Dragon 2

SpaceX Dragon 2

Dragon 2 spacecraft in a test chamber on top of the trunk.
Description
Role Placing humans and cargo into Low Earth orbit (commercial use)
and ISS commercial taxi CCtCap (government use), space colonization (planned)
Crew 7 (max. capacity)
Launch vehicle Falcon 9 Block 5 (into orbit)
Falcon Heavy (to the Moon)
Dimensions
Height 8.1 metres (27 ft) with trunk[1]
Diameter 3.7 metres (12 ft) with trunk[1]
Sidewall angle 15 degrees
Volume 10 m3 (350 cu ft) pressurized[2]
14 m3 (490 cu ft) unpressurized[2]
Dry mass about 6,400 kg (14,000 lb)[3]
Payload to ISS 3,310 kg (7,300 lb). It can return to Earth up to 2,500 kg (5,500 lb)[4]
Miscellaneous
Endurance 1 week to 2 years[2]
Re-entry at 3.5 G[5][6]
Thrusters 8 x SuperDraco positioned around the perimeter of the vehicle in 4 pairs called “jet packs”
and 18 in-space maneuvering Draco thrusters.
Propellant NTO/MMH[7]

Dragon 2 (also Crew Dragon, Dragon V2, or formerly DragonRider) is the second version of the SpaceX Dragon spacecraft, which will be a human-rated vehicle able to make a terrestrial soft landing.[8] It includes a set of four side-mounted thruster pods with two SuperDraco engines each, which can serve as a launch escape system (or launch abort system (LAS)) or potentially be used for propulsive landings. Also, it has much larger windows, new flight computers and avionics, and redesigned solar arrays, and a modified outer mold line from the initial cargo Dragon that has been flying for several years.[9]

The spacecraft was unveiled on May 29, 2014 during a press event at SpaceX headquarters in Hawthorne, California.[10][11][12] Designed to ferry astronauts to space, the capsule differs considerably from the cargo-carrying Dragon, which has been operational since 2010. Dragon 2 is scheduled to make an unmanned first orbital flight in March 2018,[13] and to carry its first astronaut crew in May 2018.[14] SpaceX completed a launch pad abort test of the spacecraft on 6 May 2015[15] and a hovering test on 24 November 2015.[16]

NASA has signed a contract to procure up to six crewed flights to the International Space Station under the Commercial Crew Development.

Dragon 2 development history

2012 DragonRider mockup, showing the launch escape system engines mounted on the outside of the capsule, when the design was not yet final.
Crewed version of Dragon CRS with powered vertical landing ability

The crewed variant of Dragon was initially called DragonRider.[17] It was intended from the beginning to support a crew of seven or a combination of crew and cargo.[18][19] It was planned to be able to perform fully autonomous rendezvous and docking with manual override ability; and was designed to use the NASA Docking System (NDS) to dock to the ISS.[20][21] For typical missions, DragonRider would remain docked to the ISS for a period of 180 days, but would be designed to be able to do so for 210 days, the same as the Russian Soyuz spacecraft.[22][23][24] From the earliest design concepts which were publicly released in 2010, SpaceX planned to use an integrated pusher launch escape system for the Dragon spacecraft, claiming several advantages over the tractor detachable tower approach used on most prior crewed spacecraft.[25][26][27] These advantages included the provision for crew escape all the way to orbit, reusability of the escape system, improved crew safety due to eliminating a stage separation, and the ability to use the escape engines during landings for a precise solid earth landing of the capsule.[28]

SpaceX originally intended to certify their propulsive landing scheme, in parallel with the parachute-to-water-landing method for Dragon 2, with the goal to hold to the development schedule and "ensure U.S. crew transportation safely and reliably in 2017." SpaceX announced that "land landing will become the baseline for the early post-certification missions" while precision water landing under parachutes was proposed to NASA as "the baseline return and recovery approach for the first few flights of Crew Dragon."[29] Thus the parachute system was initially anticipated to be only a backup system; due to the cancellation of propulsive landing, however, the parachute system will be used for all landings.[28]

As of 2011, the Paragon Space Development Corporation was assisting in developing DragonRider's life support system.[30] In 2012, SpaceX was in talks with Orbital Outfitters about developing space suits to wear during launch and re-entry.[31]

