Criticism of the Space Shuttle program

{{Short description|Claims that NASA's Space Shuttle program failed to achieve its promised goals}} '''Criticism of the Space Shuttle program''' stemmed from claims that [[NASA|NASA's]] [[Space Shuttle program]] failed to achieve its promised cost and utility goals, as well as design, cost, management, and safety issues.<ref name="Rocket">{{cite web|url=http://www.idlewords.com/2005/08/a_rocket_to_nowhere.htm|title=A Rocket To Nowhere |last=Cegłowski |first=Maciej |author-link=Maciej Cegłowski|date=2005-08-03|publisher=Idle Words|access-date=2008-09-26}}</ref> Fundamentally, it failed in the goal of reducing the cost of space access. Space Shuttle incremental per-pound launch costs ultimately turned out to be considerably higher than those of expendable launchers.<ref name="Futron">{{cite web|url=http://www.futron.com/upload/wysiwyg/Resources/Whitepapers/Space_Transportation_Costs_Trends_0902.pdf |title=Space Transportation Costs: Trends in Price Per Pound to Orbit 1990–2000 |access-date=2010-12-28 |date=September 6, 2002 |publisher=[[Futron]] |url-status=dead |archive-url=https://web.archive.org/web/20110711061933/http://www.futron.com/upload/wysiwyg/Resources/Whitepapers/Space_Transportation_Costs_Trends_0902.pdf |archive-date=July 11, 2011 }}</ref> In 2010, the incremental cost per flight of the Space Shuttle was $409 million, or {{convert|14,186|$/kg|$/lb|abbr=off}} to [[low Earth orbit]] (LEO). In contrast, the comparable [[Proton (rocket)|Proton]] launch vehicle cost was $141 million, or {{convert|6721|$/kg|$/lb|abbr=off}} to LEO and the [[Soyuz-2| Soyuz 2.1]] was $55 million, or {{convert|6665|$/kg|$/lb|abbr=off}}, despite these launch vehicles not being reusable.<ref name="Launch_Cost_Analy">{{cite journal |last1=Xu|last2=Hollingsworth|last3=Smith|first1=Qin|first2=Peter|first3=Katharine |title=Launch Cost Analysis and Optimization Based on Analysis of Space System Characteristics |journal=Transactions of the Japan Society for Aeronautical and Space Sciences |date=July 2019 |volume=62 |issue=4 |pages=177–178 |doi=10.2322/tjsass.62.175 |url=https://www.jstage.jst.go.jp/article/tjsass/62/4/62_T-17-57/_pdf/-char/ja |access-date=13 January 2024|doi-access=free }}</ref>

When all design and maintenance costs are taken into account, the final cost of the Space Shuttle program, averaged over all missions and adjusted for inflation (2008), was estimated to come out to $1.5 billion per launch, or {{convert|60,000|$/kg|$/lb|abbr=off}} to LEO.<ref name=duggins>[http://sciencepolicy.colorado.edu/admin/publication_files/resource-2656-2008.18.pdf ''The Rise and Fall of the Space Shuttle''], Book Review: Final Countdown: NASA and the End of the Space Shuttle Program by Pat Duggins, American Scientist, 2008, Vol. 96, No. 5, p. 32.</ref> This should be contrasted with the originally envisioned costs of {{convert|118|$/lb|$/kg|order=flip|abbr=off}} of payload in 1972 dollars (approximately ${{Inflation|US-GDP|118|1972|2019}} per pound adjusting for inflation to 2019).<ref name="century_of_flight">{{cite web|url=http://www.century-of-flight.net/Aviation%20history/space/Space%20Shuttle%20history.htm|title=Space Shuttle history - Shuttle operations|publisher=Century of Flight|access-date=2011-04-30}}</ref><blockquote>"The Space Shuttle was designed to be cost effective at a weekly flight rate, a goal that was never credible." - [[Michael D. Griffin]], [[NASA]] [[Administrator of NASA|administrator]], 2007, ''[[Aviation Week & Space Technology|Aviation Week]]''.</blockquote>While the Shuttle did serve a purpose servicing satellites and space stations in orbit, it failed at its original goal of achieving routine, reliable access to space, partly due to multi-year interruptions in launches following Shuttle failures. It was never as economical as expendable rockets for the task of launching satellites.<ref name="Folly">{{cite book|last=Axelrod|first=Alan|title=Profiles in Folly: History's Worst Decisions and Why They Went Wrong|publisher=Sterling Publishing Company|year=2008|pages=[https://archive.org/details/profilesinfollyh00axel/page/62 62–63]|isbn=978-1-4027-4768-7|title-link=Profiles in Folly}}</ref> NASA budget pressures partly caused by the chronically high NASA Space Shuttle program costs eliminated NASA crewed space flight beyond low earth orbit for over fifty years, until the 2026 [[Artemis II]] mission, and severely curtailed use of uncrewed probes.<ref>{{cite book|last=Handberg|first=Roger|title=Reinventing NASA: Human Spaceflight, Bureaucracy, and Politics|publisher=Greenwood Publishing Group|year=2003|isbn=978-0-275-97002-4}}</ref> NASA's promotion of and reliance on the Shuttle slowed domestic commercial [[expendable launch vehicle]] (ELV) programs until after the 1986 [[Space Shuttle Challenger disaster|''Challenger'' disaster]].<ref>{{cite book|last=Launius|first=Roger D.|author2=Howard E. McCurdy|title=Spaceflight and the Myth of Presidential Leadership: and the myth of presidential leadership|publisher=University of Illinois Press|year=1997|pages=146–55|isbn=978-0-252-06632-0}}</ref>

