Jump to content

Development of the Commercial Crew Program

From Wikipedia, the free encyclopedia
(Redirected from Commercial Crew Development)

Starting from top image: the Boeing CST-100 Starliner, Crew Dragon, Dream Chaser, and at bottom human-rated Atlas V projects all received developmental funding through CCDev awards and contracts

Development of the Commercial Crew Program (CCDev) began in the second round of the program, which was rescoped from a smaller technology development program for human spaceflight to a competitive development program that would produce the spacecraft to be used to provide crew transportation services to and from the International Space Station (ISS). To implement the program, NASA awarded a series of competitive fixed-price contracts to private vendors starting in 2011. Operational contracts to fly astronauts were awarded in September 2014 to SpaceX and Boeing, and NASA expected each company to complete development and achieve crew rating in 2017.[1] Each company performed an uncrewed orbital test flight in 2019.

Both commercial Crew vehicles Crew Dragon and Starliner docked to ports on Harmony module at the same time

SpaceX's Crew Dragon Demo-1 2019 flight of Dragon 2 arrived at the International Space Station in March 2019 and returned via splashdown in the Atlantic Ocean. After completion of its test series, a Crew Dragon spacecraft made its first operational Commercial Crew Program flight, SpaceX Crew-1. The flight launched on November 16, 2020.[2] As of September 2023 SpaceX has completed seven successful CCP flights with another, SpaceX Crew-8, currently in progress.[needs update] It is contracted with NASA for fourteen operational flights total to the ISS.

The 2019 Boeing Orbital Flight Test of the CST-100 Starliner spacecraft failed to reach the ISS in December 2019. The second test flight, Boeing Orbital Flight Test 2, occurred successfully in May 2022.[3][4][5] Pending completion of its demonstration flights, Boeing is contracted to supply six operational flights to the ISS.[6] The first group of astronauts was announced on August 3, 2018.[7] The first Starliner crewed flight test launched on June 5, 2024.[8] Starliner successfully docked with the station on June 6, 2024, after suffering several helium leaks and thruster malfunctions.[9][10][11] Due to these issues Starliner’s return to earth was delayed initially to June 26, 2024, then indefinitely.[12][13] On August 24, 2024 NASA administrator Bill Nelson made the decision to send the Starliner crew back home on SpaceX’s Crew Dragon.[14]

Commercial Crew Program vehicles Starliner and Dragon

Requirements

[edit]

Key high-level requirements for the Commercial Crew vehicles include:

  • Safely deliver and return four crew members and their equipment to the International Space Station (ISS)[15][16]
  • Provide assured crew return in the event of an emergency[15]
  • Serve as a 24-hour safe haven in the event of an emergency[15][16]
  • Capable of remaining docked to the station for 210 days[15][16]

Background

[edit]

After the retirement of STS in 2011 and the cancellation of the Constellation program, NASA had no domestic vehicles capable of launching astronauts to space.[17] Artemis, NASA's next major human spaceflight initiative, was scheduled to launch an uncrewed qualification flight in 2016, with an Orion spacecraft atop a Space Launch System (SLS) booster. The NASA had no human-qualified spacecraft available, and in any event SLS/Orion would be too expensive for routine flights to the ISS. In the meantime, NASA continued to send astronauts to the ISS on Soyuz spacecraft seats purchased from Russia.[18] The price varied over time, with the batch of seats from 2016 to 2017 costing $70.7 million per passenger per flight.[19] Artemis continued to slip, with the first uncrewed test flight scheduled for 2022.[20]

Development Program

[edit]

The CCDev program was initiated to develop safe and reliable commercial ISS crew launch capabilities to replace the Soyuz flights. CCDev followed Commercial Orbital Transportation Services (COTS), an ISS commercial cargo program.[21] CCDev contracts were issued for fixed-price, pay-for-performance milestones.[22] CCDev was implemented in several phases. CCDev 1 contracts were for development of concepts and technologies. CCDev 2 contracts were for actual vehicle designs. CCiCap contracts were for designs of complete end-to-end crew transportation hardware and services. CPC phase 1 contracts were for the development of a full certification plan. Finally CCtCap contracts were awarded for actual demonstration of crewed transportation services, which included development, testing, and production of the required hardware followed by operational flights to the ISS.