At a NASA news conference on 18 May 2012, SpaceX confirmed again that their target launch price for crewed Dragon flights is $160,000,000, 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.[32] This contrasts with the 2014 Soyuz launch price of $76,000,000 per seat for NASA astronauts.[33]

In October 2014, NASA selected the Dragon spacecraft as one of the candidates to fly American astronauts to the International Space Station under the Commercial Crew Program. SpaceX plans to use the Falcon 9 Block 5 launch vehicle for launching Dragon 2.[34][35][36]

Technical specifications

Dragon 2 includes the following features:[10][11]

The landing system was initially designed to accommodate three types of landing scenarios:

However, on July 19, 2017, Elon Musk announced that propulsive landing development had been halted and all landings would be under parachute. This also means that the Red Dragon project cannot land on Mars but in absence of confirmation it remains unclear whether those mission are indefinitely postponed, cancelled, or might be reworked to some different objective. The SuperDraco engines would still exist for aborts, but there would be no legs. The effort to qualify propulsive landing for safety as well as the lack of technology commonalities with their ultimate Interplanetary Transport System was given as a reason.[38]

The parachute system was fully redesigned from the one used in the prior Dragon capsule, due to the need to deploy the parachutes under a variety of launch abort scenarios.[37]

Planned space transport missions

Dragon has been designed to fulfill a set of mission requirements that will make the capsule useful to both commercial and government customers. SpaceX and Bigelow Aerospace are working together to support round-trip transport of commercial passengers to low Earth orbit (LEO) destinations such as the planned Bigelow Commercial Space Station. In that use, the full passenger capacity of seven passengers is planned to be used.

SpaceX competed for a contract with NASA to deliver some number of specific crew-transport missions to the ISS under the third phase of the Commercial Crew Development program.[10]

In an August 2014 presentation, SpaceX revealed that if NASA chooses to use the Dragon 2 space capsule under a Commercial Crew Transportation Capability (CCtCap, Commercial Crew Development) contract, then only four of the seven possible seats would be used for carrying NASA-designated passengers to the ISS, as NASA would like to use the added payload mass and volume ability to carry pressurized cargo. Also, all NASA landings of Dragon 2 are planned to initially use the propulsive deceleration ability of the Super Draco engines only for a propulsive assist right before final touchdown, and would otherwise use parachutes "all the way down."[37]

On September 16, 2014, NASA announced that SpaceX, together with Boeing, has been selected to provide crew transport ability to ISS. SpaceX will receive $2.6 billion under this contract.[39] NASA considers Dragon to be the cheapest proposal.[35]

In a departure from prior NASA practice during the first five decades of the space age, where NASA contracted with commercial firms to build spaceflight equipment and then NASA operated the spacecraft directly, NASA is purchasing space transport services from SpaceX with the Dragon 2 contract, and will leave the launch, transit, and operation of the spacecraft to SpaceX.[40]

According to Elon Musk in a question and answer session at the May 29, 2014 unveiling of the Dragon 2, the older version of Dragon will be used in tandem with Dragon 2 as a cargo ferry for coming years.

Following the Dragon 2 pad abort test in early May 2015, Musk revealed plans to use a variant of the Dragon 2 spacecraft—in conjunction with the Falcon Heavy launch vehicle—to transport science cargos across much of the solar system, in cislunar and inner solar system regions such as Mars in 2020 with the Red Dragon but also to outer solar system destinations such as Jupiter's moon Europa. Details include that SpaceX expects to be able to transport 2,000–4,000 kg (4,400–8,800 lb) to the surface of Mars, including a soft retropropulsive landing using SuperDraco thrusters following a limited atmospheric deceleration. For destinations with no atmosphere, the Dragon variant would omit the parachute and heat shield, and add propellant.[41] However, these plans were indefinitely postponed following the cancellation of propulsive landing development.[38]

