A SpaceX Falcon 9 rocket successfully boosted a space station cargo ship into orbit Saturday, but an unprecedented attempt to land the rocket's first stage on a barge stationed off the coast of Florida was not successful, ending with an apparent crash landing that prompted company founder Elon Musk to tweet: "close, but no cigar."
Recovering, refurbishing and relaunching rocket stages that otherwise would be thrown away is a major element in Musk's ambitious push to reduce the cost of spaceflight by operating a rocket company much like a commercial airline, re-flying boosters rather than building them from scratch for each flight.
In a series of tweets, Musk confirmed the first stage made it from the edge of space back down to the "autonomous spaceport drone ship" but said its velocity was apparently too high and the booster "landed hard. Close, but no cigar this time. Bodes well for the future tho."
He said the landing barge came through in good shape, but "some of the support equipment on the deck will need to be replaced." He added a few moments later: "Didn't get good landing/impact video. Pitch dark and foggy. Will piece it together from telemetry and ... actual pieces."
This was the company's third attempt to guide a Falcon 9 first stage booster through a controlled vertical descent back into the atmosphere following two successful ocean splashdowns. But Saturday's test marked the first attempt to actually land a booster, using a modified barge with a deck measuring 170 feet by 300 feet, as a platform.
The mission got underway at 4:47 a.m. EST (GMT-5) when the Falcon 9's nine Merlin 1D first stage engines thundered to life at Cape Canaveral Air Force Station. The 208-foot-tall rocket quickly climbed away from launch complex 40, arcing away to the northeast as it took off directly into the plane of the space station's orbit.
The launch originally was planned for December, but the flight was delayed three weeks because of problems encountered during an engine test firing and temperature constraints related to the space station's orbit. A launch try Tuesday was scrubbed less than 90 seconds before liftoff because of unusual readings from one of two second-stage engine steering actuators. The actuator was replaced, clearing the way for launch Saturday.
This time around, the countdown made it to zero without incident, and the climb out of the dense lower atmosphere appeared to go smoothly. Two minutes and 37 seconds after liftoff, the first stage engines shut down and the stage fell away, followed seconds later by ignition of a single Merlin engine powering the booster's second stage. The cargo ship was released into the planned preliminary orbit about 10 minutes after launch, kicking off a two-day flight to the International Space Station.
The first stage normally would have tumbled back into the lower atmosphere, breaking apart due to high temperatures and aerodynamic stresses, with surviving components crashing back into the Atlantic Ocean.
But this time around, the booster's flight computer was programmed to carry out three engine firings to adjust its trajectory and reduce its velocity, slowing the booster from about 2,900 mph to about 560 mph and then to a much more sedate 4.5 mph, deploying four landing legs shortly before touchdown.
The stage featured four deployable fins mounted around the upper end of the booster that could be repositioned in flight to help control the rocket's lift and orientation. The use of the fins, along with steering by the first stage engines, "will allow for precision landing -- first on the autonomous spaceport drone ship, and eventually on land," the company said in a blog post last month.
The company said "stabilizing the Falcon 9 first stage for re-entry is like trying to balance a rubber broomstick on your hand in the middle of a wind storm."
Going into the mission, Musk downplayed expectations, predicting just a 50 percent chance of success. It was not immediately known why the booster apparently landed with an higher-than-expected descent velocity. But after assessing the results of Saturday's attempt, SpaceX engineers are expected to try again on subsequent flights with the long-range goal of flying boosters back to the launch site for refurbishment and reuse.
"If commercial spaceflight is ever going to be anything like a 'normal' industry, fast turnaround and (relatively) low costs are imperative," Joan Johnson-Freese, professor of national security affairs at the U.S. Naval War College, told CBS News in an email exchange last month.
"Airplanes land ready to use again -- not requiring months of hanger time between flights," she said. "The analogy with recoverable rocket boosters isn't perfect, but it's close."
While the landing attempt marked a significant step toward what Musk calls "rapid reusability," the primary goal of the flight was putting the Dragon capsule on course for a rendezvous with the space station early Monday.
The launch marked the company's fifth operational resupply mission under a $1.6 billion contract with NASA calling for 12 space station cargo missions to deliver some 20 tons of equipment and supplies.
It was the first U.S. station supply flight since an Orbital Sciences Antares booster exploded seconds after liftoff Oct. 28. A Cygnus cargo ship making the company's third flight under a separate $1.9 billion contract was destroyed in the mishap.
Orbital's Antares rocket is now grounded pending a switch to different engines, leaving SpaceX as the only provider of U.S.-based resupply services. The Russians also launch supplies using unmanned Progress cargo ships, and larger Japanese HTV supply ships fly once every year or so.
But with Orbital out of action in the near term, the SpaceX flights are critical for sustaining the station's six-person crews. Space station Program Manager Mike Suffredini said a SpaceX failure in the months ahead, depending on its severity and the steps needed to recover, could force NASA to reduce the station's crew from six to three or, in a worst-case scenario, to briefly abandon the laboratory.
But he said the station always has enough supplies on board for four to six months of normal operation and that even with a second U.S. resupply failure, NASA and its partners would have months to decide on a course of action.
"In all cases, we have plenty of time to decide what to do next, figure out what we're really dealing with and then figure out how we want to react to it," he said.
The Dragon capsule that launched Saturday is loaded with more than 4,000 pounds of cargo in the ship's pressurized hold, along with a 1,000-pound atmospheric research instrument mounted in an unpressurized trunk section accessible by the lab's robot arm.
The Cloud Aerosol Transport System, or CATS, instrument will be extracted from the trunk later this month by the station's robot arm and mounted on a platform attached to the Japanese Kibo lab module.
Cargo packed into the Dragon capsule's pressurized compartment includes food, clothing and personal items for the station's crew, research equipment and spare parts along with high-priority items intended to replace cargo lost in the Antares launch failure in October, including a variety of student experiments.
Among the science gear is a fruit fly lab for studies of the immune system, a flatworm regeneration experiment to learn more about how the organisms replace damaged cells and an investigation to learn how proteins clump together in fibrous plaques like those believed to play a role in Alzheimer's disease.
If all goes well, the Dragon will catch up with the station early Monday, approaching from behind and below, pulling up to within about 30 feet and standing by while Expedition 42 commander Barry "Butch" Wilmore, operating the lab's robot arm, locks onto a grapple fixture.
Ground controllers then will take over arm operations, moving the Dragon capsule into position for berthing at the Earth-facing port of the forward Harmony module. Wilmore, assisted by European Space Agency astronaut Samantha Cristoforetti, will operate the common berthing mechanism, driving home motorized bolts to lock the spacecraft in place.
The Dragon is expected to remain attached to the station for about a month. After reloading the spacecraft with some 3,600 pounds of experiment samples, no-longer-needed gear and trash, the astronauts will release the capsule for a Feb. 10 splashdown in the Pacific Ocean southwest of San Diego.