CCDev 1

[edit]
Construction of the Starliner pressure vessel was one of Boeing's CCDev 1 milestones

Commercial Crew Development phase 1 (CCDev 1) consisted of $50 million awarded in 2010 to five US companies to develop human spaceflight concepts and technologies.[21][23][24] NASA awarded development funds to five companies under CCDev 1:

CCDev 2

[edit]
The construction of a Dragon crew mock-up was one of SpaceX's CCDev 2 milestones[disputeddiscuss]

On April 18, 2011, NASA awarded nearly $270 million to four companies for developing U.S. vehicles that could fly astronauts after the Space Shuttle fleet's retirement.[30] Funded proposals:[31]

Proposals selected without NASA funding:

Proposals not selected:

CCiCap

[edit]
Flight testing of the Dream Chaser Engineering Test Article was one of Sierra Nevada's CCiCap milestones[disputeddiscuss]

Commercial Crew integrated Capability (CCiCap) was originally called CCDev 3.[46] For this phase of the program, NASA wanted proposals to be complete, end-to-end concepts of operation, including spacecraft, launch vehicles, launch services, ground and mission operations, and recovery. In September 2011, NASA released a draft request for proposals (RFP).[47] The final RFP was released on February 7, 2012, with proposals due on March 23, 2012.[48][49] The funded Space Act Agreements were awarded on August 3, 2012, and amended on August 15, 2013.[50][51]

The selected proposals were announced August 3, 2012:

CPC phase 1

[edit]

The first phase of the Certification Products Contract (CPC) involved the development of a certification plan with engineering standards, tests, and analyses.[52] Winners of funding of phase 1 of the CPC, announced on December 10, 2012, were:[52]

  • Sierra Nevada Corporation: $10 million
  • SpaceX: $9.6 million
  • Boeing: $9.9 million

CCtCap – crew flights awarded

[edit]

The Commercial Crew Transportation Capability (CCtCap) is the second phase of the CPC and included the final development, testing and verifications to allow crewed demonstration flights to the ISS.[52][53] NASA issued the draft CCtCap contract's Request For Proposals (RFP) on July 19, 2013, with a response date of August 15, 2013.[53] On September 16, 2014, NASA announced that Boeing and SpaceX had received contracts to provide crewed launch services to the ISS. Boeing could receive up to US$4.2 billion, while SpaceX could receive up to US$2.6 billion.[1] Dragon was the less expensive proposal, but NASA's William H. Gerstenmaier considered the Boeing Starliner proposal the stronger of the two.[54] In November 2019 NASA published a first cost per seat estimate: US$55 million for SpaceX's Dragon and US$90 million for Boeing's Starliner. Boeing was also granted an additional $287.2 million above the fixed price contract. Seats on Soyuz had an average cost of US$80 million.[55] However, adjusting for the additional cargo carried by Boeing's Starliner inside its crew capsule, the adjusted cost per seat figure is approximately $70 million, which is still higher than SpaceX's Crew Dragon even if the Dragon does not carry the equivalent of a fifth passenger in cargo.[56] Both the CST-100 Starliner and Crew Dragon were to fly an uncrewed flight, then a crewed certification flight, then up to six operational flights to the ISS.[57][58]

Timeline

[edit]
Commercial Crew Program

Ongoing delays

[edit]

The first flight of the Commercial Crew Program was planned to occur in 2015, but insufficient funding caused delays.[59][60][61] As the spacecraft entered the testing and production phase, technical issues also caused delays, especially the parachute system, propulsion, and the launch abort system of both capsules.[62]

Starliner 2018 valve issue

[edit]

In July 2018, a test anomaly was reported in which there was a hypergolic propellant leak due to several faulty abort system valves. Consequentially, the first unpiloted orbital mission was delayed to April 2019, and the first crew launch rescheduled to August 2019.[63][64] In March 2019, Reuters reported these test flights had been delayed by at least three months,[65] and in April 2019 Boeing announced that the unpiloted orbital mission was scheduled for August 2019.[66]