Two out of the five spacecraft were destroyed in accidents, killing 14 astronauts, the largest loss of life in space flight.<ref>{{Cite web |last=Borenstein |first=Seth |title=A look at people killed during space missions |url=https://phys.org/news/2014-11-people-space-missions.html |access-date=2023-02-13 |website=phys.org |language=en}}</ref>

==Purpose of the system== The "Space Transportation System" (NASA's formal name for the overall Shuttle program) was created to transport crewmembers and payloads into [[low Earth orbit]]s.<ref>{{cite web |url=http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_overview.html |title=Space Transportation System |publisher=NASA KSC |access-date=2009-01-02 |archive-date=2019-11-30 |archive-url=https://web.archive.org/web/20191130213151/https://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_overview.html |url-status=dead }}</ref> It would afford the opportunity to conduct science experiments on board the shuttle to be used to study the effects of space flight on humans, animals and plants. Other experiments would study how things can be manufactured in space. The shuttle would also enable astronauts to launch satellites from the shuttle and even repair satellites already out in space.<ref>{{cite web|url=http://wings.avkids.com/Book/History/advanced/stations-01.html|title=The Space Shuttle and Space Stations|date=1997-09-06|publisher=The K–8 Aeronautics Internet Textbook|access-date=2008-09-26}}</ref> The Shuttle was also intended for research into the human response to [[zero-g]].<ref name="usatoday">{{Cite news |url=https://www.usatoday.com/news/nation/2003-02-04-shuttle-critics_x.htm |title=Critics scrutinize cost of shuttle |access-date=2008-09-26 |date=2003-02-04 |work=USA Today}}</ref>

The Shuttle was originally billed as a space vehicle that would be able to launch once a week and give low launch costs through [[amortization (accounting)|amortization]]. Development costs were expected to be recouped through frequent access to space. These claims were made in an effort to obtain budgetary funding from the [[United States Congress]].<ref>{{cite book|last=Lardas|first=Mark|author2=Ian Palmer|title=Space Shuttle Launch System 1972–2004: System 1975–2004|url=https://archive.org/details/spaceshuttlelaun00lard|url-access=limited|publisher=Osprey Publishing|isbn=978-1-84176-691-1|page=[https://archive.org/details/spaceshuttlelaun00lard/page/n8 7]|year=2004}}</ref> Beginning in 1981, the space shuttle began to be used for space travel. However, by the mid-1980s the concept of flying that many shuttle missions proved unrealistic and scheduled launch expectations were reduced 50%.<ref>{{cite web|url=http://www.daviddarling.info/encyclopedia/S/Space_Shuttle.html|title=Space Shuttle|publisher=The Internet Encyclopedia of Science|access-date=2008-09-26}}</ref> Following the [[Space Shuttle Challenger disaster|''Challenger'']] accident in 1986, missions were halted pending safety review. This hiatus became lengthy and ultimately lasted almost three years as arguments over funding and the safety of the program continued. Eventually the military resumed the use of expendable launch vehicles instead.<ref name="usatoday"/> Missions were put on hold again after the loss of ''Columbia'' in 2003. Overall, 135 missions were launched during the 30 years after the first orbital flight of ''Columbia'', averaging approximately one every 3 months.

