By Mike Wall This story originally appeared on Space.com
A private unmanned space capsule designed to ferry cargo to the International Space Station is all set for a key demonstration flight tomorrow (Dec. 7).
The Dragon space capsule built by the California company Space Explorations Technologies (SpaceX) is poised to launch from a seaside pad at the Cape Canaveral Air Force Station in Florida during a nearly 3 1/2-hour launch window that opens tomorrow at about 9 a.m. The launch will test the spacecraft SpaceX plans to use to fulfill a $1.6 billion contract with NASA for 12 resupply flights after the agency's space shuttle fleet retires next year.SpaceX is one of two companies with contracts for commercial cargo deliveries to the station. The other company is Virginia-based Orbital Sciences, which plans to deliver supplies to the station using its new Taurus 2 rocket and unmanned Cygnus space vehicles. The first test flights for those spacecraft are slated for next year.
Space Dragon Debuts
Dragon will launch into orbit atop SpaceX's two-stage Falcon 9 rocket.
For this maiden flight, the Dragon capsule is expected to make as many as four orbits around Earth, showing the ability to transmit telemetry data, receive commands and maneuver, SpaceX officials have said. The Dragon capsule should then re-enter the atmosphere and make a water landing in the Pacific Ocean, after which SpaceX personnel will recover it by ship.
The entire operation should take about four or five hours, according to SpaceX CEO Elon Musk.
The Dec. 7 flight will be Dragon's first demonstration under NASA's Commercial Orbital Transportation Services program, or COTS, which aims to advance the capabilities of U.S. commercial spaceflight.
"As we move forward with our first demo flight under the COTS program, we look forward to helping jumpstart America's space program and secure our leadership position in space," Musk wrote in an October mission status update.
If all goes well, several more test flights are on the docket for Dragon vehicles and Falcon 9 rockets after tomorrow's debut mission. SpaceX could start delivering cargo to the station sometime next year, company officials have said. [Photos of first Falcon 9 launch]
For Dragon, the progress marks the culmination of a five-year journey, as SpaceX started developing the craft in 2005. Here's the skinny on the capsule, which could help spur a boom in private spaceflight:
Dragon: The Basics
The gumdrop-shaped Dragon capsule stands 9.5 feet (2.9 meters) tall and is about 11.8 feet (3.6 m) wide at its base. It weighs 9,260 pounds (4,200 kilograms).
The spacecraft is composed of three parts: A protective nose cone, a pressurized capsule for crew and/or cargo and an unpressurized trunk, which houses solar arrays and thermal radiators. The trunk can also hold cargo that doesn't need a pressurized environment.
Dragon can haul 13,228 pounds (6,000 kg) of payload up to Earth orbit and bring 6,614 pounds (3,000 kg) back down, according to SpaceX.
While the spacecraft will initially be used chiefly as an unmanned cargo vessel, SpaceX is developing a crewed version, which the company says could carry up to seven people on round trips to low-Earth orbit.
On its supply runs, Dragon will launch atop SpaceX's Falcon 9, a 180-foot-tall (55-m-tall) rocket that passed a big test of its own this summer. In June, a Falcon 9 carrying a Dragon mock-up made its maiden flight, reaching an orbit about 155 miles (250 kilometers) above Earth.
"The upcoming demonstration mission will launch from Cape Canaveral and should follow a flight plan nearly identical to the first Falcon 9 launch, but this time the Dragon spacecraft will separate from the second stage and will demonstrate operational communications, navigation, maneuvering and re-entry," Musk wrote.
This SPACE.com graphic gives some details about Dragon and the Falcon 9.
Eventually, Dragon capsules are expected to fly themselves to the space station, where astronauts aboard the orbiting lab will use the outpost's robotic arm to grapple the craft and attach it to a docking port. A similar process is used for Japanese cargo ships that visit the station.
For this test flight, however, the first Dragon capsule will stay well clear of the space station, and then test its re-entry capabilities and parachutes for a Pacific splashdown.
"Although it does not have wings like shuttle, the Dragon spacecraft is controlled throughout re-entry by the onboard Draco thrusters which enable the spacecraft to touchdown at a very precise location Â? ultimately within a few hundred yards of its target," Musk wrote in the recent update.
Tomorrow's demonstration flight will send the capsule toward splash down in the Pacific Ocean off the Southern California coast. But that's not how things will always go.
"While Dragon will initially make water landings, over the long term, Dragon will be landing on land," Musk wrote.
SpaceX began developing Dragon internally in 2005. In December 2008, NASA awarded the company a $1.6 billion dollar COTS contract to make a minimum of 12 supply flights to the space station using Dragon and the Falcon 9.
NASA also left the door open to add more missions, which could bring the value of the contract up to $3.1 billion, SpaceX officials have said.
Cygnus: Another Private Capsule
SpaceX isn't the only company NASA is counting on to resupply the space station. Orbital Sciences a $1.9 billion deal to make eight flights using the company's Cygnus capsule and Taurus 2 rocket, both of which are under development.
The first test flight of the Taurus 2 should come in 2011, according to company officials.
After that, Orbital plans to make a full demo run under its COTS contract, likely toward the end of 2011. During that second flight, a fully operational Cygnus capsule will dock with the station, Orbital Sciences officials have said.
"As it stands right now, we're about a year away," Barron Beneski, vice president of corporate communications for Orbital Sciences, told SPACE.com. "We have our nose to the grindstone, working hard to develop our system."
Next year will also be a busy one for SpaceX since the company's Dragon capsules will still have a few more hurdles left after tomorrow's test flight before they can begin hauling cargo to the International Space Station.
In 2011, Dragon capsules and Falcon 9 rockets are expected to make at least two more demonstration flights, according to SpaceX officials.
The first 2011 demo, which is expected to last five days, includes a space station flyby, during which a Dragon capsule should approach within 6 miles (10 km) of the station. The next demo should last about 3 days and will include an actual docking with the station.
In his update, Musk said he applauded last month's approval by the U.S. Congress of a new NASA authorization act that includes a larger role for commercial spaceflight efforts to provide transportation to low-Earth orbit.
"The bill sets NASA on an exciting course to focus on exploration beyond low-Earth orbit, while recognizing the valuable role American companies are ready to undertake in ending our reliance on Russia to carry our astronauts to the International Space Station," Musk wrote. "Investing in commercial crew transport will build on NASA's proud record of innovation and will create competition that will force companies to improve reliability, increase safety, and reduce costs."More Tech and Science Stories from Space.com