Crew Dragon explosion

[edit]

On April 20, 2019, an issue arose during a static fire test of Crew Dragon.[67] The accident destroyed the capsule which was planned to be used for the In-Flight Abort Test (IFAT).[68] SpaceX confirmed that the capsule exploded.[69] NASA stated that the explosion would delay the planned in-flight abort and crewed orbital tests.[70]

Starliner Orbital Flight Test failure

[edit]

During the first orbital flight test of Starliner in December 2019, the spacecraft reached orbit but was unable to dock with ISS due to a critical software error. Subsequent analysis revealed a second critical software error that could cause the service module to collide with the capsule after separation during the de-orbiting sequence.

Crew Dragon crewed flight

[edit]

On May 30, 2020, two astronauts were launched to the ISS with a Crew Dragon as part of Crew Dragon Demo-2. The end and safe landing of Demo-2 on August 2, 2020, marked the first splashdown in 45 years for NASA astronauts since the first Apollo–Soyuz U.S./U.S.S.R international space mission in July 1975, as well as the first splashdown of a crew spacecraft in the Gulf of Mexico.

Starliner 2021 valve issue

[edit]

Shortly before the scheduled launch of the second orbital flight test in August 2021, routine pre-launch testing showed that thirteen valves in the propulsion system were inoperable and the launch was scrubbed. The problem required extensive analysis that was still ongoing in October 2021, and NASA and Boeing estimated that a new launch date would be scheduled in the first half of 2022.

Starliner Orbital Flight Test 2

[edit]

Boeing Starliner Spacecraft 2 launched as part of the Boeing Orbital Flight Test 2, on May 19, 2022. It successfully docked on May 21, where it stayed for four days.[71] On May 25, the spacecraft undocked and landed successfully in the White Sands Missile Range.[72]

Starliner Crewed Flight Test

[edit]

Days before a planned launch, Boeing announced in June 2023 that it would delay the Crewed Flight Test indefinitely due to issues with the parachute system and wiring harnesses.[73] The mission entails flying a crew of two NASA astronauts to the International Space Station for a one-week test flight. The Crewed Flight Test successfully launched on June 5, 2024.[8] The Starliner spacecraft docked to the International Space Station the next day after troubleshooting issues with the thrusters on the vehicle.[74] After more thruster testing, both in space and using another Starliner vehicle on Earth, NASA announced on August 24, 2024, that the two astronauts on the mission, Butch Wilmore and Suni Williams, will not return to earth on Starliner, but instead fly back on Crew Dragon with the SpaceX Crew-9 mission.[75][76] The Starliner spacecraft will return to Earth autonomously, with no crew onboard, in September 2024.[14]

Funding

[edit]
Requested vs appropriated funding by year up to 2015

The first flight of the Commercial Crew Program was planned to occur in 2015, but insufficient funding caused delays.[59][61] For the fiscal year (FY) 2011 budget, US$500 million was requested for the CCDev program, but Congress granted only $270 million.[77] For the FY 2012 budget, $850 million was requested and $406 million approved.[60] For the FY 2013 budget, 830 million was requested and $488 million approved.[78] For the FY 2014 budget, $821 million was requested and $696 million approved.[59][79] In FY 2015, $848 million was requested and $805 million, or 95%, was approved.[80] On November 14, 2019, NASA's inspector general published an auditing report listing per-seat prices of $90 million for Starliner and $55 million for Dragon Crew. With these, Boeing's price is higher than what NASA has paid the Russian space corporation, Roscosmos, for Soyuz spacecraft seats to fly US and partner-nation astronauts to the space station. The report also states that NASA agreed to pay an additional $287.2 million above Boeing's fixed prices to mitigate a perceived 18-month gap in ISS flights anticipated in 2019 and to ensure the contractor continued as a second commercial crew provider, without offering similar opportunities to SpaceX.[81] On November 18, 2019, Boeing's Jim Chilton replied that the inspector general's report failed to list Starliner’s positive features and objected to the per seat pricing as they believe the cost is lower than $90 million given its cargo capacity. Boeing's reasoning for the extra funding was due to a later start to its development than SpaceX with comparable deadlines. Boeing also stated it committed to the program.[82] The funding of all commercial crew contractors for each phase of the CCP program is as follows—CCtCap values are maxima and include six post-development operational flights for each vendor.

