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en:Red Dragon

Red Dragon
Dati della missione
OperatoreSpaceX
DestinazioneMarte
EsitoCancellata
Piattaforma satellitareDragon 2
Proprietà del veicolo spaziale
Massa6,5 t
CostruttoreSpaceX
Elemento Wikidata assente · Manuale

Il Red Dragon è stato un progetto ideato tra il 2011 e il 2017 che prevedeva di usare una capsula Dragon 2 come un lander a basso costo per atterrare su Marte dopo averla lanciata con un Falcon Heavy.

L'obbiettivo primario della missione originaria era di testare le tecniche e le tecnologie rientro nell'atmosfera marziana utilizzando un equipaggiamento che un equipaggio umano avrebbe potuto realisticamente sfruttare. La serie di missioni su Marte avrebbero svolto un ruolo propedeutico al molto complesso programma di colonizzazione marziano proposto da SpaceX annunciato nel settembre del 2016. Un'ulteriore proposta era di riportare sulla Terra una capsula contenente campioni del suolo marziano.

Il programma è stato concepito nel 2011 come potenziale missione del programma NASA Discovery con lancio previsto non prima del 2022, e in svariati anni si è evoluto finché li sono stati negati i fondi per entrare tra le missioni che sarebbero state lanciate tra il 2013 e il 2015. Nell'aprile 2016 la SpaceX ha annunciato di aver firmato con la NASA per provvedere i servizi di lancio non prima del 2018. Nel febbraio 2017 la SpaceX ha però affermato che la missione era stata spostata a non prima del 2020, mentre nel luglio 2017 è arrivato l'annuncio della cancellazione della missione.

Development history modifica

SpaceX worked with NASA's Ames Research Center in 2011 to produce a feasibility study for a mission that would search for evidence of life on Mars (biosignatures), past or present.[1][2][3] SpaceX's Dragon version 1 capsule is used to ferry cargo, and Dragon 2 is proposed to carry astronauts to and from the International Space Station in the future. The Red Dragon proposal called for modifications so it could be used to transport payload to Mars,[1] land using retrorockets, and to become a precursor to a human mission to Mars.[4][5]

2011 concept modifica

SpaceX initially planned to propose Red Dragon for funding in 2013 and 2015 as the United States NASA Discovery mission #13 for launch in 2022,[6][4][5] but it was not submitted.

The 2011 Red Dragon concept was conceived to use a modified 3,6 metri (12 ft)[converti: opzione non valida] diameter Dragon module, with a mass of 6,5 tonnellate (14 000 lb) and an interior volume of 7 metri cubi (250 cu ft) for up to 1 tonnellata (2 200 lb)[converti: opzione non valida] of Mars-landed payload.[3] The instruments were proposed to drill approximately 1,0 metro (3,3 ft) under ground to sample reservoirs of water ice known to exist in the shallow subsurface. The mission cost was projected in 2011 to be less than US$400 million,[4] plus $150 million to $190 million for a launch vehicle and lander.[2][5]

The goals for a NASA-funded mission, as originally proposed by NASA Ames Research Center, were:

Scientific goals[2]
  • Search for evidence of life (biosignatures), past or present
  • Assess subsurface habitability
  • Establish the origin, distribution, and composition of ground ice
  • Understand past climate using ground ice record
Human precursor goals[2]
  • Conduct human-relevant entry, descent and landing (EDL) demonstrations
  • Assess potential hazards in dust, regolith, and ground ice
  • Characterize natural resources
  • Demonstrate access to subsurface resources
  • Conduct in-situ resource utilization (ISRU) demonstration: water extraction and propellant production

2014 concept modifica

A 2014 study of a potential 2021 NASA-funded Red Dragon mission suggested that it could offer a low-cost way for NASA to achieve a Mars sample return. In the concept, the Red Dragon capsule would be equipped with the system needed to return samples gathered on Mars, including a Mars Ascent Vehicle (MAV), an Earth Return Vehicle (ERV), and hardware to transfer the sample collected by a previously landed rover mission, such as NASA's planned Mars 2020 rover, to the ERV.[1][7] The ERV would transfer the samples to high Earth orbit, where a separate future mission would pick up the samples and de-orbit to Earth.[1] NASA did not fund either concept.