==Costs== Some reasons for the higher-than-expected operational costs were: * NASA secured funding from the US Air Force's budget in exchange for USAF input to the design process. In order to fulfill the USAF's mission to launch payloads into [[polar orbit]], the USAF insisted on a very large cross-range requirement. This necessitated the Shuttle's huge delta wings, which are far larger than the stub wings of the original design. Besides adding drag and weight (almost 20 percent),<ref name="wade">{{cite web|last=Wade|first=Mark|title=Space Shuttle|url=http://www.astronautix.com/s/spaceshuttle.html|access-date=2020-12-31|date=1997–2008|url-status=dead|archive-url=https://web.archive.org/web/20170220034647/http://www.astronautix.com/s/spaceshuttle.html|archive-date=2017-02-20}}</ref> the excessive number of heat tiles needed to protect the delta wings added greatly to maintenance costs, besides increasing operational risks such as those that resulted in the ''Columbia'' disaster.<ref>{{cite book |last1=Heppenheimer |first1=T.A. |title=The Space Shuttle Decision |date=April 2002 |publisher=Smithsonian Institution Scholarly Press |isbn=978-1588340146 }}</ref> * At [[Vandenberg Space Launch Complex 6|Vandenberg Air Force Base]] in [[California]], the USAF duplicated the entire infrastructure needed to launch and service the Space Shuttle, at a cost of over 4 billion dollars. Following the ''Challenger'' explosion, the facility was dismantled without ever having launched a single Shuttle mission. * Aerospace engineer [[Robert Zubrin]] describes the Shuttle as having been designed "backwards" in that the Orbiter, the harder-to-reuse portion, is made reusable, while part of the booster (the liquid fuel tank) is thrown away even though it is easier to recover since it does not fly so high or fast.<ref>{{cite book |last1=Zubrin |first1=Robert |title=Entering Space |date=August 7, 2000 |publisher=TarcherPerigee |isbn=978-1585420360 }}</ref> * Maintenance of the thermal protection tiles was a very labor-intensive and costly process, with some 35,000 tiles needing to be inspected individually and with each tile specifically manufactured for one specific slot on the shuttle.<ref name="Van Pelt">{{cite book|last=Van Pelt|first=Michael|title=Space tourism: adventures in Earth's orbit and beyond|year=2005|publisher=Springer|isbn=978-0-387-40213-0|pages=[https://archive.org/details/spacetourismadve0000vanp/page/75 75–76]|url=https://archive.org/details/spacetourismadve0000vanp/page/75}}</ref> * Due to the complexity of the [[RS-25]] engines, following each flight they required removal for thorough inspection and meticulous maintenance. Prior to the delivery of the Block II engines, the primary engine component, the [[turbopump]], had to be removed, disassembled, and overhauled after each use.<ref>{{cite web|url=http://www.nasa.gov/pdf/361842main_15%20-%20Augustine%20Sidemount%20Final.pdf|title=Shuttle-Derived Heavy Lift Launch Vehicle|last=Shannon|first=John|date=June 17, 2009|publisher=NASA|access-date=May 11, 2021}}</ref><ref>{{cite web|title=High Performance Liquid Hydrogen Turbopumps|url=https://llis.nasa.gov/lesson/750|date=February 1, 1999|access-date=May 11, 2021|publisher=NASA: Lessons Learned Information System}}</ref> * The toxic propellants used for the [[Space Shuttle Orbital Maneuvering System|OMS/RCS thrusters]] required special handling, during which time no other activities could be performed in areas sharing the same ventilation system. This increased turn-around time. * The launch rate was significantly lower than initially expected. While not reducing absolute operating costs, more launches per year gives a lower cost per launch. Some early hypothetical studies examined the possibility of making 55 launches per year (see above), but the maximum possible launch rate was limited to 24 per year based on manufacturing capacity of the [[Michoud Assembly Facility|Michoud facility]] in [[Louisiana]] that constructs the [[Space Shuttle external tank|external tank]]. Early in shuttle development, the expected launch rate was about 12 per year.<ref name="columbia_hearing">{{cite web |url=http://caib.nasa.gov/events/public_hearings/20030423/transcript_am.html |title=Columbia accident investigation board, public hearing |date=23 April 2003 |publisher=[[NASA]] |access-date=2006-08-06 |url-status=dead |archive-url=https://web.archive.org/web/20060812151208/http://caib.nasa.gov/events/public_hearings/20030423/transcript_am.html |archive-date=2006-08-12 }}</ref> Launch rates reached a peak of 9 per year in 1985 but averaged 4.5 for the entire program. * When the decision was made on the main shuttle contractors in 1972, work was spread among companies to make the program more attractive to Congress, such as the contract for the [[Space Shuttle Solid Rocket Booster|Solid Rocket Booster]]s to [[Morton Thiokol]] in [[Utah]]. Over the course of the program, this raised operational costs, though the consolidation of the US aerospace industry in the 1990s meant that the majority of the Shuttle program expenditure was now with one company: the [[United Space Alliance]], a joint venture of [[Boeing]] and [[Lockheed Martin]].

