Development of the Commercial Crew Program explained
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. Each company performed an uncrewed orbital test flight in 2019.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.[1] SpaceX has completed seven successful CCP flights with another, SpaceX Crew-8, currently in progress. 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.[2] [3] [4] Pending completion of its demonstration flights, Boeing is contracted to supply six operational flights to the ISS.[5] The first group of astronauts was announced on August 3, 2018.[6] The first Starliner crewed flight test launched on June 5, 2024.[7]
Requirements
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)[8] [9]
- Provide assured crew return in the event of an emergency[8]
- Serve as a 24-hour safe haven in the event of an emergency[8] [9]
- Capable of remaining docked to the station for 210 days[8] [9]
Background
See also: Space Shuttle retirement and Artemis program. 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.[10] 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.[11] The price varied over time, with the batch of seats from 2016 to 2017 costing $70.7 million per passenger per flight.[12] Artemis continued to slip, with the first uncrewed test flight scheduled for 2022.[13]
Development Program
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. CCDev contracts were issued for fixed-price, pay-for-performance milestones.[14] 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
Commercial Crew Development (CCDev 1) consisted of $50 million awarded in 2010 to five US companies to develop human spaceflight concepts and technologies.[15] [16] [17] NASA awarded development funds to five companies under CCDev 1:
CCDev 2
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.[22] Funded proposals:[23]
Proposals selected without NASA funding:
Proposals not selected:
CCiCap
Commercial Crew integrated Capability (CCiCap) was originally called CCDev 3.[38] 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).[39] The final RFP was released on February 7, 2012, with proposals due on March 23, 2012.[40] [41] The funded Space Act Agreements were awarded on August 3, 2012, and amended on August 15, 2013.[42]
The selected proposals were announced August 3, 2012:
CPC phase 1
The first phase of the Certification Products Contract (CPC) involved the development of a certification plan with engineering standards, tests, and analyses.[43] Winners of funding of phase 1 of the CPC, announced on December 10, 2012, were:[43]
- Sierra Nevada Corporation: $10 million
- SpaceX: $9.6 million
- Boeing: $9.9 million
CCtCap – crew flights awarded
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.[43] NASA issued the draft CCtCap contract's Request For Proposals (RFP) on July 19, 2013 with a response date of August 15, 2013.[44] On 16 September 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.[45] Dragon was the less expensive proposal, but NASA's William H. Gerstenmaier considered the Boeing Starliner proposal the stronger of the two.[46] 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.[47] 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.[48] 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.[49] [50]
Timeline
Ongoing delays
The first flight of the Commercial Crew Program was planned to occur in 2015, but insufficient funding caused delays.[51] [52] 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.[53]
Starliner 2018 valve issue
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.[54] [55] In March 2019, Reuters reported these test flights had been delayed by at least three months,[56] and in April 2019 Boeing announced that the unpiloted orbital mission was scheduled for August 2019.[57]
Crew Dragon explosion
On April 20, 2019, an issue arose during a static fire test of Crew Dragon.[58] The accident destroyed the capsule which was planned to be used for the In-Flight Abort Test (IFAT).[59] SpaceX confirmed that the capsule exploded.[60] NASA stated that the explosion would delay the planned in-flight abort and crewed orbital tests.[61]
Starliner Orbital Flight Test failure
See main article: Boeing Orbital Flight Test. 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
See main article: Crew Dragon Demo-2. 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
See main article: Boeing Orbital Flight Test 2. 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
See main article: Boeing Orbital Flight Test 2. 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.[62] On May 25, the spacecraft undocked and landed successfully in the White Sands Missile Range.[63]
Starliner Crewed Flight Test
See main article: Boeing Crewed Flight Test. 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.[64] 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.
Funding
The first flight of the Commercial Crew Program was planned to occur in 2015, but insufficient funding caused delays.[51] [52] For the fiscal year (FY) 2011 budget, US$500 million was requested for the CCDev program, but Congress granted only $270 million.[65] For the FY 2012 budget, $850 million was requested and $406 million approved.[66] For the FY 2013 budget, 830 million was requested and $488 million approved.[67] For the FY 2014 budget, $821 million was requested and $696 million approved.[51] [68] In FY 2015, $848 million was requested and $805 million, or 95%, was approved.[69] 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.[70] 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.[71] 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.
