After a day's delay, SpaceX launched its robotic Dragon cargo craft to the International Space Station on Tuesday — and then brought the first stage of its Falcon 9 rocket down to a nearly successful landing on a floating platform.
Liftoff came at 4:10 p.m. ET from Cape Canaveral Air Force Station, almost exactly 24 hours after an earlier countdown was scrubbed when threatening clouds drifted too close to the launch pad.
Minutes after launch, the Dragon and the Falcon 9's second stage separated from the first stage and continued onward into space. Meanwhile, the first stage relit its rocket engines, decelerated from supersonic speeds and guided itself toward a landing on an "autonomous spaceport drone ship," stationed hundreds of miles off the Florida coast in the Atlantic.
SpaceX's billionaire founder, Elon Musk, reported in a tweet that the rocket landed on the drone ship, "but too hard for survival." Later, he tweeted that the Falcon "landed fine, but excess lateral velocity caused it to tip over post-landing."
Musk also reported that the Dragon was successfully en route to the space station, a view seconded by NASA. The Dragon is due to link up with the station on Friday.
This is the sixth of at least 12 cargo deliveries covered by a $1.6 billion contract between SpaceX and NASA. The mission's prime objective is to transport more than 4,300 pounds (1,950 kilograms) of supplies and payloads, including the first zero-G espresso machine to go into orbit.
The Italian-built ISSpresso device was supposed to be delivered to the space station in January, but the loss of an Orbital Sciences shipment in October forced a reordering of the delivery schedule.
NASA's deputy manager for the space station program, Dan Hartman, said the fancy coffeemaker is a commercial experiment that the space agency hopes will "boost spirits" during long-duration space missions.
Try, try again
SpaceX was also looking for a boost in its effort to make rockets reusable and drive the cost of spaceflight dramatically downward.
In January, an earlier Falcon 9 found its way to the deck — but the control system ran out of hydraulic fluid prematurely. As a result, the stage came down crooked and blew apart in a fiery blast. A second landing opportunity, in February, turned into an ocean splashdown test when SpaceX determined that the seas were too rough to use the platform.
Before Tuesday's launch, Musk said there was only a 50-50 chance that the third attempt would be completely successful — and SpaceX wound up on the wrong side of the odds this time around. But he estimated the chances of success by the end of the year at 75 to 80 percent, if only because there were so many opportunities to get it right.
The next opportunity could come as early as June, when the next Dragon shipment is due for launch to the International Space Station. Hans Koenigsmann, SpaceX's vice president for mission assurance, told reporters on Tuesday that the Falcon 9's autonomous landing procedure "needs more work in the next couple of missions."
Eventually, SpaceX plans to have rockets fly themselves back to land after launching space missions. The strategy is part of Musk's drive to reduce the cost of spaceflight to as little as 1 percent of what it is today — and blaze a trail for human settlements on Mars.
That aim may sound like science fiction, but Musk is capitalizing on the sci-fi appeal: He named the thruster-stabilized drone ship "Just Read the Instructions," which was a name that was used for one of the planet-sized drone spaceships in Iain M. Banks' Culture novels.