The SpaceX Dragon capsule in the grip of the robotic arm of the International Space Station (ISS) during a May 2012 test run. A fully-stocked Dragon will lift off tonight from Cape Canaveral on SpaceX's first official ISS supply mission. Photo: NASA
The mission's name – Commercial Resupply Services-1 – lacks the lyrical spirit of Friendship 7 or Apollo 11.
But someday, what SpaceX plans to do tonight might stand alongside the most significant moments in space travel.
It's also extremely important to laboratories filled with scientists eager to send experiments into space - and get them back.
SpaceX – the commercial space venture launched by entrepreneur and PayPal co-founder Elon Musk – is scheduled to launch its first resupply mission to the International Space Station (ISS). It's the first of a dozen planned missions for SpaceX under a $1.6 billion NASA contract signed in December 2008. And it's the first time a private company will have sent a supply ship into space.
If the weather at Florida's Cape Canaveral cooperates, and forecasters say there's a 60 percent chance that it will, a SpaceX Falcon 9 rocket topped with a Dragon capsule packed with a half-ton of supplies will blast off at 5:35 p.m. PDT Sunday.
Orbital resupply is the sort of stuff NASA used to do routinely when the space shuttle was flying. But the last shuttle to spend any time in the sky is now sitting at Los Angeles International Airport, literally a museum piece getting ready for display at the California Science Center in downtown LA.
Keeping the ISS well-stocked is now a job for SpaceX and other American commercial space ventures, as well as the occasional Russian, Japanese or European rocket.
A SpaceX spacecraft has already made this trip once before. On May 25, a nearly empty Dragon space capsule docked with the ISS and stayed attached for six days before returning to Earth with a cargo load for NASA.
The Dragon capsule that sails into orbit Sunday night will not only take supplies up to the ISS; when it leaves the ISS in late October, it will bring science experiments back to Earth. That includes 384 syringes of urine and 112 tubes of blood that astronauts on board the ISS have been collecting for more than a year.
Dr. Scott Smith – NASA's lead scientist at the Nutritional Biochemistry Lab at Johnson Space Center – needs those samples to continue a variety of tests into astronaut health and nutrition, including an examination of bone density loss that astronauts suffer while in space. The samples that the Dragon capsule will bring back to Earth will add to data NASA has already complied.
“My typical line is that it may be urine to you, but it's gold to us. There's a lot of science that comes out of this,” said Dr. Simon at a NASA science briefing at Cape Canaveral. “In fact, yesterday marked the sixth anniversary of our first blood collection on board the International Space Station.”
NASA is studying what effects long stretches in a zero gravity environment have on the human body. Knowing that is key to developing a diet and exercise regimen that will keep astronauts strong and healthy on long missions, like a trip to Mars.
Dr. Smith said his research team has learned a great deal about what it will take to do that, and it published some of its findings last month in the “Journal of Bone and Mineral Research.”
“Crew members that eat well, have good vitamin D status, that exercise hard, can maintain their bone mineral density,” said Dr. Smith. “We have shown for the first time in 51 years of human spaceflight significant progress in maintaining bone density.”
But Dr. Smith said there is much more still to learn, and the blood and urine that the Dragon capsule will bring back are vital to that effort. The Dragon itself is vital to science in space, too.
“We have not brought any samples back (from the ISS) since the last shuttle flight,” said Dr. Smith. “When NASA knew the shuttle was going to retire, we actually flew extra freezers to the space station to hold those samples so the crews could continue to collect them in orbit, knowing we would bring them back when we had a chance.”
“The novelty of SpaceX is that this is the first real return vehicle for this type of samples. Obviously, we can get the crew home on the (Russian space capsule) Soyuz, but the cargo capability of the Soyuz is extremely limited.”
Other science experiments on board the Dragon capsule is one that will examine the effects of microgravity on Candida albicans, a common yeast that can cause thrush or fungal nails in humans with compromised immune systems. The experiment will help researchers develop ways to prevent or treat infections in astronauts during long space flights.
Also among the items going up and coming back on the Dragon are a dozen student experiments that flew aboard the SpaceX capsule in May, but were not properly activated by the station crew. NASA offered this second chance.
SpaceX plans to do more than serve as NASA's supply truck. It aims to become the first private space venture to carry astronauts into orbit. It's modifying a Dragon capsule for human spaceflight. The target date for launch is 2015.
Twitter followers can keep track of Sunday's launch and supply mission with updates from @SpaceX. The official SpaceX mission hashtag is #Dragon.