==Cultural issues and problems== {{Quotation|For a successful technology, reality must take precedence over public relations, for nature cannot be fooled.|[[Richard Feynman]]|[[Rogers Commission Report]], on the [[Space Shuttle Challenger disaster|''Challenger'' disaster]].}} Some researchers have criticized a pervasive shift in NASA culture away from safety in order to ensure that launches took place in a timely fashion, sometimes called "[[go fever]]". Allegedly, NASA upper-level management embraced this decreased safety focus in the 1980s while some engineers remained wary. According to sociologist [[Diane Vaughan]], the aggressive launch schedules arose in the [[Ronald Reagan|Reagan]] years as an attempt to rehabilitate America's post-[[Vietnam War]] prestige.<ref name=vaughn>{{cite book| last=Vaughan| first=Diane| title=The Challenger Launch Decision: Risky Technology, Culture, and Deviance at NASA| url=https://archive.org/details/challengerlaunch00dian| url-access=registration| publisher=[[University of Chicago Press]]| year=1996| isbn=978-0-226-85175-4}}</ref>

The physicist [[Richard Feynman]], who was appointed to the [[Rogers Commission|official inquiry on the ''Challenger'' disaster]], wrote in his report that working NASA engineers estimated the risk of mission failure to be "on the [[order of magnitude|order]] of a percent", adding, "Official management, on the other hand, claims to believe the probability of failure is a thousand times less. One reason for this may be an attempt to assure the government of NASA perfection and success in order to ensure the supply of funds. The other may be that they sincerely believed it to be true, demonstrating an almost incredible lack of communication between themselves and their working engineers."<ref name=Feynman>{{cite web| url=http://science.ksc.nasa.gov/shuttle/missions/51-l/docs/rogers-commission/Appendix-F.txt| title=Personal observations on the reliability of the Shuttle| last=Feynman| first=Richard| publisher=[[NASA]]| work=[[Rogers Commission Report]]| access-date=6 August 2009| archive-date=7 December 2019| archive-url=https://web.archive.org/web/20191207012843/https://science.ksc.nasa.gov/shuttle/missions/51-l/docs/rogers-commission/Appendix-F.txt| url-status=dead}}</ref>

Despite Feynman's warnings, and despite the fact that Vaughan served on safety boards and committees at NASA, the subsequent press coverage has found some evidence that NASA's relative disregard for safety still persisted. For example, leading up to the [[Space Shuttle Columbia disaster|''Columbia'' disaster]], NASA discounted the risk from small foam chunk breakage at launch and assumed that the lack of damage from prior foam collisions suggested the future risk was low.<ref>{{cite web |author=Columbia Accident Investigation Board |title=6.1 A History of Foam Anomalies (PDF) |date=August 2003 |url=http://anon.nasa-global.speedera.net/anon.nasa-global/CAIB/CAIB_lowres_chapter6.pdf |access-date=February 26, 2013 |url-status=live |archive-url=http://archive.wikiwix.com/cache/20110806231858/http://anon.nasa-global.speedera.net/anon.nasa-global/CAIB/CAIB_lowres_chapter6.pdf |archive-date=August 6, 2011}}</ref>