Funding summary (in millions of US$)
Round
(year)
CCDev1
(2010)
CCDev2
(2011)
CCiCap
(2012)
CPC1
(2013)
CCtCap
(2014)
Add. Fund.
(2017)
Total
Boeing 18.0 112.9 480.0 9.9 4,200.0 287.2 5,108.0
SpaceX 75.0 460.0 9.6 2,600.0 3,144.6
Sierra Nevada Corporation 20.0 105.6 227.5 10.0 363.1
Blue Origin 3.7 22.0 25.7
United Launch Alliance 6.7 6.7
Paragon Space Development Corporation 1.4 1.4
Total 49.8 315.5 1,167.5 29.5 6,800.0 287.2 8,648.5
References: [83] [84][85] [50][51] [52] [58] [86]

Test Missions

[edit]

Each system is required to successfully complete abort testing, an uncrewed orbital flight test, and a crewed orbital flight test to meet NASA's requirements for human-rating certification. The agency did allow the companies to propose how they would complete the required tests, with Boeing opting not to perform an in-flight abort test, which NASA approved.[87]

Crew Dragon completed its flight tests in mid-2020 and began operational flights in November 2020. NASA will decide after September 2024 if Boeing has met its certification requirements after the problems experienced on its crew flight test.[88]

Operational missions

[edit]

See also

[edit]

