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"DragonRider" redirects here. For other uses, see Dragon Rider.
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| Description | |
|---|---|
| Role | Placing humans and cargo into Low Earth orbit (commercial use)[1] ISS resupply (governmental use) |
| Crew | None (cargo variant) 7 (DragonRider variant) |
| Launch vehicle |
Falcon 9 v1.0 (Dragon C1–Dragon C4)[2] Falcon 9 v1.1 (Dragon C5–)[2] |
| Maiden flight | 8 December 2010 (launch of first orbital flight)[3] 22 May 2012 (launch of first cargo delivery flight to the ISS)[4] |
| Dimensions | |
| Height | 6.1 meters (20 feet)[5] |
| Diameter | 3.7 meters (12.1 feet)[5] |
| Sidewall angle | 15 degrees |
| Volume | 10 m3 (350 cu ft) pressurized[6] 14 m3 (490 cu ft) unpressurized[6] 34 m3 (1,200 cu ft) unpressurized with extended trunk[6] |
| Dry mass | 4,200 kg (9,300 lb)[5] |
| Payload | to ISS 3,310 kg (7,300 lb), which can be all pressurized, all unpressurized or anywhere in between. It can return to Earth 3,310 kg (7,300 lb), which can be all unpressurized disposal mass or up to 2,500 kg (5,500 lb) of return pressurized cargo[7] |
| Miscellaneous | |
| Endurance | 1 week to 2 years[6] |
| Re-entry at | 3.5 Gs[8][9] |
| Propellant | NTO/MMH[10] |
During its uncrewed maiden flight in December 2010, Dragon became the first commercially built and operated spacecraft to be recovered successfully from orbit.[3] On 25 May 2012, an uncrewed variant of Dragon became the first commercial spacecraft to successfully rendezvous with and be attached to the International Space Station (ISS).[11][12][13] SpaceX is contracted to deliver cargo to the ISS under NASA's Commercial Resupply Services program, and Dragon began regular cargo flights in October 2012.[14][15][16][17]
SpaceX is additionally developing a crewed variant of the Dragon called DragonRider. DragonRider will be able to carry up to seven astronauts, or some combination of crew and cargo, to and from low Earth orbit. SpaceX has received several U.S. Government contracts to develop its crewed variant, including a Commercial Crew Development 2 (CCDev 2)-funded Space Act Agreement in April 2011, and a Commercial Crew integrated Capability (CCiCap)-funded space act agreement in August 2012. The spacecraft's heat shield is furthermore designed to withstand Earth re-entry velocities from potential Lunar and Martian spaceflights.[18]
Contents
General characteristics
The spacecraft is launched atop a Falcon 9 booster.[23] The Dragon capsule is equipped with 18 Draco thrusters, dual-redundant in all axes: any two can fail without compromising the vehicle's control over its pitch, yaw, roll and translation.[20] During its initial cargo and crew flights, the Dragon capsule will land in the Pacific Ocean and be returned to the shore by ship.[24] SpaceX plans to eventually install deployable landing gear and use eight upgraded SuperDraco thrusters to perform a solid earth propulsive landing.[25][26][27]
The trunk section, which carries the spacecraft's solar panels and allows the transport of unpressurized cargo to the ISS, was first used for cargo on the SpaceX CRS-2 mission.
Name
SpaceX's CEO, Elon Musk, named the spacecraft after the 1963 song "Puff, the Magic Dragon" by Peter, Paul and Mary, reportedly as a response to critics who considered his spaceflight projects impossible.[28]Production
In December 2010, the SpaceX production line was reported to be manufacturing one new Dragon spacecraft and Falcon 9 rocket every three months. Elon Musk stated in a 2010 interview that he planned to increase production turnover to one Dragon every six weeks by 2012.[29] Composite materials are extensively used in the spacecraft's manufacture to reduce weight and improve structural strength.[30]By September 2013, SpaceX total manufacturing space had increased to nearly 1,000,000 square feet (93,000 m2) and the factory had six Dragons in various stages of production. SpaceX published a photograph showing the six, including the next four NASA Commercial Resupply Services (CRS) mission Dragons (CRS-3, CRS-4, CRS-5, CRS-6) plus the drop-test Dragon, and the pad-abort Dragon weldment for commercial crew.[31]
History
SpaceX began developing the Dragon spacecraft in late 2004.[32] In 2006, SpaceX won a contract to use the Dragon spacecraft for commercially supplied resupply services to the International Space Station for the American federal space agency, NASA.[33]NASA ISS resupply contract
In 2005, NASA solicited proposals for a commercial ISS resupply cargo vehicle to replace the then-soon-to-be-retired Space Shuttle, through its Commercial Orbital Transportation Services (COTS) development program. The Dragon spacecraft was a part of SpaceX's proposal, submitted to NASA in March 2006. SpaceX's COTS proposal was issued as part of a team, which also included MD Robotics, the Canadian company that had built the ISS's Canadarm2.