Crewed Circumlunar Flight

On February 27, 2017, SpaceX CEO Elon Musk announced that the company will attempt to fly two private citizens on a free return trajectory around the moon in late 2018.[42] The Dragon 2 spacecraft would launch on the Falcon Heavy booster. The two private citizens, who have not yet been named, approached SpaceX about taking a trip around the moon, and have "already paid a significant deposit" for the cost of the mission, according to a statement from the company. The names of the two individuals will be announced later, pending the result of initial health tests to ensure their fitness for the mission, the statement said.[43] The two passengers would be the only people on board what SpaceX expects to be about a week-long trip around the moon, according to Musk, who spoke with reporters during a phone conference. "This would be a long loop around the moon. . .It would skim the surface of the moon, go quite a bit further out into deep space and then loop back to Earth," Musk said during the teleconference. "So I'm guessing, distance-wise, maybe [about 500,000 to 650,000 kilometers].[44] The Dragon spacecraft would operate, in large part, autonomously, but the passengers would have to train for emergency procedures. The Dragon 2 capsule will require some upgrades for the deep-space flight, but Musk said those would be limited mainly to installing a long-range communications system.

Flight testing

SpaceX is planning a program of four tests for the Dragon 2 that will include both a "pad abort" test, and an in-flight abort test, plus both an uncrewed robotic orbital flight to the ISS, and finally a 14-day crewed demonstration mission to the ISS in 2018.[45][46]

Dragon 2 spacecraft conducting a propulsive hover test
An infographic of the SpaceX Dragon 2 Pad Abort Test for the May 2015 test, produced by SpaceX

Pad abort test

In August 2014, it was announced that the pad abort test would occur in Florida, at SpaceX's leased pad at SLC 40. While a flight-like Dragon 2 and trunk were used for the pad abort test, they rested atop a truss structure for the test rather than a full Falcon 9 rocket. A crash test dummy embedded with a suite of sensors was placed inside the test vehicle to record acceleration loads and forces at the crew seat, while the remaining six seats were loaded with weights to simulate full-passenger-load weight.[37][40][47] The test objective was to demonstrate sufficient total impulse, thrust and controllability to conduct a safe pad abort.

The pad abort test was conducted successfully on 6 May 2015 at approximately 0900 Eastern Daylight Time (EDT). The vehicle splashed down safely in the ocean to the east of the launchpad 99 seconds later.[15] A fuel mixture ratio issue was detected after the flight in one of the eight SuperDraco engines, but did not materially affect the flight.[48] More detailed test results were to be subsequently analyzed by both SpaceX and NASA engineers.[49]

Crew Dragon Pad Abort Test Launch

Hovering test

On November 24, 2015, SpaceX conducted a test of Dragon 2's hovering abilities at the firm’s rocket development facility in McGregor, Texas. In a video published by the firm,[16] the spacecraft is shown suspended to a hoisting cable and igniting its SuperDraco engines. The capsule hovers in equilibrium for about 5 seconds, kept in balance by its 8 engines firing at reduced thrust to compensate exactly for gravity.

This video shows the second test of the two-part milestone under NASA’s Commercial Crew Development program. The first test, a short firing of the engines intended to verify a healthy propulsion system, was completed two days earlier on November 22.

Uncrewed orbital test flight

The first orbital test of Dragon 2 will be an uncrewed mission, designated SpX-DM1[40] and scheduled for March 2018.[50] The spacecraft will test the approach and automated docking procedures with the ISS, remain docked for a few weeks, then conduct the full re-entry, splashdown and recovery steps to qualify for a crewed mission. Life support systems will be monitored all along the test flight. The same capsule will be re-used later for an in-flight abort test.[14]

In-flight abort test

SpaceX plans to conduct an in-flight abort test from Kennedy Space Center Launch Complex 39A in Florida after the first uncrewed orbital test flight and prior to the first crewed test flight.[51] The test will be conducted with the refurbished capsule from the uncrewed test flight.[52] Earlier, this test had been scheduled before the uncrewed orbital test,[14] however SpaceX and NASA consider it safer to use the more recently designed capsule rather than the older test article from the pad abort test.[52]

The Dragon 2 test capsule will be launched in a sub-orbital flight to conduct a separation and abort scenario in the troposphere at transonic velocities, at Max Q, where the vehicle experiences maximum aerodynamic pressure.[53] The test objective is to demonstrate the ability to safely move away from the ascending rocket under the most challenging atmospheric conditions of the flight trajectory, imposing the worst structural stress of a real flight on the rocket and spacecraft.[37] The capsule will then splash down in the ocean with traditional parachutes, possibly with assistance of its integrated thrusters to smooth the final moments of the descent.

