Photo: SpaceX
SpaceX successfully completed its second mission to the International Space Station on Sunday when the Dragon spacecraft splashed down in the Pacific with more than 1,600 pounds of cargo. The mission was the first of 12 scheduled flights to the ISS under a NASA contract that has SpaceX delivering cargo through 2016. The flight marked a major milestone as it was the first time since the retirement of the space shuttle that scientists have been able to return a significant amount of research samples, including frozen blood.
“This historic mission signifies the restoration of America’s ability to deliver and return critical space station cargo,” SpaceX CEO and Chief Technical Officer Elon Musk said in a statement. “The reliability of SpaceX’s technology and the strength of our partnership with NASA provide a strong foundation for future missions and achievements to come.”
Yesterday’s return flight began in the morning when astronauts aboard the ISS used the station’s robotic arm to detach the Dragon and release it a few hours later. Following a series of short pulses from its Draco thrusters, the spacecraft entered a free-fly orbit as the SpaceX team in California waited until Dragon was in position for re-entry. At 2:28 p.m. EDT Dragon performed its longest burn of the thrusters in order to significantly slow it down so it would begin to fall back to Earth. A little less than an hour later the capsule splashed into the Pacific Ocean about 250 miles off the coast of southern California.
The spacecraft is on its way back to Los Angeles by boat where the time critical cargo will be delivered to NASA. Dragon will then be transported to McGregor, Texas, where it will be processed and inspected, similar to the last Dragon spacecraft we saw being taken apart at SpaceX’s rocket testing facility this summer.
This mission was the longest for SpaceX to date. After the Oct. 7 launch, Dragon spent 18 days berthed to the ISS. After an “off-nominal” ascent in which an engine had to be shut down, the Dragon successfully delivered 883 pounds of cargo to the ISS. After unloading the supplies – including some tasty ice cream – the astronauts then reloaded Dragon with 1,673 pounds of cargo for the flight back to Earth. Currently the Dragon is the only spacecraft capable of returning this much cargo.
The other transfer vehicles from Europe and Japan can be filled with cargo, but only items considered to be trash, as both vehicles burn up during re-entry. The Soyuz capsule can carry a small amount of supplies during its return flight, but almost all of the volume and mass carrying capability is reserved for human passengers.
In addition to the frozen blood samples, frozen urine samples are also being returned to researchers who hope to better understand the effects of long-term micro-gravity on the human body. Numerous other research samples are being returned, including plant seedlings grown in space, making up more than half of the total mass inside Dragon.
The next resupply mission is currently scheduled for January, but because of the engine issue during the launch of CRS-1, that date may slip as SpaceX and NASA investigate the issue.
“Analysis to date supports initial findings: the engine experienced a rapid loss of pressure and Falcon 9’s flight computer immediately commanded shutdown, as it is designed to do in such cases,” the company said in its statement.
SpaceX and NASA have agreed to delay the shipment of the Falcon 9 launch vehicle from its hangar in Texas where we saw it being assembled back in August, to the launch pad in Florida while the investigation continues.
At the same time Orbital Sciences delayed its planned resupply missions to the ISS until spring. The company hopes to make the first of its two NASA demonstration flights with the Antares rocket and Cygnus spacecraft by the end of the year. That date could also be postponed as Orbital Sciences had to stop all testing this week while hurricane Sandy makes an almost direct hit on its facilities at Wallops Island on the Virginia Coast.
Video: SpaceX/YouTube
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