satellite ended up in a lower-than-expected orbit.
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Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.