==Shuttle operations== {{More citations needed|section|date=August 2022}} [[File:SpaceShuttleGroundProcessingVision.jpg|thumb|right|The original, simplified, vision of Space Shuttle ground processing]] [[File:SpaceShuttleGroundProcessingActual.jpg|thumb|right|The actual, vastly more complex and much slower, Space Shuttle ground processing]] The Shuttle was originally conceived to operate somewhat like an airliner. After landing, the orbiter would be checked out and start being mated to the [[Space Shuttle External Tank|External Tank]] and [[Space Shuttle Solid Rocket Booster|Solid Rocket Boosters]], and be ready for launch in as little as two weeks.

In practice, before the loss of ''Challenger'', about half of the turnaround time after a mission was unplanned tests and modifications based on unexpected events that occurred during flight.{{r|pincus19860305}} The process usually took months; [[Space Shuttle Atlantis|''Atlantis'']] set the pre-''Challenger'' record by launching twice within 54 days, while [[Space Shuttle Columbia|''Columbia'']] set the post-''Challenger'' record of 88 days. The Shuttle program's goal of returning its crew to Earth safely conflicted with the goal of a rapid and inexpensive payload launch. Furthermore, because in many cases there were no survivable [[Space Shuttle abort modes|abort modes]], many pieces of hardware had to function perfectly and so required careful inspection before each flight. The result was high labor cost, with around 25,000 workers in Shuttle operations and labor costs of about $1 billion per year.<ref name="century_of_flight" />

Some shuttle features initially presented as important to Space Station support have proved superfluous: * As the Soviets demonstrated, capsules and uncrewed supply rockets are sufficient to supply a space station. * NASA's initial policy of using the Shuttle to launch all crewless payloads declined in practice, and eventually was discontinued. [[Expendable launch vehicles]] (ELVs) proved much cheaper and more flexible. * Following the ''Challenger'' disaster, use of the Shuttle to carry the powerful [[liquid rocket|liquid fueled]] [[Centaur (rocket stage)|Centaur]] upper stages planned for interplanetary probes was ruled out for Shuttle safety reasons.<ref>{{cite book|chapter-url=http://www.satobs.org/faq/Chapter-08.txt|title=Visual Satellite Observing |chapter= Chapter 8: What Are Some Of The Rockets Used To Place Satellites In Orbit?|date=February 1998|publisher=Visual Satellite Observer's Home Page|access-date=16 July 2010}}</ref><ref>{{cite web|url=http://www.centennialofflight.gov/essay/SPACEFLIGHT/upper_stages/SP12.htm|title=Upper Stages|publisher=U.S. Centennial of Flight Commission|access-date=16 July 2010|url-status=dead|archive-url=https://web.archive.org/web/20100527224252/http://www.centennialofflight.gov/essay/SPACEFLIGHT/upper_stages/SP12.htm|archive-date=27 May 2010}}</ref> * The Shuttle's history of unexpected delays also made it liable to miss narrow [[launch window]]s. * Advances in technology have made probes smaller and lighter. As a result, many robotic probes and communications satellites can now use [[expendable launch vehicle]]s, such as the [[Delta (rocket family)|Delta]] and [[Atlas V]], which are less expensive and perceived to be more reliable than the Shuttle. * Advances in technology today happen much faster than in the years the Shuttle was developed. Thus the notion that Shuttle would be useful for recovering expensive satellites for return to Earth for refurbishment and updating with new technology is obsoleted; costs have dropped and capabilities increased so much that it is much more cost-effective to abandon old satellites and simply launch new ones.