2016 concept modifica

Over time, the Red Dragon concept changed but the basic idea was: use a modified Dragon capsule to test developmental technologies with an uncrewed mission to Mars. The launch vehicle would be the Falcon Heavy, and the capsule would be a Dragon 2. In April 2016, SpaceX announced that they were proceeding with the robotic mission for a 2018 launch[8] and NASA would be providing technical support:[9] a departure from the original NASA-funded mission.

SpaceX is planning the initial Falcon Heavy rocket launch for late 2017 and Dragon 2 is scheduled to undergo flight tests in mid to late 2017.[10] In April 2016, SpaceX reiterated their plan for a 2018 launch to Mars.[11][12]

The first Red Dragon mission was intended as a technology demonstrator and no payload was announced.[13][14] NASA would have been involved in the mission at the level of technical interchange.[11] In exchange for Martian entry, descent, and landing data from SpaceX, NASA offered technical support and telemetry for the Red Dragon mission.[9][12] In 2016, NASA anticipated spending about $30 million of its public budgetary funds for employees and equipment to be used to monitor the mission.[15] In May 2017, NASA revealed that SpaceX would launch twin Red Dragons to assure mission success with redundant spacecraft as insurance, one at the beginning of the 2020 launch window and one at the end, so that the second arrival can learn from the first's arrival,[16] but in July 2017 the mission was halted in favor of using a larger lander yet to be described.[17]

2017 cancellation modifica

SpaceX announced in 2017 that propulsive landing for Dragon 2 would no longer be developed and landing legs would not be added to the Dragon 2 capsule. The end of propulsive landing development means a Dragon will not be able to land on Mars,[2] and the Red Dragon program has been put on the back burner.[18] Musk stated on Twitter that a "vastly bigger ship" would be used to test a different landing method now thought to be better than the concept of heat shield on the bottom and thrusters on the sides.[17] SpaceX is redirecting engineering development resources to develop the propulsive landing technologies for the much larger ship.[19]

Sistema di atterraggio modifica

Thanks to its design integrating a robust heat shield and powerful thrusters, a modified Dragon 2 capsule might, with further development, have been able to perform all the necessary entry, descent and landing (EDL) functions in order to deliver payloads of 1 tonnellata (2 200 lb) or more to the Martian surface without using a parachute; the use of parachutes is not feasible without significant vehicle modifications.[2]

After direct entry into the atmosphere at 6.0 km/s[20] it was calculated that the capsule's own aerodynamic drag may slow it sufficiently for the remainder of descent to be within the capability of the SuperDraco retro-propulsion thrusters.[1] It could be designed with a center of gravity (CG) offset to enter with a Lift-to-drag ratio of 0.24 (like Mars Science Laboratory). The CG offset could be removed by ejecting 120 kg of ballast mass.[20] It would transition directly from atmospheric flight to powered descent at Mach 2.24.[20] The retrorockets would slow the craft as it descends into Mars' upper atmosphere at supersonic speed. 1900 kg of propellant would provide the Δv required for soft landing at 2.4 m/s.[20]

This approach was expected to allow the capsule to land at much higher Martian elevations than could be done with a parachute, and within 10 km (6,2 mi) landing accuracy.[3] Template:As of the SpaceX engineering team was developing options for payload integration with the Dragon capsule.[5] Potential landing sites would have been polar or mid-latitude sites with proven near-surface ice.[2]

In July 2017 Musk announced that development of propulsive landing had ceased in favor of a "much better" landing technique, as yet unrevealed, for a larger spacecraft not derived from the Dragon capsule.[17]