On 23 December 2008, NASA awarded a $1.6 billion Commercial Resupply Services (CRS) contract to SpaceX, with contract options that could potentially increase the maximum contract value to $3.1 billion.[38] The contract called for 12 flights to the ISS, with a minimum of 20,000 kg (44,000 lb) of cargo carried to the ISS.[38]
On 23 February 2009, SpaceX announced that its chosen heat shield material, PICA-X, had passed heat stress tests in preparation for Dragon's maiden launch.[39] PICA-X is reportedly ten times cheaper to manufacture than NASA's PICA heat shield material.[40]
The primary proximity-operations sensor for the Dragon spacecraft, the DragonEye, was tested in early 2009 during the STS-127 mission, when it was mounted near the docking port of the Space Shuttle Endeavour and used while the Shuttle approached the International Space Station. The DragonEye's LIDAR and thermal imaging capabilities were both tested successfully.[41][42] The COTS UHF Communication Unit (CUCU) and Crew Command Panel (CCP) were delivered to the ISS during the late 2009 STS-129 mission.[43] The CUCU allows the ISS to communicate with Dragon and the CCP allows ISS crew members to issue basic commands to Dragon.[43] In summer 2009, SpaceX hired former NASA astronaut Ken Bowersox as vice president of their new Astronaut Safety and Mission Assurance Department, in preparation for crews using the spacecraft.[44]
As a condition of the NASA CRS contract, SpaceX analyzed the orbital radiation environment on all Dragon systems, and how the spacecraft would respond to spurious radiation events. That analysis and the Dragon design – which uses an overall fault-tolerant triple-redundant computer architecture, rather than individual radiation hardening of each computer processor – was reviewed by independent experts before being approved by NASA for the cargo flights.[45]
Demonstration flights
NASA contracted for three test flights from SpaceX, but later reduced that number to two. The first Dragon spacecraft launched on its first mission – contracted to NASA as COTS Demo Flight 1 – on 8 December 2010, and was successfully recovered following reentry to Earth's atmosphere; the mission furthermore marked the second flight of the Falcon 9 launch vehicle.[48] The DragonEye sensor flew again on STS-133 in February 2011 for further on-orbit testing.[49] In November 2010, the Federal Aviation Administration (FAA) had issued a reentry license for the Dragon capsule, the first such license ever awarded to a commercial vehicle.[50]
The second Dragon flight, also contracted to NASA as a demonstration mission, launched successfully on 22 May 2012, after NASA had approved SpaceX's proposal to combine the COTS 2 and 3 mission objectives into a single Falcon 9/Dragon flight, renamed COTS 2+.[4][51] Dragon conducted orbital tests of its navigation systems and abort procedures, before being grappled by the ISS' Canadarm2 and successfully berthing with the station on 25 May to offload its cargo.[11][52][53][54][55] Dragon returned to Earth on 31 May 2012, landing as scheduled in the Pacific Ocean, and was again successfully recovered.[56][57]
On 23 August 2012, NASA Administrator Charles Bolden announced that SpaceX had completed all required milestones under the COTS contract, and was cleared to begin operational re-supply missions to the ISS.[58]
Operational flights
Dragon was launched on its first operational CRS-contract mission on 8 October 2012,[14] and completed the mission successfully on 28 October.[59]SpaceX CRS-2, the second CRS mission from SpaceX, was successfully launched on March 1, 2013. SpaceX CRS-3, SpaceX's third CRS mission, was launched on April 18, 2014 and has been berthed with the ISS since April 20, 2014.