==Accidents== [[File:NASA STS 51L Challenger Camera E207.gif|thumb|250px|[[Solid rocket booster|SRB]] Destruction of Space Shuttle ''Challenger'' during STS-51L. O-Ring sealant failure resulted in visible SRB thrust gas impinging against, penetrating, and then detonating the LH2 reservoir of the ET.]] While the technical details of the [[Space Shuttle Challenger disaster|''Challenger'']] and [[Space Shuttle Columbia disaster|''Columbia'']] accidents are different, the organizational problems show similarities. Flight engineers' concerns about possible problems were not properly communicated to or understood by senior NASA managers. The vehicle gave ample warning beforehand of abnormal problems. A heavily layered, procedure-oriented bureaucratic structure inhibited necessary communication and action. In addition, both mission failures have been attributed to the flawed notion of a crewed orbiter attached to the flank of the launch vehicle, precluding the possibility of ejection in the case of the Challenger disaster, and exposing the heat shield to damage in the case of Columbia.

With ''Challenger'', an [[O-ring]] which should not have eroded at all did erode on earlier shuttle launches. Yet managers felt that because it had previously eroded by no more than 30%, this was not a hazard as there was "a factor of three [[safety factor|safety margin]]" (in reality, the part had failed, and there was no safety factor). [[Thiokol|Morton-Thiokol]] designed and manufactured the SRBs, and during a pre-launch conference call with NASA, [[Roger Boisjoly]], the Thiokol engineer most experienced with the O-rings, pleaded with management repeatedly to cancel or reschedule the launch. He raised concerns that the unusually low temperatures would stiffen the O-rings, preventing a complete seal during flexing of the rocket motor segments, which was exactly what happened on the fatal flight. However, Thiokol's senior managers, under pressure from NASA management, overruled him and allowed the launch to proceed. One week prior to the launch, Thiokol's contract to reprocess the solid rocket boosters was also due for review, and cancelling the flight was an action that Thiokol management wanted to avoid. ''Challenger'''s O-rings eroded completely through as predicted, resulting in the complete destruction of the spacecraft and the death of all seven astronauts on board.

[[File:ColumbiaFLIR2003.gif|thumb|left|The breakup of ''Columbia'' was captured by a [[forward-looking infrared]] (FLIR) camera mounted on an [[Boeing AH-64 Apache|Apache]] helicopter conducting training in Fort Hood, Texas.<ref name="aviationist-20140201">{{Cite news |last=Cenciotti |first=David |date=February 1, 2014 |title=Space Shuttle Columbia Disaster as seen through AH-64 Apache camera |work=The Aviationist |url=https://theaviationist.com/2014/02/01/sts-107-disaster-video/ |url-status=live |archive-url=https://web.archive.org/web/20230331125749/https://theaviationist.com/2014/02/01/sts-107-disaster-video/ |archive-date=March 31, 2023 }}</ref>]] [[Space Shuttle Columbia disaster|''Columbia'']] was destroyed because of damaged [[Space Shuttle thermal protection system|thermal protection]] from foam debris that broke off from the [[external tank]] during ascent. The foam had not been designed or expected to break off, but had been observed in the past to do so without incident. The original shuttle operational specification said the orbiter [[Thermal Protection System|thermal protection tiles]] were not designed to withstand any debris hits at all. Over time NASA managers gradually accepted more tile damage, similar to how O-ring damage was accepted. The [[Columbia Accident Investigation Board]] called this tendency the "[[normalization of deviance]]" – a gradual acceptance of events outside the design tolerances of the craft simply because they had not been catastrophic to date.<ref name="CAIBREP">{{cite web | url=http://caib.nasa.gov/news/report/default.html | title=''Columbia'' Accident Investigation Board Report | url-status=dead | archive-url=https://web.archive.org/web/20070916094919/http://caib.nasa.gov/news/report/default.html | archive-date=2007-09-16 }}</ref> [[File:STS-1 Columbia Cargo Bay.jpg|thumb|[[STS-1]] photo showing missing thermal tiles on [[Space Shuttle Orbital Maneuvering System|OMS]] pods to the left and right of the vertical tail fin]] The subject of missing or damaged thermal tiles on the Shuttle fleet only became an issue following the loss of ''Columbia'' in 2003, as it broke up on [[atmospheric reentry|re-entry]]. In fact, Shuttles had previously come back missing as many as 20 tiles without any problem. [[STS-1]] and [[STS-41]] had both flown with missing thermal tiles from the [[Space Shuttle Orbital Maneuvering System|Orbital Maneuvering System]] pods (visible to the crew). The problem on ''Columbia'' was that the damage was sustained from a foam strike to the [[reinforced carbon-carbon]] leading edge panel of the wing, not the heat tiles. The first Shuttle mission, STS-1, had a protruding gap filler that diverted hot gas into the right wheel well on re-entry, resulting in a buckling of the right main landing gear door.<ref>{{cite web |url=http://www.jsc.nasa.gov/news/columbia/anomaly/STS1.pdf | title= STS-1 In Flight Anomaly List | date=2003-02-27}}</ref>

