A SpaceX Falcon 9 rocket blasted off through thick fog in California to send an ocean science satellite on its way to orbit, then flipped around and tried to land itself on a platform floating in the Pacific Ocean.
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It found the target, but one of the rocket's landing legs didn't latch into place and the rocket tipped over, SpaceX founder Elon Musk wrote on Twitter. "At least the pieces were bigger this time," he said, with a photo of the landing aftermath. "Am optimistic about upcoming ship landing."
SpaceX had hoped to build on last month's stunningly successful rocket return to a landing pad in Florida with an ocean platform touchdown, part of Musk's ongoing quest to develop cheap, reusable rockets.
Landing on the ground saves the time, trouble and expense of dispatching a floating landing platform and support ships, but not all of SpaceX's rockets will have the spare fuel to make it back to the launch site.
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The company also is still waiting for environmental approval to bring its rockets back to its west coast launch site at Vandenberg Air Force Base, which is why SpaceX opted for an ocean landing attempt on Sunday.
The primary goal of the mission was to put the Jason-3 satellite into an 830-mile high orbit inclined 66 degrees relative to the equator. From that vantage point, the spacecraft, a joint venture of several U.S. and European agencies, will use its instruments to measure the height of the oceans to an accuracy of one inch.
The oceans are becoming ground zero in efforts to track and predict Earth's changing climate.
"With all the extra heat that's being absorbed by the ocean, the waters are expanding," said oceanographer Josh Willis, with NASA's Jet Propulsion Laboratory in Pasadena, Calif.
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Oceans also collect runoff water from melting glaciers and ice sheets, which also are reacting to warming temperatures, he added.
"These two things together cause global sea levels to rise ... That rise is really our most powerful tool for measuring human-caused climate change," Willis said.
Jason-3 is the fourth in s series of ocean science satellites, which also are used to predict severe weather events, such as this year's El Nino system, monitor tsunamis and track oil spills.