Test Missions
Each system is required to complete three specific uncrewed test flights and one crewed flight test before NASA will consider the system human-rated. Crew Dragon completed its crewed flight test in 2020 and began operational flights in November 2020., Starliner is expected to conduct its crewed flight test no earlier than 7 May 2024.[77]
Mission | Patch | Spacecraft | Description | Crew | Date | Outcome |
---|
| | Dragon 2 C201 DragonFly (1) | Pad abort test, Cape Canaveral Air Force Station, Florida | | May 6, 2015 | |
---|
| | Dragon 2 C204 (1) | Uncrewed test flight. DM-1 launched on 2 March 2019 and docked to ISS PMA-2/IDA-2 docking port a little under 24 hours after launch. The Dragon spent five days docked to ISS before undocking and landing on 8 March 2019. | | March 2, 2019[78] | |
---|
| | CST-100 Starliner Spacecraft 1 (1) | Uncrewed Pad Abort Test | | November 4, 2019 | |
---|
| | CST-100 Starliner Spacecraft 3 Calypso (1) | Uncrewed test flight. Was the first flight of an Atlas V with a dual engine Centaur upper stage. Was originally planned to spend eight days docked to ISS before landing. However, Starliner was unable to rendezvous with the station due to the MET anomaly forcing it to enter a lower-than-expected orbit.[79] The spacecraft returned on 22 December 2019 after spending two days in orbit. OFT-2 was proposed to meet all objectives. | | December 20, 2019[80] | due to MET anomaly |
---|
| | Dragon 2 C205 (1) | A Falcon 9 booster launched a Dragon 2 capsule from LC-39A to perform an in-flight abort shortly after Max q in order to test Dragon 2's launch abort system. Abort occurred at 84 seconds after launch and Dragon 2 successfully separated from the Falcon 9 and flew away using its SuperDraco thrusters. The Falcon 9 booster disintegrated as a result of aerodynamic forces. Dragon 2 splashed down nine minutes after launch after successfully deploying its four parachutes. | | January 19, 2020 | |
---|
| | Dragon 2 C206 Endeavour (1) | Crewed test flight. Dragon 2 launched with two crew members and docked to the ISS about 18 hours later. Dragon and its crew spent 62 days on board the ISS.[81] | Doug Hurley Bob Behnken | May 30, 2020 | |
---|
| | CST-100 Starliner Spacecraft 2 (1) | Uncrewed test flight. Suggested by Boeing and approved by NASA on April 6, 2020 due to the partial failure of Boe-OFT. A Boe-OFT 2 flight attempt was scrubbed before launch on August 3, 2021. It was rescheduled and took place successfully on May 19, 2022. | | May 19, 2022[82] | |
---|
| | CST-100 Starliner Spacecraft 3 Calypso (2) | Crewed test flight. | Barry E. Wilmore
| June 5, 2024[83] | | |
---|
See also
External links
Notes and References
- Web site: Astronauts fly with SpaceX in landmark launch for commercial spaceflight. Spaceflight Now. 16 November 2020. 18 November 2020.
- Web site: Foust . Jeff . Starliner test flight faces months-long delay . . 13 August 2021 . 13 August 2021.
- Web site: 2021-12-20 . Boeing Starliner test flight planned for spring 2022 . 2022-03-27 . SpaceNews . en-US.
- Web site: Berger . Eric . 2021-12-14 . Leaky valve issue forces Boeing to swap out Starliner's service module . 2022-03-27 . Ars Technica . en-us.
- Web site: Boeing, SpaceX Secure Additional Crewed Missions Under NASA's Commercial Space Transport Program. 4 January 2017.
- Web site: NASA Assigns Crews to First Test Flights, Missions on Commercial Spacecraft. August 3, 2018. NASA.