References

[edit]
  1. ^ a b Bolden, Charlie. "American Companies Selected to Return Astronaut Launches to American Soil". NASA.gov. Archived from the original on September 16, 2014. Retrieved September 16, 2014.
  2. ^ "Astronauts fly with SpaceX in landmark launch for commercial spaceflight". Spaceflight Now. November 16, 2020. Retrieved November 18, 2020.
  3. ^ Foust, Jeff (August 13, 2021). "Starliner test flight faces months-long delay". SpaceNews. Retrieved August 13, 2021.
  4. ^ "Boeing Starliner test flight planned for spring 2022". SpaceNews. December 20, 2021. Retrieved March 27, 2022.
  5. ^ Berger, Eric (December 14, 2021). "Leaky valve issue forces Boeing to swap out Starliner's service module". Ars Technica. Retrieved March 27, 2022.
  6. ^ "Boeing, SpaceX Secure Additional Crewed Missions Under NASA's Commercial Space Transport Program". January 4, 2017.
  7. ^ "NASA Assigns Crews to First Test Flights, Missions on Commercial Spacecraft". NASA. August 3, 2018.
  8. ^ a b Strickland, Ashley (June 5, 2024). "Boeing spacecraft carrying two astronauts lifts off on historic voyage". CNN.
  9. ^ Space Center, NASA Johnson (June 5, 2024). "The #Starliner crew continues to make their way to the @Space_Station and are in a sleep period. Teams have identified three helium leaks on the spacecraft. One of these was previously discussed before flight along with a management plan. The other two are new since the spacecraft arrived on orbit. Two of the affected helium valves have been closed and the spacecraft remains stable. Follow along for continuous coverage". X.com. Retrieved August 25, 2024.
  10. ^ Hardwood, William (June 6, 2024). "A5/Starliner CFT: Four jets apparently were deselected earlier because of suspect readings; two of them operated normally during the hot fire tests and are now considered useable as needed; flight controllers are still assessing the other two; Wilmore and Williams were cleared to press ahead with a manual flying demo before docking, but the commander said his manual operation of the Starliner while the hot fire tests were being conducted was sufficient to meet the goals of the manual demo". X.com. Retrieved August 25, 2024.
  11. ^ "Boeing Starliner Spacecraft Completes Successful Crewed Docking with International Space Station". investors.boeing.com. Retrieved August 25, 2024.
  12. ^ Foust, Jeff (June 18, 2024). "NASA's Steve Stich says the Starliner CFT landing has been rescheduled for no earlier than June 26, at White Sands NM at 4:51 am EDT. Was previously scheduled for June 22". X.com. Retrieved August 25, 2024.
  13. ^ Berger, Eric (June 22, 2024). "NASA indefinitely delays return of Starliner to review propulsion data". Ars Technica. Retrieved August 25, 2024.
  14. ^ a b Berger, Eric (August 24, 2024). "It's official: NASA calls on Crew Dragon to rescue the Starliner astronauts". Ars Technica. Retrieved August 25, 2024.
  15. ^ a b c d Bayt, Rob (July 26, 2011). "Commercial Crew Program: Key Driving Requirements Walkthrough". NASA. Archived from the original on March 28, 2012. Retrieved July 27, 2011.
  16. ^ a b c "Commercial Crew Program – fact sheet" (PDF). NASA. February 2012. Archived from the original (PDF) on February 16, 2017. Retrieved July 14, 2012.
  17. ^ Denise Chow (April 14, 2011). "NASA Faces Awkward, Unfortunate Spaceflight Gap". Space.com. Retrieved August 10, 2018.
  18. ^ "NASA officials mulling the possibility of purchasing Soyuz seats for 2019". September 29, 2016.
  19. ^ "NASA to Pay $70 Million a Seat to Fly Astronauts on Russian Spacecraft". Space.com. April 30, 2013.
  20. ^ Daines, Gary (December 1, 2016). "First Flight With Crew Will Mark Important Step on Journey to Mars". Archived from the original on July 28, 2020. Retrieved December 23, 2016.
  21. ^ a b "Selection Statement For Commercial Crew Development" (PDF). JSC-CCDev-1. NASA. December 8, 2009. Retrieved February 10, 2011.
  22. ^ "Moving Forward: Commercial Crew Development Building the Next Era in Spaceflight" (PDF). Rendezvous. NASA. 2010. pp. 10–17. Retrieved February 14, 2011. Just as in the COTS projects, in the CCDev project we have fixed-price, pay-for-performance milestones," Thorn said. "There's no extra money invested by NASA if the projects cost more than projected.
