Space Exploration Technologies (SpaceX) this week is set to begin prelaunch checks of the first fully operational Dragon spacecraft destined to be launched under NASA’s Commercial Orbital Transportation Services (COTS) program.
The demonstration will be the first of up to three COTS flights set up under plans made in 2006 designed to encourage private companies to develop commercial space transport capabilities.
The test flight, called COTS 1, follows the successful inaugural launch of the first Falcon 9 vehicle and a non-operational Dragon payload on June 4, and is a critical step on the path to proving the feasibility of commercial resupply to the International Space Station (ISS).
“We’re gearing up for the flight of the first operational Dragon and the second Falcon 9,” SpaceX chief executive and Chief Technical Officer Elon Musk says. “The vehicle’s upper and second stage are at the Cape in the hangar and the Dragon is about to arrive — so all three pieces will be in place.” The first stage arrived at Cape Canaveral Air Force Station’s Launch Complex 40 from SpaceX’s McGregor, Texas, test site in mid-July.
Checkout and integration is expected to be a thorough process as the Dragon “is an extremely sophisticated spaceship,” Musk says. “So over the next few months we will be doing a lot of prelaunch checkout, and as it’s the first time we will have done this, we’re being super careful.”
The operational Dragon is equipped with 18 SpaceX-developed Draco thrusters, each rated at around 100-lb. thrust. “These are capable of firing continuously or in short pulses,” Musk says, adding they will be tested to check maneuverability control functions in orbit as well as during descent.
The flight also will test the Dragon’s avionics, flight computers, guidance, navigation and control systems, back shell heat shield, re-entry and recovery systems. The Dragon vehicle is due to be recovered with a splashdown in the Pacific test range close to the Southern California coast after three orbits. “In the long term we intend to land back on land,” Musk says. “For the moment we are landing in the ocean because it is far too difficult to get FAA permission to land on land.” For land recovery, SpaceX is devising a Dragon configuration with four landing legs with shock absorbers or crushable cartridges.
SpaceX hopes to complete the checkout process by the end of September. “We’re looking at six to eight weeks,” Musk says, adding the launch window target could be from late September to early October.
A second operational Dragon is currently penciled in for a February 2011 launch, and will maneuver within six miles of the ISS, while a provisional third test will see the Dragon actually berth with the station. The California-based company has a $1.6 billion contract to fly 12 missions to the space station through 2016.
Dragon is a free-flying, reusable spacecraft being developed by SpaceX under NASA’s Commercial Orbital Transportation Services (COTS) program. Initiated internally by SpaceX in 2005, the Dragon spacecraft is made up of a pressurized capsule and unpressurized trunk used for Earth to LEO transport of pressurized cargo, unpressurized cargo, and/or crew members.
The Dragon spacecraft is comprised of 3 main elements: the Nosecone, which protects the vessel and the docking adaptor during ascent; the Spacecraft, which houses the crew and/or pressurized cargo as well as the service section containing avionics, the RCS system, parachutes, and other support infrastructure; and the Trunk, which provides for the stowage of unpressurized cargo and will support Dragon’s solar arrays and thermal radiators.
In December 2008, NASA announced the selection of SpaceX’s Falcon 9 launch vehicle and Dragon spacecraft to resupply the International Space Station (ISS) when the Space Shuttle retires. The $1.6 billion contract represents a minimum of 12 flights, with an option to order additional missions for a cumulative total contract value of up to $3.1 billion.
Though designed to address cargo and crew requirements for the ISS, as a free-flying spacecraft Dragon also provides an excellent platform for in-space technology demonstrations and scientific instrument testing. SpaceX is currently manifesting fully commercial, non-ISS Dragon flights under the name “DragonLab”. DragonLab represents an emergent capability for in-space experimentation.
Dragon Spacecraft with Solar Panels deployed
- Fully autonomous rendezvous and docking with manual override capability in crewed configuration
- 6,000 kg (13,228 lbs) payload up-mass to LEO; 3,000 kg (6,614 lbs) payload down-mass
- Payload Volume: 10 m3 (245 ft3) pressurized, 14 m3 (490 ft3) unpressurized
- Supports up to 7 passengers in Crew configuration
- Two-fault tolerant avionics system with extensive heritage
- Reaction control system with 18 MMH/NTO thrusters designed and built in-house; these thrusters are used for both attitude control and orbital maneuvering
- 1290 kg of propellant supports a safe mission profile from sub-orbital insertion to ISS rendezvous to reentry
- Integral common berthing mechanism, with LIDS or APAS support if required
- Designed for water landing under parachute for ocean recovery
- Lifting re-entry for landing precision & low-g’s
- Ablative, high-performance heat shield and sidewall thermal protection
To ensure a rapid transition from cargo to crew capability, the cargo and crew configurations of Dragon are almost identical, with the exception of the crew escape system, the life support system and onboard controls that allow the crew to take over control from the flight computer when needed. This focus on commonality minimizes the design effort and simplifies the human rating process, allowing systems critical to Dragon crew safety and ISS safety to be fully tested on uncrewed demonstration flights.
For cargo launches the inside of the spacecraft is outfitted with a modular cargo rack system designed to accommodate pressurized cargo in standard sizes and form factors. For crewed launches, the interior is outfitted with crew couches, controls with manual override capability and upgraded life-support.
In fulfillment of the COTS phase I contract, Dragon will perform three cargo demonstration missions:
|1||2010||5 hours||Launch and separate from Falcon 9, orbit Earth, transmit telemetry, receive commands, demonstrate orbital maneuvering and thermal control, re-enter atmosphere, and recover Dragon spacecraft|
|2||2011||5 days||ISS Fly-by. Dragon will approach to within 10 km of ISS and exercise the radio cross-link, demonstrating the ability of ISS crew to receive telemetry from Dragon and their ability to send a command to the spacecraft. After this primary objective is completed, Dragon will leave the vicinity of ISS and perform a comprehensive set of in-space check-outs before returning to earth.|
|3||2011||3 days||Full cargo mission profile including mate to ISS|