The in-flight abort capsule was originally planned to launch on F9R Dev2 before the Falcon 9 Full Thrust vehicle (and its densified propellants) made F9R Dev2 incompatible with both of SpaceX's active orbital launch pads. Then a special version of the Falcon 9 first stage with just three engines was prepared for this test and carried to the launch pad at Vandenberg in April 2015 to conduct a tanking test. It was erected on the revised and rebuilt transporter erector (TE) and fully loaded with propellants on 9 April 2015 to test both the vehicle and ground support equipment.[53] Those plans were later scrapped, and as of August 2016 it is not known which vehicle SpaceX will use for the in-flight abort test.

Crewed orbital test flight

As of December 2016, Dragon 2 was scheduled to carry its first crew, of two NASA astronauts, on a 14-day test flight mission to the ISS in May 2018.[54] If this schedule is followed they may be the first people to ride an American spacecraft into orbit since the last Shuttle flight in 2011,[14] as Boeing's CST-100 Starliner is currently slated to fly its first astronauts in August 2018.[54][55] However, with the uncrewed demonstration mission being delayed from November 2017 to March 2018,[50] the May 2018 date may also be delayed. NASA has named its first Commercial Crew astronaut cadre of four veteran astronauts to work with SpaceX and Boeing – Robert Behnken, Eric Boe, Sunita Williams, and Douglas Hurley.[56] The SpX-DM2 mission will complete the last milestone of the Commercial Crew Development program, paving the way to starting commercial services under an upcoming ISS Crew Transportation Services contract.[40][57]