Note modifica

  1. ^ a b c d e Leonard David, Project 'Red Dragon': Mars Sample-Return Mission Could Launch in 2022 with SpaceX Capsule, in Space.com, 7 March 2014. URL consultato l'8 March 2014.
  2. ^ a b c d e f g Feasibility of a Dragon-derived Mars lander for scientific and human-precursor investigations, 8m.net, October 31, 2011.
  3. ^ a b c M. R. Grover E. Sklyanskiy, RED DRAGON-MSL HYBRID LANDING ARCHITECTURE FOR 2018 (PDF), in Jet Propulsion Laboratory, NASA, February 2012. URL consultato il 4 July 2012.
  4. ^ a b c Mike Wall, 'Red Dragon' Mission Mulled as Cheap Search for Mars Life, July 31, 2011. URL consultato il 1º May 2012.
  5. ^ a b c d NASA ADVISORY COUNCIL (NAC) - Science Committee Report (PDF), in Ames Research Center, NASA, 1º November 2011. URL consultato il 1º May 2012.
  6. ^ Spacex Dragon lander could land on Mars with a mission under the NASA Discovery Program cost cap. 20 June 2014.
  7. ^ Mike Wall, 'Red Dragon' Mars Sample-Return Mission Could Launch by 2022, in Space.com, 10 September 2015. URL consultato il 20 settembre 2015.
  8. ^ SpaceX, Planning to send Dragon to Mars as soon as 2018. Red Dragons will inform overall Mars architecture, details to come (Tweet), su Twitter, April 27, 2016.
  9. ^ a b Exploring Together, su blogs.nasa.gov. URL consultato il 27 April 2016.
  10. ^ Lisa Grossman, SpaceX claims it can get to Mars by 2018 – what are its chances?, in New Scientist, 28 April 2016. URL consultato il 28 aprile 2016.
  11. ^ a b Christian Davenport, Elon Musk provides new details on his ‘mind blowing’ mission to Mars, in Washington Post, 13 giugno 2016. URL consultato il 14 giugno 2016.
  12. ^ a b Nadia Drake, SpaceX Plans to Send Spacecraft to Mars in 2018, in National Geographic News, April 27, 2016. URL consultato il 28 aprile 2016.
  13. ^ Sid Perkins, Elon Musk's path to Mars begins with Red Dragon—but what science will it do?, in Science Magazine, 27 September 2016. URL consultato il 29 settembre 2016.
  14. ^ Frank Morring, NASA May Pay Elon Musk To Land Scientific Instruments On Mars, in Aviation Week & Space Technology, 29 June 2016. URL consultato il 29 settembre 2016.
  15. ^ NASA Outlines Mars 'Red Dragon' Deal With SpaceX, su aviationweek.com. URL consultato il 14 May 2016.
  16. ^ Agamoni Ghosh, Nasa says SpaceX may send two Red Dragon spacecraft to Mars in 2020 in case one fails, International Business Times, 11 May 2017.
  17. ^ a b c Loren Grush, Elon Musk suggests SpaceX is scrapping its plans to land Dragon capsules on Mars, in The Verge, July 19, 2017.
  18. ^ Stephen Clark, SpaceX informed NASA of slowdown in its commercial Mars program, in SpaceFlightNow, August 18, 2017. URL consultato il August 18, 2017.
  19. ^ http://www.teslarati.com/spacex-skipping-red-dragon-vastly-bigger-ships-mars-confirms-musk/ http://www.teslarati.com/spacex-skipping-red-dragon-vastly-bigger-ships-mars-confirms-musk/
  20. ^ a b c d Red Dragon-MSL Hybrid Landing Architecture for 2018 Concepts and Approaches for Mars Exploration, held June 12–14, 2012 in Houston, Texas. LPI Contribution No. 1679, id.4216

Voci correlate modifica

Collegamenti esterni modifica

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