- Web site: Boeing spacecraft carrying two astronauts lifts off on historic voyage . CNN. June 5, 2024. Ashley. Strickland.
- Web site: Commercial Crew Program: Key Driving Requirements Walkthrough . Bayt . Rob . July 26, 2011 . NASA . July 27, 2011 . dead . https://web.archive.org/web/20120328055242/http://commercialcrew.nasa.gov/document_file_get.cfm?docid=107 . March 28, 2012 . mdy-all .
- Web site: Commercial Crew Program – fact sheet . February 2012 . NASA . 14 July 2012 . 16 February 2017 . https://web.archive.org/web/20170216084029/https://www.nasa.gov/pdf/660622main_2012.06.18_CCP.pdf . dead .
- News: Denise Chow . NASA Faces Awkward, Unfortunate Spaceflight Gap . August 10, 2018 . Space.com . April 14, 2011.
- Web site: NASA officials mulling the possibility of purchasing Soyuz seats for 2019. 29 September 2016.
- Web site: NASA to Pay $70 Million a Seat to Fly Astronauts on Russian Spacecraft. Space.com. 30 April 2013.
- Web site: First Flight With Crew Will Mark Important Step on Journey to Mars. Gary. Daines. December 1, 2016. December 23, 2016. July 28, 2020. https://web.archive.org/web/20200728214952/https://www.nasa.gov/feature/nasa-s-first-flight-with-crew-will-mark-important-step-on-journey-to-mars. dead.
- Web site: Moving Forward: Commercial Crew Development Building the Next Era in Spaceflight . Rendezvous . NASA . 10–17 . 2010 . 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.".
- Web site: Selection Statement For Commercial Crew Development . JSC-CCDev-1 . December 8, 2009 . NASA . February 10, 2011.
- News: NASA Selects Commercial Firms to Begin Development of Crew Transportation Concepts and Technology Demonstrations for Human Spaceflight Using Recovery Act Funds . February 1, 2010 . press release . NASA . February 2, 2010 . February 3, 2010 . https://web.archive.org/web/20100203061828/http://www.nasa.gov/home/hqnews/2010/feb/HQ_C10-004_Commercia_Crew_Dev.html . dead .
- Web site: Commercial Crew and Cargo Program . dead . https://web.archive.org/web/20100305034240/http://www.aiaa.org/pdf/industry/presentations/Lindenmoyer_C3PO.pdf . March 5, 2010 . mdy .
- News: Blue Origin proposes orbital vehicle . Jeff Foust.
- Web site: CCDev Information . July 20, 2010 . NASA . February 1, 2011 . November 9, 2018 . https://web.archive.org/web/20181109103152/https://www.nasa.gov/offices/c3po/partners/ccdev_info.html . dead .
- Web site: SNC receives largest award of NASA's CCDev Competitive Contract . February 1, 2010 . SNC . dead . https://web.archive.org/web/20100207081838/http://sncorp.com/news/press/pr10/snc_ccdev_spacenews.shtml . February 7, 2010 . mdy-all .
- Web site: NASA Selects United Launch Alliance for Commercial Crew Development Program . February 2, 2010 . May 19, 2010 . https://web.archive.org/web/20131207160150/http://www.ulalaunch.com/site/pages/News.shtml#/45 . December 7, 2013 . dead . mdy-all .
- Dean, James. "NASA awards $270 million for commercial crew efforts". space.com, April 18, 2011.
- News: Morring . Frank Jr. . Five Vehicles Vie To Succeed Space Shuttle . Aviation Week . 2011-04-22 . 2011-02-23 . the CCDev-2 awards, ... went to Blue Origin, Boeing, Sierra Nevada Corp. and Space Exploration Technologies Inc. (SpaceX). . dead . https://web.archive.org/web/20111221070704/http://www.aviationweek.com/aw/generic/story_generic.jsp?channel=awst&id=news%2Fawst%2F2011%2F04%2F25%2FAW_04_25_2011_p24-313867.xml&headline=Five%20Vehicles%20Vie%20To%20Succeed%20Space%20Shuttle . December 21, 2011 . mdy-all .