Crewed development program
NASA Commercial Crew Development program
SpaceX was not awarded funding during the first phase of NASA's Commercial Crew Development (CCDev) milestone-based program. However, the company was selected on 18 April 2011, during the second phase of the program, to receive an award valued at $75 million to help develop its crew system.[65][66]Their CCDev2 milestones involve the further advancement of the Falcon 9/Dragon crew transportation design, the advancement of the Launch Abort System propulsion design, completion of two crew accommodations demos, full-duration test firings of the launch abort engines, and demonstrations of their throttle capability.[67]
SpaceX's launch abort system received preliminary design approval from NASA in October 2011.[68] In December 2011, SpaceX performed its first crew accommodations test; the second such test is expected to involve spacesuit simulators and a higher-fidelity crewed Dragon mock-up.[69][70] In January 2012, SpaceX successfully conducted full-duration tests of its SuperDraco landing/escape rocket engine at its Rocket Development Facility in McGregor, Texas.[71]
On 3 August 2012, NASA announced the award of $440 million to SpaceX for the continuation of work on the Dragon under CCiCap.[72] On 20 December 2013, SpaceX completed a parachute drop test in order to validate the new parachute design.[73] This involved carrying a 12,000 pounds (5,400 kg) Dragon test article by helicopter to an altitude of 8,000 feet (2,400 m) above the Pacific ocean.[74] The test article was released and intentionally forced into a tumble.[74] Dragon then released its two drogue parachutes, followed by its three main parachutes and splashed down into the ocean.[74] The test article was then retrieved by helicopter and returned to shore.[74]
In July 2013, SpaceX stated that a pad abort test is planned to occur no sooner than December 2013.[75] During this test, the Dragon capsule will use its abort engines to launch away from a test stand at Launch Complex 40.[76][77] It will travel to an altitude of 5,000 feet (1,500 m), deploy its parachutes, splashdown into the ocean and be recovered.[76][77] An in-flight abort is planned for no sooner than April 2014, which would see Dragon using its launch abort engines to escape from a Falcon 9 that is already in flight.[76][78] This test would occur at the point of worst-case dynamic loads, which is also when Dragon has the smallest performance margin for separation from its launch vehicle.[78]
As part of an optional milestone of CCiCap, the first crewed Dragon flight would occur no sooner than mid-2015.[78] This orbital flight would see Dragon being launched into a 200-nautical-mile (370-km) orbit. The first crewed mission is planned to last at least three days and be performed with a crew of three non-NASA personnel.[78] As part of another optional milestone, the first crewed Dragon flight to the ISS is planned to be launched no sooner than December 2015; this mission will also carry a non-NASA crew.[78]
Red Dragon
Main article: Red Dragon (spacecraft)
Red Dragon is a concept for a low-cost uncrewed Mars lander that would utilize a SpaceX Falcon Heavy
launch vehicle and a modified Dragon capsule to enter the Martian
atmosphere. The concept will be proposed for funding in 2013 as a NASA Discovery mission, for launch in 2018.[79][80] The mission would search for the biosignatures of past or present life on Mars. Red Dragon would drill about 1 meter (3.3 ft) underground in an effort to sample reservoirs of water ice known to exist in the shallow Martian subsurface.[79][80]A Dragon capsule is capable of performing all the entry, descent and landing (EDL) functions required to deliver payloads of 1 tonne (2,200 lb) or more to the Martian surface without using a parachute. Preliminary analysis shows that the capsule's atmospheric drag will slow it sufficiently for the final stage of its descent to be within the capabilities of its SuperDraco retro-propulsion thrusters.[79][80]
Mars One Dragon
The private Mars One colonization project developed an initial concept of using a 5-meter (16 ft)-diameter variant of Dragon, launched on a SpaceX Falcon Heavy rocket, to transport crew and cargo to the Martian surface.[citation needed]According to the Mars One 2014 timetable, the first launch would need to occur in July 2022, in preparation for the projected arrival of human colonists in 2025.[81] As of May 2013, they had no relationship with SpaceX,[82] and SpaceX has made no comment on any early Mars mission for any customers.
Design
Dragon CRS
For the ISS Dragon cargo flights, the ISS's Canadarm2 grapples its Flight-Releasable Grapple Fixture and berths Dragon to the station's US Orbital Segment using a Common Berthing Mechanism.[83] The CRS Dragon does not have an independent means of maintaining a breathable atmosphere for astronauts and instead circulates in fresh air from the ISS.[84] For typical missions, Dragon is planned to remain berthed to the ISS for about 30 days.[85]The CRS Dragon's capsule can transport 3,310 kg (7,300 lb) of cargo, which can be all pressurized, all unpressurized or anywhere in between. It can return to Earth 3,310 kg (7,300 lb), which can be all unpressurized disposal mass or up to 2,500 kg of return pressurized cargo, driven by parachute limitations. There is a volume constraint of 14 m3 (490 cu ft) trunk unpressurized cargo and 11.2 m3 (400 cu ft) of pressurized cargo (up or down).[7] The trunk was first used operationally on the Dragon's CRS-2 mission in March 2013.[86] Its solar arrays produce a peak power of 4 kW.[10]