  23. ^ "NASA Selects Commercial Firms to Begin Development of Crew Transportation Concepts and Technology Demonstrations for Human Spaceflight Using Recovery Act Funds". press release. NASA. February 1, 2010. Archived from the original on February 3, 2010. Retrieved February 2, 2010.
  24. ^ "Commercial Crew and Cargo Program" (PDF). Archived from the original (PDF) on March 5, 2010.
  25. ^ Jeff Foust. "Blue Origin proposes orbital vehicle".
  26. ^ NASA Selects Boeing for American Recovery and Reinvestment Act Award to Study Crew Capsule-based Design
  27. ^ "CCDev Information". NASA. July 20, 2010. Archived from the original on November 9, 2018. Retrieved February 1, 2011.
  28. ^ "SNC receives largest award of NASA's CCDev Competitive Contract". SNC. February 1, 2010. Archived from the original on February 7, 2010.
  29. ^ "NASA Selects United Launch Alliance for Commercial Crew Development Program". February 2, 2010. Archived from the original on December 7, 2013. Retrieved May 19, 2010.
  30. ^ Dean, James. "NASA awards $270 million for commercial crew efforts". space.com, April 18, 2011.
  31. ^ Morring, Frank Jr. (April 22, 2011). "Five Vehicles Vie To Succeed Space Shuttle". Aviation Week. Archived from the original on December 21, 2011. Retrieved February 23, 2011. the CCDev-2 awards, ... went to Blue Origin, Boeing, Sierra Nevada Corp. and Space Exploration Technologies Inc. (SpaceX).
  32. ^ "Archived copy" (PDF). Archived from the original (PDF) on February 15, 2013. Retrieved December 5, 2013.{{cite web}}: CS1 maint: archived copy as title (link), p. 2-1
  33. ^ " Blue Origin Technology" Archived January 10, 2018, at the Wayback Machine. Blue Origin. Retrieved February 1, 2016.
  34. ^ "Taking the next step: Commercial Crew Development Round 2". SpaceX Updates webpage. SpaceX. January 17, 2010. Archived from the original on July 27, 2013. Retrieved January 17, 2011.
  35. ^ Boeing Submits Proposal for 2nd Round Of Commercial Crew Dev Archived June 23, 2019, at the Wayback Machine. moonandback.com spaceflight news, December 14, 2010, accessed December 27, 2010.
  36. ^ "NASA Begins Commercial Partnership With United Launch Alliance". NASA. Archived from the original on November 11, 2020. Retrieved July 18, 2011.
  37. ^ Malik, Tariq (February 8, 2010). "Scrapped NASA Rocket May be Resurrected for Commercial Launches". SPACE.com. Retrieved February 10, 2010.
  38. ^ "NASA, private firm may team up on Liberty rocket". USA Today. Retrieved September 13, 2011.
  39. ^ "Commercial Crew Program Forum Presentation" Archived October 20, 2011, at the Wayback Machine, p. 7. commercialcrew.nasa.gov, September 16, 2011.
  40. ^ "CCP and Excalibur Sign Space Act Agreement". NASA. Archived from the original on June 11, 2017. Retrieved November 18, 2011.
  41. ^ ""Excalibur Almaz, NASA sign commercial spaceflight deal"".
  42. ^ "The Shape of Things to Come – Orbital's Prometheus™ Space Plane Ready for NASA's Commercial Crew Development Initiative" (PDF).
  43. ^ "(press release) Paragon Space Development Corporation Completes All Development Milestones on the NASA Commercial Crew Development Program" (PDF). Paragon. January 31, 2011. Archived from the original (PDF) on July 15, 2011.
  44. ^ Boyle, Alan (February 11, 2011). "Let's talk about the final frontier". Cosmic Log. MSNBC. Archived from the original on February 15, 2011. Retrieved February 13, 2011. the proposal calls for the development of a spaceship that could be sent into space on a variety of launch vehicles. ... "Up to eight crew, Soyuz-like architecture (recoverable reusable crew element, expendable orbital/cargo module). Incorporates HMX's patented integral abort system (uses OMS/RCS propellant in separate abort engines). Can fly on Atlas 401 [a configuration for the Atlas 5 rocket], F9 [SpaceX's Falcon 9] or Taurus II (enhanced) but with a reduced cargo and crew capability on the latter vehicle. Goal is to be the lowest-price provider on a per-seat basis. Nominal land recovery with water backup."
  45. ^ "NASA weighs plan to keep shuttle until 2017 – Technology & science – Space – NBC News". NBC News. February 3, 2011.