- Web site: Archived copy . 2013-12-05 . dead . https://web.archive.org/web/20130215051509/http://procurement.ksc.nasa.gov/documents/NNK11MS02S_SAA_BlueOrigin_04-18-2011.pdf . February 15, 2013 . mdy ., p. 2-1
- https://www.blueorigin.com/technology " Blue Origin Technology"
- Web site: Taking the next step: Commercial Crew Development Round 2 . SpaceX Updates webpage . . 2010-01-17 . 2011-01-17 . 2013-07-27 . https://web.archive.org/web/20130727153858/http://www.spacex.com/updates.php . dead .
- http://moonandback.com/2010/12/14/boeing-submits-proposal-for-2nd-round-of-commercial-crew-dev/ Boeing Submits Proposal for 2nd Round Of Commercial Crew Dev
- Web site: NASA Begins Commercial Partnership With United Launch Alliance . . 18 July 2011 . 11 November 2020 . https://web.archive.org/web/20201111234015/https://www.nasa.gov/centers/kennedy/news/releases/2011/release-20110718.html . dead .
- News: Malik. Tariq . Scrapped NASA Rocket May be Resurrected for Commercial Launches . 2010-02-10 . SPACE.com . 2010-02-08.
- Web site: NASA, private firm may team up on Liberty rocket . 2011-09-13 . USA Today.
- http://commercialcrew.nasa.gov/document_file_get.cfm?docid=278 "Commercial Crew Program Forum Presentation"
- Web site: CCP and Excalibur Sign Space Act Agreement. NASA. 2011-11-18. 2017-06-11. https://web.archive.org/web/20170611000603/https://www.nasa.gov/exploration/commercial/CCP-Excalibur.html. dead.
- Web site: "Excalibur Almaz, NASA sign commercial spaceflight deal".
- Web site: The Shape of Things to Come – Orbital's Prometheus™ Space Plane Ready for NASA's Commercial Crew Development Initiative.
- Web site: (press release) Paragon Space Development Corporation Completes All Development Milestones on the NASA Commercial Crew Development Program . Paragon . 2011-01-31 . dead . https://web.archive.org/web/20110715043642/http://www.paragonsdc.com/docs/CCT-ARS%20Press%20Release.pdf . July 15, 2011 . mdy-all .
- Web site: Boyle . Alan . Let's talk about the final frontier . Cosmic Log . MSNBC . 2011-02-13 . 2011-02-11 . 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." . dead . https://web.archive.org/web/20110215002006/http://cosmiclog.msnbc.msn.com/_news/2011/02/11/6035600-lets-talk-about-the-final-frontier . February 15, 2011 . mdy .
- Web site: NASA weighs plan to keep shuttle until 2017 – Technology & science – Space – NBC News. NBC News. 3 February 2011 .
- Web site: COMMERCIAL CREW INTEGRATED CAPABILITY . 2012-01-23 . NASA . 25 January 2012.
- Web site: 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 . 6–7 . October 12, 2011 . October 12, 2011 . https://web.archive.org/web/20120921125017/http://science.house.gov/sites/republicans.science.house.gov/files/documents/hearings/101211_Gerstenmaier.pdf . September 21, 2012 . dead.
- Web site: CCiCap Solicitation . 2012-02-07 . NASA . 11 February 2012 . dead . https://web.archive.org/web/20130216214755/http://prod.nais.nasa.gov/cgi-bin/eps/sol.cgi?acqid=149848 . February 16, 2013 . mdy-all .
- Web site: Commercial Crew Integrated Capability Pre-Proposal Conference . February 14, 2012 . NASA . February 14, 2012 . dead . https://web.archive.org/web/20130217052232/http://commercialcrew.nasa.gov/document_file_get.cfm?docid=579 . February 17, 2013 . mdy-all .
- Web site: NASA Announces Next Steps in Effort to Launch Americans from U.S. Soil . August 3, 2012 . NASA . August 3, 2012. https://web.archive.org/web/20120805185336/https://www.nasa.gov/centers/kennedy/news/releases/2012/release-20120803.htm. August 5, 2012. dead.