===Risk contributors=== An example of technical risk analysis for an STS mission is SPRA iteration 3.1 top risk contributors for [[STS-133]]:<ref name="copv">{{cite web |url=http://www.nasaspaceflight.com/2010/07/nasa-reviews-copv-for-final-program-flights/ |title=NASA Reviews COPV Reliability Concerns for Final Program Flights |access-date=December 14, 2010 |publisher=NASASpaceflight.com |author=Chris Gebhardt|date=18 July 2010 }}</ref><ref>Hamlin, et al. [https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20100005659_2010007106.pdf 2009 ''Space Shuttle Probabilistic Risk Assessment Overview''] (.pdf). NASA.</ref>{{pb}}

# Micro-Meteoroid Orbital Debris (MMOD) strikes # RS-25-induced or RS-25 catastrophic failure (the Space Shuttle Main Engine) # Ascent debris strikes to TPS leading to LOCV on orbit or entry # Crew error during entry # RSRM-induced RSRM catastrophic failure (RSRM are the rocket motors of the SRBs) # COPV failure (COPV are tanks inside the orbiter that hold gas at high pressure) {{np}}{{pb}}

[[File:STS-133 docked to ISS.jpg|thumb|right|''Discovery'' at ISS in 2011 ([[STS-133]]).]] [[John Young (astronaut)|John Young]] and [[Jerry L. Ross]] were among those astronauts who believed that the shuttle was always an experimental craft, not an operational vehicle for routine spaceflight as President [[Ronald Reagan]] declared after [[STS-4]]. [[Rick Hauck]] said in 2017 that before STS-1 he saw an analysis estimating the risk of loss of the vehicle as 1 in 280,{{r|cfu2019}} but an internal NASA risk assessment study (conducted by the Shuttle Program Safety and Mission Assurance Office at [[Lyndon B. Johnson Space Center|Johnson Space Center]]) released in late 2010 or early 2011 concluded that the agency had seriously underestimated the level of risk involved in operating the Shuttle. The report assessed that there was a 1 in 9 chance of a catastrophic disaster during the first nine flights of the Shuttle but that safety improvements had later improved the risk ratio to 1 in 90.<ref>''[[Florida Today]]'', "[http://www.airforcetimes.com/news/2011/02/gannett-nasa-report-says-shuttle-dangers-underestimated-021311w/ Report says NASA underestimated Shuttle dangers]", ''[[Military Times]]'', February 13, 2011. Retrieved February 15, 2011.</ref> In 1984 Reagan signed a [[National Security Decision Directive]] stating that the shuttle would not be "fully operational" until it could fly 24 missions a year, perhaps by 1988;<ref name="pincus19860305">{{Cite news |last=Pincus |first=Walter |date=1986-03-05 |title=NASA's Push to Put Citizen in Space Overtook Fully 'Operational' Shuttle |language=en-US |newspaper=Washington Post |url=https://www.washingtonpost.com/archive/politics/1986/03/05/nasas-push-to-put-citizen-in-space-overtook-fully-operational-shuttle/29fe2714-39b7-40dd-b15e-073441de636e/ |access-date=2020-07-14 |issn=0190-8286}}</ref> the shuttle never flew more often than the nine missions of 1985,{{r|cfu2019}} and averaged about six missions a year between 1988 and 2003.<ref name="portree20120324">{{Cite magazine |last=Portree |first=David S. F. |date=2012-03-24 |title=What Shuttle Should Have Been: The October 1977 Flight Manifest |url=https://www.wired.com/2012/03/what-shuttle-should-have-been-the-october-1977-flight-manifest/ |magazine=Wired |issn=1059-1028}}</ref>