  46. ^ "COMMERCIAL CREW INTEGRATED CAPABILITY". NASA. January 23, 2012. Retrieved January 25, 2012.
  47. ^ "Statement of William H. Gerstenmaier, Associate Administrator for Human Exploration and Operations, National Aeronautics and Space Administration; before the Subcommittee on Space and Aeronautics Committee on Science, Space and Technology; U. S. House of Representatives" (PDF). October 12, 2011. pp. 6–7. Archived from the original (PDF) on September 21, 2012. Retrieved October 12, 2011.
  48. ^ "CCiCap Solicitation". NASA. February 7, 2012. Archived from the original on February 16, 2013. Retrieved February 11, 2012.
  49. ^ "Commercial Crew Integrated Capability Pre-Proposal Conference". NASA. February 14, 2012. Archived from the original on February 17, 2013. Retrieved February 14, 2012.
  50. ^ a b c d e "NASA Announces Next Steps in Effort to Launch Americans from U.S. Soil". NASA. August 3, 2012. Archived from the original on August 5, 2012. Retrieved August 3, 2012.
  51. ^ a b "NASA Announces Additional Commercial Crew Development Milestones". Space Ref. SpaceRef Interactive Inc. August 15, 2013. Archived from the original on September 18, 2020. Retrieved August 16, 2013.
  52. ^ a b c d "NASA Awards Contracts In Next Step Toward Safely Launching American Astronauts From U.S. Soil". NASA. December 10, 2012. Archived from the original on October 21, 2020. Retrieved December 11, 2012.
  53. ^ a b "NASA Commercial Crew Transportation Capability Contract CCTCAP Draft RFP". SpaceREF. July 19, 2013. Retrieved July 22, 2013.[permanent dead link]
  54. ^ "Why NASA Rejected Sierra Nevada's Commercial Crew Vehicle". Aviation Week. Archived from the original on October 27, 2014. Retrieved March 3, 2019.
  55. ^ "NASA report finds Boeing seat prices are 60% higher than SpaceX". November 14, 2019.
  56. ^ "Boeing fires back at NASA Inspector General regarding commercial crew report". SpaceNews.com. November 19, 2019. Retrieved May 25, 2020.
  57. ^ Foust, Jeff (September 19, 2014). "NASA Commercial Crew Awards Leave Unanswered Questions". Space News. Archived from the original on September 21, 2014. Retrieved September 21, 2014. We basically awarded based on the proposals that we were given," Kathy Lueders, NASA commercial crew program manager, said in a teleconference with reporters after the announcement. "Both contracts have the same requirements. The companies proposed the value within which they were able to do the work, and the government accepted that.
  58. ^ a b "RELEASE 14-256 NASA Chooses American Companies to Transport U.S. Astronauts to International Space Station". www.nasa.gov. NASA. Retrieved October 29, 2014.
  59. ^ a b c Norris, Guy (May 31, 2013). "NASA Chief Repeats Warnings On Commercial Crew Delays". Aviation Week.
  60. ^ a b Clark, Stephen (November 23, 2011). "Reduced budget threatens delay in private spaceships". Spaceflightnow. Retrieved April 18, 2012.
  61. ^ a b "CSF President Michael Lopez-Alegria Statement on NASA Contract Extension with Roscosmos". Commercial Spaceflight Federation. May 2, 2013. Archived from the original on April 20, 2016. Retrieved May 2, 2013.
  62. ^ "NASA's management of crew transportation to the International Space Station" (PDF). NASA Office of Audits. November 14, 2019. p. 3.
  63. ^ "NASA's Commercial Crew Program Target Test Flight Dates". October 4, 2018. Retrieved October 5, 2018.
  64. ^ "Commercial Crew Program – February 6, 2019". blogs.nasa.gov. February 6, 2019. Retrieved February 6, 2019.
  65. ^ Eric M. Johnson (March 20, 2019). "Boeing delays by months test flights for U.S. human space program: sources". Reuters. Retrieved March 22, 2019.
  66. ^ Clark, Stephen (April 2, 2019). "Boeing delays first Starliner test flight to August, NASA extends duration of first crew mission". Spaceflight Now. Retrieved April 3, 2019.
  67. ^ Bridenstine, Jim. "NASA has been notified about the results of the @SpaceX Static Fire Test and the anomaly that occurred during the final test. We will work closely to ensure we safely move forward with our Commercial Crew Program". TWITTER. Retrieved April 21, 2019.
  68. ^ Gebhardt, Chris (August 11, 2017). "SpaceX and Boeing in home stretch for Commercial Crew readiness". NASASpaceFlight.com. Retrieved August 17, 2017.