- Web site: NASA Awards Contracts In Next Step Toward Safely Launching American Astronauts From U.S. Soil . 10 December 2012 . NASA . 11 December 2012 . 21 October 2020 . https://web.archive.org/web/20201021001939/https://www.nasa.gov/centers/kennedy/news/releases/2012/release-20121210.html . dead .
- News: NASA Commercial Crew Transportation Capability Contract CCTCAP Draft RFP . July 19, 2013 . SpaceREF . July 22, 2013 .
- Web site: American Companies Selected to Return Astronaut Launches to American Soil . Bolden . Charlie . NASA.gov . September 16, 2014. https://web.archive.org/web/20140916202209/http://blogs.nasa.gov/bolden/2014/09/16/american-companies-selected-to-return-astronaut-launches-to-american-soil/. September 16, 2014. dead.
- Web site: Why NASA Rejected Sierra Nevada's Commercial Crew Vehicle. Aviation Week. https://web.archive.org/web/20141027174620/http://aviationweek.com/space/why-nasa-rejected-sierra-nevadas-commercial-crew-vehicle. dead. 27 October 2014. 3 March 2019.
- News: NASA report finds Boeing seat prices are 60% higher than SpaceX. November 14, 2019.
- Web site: Boeing fires back at NASA Inspector General regarding commercial crew report. 2019-11-19. SpaceNews.com. en-US. 2020-05-25.
- News: Foust. Jeff . NASA Commercial Crew Awards Leave Unanswered Questions . https://archive.today/20140921132432/http://www.spacenews.com/article/civil-space/41924nasa-commercial-crew-awards-leave-unanswered-questions . dead . September 21, 2014 . 2014-09-21 . Space News . 2014-09-19 . "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.".
- Web site: RELEASE 14-256 NASA Chooses American Companies to Transport U.S. Astronauts to International Space Station . www.nasa.gov . NASA . 29 October 2014.
- Web site: NASA Chief Repeats Warnings On Commercial Crew Delays. Norris. Guy. 31 May 2013. Aviation Week.
- Web site: CSF President Michael Lopez-Alegria Statement on NASA Contract Extension with Roscosmos . 2 May 2013 . Commercial Spaceflight Federation . 2 May 2013.
- Web site: NASA's management of crew transportation to the International Space Station. NASA Office of Audits. November 14, 2019. 3.
- Web site: NASA's Commercial Crew Program Target Test Flight Dates. October 4, 2018. October 5, 2018.
- Web site: Commercial Crew Program - February 6, 2019. blogs.nasa.gov. 6 February 2019 . February 6, 2019.
- News: Boeing delays by months test flights for U.S. human space program: sources. Eric M. Johnson. Reuters. March 20, 2019. March 22, 2019.
- News: Boeing delays first Starliner test flight to August, NASA extends duration of first crew mission. Clark. Stephen. Spaceflight Now . April 2, 2019. April 3, 2019.
- Web site: 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 . 21 April 2019.
- News: SpaceX and Boeing in home stretch for Commercial Crew readiness. Gebhardt. Chris. August 11, 2017. August 17, 2017. NASASpaceFlight.com.
- Web site: SpaceX confirmed that its Crew Dragon spaceship for NASA was 'destroyed' by a recent test. Here's what we learned about the explosive failure.. Mosher. Dave. Business Insider. 2019-05-06.
- Web site: NASA boss says no doubt SpaceX explosion delays flight program . June 18, 2019 . June 18, 2019.
- Web site: Josh Dinner . 2022-05-17 . The science and cargo of Boeing's OFT-2 Starliner test flight to space station . 2022-05-26 . Space.com . en.
- Web site: NASA . 2022-05-25 . Boeing's Starliner Safely Lands on Earth – Completing Critical Test Flight to Space Station . 2022-05-26 . SciTechDaily . en-us.
- News: Berger . Eric . Boeing finds two serious problems with Starliner just weeks before launch . Ars Technica . June 1, 2023 . en-us.