The CRS Dragon design was modified beginning with the fifth Dragon flight on the SpaceX CRS-3 mission to the ISS in March 2014. While the outer mold line of the Dragon was unchanged, the avionics and cargo racks were redesigned in order to supply substantially more electrical power to powered cargo devices, including the GLACIER and MERLIN freezer modules for transporting critical science payloads.[87]
DragonLab
When used for non-NASA, non-ISS commercial flights, the uncrewed version of the Dragon spacecraft is called DragonLab.[19] It is reusable, free-flying, and capable of carrying both pressurized and unpressurized payloads. Its subsystems include propulsion, power, thermal and environmental control, avionics, communications, thermal protection, flight software, guidance and navigation systems, and entry, descent, landing, and recovery gear.[6] It has a total combined upmass of 6,000 kilograms (13,000 lb) upon launch, and a maximum downmass of 3,000 kilograms (6,600 lb) when returning to Earth.[6] As of April 2014, there are two DragonLab missions listed on the SpaceX launch manifest: one in 2016 and another in 2018.[88] The same two missions were listed on the SpaceX manifest in November 2011.[89] The Russian Bion satellites and the American Biosatellites once performed similar uncrewed payload-delivery functions.DragonRider
The Paragon Space Development Corporation is assisting in the development of DragonRider's life support system.[101] SpaceX is also in talks with Orbital Outfitters regarding the development of a spacesuit that would be worn during launch and re-entry.[102]
At a NASA news conference on 18 May 2012, SpaceX confirmed again that their target launch price for crewed Dragon flights is $140,000,000, or $20,000,000 per seat if the maximum crew of 7 is aboard, and if NASA orders at least four DragonRider flights per year.[103] This contrasts with the 2012 Soyuz launch price of $63,000,000 per seat for NASA astronauts.[104]
Dragon version 2
The version 2 Dragon spacecraft will be capable of land touchdowns.[105] It will include side-mounted thruster pods as well as much larger windows, and landing legs which extend from the bottom of the spacecraft. The Dragon v2 design was originally expected to be unveiled in 2013,[106] but has been moved to 2014.[105] On April 30th 2014 Elon Musk stated in his Twitter feed that an actual flight design (not a mock-up) of the Crew Dragon will be unveiled on May 29th 2014.Specifications
Uncrewed version
The following specifications are published by SpaceX for the non-NASA, non-ISS commercial flights of the refurbished Dragon capsules, listed as "DragonLab" flights on the SpaceX manifest. The specifications for the NASA-contracted Dragon Cargo were not included in the 2009 DragonLab datasheet.[6]- Pressure vessel
- 10 m3 (350 cu ft) interior pressurized, environmentally controlled, payload volume.[6]
- Onboard environment: 10–46 °C (50–115 °F); relative humidity 25~75%; 13.9~14.9 psia air pressure (958.4~1027 hPa).[6]
- Unpressurized sensor bay (recoverable payload)
- 0.1 m3 (4 cu ft) unpressurized payload volume.
- Sensor bay hatch opens after orbital insertion to allow full sensor access to the space environment, and closes prior to reentry to Earth's atmosphere.[6]
- Unpressurized trunk (non-recoverable)
- 14 m3 (490 cu ft) payload volume in the 2.3 m (7 ft 7 in) trunk, aft of the pressure vessel heat shield, with optional trunk extension to 4.3 m (14 ft 1 in) total length, payload volume increases to 34 m3 (1,200 cu ft).[6]
- Supports sensors and space apertures up to 3.5 m (11 ft 6 in) in diameter.[6]
- Power, telemetry and command systems
- Power: twin solar panels providing 1,500 W average, 4,000 W peak, at 28 and 120 VDC.[6]
- Spacecraft communications: commercial standard RS-422 and military standard 1553 serial I/O, plus Ethernet communications for IP-addressable standard payload service.
- Command uplink: 300 kbps.[6]
- Telemetry/data downlink: 300 Mbit/s standard, fault-tolerant S-band telemetry and video transmitters.[6]
Radiation tolerance
Dragon uses a "radiation-tolerant" design in the electronic hardware and software that make up its flight computers. The system uses three pairs of computers, each constantly checking on the others, to instantiate a fault-tolerant design. In the event of a radiation upset or soft error, one of the computer pairs will perform a soft reboot.[45] Including the six computers that make up the main flight computers, Dragon employs a total of 18 triple-processor computers.[45]See also
- Comparison of space station cargo vehicles
- List of human spaceflight programs
- Space Shuttle successors
- Comparable vehicles
- Automated Transfer Vehicle – a single-use, expendable cargo vehicle currently in use by the ESA
- Blue Origin orbital spacecraft – an American private biconic nose cone design vehicle
- CST-100 – a spacecraft being developed by Boeing, in collaboration with Bigelow Aerospace
- Cygnus spacecraft – a single-use, expendable cargo vehicle under development by Orbital Sciences Corporation
- Dream Chaser – a spaceplane being developed by Sierra Nevada Corporation
- H-II Transfer Vehicle – an expendable cargo vehicle currently in use by JAXA
- Orion Multi-Purpose Crew Vehicle – a beyond-low-Earth-orbit spacecraft being developed by Lockheed Martin for NASA
- Progress spacecraft – an expendable cargo vehicle currently in use by the Russian Federal Space Agency
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