See also

References

  1. 1 2 "Falcon 9". SpaceX. Retrieved 14 July 2017.
  2. 1 2 3 "DragonLab datasheet" (PDF). Hawthorne, California: SpaceX. 8 September 2009. Archived from the original (PDF) on 4 January 2011. Retrieved 19 October 2010.
  3. ↑ http://www.faa.gov/about/office_org/headquarters_offices/ast/media/DragonFly_Final_EA_sm.pdf
  4. ↑ "The ISS CRS contract (signed December 23, 2008)"
  5. ↑ Bowersox, Ken (25 January 2011). "SpaceX Today" (PDF). SpaceX. Retrieved 13 October 2011.
  6. ↑ Musk, Elon (17 July 2009). "COTS Status Update & Crew Capabilities" (PDF). SpaceX. Retrieved 16 April 2012.
  7. ↑ "The Annual Compendium of Commercial Space Transportation: 2012" (PDF). Federal Aviation Administration. February 2012. Retrieved 8 February 2013.
  8. ↑ Gwynne Shotwell (2014-03-21). Broadcast 2212: Special Edition, interview with Gwynne Shotwell (audio file). The Space Show. Event occurs at 24:05–24:45 and 28:15–28:35. 2212. Archived from the original (mp3) on 2014-03-22. Retrieved 2014-03-22. we call it v2 for Dragon. That is the primary vehicle for crew, and we will retrofit it back to cargo.
  9. ↑ Clark, Stephen (2014-10-09). "NASA clears commercial crew contractors to resume work". Spaceflight Now. Retrieved 2014-10-10. a highly-modified second-generation Dragon capsule fitted with myriad upgrades and changes – including new rocket thrusters, computers, a different outer mold line, and redesigned solar arrays – from the company's Dragon cargo delivery vehicle already flying to the space station.
  10. 1 2 3 4 Norris, Guy (2014-05-30). "SpaceX Unveils ‘Step Change’ Dragon ‘V2’". Aviation Week. Retrieved 2014-05-30.
  11. 1 2 Kramer, Miriam (2014-05-30). "SpaceX Unveils Dragon V2 Spaceship, a Manned Space Taxi for Astronauts — Meet Dragon V2: SpaceX's Manned Space Taxi for Astronaut Trips". space.com. Retrieved 2014-05-30.
  12. 1 2 Bergin, Chris (2014-05-30). "SpaceX lifts the lid on the Dragon V2 crew spacecraft". NASAspaceflight.com. Retrieved 2014-05-30.
  13. ↑ "Space Flight Now Launch Schedule". SpaceFlightNow. Retrieved May 30, 2017.
  14. 1 2 3 4 Foust, Jeff (February 4, 2016). "SpaceX seeks to accelerate Falcon 9 production and launch rates this year". SpaceNews. Retrieved March 21, 2016. Shotwell said the company is planning an in-flight abort test of the Crew Dragon spacecraft before the end of this year, where the vehicle uses its thrusters to separate from a Falcon 9 rocket during ascent. That will be followed in 2017 by two demonstration flights to the International Space Station, the first without a crew and the second with astronauts on board, and then the first operational mission.
  15. 1 2 Clark, Stephen (6 May 2015). "SpaceX crew capsule completes dramatic abort test". Spaceflight Now. Retrieved 14 May 2015.
  16. 1 2 Dragon 2 Propulsive Hover Test. SpaceX. 2016-01-21. Retrieved 2016-01-21.
  17. ↑ "Final Environmental Assessment for Issuing an Experimental Permit to SpaceX for Operation of the DragonFly Vehicle at the McGregor Test Site, McGregor, Texas" (PDF). faa.gov. Federal Aviation Administration. pp. 2–3. Retrieved 2014-08-22.
  18. ↑ "Q+A: SpaceX Engineer Garrett Reisman on Building the World's Safest Spacecraft". PopSci. 13 April 2012. Retrieved 15 April 2012. DragonRider, SpaceX's crew-capable variant of its Dragon capsule
  19. ↑ "SpaceX Completes Key Milestone to Fly Astronauts to International Space Station". SpaceX. 20 October 2011. Retrieved 9 May 2012.
  20. ↑ "Dragon Overview". SpaceX. Retrieved 16 April 2012.
  21. ↑ Parma, George (20 March 2011). "Overview of the NASA Docking System and the International Docking System Standard" (PDF). NASA. Retrieved 30 March 2012. iLIDS was later renamed the NASA Docking System (NDS), and will be NASA’s implementation of an IDSS compatible docking system for all future US vehicles
  22. ↑ Bayt, Rob (26 July 2011). "Commercial Crew Program: Key Driving Requirements Walkthrough". NASA. Retrieved 27 July 2011.
  23. ↑ Oberg, Jim (28 March 2007). "Space station trip will push the envelope". MSNBC. Retrieved 9 May 2012.
  24. ↑ Bolden, Charles (9 May 2012). "2012-05-09_NASA_Response" (PDF). NASA. Retrieved 20 June 2012.
  25. ↑ With the exception of the Project Gemini spacecraft, which used twin ejection seats: "Encyclopedia Astronautica: Gemini Ejection". Astronautix.com. Retrieved 24 January 2013.
  26. ↑ Chow, Denise (18 April 2011). "Private Spaceship Builders Split Nearly $270 Million in NASA Funds". New York: Space.com. Archived from the original on 18 December 2011. Retrieved 18 December 2011.