- Web site: Senate Panel Cuts Commercial Crew, Adds Funds for Orion and Heavy Lift . https://archive.today/20120909193900/http://www.spacenews.com/civil/072110senate-panel-cuts-commercial-crew-adds-funds-for-orion-and-heavy-lift.html . dead . September 9, 2012 . July 21, 2010 . Space News . 18 April 2012.
- Web site: Reduced budget threatens delay in private spaceships. Clark. Stephen . 2011-11-23 . Spaceflightnow . 18 April 2012.
- Web site: Commercial Spaceflight Update . McAlister . Phillip . 18 April 2013 . NASA . 10 August 2013.
- Web site: Is the Relationship Between NASA and Private Space About to Sour?. Joe Pappalardo. September 16, 2014. Popular Mechanics.
- News: Clark . Stephen . NASA gets budget hike in spending bill passed by Congress . 2014-12-15 . Spaceflight Now . 2014-12-14.
- Web site: BERGER . ERIC . NASA report finds Boeing seat prices are 60% higher than SpaceX . Arstechnica . 14 November 2019 . 14 November 2019.
- Web site: Messier . Doug . Boeing Fires Back at Critical NASA IG Report on Starliner . https://web.archive.org/web/20191119040420/http://www.parabolicarc.com/2019/11/18/boeing-fires-back-at-critical-nasa-ig-report-on-starliner/ . dead . November 19, 2019 . Parabolic Arc . November 18, 2019 . May 13, 2020.
- News: NASA Selects Commercial Firms to Begin Development of Crew Transportation Concepts and Technology Demonstrations for Human Spaceflight Using Recovery Act Funds . February 1, 2010 . press release . NASA . June 9, 2012 . February 3, 2010 . https://web.archive.org/web/20100203061828/http://www.nasa.gov/home/hqnews/2010/feb/HQ_C10-004_Commercia_Crew_Dev.html . dead .
- News: NASA Awards Next Set Of Commercial Crew Development Agreements . press release . April 18, 2011 . NASA . June 9, 2012 . November 10, 2018 . https://web.archive.org/web/20181110083048/https://www.nasa.gov/offices/c3po/home/agreementsfeature.html . dead .
- News: NASA Releases Commercial Crew Draft RFP, Announces CCDEV2 Optional Milestones . September 19, 2011 . press release . NASA . June 9, 2012 . June 12, 2012 . https://web.archive.org/web/20120612114419/http://www.nasa.gov/home/hqnews/2011/sep/HQ_11-312_CCDEV_Announ.html . dead .
- Web site: NASA Announces Additional Commercial Crew Development Milestones. Space Ref. August 15, 2013. SpaceRef Interactive Inc.. August 16, 2013. September 18, 2020. https://web.archive.org/web/20200918163547/http://spaceref.biz/2013/08/nasa-announces-additional-commercial-crew-development-milestones.html. dead.
- Web site: NASA'S MANAGEMENT OF CREW TRANSPORTATION TO THE INTERNATIONAL SPACE STATION . Nasa.gov . 28 June 2020.
- News: Boeing resets Starliner plan to be ready for first NASA crew flight by March. Michael. Sheetz. CNBC. 7 August 2023. 7 August 2023.
- Web site: Demo-1 Flight Readiness Concludes. blogs.nasa.gov. 22 February 2019 . en-US. 2019-02-22.
- Web site: 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 . Bridenstine . Jim . 2019-12-20 . @JimBridenstine . en . 2019-12-20.
- Web site: Foust . Jeff . Boeing, SpaceX press towards commercial crew test flights this year . Spacenews . 9 October 2019 . 9 October 2019.
- Web site: Launch America – a partnership between NASA and private space companies – will help open the space above Earth to people besides government astronauts.. NASA.
- Web site: Clark . Stephen . Live coverage: Atlas 5 rocket sends Starliner toward space station . Spaceflight Now . 19 May 2022 . 20 May 2022.
- Web site: Atlas V N22 | Starliner CFT .