Washington: Private US spaceflight company SpaceX has launched its sixth cargo mission to the International Space Station (ISS), but failed in an attempt to land a part of its Falcon 9 rocket on a ship in the Atlantic Ocean.
The California-based company's Dragon cargo ship, filled with over 1,950 kg of supplies and payload, lifted off at 4.10 p.m. aboard the Falcon 9 rocket from Cape Canaveral Air Force Station in the US state of Florida, Xinhua reported on Tuesday.
The world, however, would have been more interested in the precision landing of the Falcon 9 rocket's first stage, after it separated from the second stage, as part of a reusable-rocket test. The first stage, however, had a hard landing again.
"Rocket landed on drone ship, but too hard for survival," SpaceX CEO Elon Musk tweeted. "Looks like Falcon landed fine, but excess lateral velocity caused it to tip over post-landing."
SpaceX first attempted to land the rocket on the company's autonomous spaceport drone ship in January, but the attempt ended in a crash, with the rocket's steering fins running out of hydraulic fluid.
The company intended to go for it again in February, during the launch of a satellite called the Deep Space Climate Observatory, but high waves scrubbed the attempt.
At a pre-launch press conference on Sunday, SpaceX Vice President Hans Koenigsmann had put the chances of success this time around at 75 or 80 percent, but Musk said on Monday that the odds were still less than 50 percent.
The mission to deliver cargo to the ISS was, however, unaffected. If all goes as planned, the Dragon cargo ship will arrive at the space station on Friday for an expected five-week visit.
"We watched live!" Italian astronaut Samantha Cristoforetti aboard the ISS wrote on Twitter. "Amazing to think that in 3 days Dragon will be knocking on our door."
One of the interesting pieces of cargo on this run is an espresso machine, dubbed ISSpresso, for Cristoforetti and other space station crew members to make tea, coffee, broth or other hot beverages.
"Crew members may enjoy an ISSpresso beverage using specially designed space cups as part of the Capillary Beverage study -- an improvement to the standard drinking pouch with a straw," NASA said in a statement.
The agency said proving this technology in microgravity "may lead to new or improved brewing methods".
The $1.6-billion contract that SpaceX has with NASA, requires at least a dozen cargo delivery flights in all.
Besides SpaceX, NASA has also signed a deal with another private company called Orbital Sciences Corp. to supply the ISS with cargo.
Orbital's first two flights went smoothly, but the third one failed when the company's Antares rocket exploded seconds after liftoff in late October.