  69. ^ Mosher, Dave. "SpaceX confirmed that its Crew Dragon spaceship for NASA was 'destroyed' by a recent test. Here's what we learned about the explosive failure". Business Insider. Retrieved May 6, 2019.
  70. ^ "NASA boss says no doubt SpaceX explosion delays flight program". June 18, 2019. Retrieved June 18, 2019.
  71. ^ Josh Dinner (May 17, 2022). "The science and cargo of Boeing's OFT-2 Starliner test flight to space station". Space.com. Retrieved May 26, 2022.
  72. ^ NASA (May 25, 2022). "Boeing's Starliner Safely Lands on Earth – Completing Critical Test Flight to Space Station". SciTechDaily. Retrieved May 26, 2022.
  73. ^ Berger, Eric (June 1, 2023). "Boeing finds two serious problems with Starliner just weeks before launch". Ars Technica.
  74. ^ Sheetz, Michael (June 6, 2024). "Boeing Starliner docks with ISS, delivering its first NASA crew to space station". CNBC. Retrieved August 26, 2024.
  75. ^ Davis, Wes; Liszewski, Andrew (August 24, 2024). "NASA will bring the Starliner astronauts home next year on SpaceX's Crew-9 mission". The Verge. Retrieved August 26, 2024.
  76. ^ Sheetz, Michael; Luhn, Michele (August 24, 2024). "Boeing Starliner returning empty as NASA turns to SpaceX to bring astronauts back from ISS". CNBC. Retrieved August 26, 2024.
  77. ^ "Senate Panel Cuts Commercial Crew, Adds Funds for Orion and Heavy Lift". Space News. July 21, 2010. Archived from the original on September 9, 2012. Retrieved April 18, 2012.
  78. ^ McAlister, Phillip (April 18, 2013). "Commercial Spaceflight Update" (PDF). NASA. Archived from the original (PDF) on March 4, 2016. Retrieved August 10, 2013.
  79. ^ Joe Pappalardo (September 16, 2014). "Is the Relationship Between NASA and Private Space About to Sour?". Popular Mechanics.
  80. ^ Clark, Stephen (December 14, 2014). "NASA gets budget hike in spending bill passed by Congress". Spaceflight Now. Retrieved December 15, 2014.
  81. ^ BERGER, ERIC (November 14, 2019). "NASA report finds Boeing seat prices are 60% higher than SpaceX". Arstechnica. Retrieved November 14, 2019.
  82. ^ Messier, Doug (November 18, 2019). "Boeing Fires Back at Critical NASA IG Report on Starliner". Parabolic Arc. Archived from the original on November 19, 2019. Retrieved May 13, 2020.
  83. ^ "NASA Selects Commercial Firms to Begin Development of Crew Transportation Concepts and Technology Demonstrations for Human Spaceflight Using Recovery Act Funds". press release. NASA. February 1, 2010. Archived from the original on February 3, 2010. Retrieved June 9, 2012.
  84. ^ "NASA Awards Next Set Of Commercial Crew Development Agreements". press release. NASA. April 18, 2011. Archived from the original on November 10, 2018. Retrieved June 9, 2012.
  85. ^ "NASA Releases Commercial Crew Draft RFP, Announces CCDEV2 Optional Milestones". press release. NASA. September 19, 2011. Archived from the original on June 12, 2012. Retrieved June 9, 2012.
  86. ^ "NASA'S MANAGEMENT OF CREW TRANSPORTATION TO THE INTERNATIONAL SPACE STATION" (PDF). Nasa.gov. Retrieved June 28, 2020.
  87. ^ "Boeing tests crew capsule escape system – Spaceflight Now". Retrieved August 24, 2024.
  88. ^ "NASA Decides to Bring Starliner Spacecraft Back to Earth Without Crew – NASA". Retrieved August 24, 2024.
  89. ^ "Demo-1 Flight Readiness Concludes". blogs.nasa.gov. February 22, 2019. Retrieved February 22, 2019.
  90. ^ Foust, Jeff (October 9, 2019). "Boeing, SpaceX press towards commercial crew test flights this year". Spacenews. Retrieved October 9, 2019.
  91. ^ Bridenstine, Jim (December 20, 2019). "Update: #Starliner had a Mission Elapsed Time (MET) anomaly causing the spacecraft to believe that it was in an orbital insertion burn, when it was not. More information at 9am ET:http://nasa.gov/live". @JimBridenstine. Retrieved December 20, 2019.
  92. ^ "Launch America – a partnership between NASA and private space companies – will help open the space above Earth to people besides government astronauts". NASA.
  93. ^ Clark, Stephen (May 19, 2022). "Live coverage: Atlas 5 rocket sends Starliner toward space station". Spaceflight Now. Retrieved May 20, 2022.
[edit]