  27. ↑ "Spaceship teams seek more funding" Archived March 4, 2012, at the Wayback Machine.. MSNBC Cosmic Log. 10 December 2010. Retrieved 14 December 2010.
  28. 1 2 "SpaceX Updates – Taking the next step: Commercial Crew Development Round 2". SpaceX. 17 January 2010. Retrieved 17 January 2011.
  29. 1 2 3 4 5 6 Reisman, Garrett (27 February 2015). "Statement of Garrett Reisman, Director of Crew Operations, Space Explorations Technologies Corp. (SpaceX) before the Subcommittee on Space, Committee on Science, Space, and Technology, U.S. House Of Representatives" (pdf). science.house.gov. US House of Representatives, Committee on Science, Space, and Technology. Retrieved 28 February 2015. (document source: SpaceX)
  30. ↑ "In the news Paragon Space Development Corporation Joins SpaceX Commercial Crew Development Team". Paragon Space Development Corporation. 16 June 2011. Retrieved 15 April 2012.
  31. ↑ Sofge, Eric (19 November 2012). "The Deep-Space Suit". PopSci. Retrieved 19 November 2012.
  32. ↑ Star Wars: The Battle to Build the Next Shuttle: Boeing, SpaceX and Sierra Nevada. Bloomberg News. May 2014. Event occurs at 2:05. Retrieved 2014-05-06.
  33. ↑ "SpaceX scrubs launch to ISS over rocket engine problem". Deccan Chronicle. 19 May 2012. Retrieved 23 May 2012.
  34. ↑ http://www.spacex.com/news/2014/09/16/nasa-selects-spacex-be-part-americas-human-spaceflight-program
  35. 1 2 Norris, Guy. "Why NASA Rejected Sierra Nevada's Commercial Crew Vehicle" Aviation Week & Space Technology, 11 October 2014. Accessed: 13 October 2014. Archived on 13 October 2014
  36. ↑ Berger, Eric (9 June 2017). "So SpaceX is having quite a year". Ars Technica. Retrieved 9 June 2017.
  37. 1 2 3 4 5 Bergin, Chris (2014-08-28). "Dragon V2 will initially rely on parachute landings". NASAspaceflight.com. Retrieved 2014-08-29.
  38. 1 2 Elon Musk suggests SpaceX is scrapping its plans to land Dragon capsules on Mars The Verge July 19, 2017
  39. ↑ "NASA Chooses American Companies to Transport U.S. Astronauts to International Space Station". Retrieved 16 September 2014.
  40. 1 2 3 4 Bergin, Chris (2015-03-05). "Commercial crew demo missions manifested for Dragon 2 and CST-100". NASASpaceFlight.com. Retrieved 7 March 2015.
  41. ↑ Bergin, Chris (2015-05-11). "Falcon Heavy enabler for Dragon solar system explorer". NASASpaceFlight.com. Retrieved 12 May 2015.
  42. ↑ SpaceX Plans to Send 2 Tourists Around Moon in 2018
  43. ↑ SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year
  44. ↑ SpaceX to Fly Passengers On Private Trip Around the Moon in 2018
  45. ↑ SpaceX's first crewed launch moved back to 2018
  46. ↑ Space exploration technologies second SpaceX crew flight ordered by NASA
  47. ↑ Bergin, Chris (2015-04-03). "SpaceX preparing for a busy season of missions and test milestones". NASASpaceFlight.com. Retrieved 4 April 2015.
  48. ↑ "SpaceX Crew Dragon pad abort: Test flight demos launch escape system". CollectSpace. 6 May 2015. Retrieved 14 May 2015.
  49. ↑ Bergin, Chris (6 May 2015). "Dragon 2 conducts Pad Abort leap in key SpaceX test". NASASpaceFlight.com. Retrieved 6 May 2015.
  50. 1 2 https://spaceflightnow.com/launch-schedule/
  51. ↑ Richardson, Derek (30 July 2016). "Second SpaceX Crew Flight Ordered by NASA". Spaceflight Insider. Retrieved 9 August 2016. Currently, the first uncrewed test of the spacecraft is expected to launch in May 2017. Sometime after that, SpaceX plans to conduct and in-flight abort to test the SuperDraco thrusters while the rocket is traveling through the area of maximum dynamic pressure – Max Q.
  52. 1 2 Siceloff, Steven (2015-07-01). "More Fidelity for SpaceX In-Flight Abort Reduces Risk". NASA. Retrieved 2016-06-19. In the updated plan, SpaceX would launch its uncrewed flight test (DM-1), refurbish the flight test vehicle, then conduct the in-flight abort test prior to the crew flight test. Using the same vehicle for the in-flight abort test will improve the realism of the ascent abort test and reduce risk.
  53. 1 2 Bergin, Chris (10 April 2015). "SpaceX conducts tanking test on In-Flight Abort Falcon 9". NASASpaceFlight.com. Retrieved 11 April 2015.
  54. 1 2 "International Space Station Calendar". Spaceflight 101. 14 December 2016. Retrieved 22 December 2016.
  55. ↑ Foust, Jeff (May 12, 2016). "Boeing delays first crewed CST-100 flight to 2018". SpaceNews.
  56. ↑ http://www.collectspace.com/news/news-070915a-commercial-crew-astronauts.html
  57. ↑ Kramer, Miriam (27 January 2015). "Private Space Taxis on Track to Fly in 2017". Scientific American. Retrieved 27 January 2015.
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