Although many NASA astronauts criticized the [[payload specialist]] program, in part because they did not believe less-trained outsiders were fully aware of the risks of spaceflight, full-time astronauts may not have been either.{{r|cfu2019}} [[Charles Bolden]] was amazed to learn after the loss of ''Columbia'' that the "impenetrable" leading wing edges of the vehicle he flew for 14 years were less than an inch thick.<ref name="bolden20040106">{{cite interview | title=Charles F. Bolden | date=January 6, 2004 | access-date=January 6, 2014 | last=Bolden | first=Charles F. | subject-link=Charles F. Bolden | interviewer1=Johnson, Sandra | interviewer2=Wright, Rebecca | interviewer3=Ross-Nazzal, Jennifer | work=NASA Johnson Space Center Oral History Project | location=Houston, Texas | url=http://www.jsc.nasa.gov/history/oral_histories/BoldenCF/BoldenCF_1-6-04.htm | url-status=dead | archive-url=https://web.archive.org/web/20140107031937/http://www.jsc.nasa.gov/history/oral_histories/BoldenCF/BoldenCF_1-6-04.htm | archive-date=January 7, 2014 | df=mdy-all }}</ref> NASA in October 1982 predicted 37 shuttle flights by early 1986,{{r|pincus19860305}} but ''Challenger''{{'}}s loss was the 25th shuttle flight. Hauck, with much experience flying dangerous aircraft at the [[United States Naval Test Pilot School]], said "If I knew in advance that one in twenty-five would fail, I would probably think twice about flying three (as I did) out of the first twenty-six flights".<ref name="cfu2019">{{Cite book |last1=Croft |first1=Melvin |title=Come Fly with Us: NASA's Payload Specialist Program |last2=Youskauskas |first2=John |publisher=University of Nebraska Press |year=2019 |isbn=9781496212252 |pages=42–43,47 |series=Outward Odyssey: a People's History of Spaceflight}}</ref>

==Retrospect== While the system was ''developed'' within the original cost and time estimates given to President [[Richard M. Nixon]] in 1971, the operational costs, flight rate, payload capacity, and reliability by the time of the February 2003 [[Space Shuttle Columbia disaster|''Columbia'' accident]] proved to be much worse than originally anticipated.<ref>{{cite web |url=http://caib.nasa.gov/events/public_hearings/20030423/transcript_am.html |title=''Columbia'' Accident Investigation Board public hearing |date=2003-04-23 |publisher=NASA – Columbia Accident Investigation Board |access-date=2008-09-26 |url-status=dead |archive-url=https://web.archive.org/web/20081016135918/http://caib.nasa.gov/events/public_hearings/20030423/transcript_am.html |archive-date=2008-10-16 }}</ref> A year before [[STS-1]]'s April 1981 launch, [[Gregg Easterbrook]] in ''[[The Washington Monthly]]'' accurately forecasted many of the Shuttle's issues, including an overambitious launch schedule and the consequently higher-than-expected marginal cost per flight; the risks of depending on the Shuttle for all payloads, civilian and military; the lack of a survivable abort scenario if a Solid Rocket Booster were to fail; and the fragility of the Shuttle's thermal protection system.<ref name="easterbrook198004">{{cite news | url=http://www.washingtonmonthly.com/features/2001/8004.easterbrook-fulltext.html | title=Beam Me Out Of This Death Trap, Scotty | work=The Washington Monthly | date=April 1980 | access-date=15 September 2016 | author=Easterbrook, Gregg | archive-url=https://web.archive.org/web/20030203074859/http://www.washingtonmonthly.com/features/2001/8004.easterbrook-fulltext.html | archive-date=2003-02-03}}</ref><ref name="day20110627">{{cite web | url=http://www.thespacereview.com/article/1872/1 | title=Gazing back through the crystal ball | work=The Space Review | date=2011-06-27 | access-date=June 27, 2011 | author=Day, Dwayne Allen}}</ref> General [[Lew Allen]], [[Chief of Staff of the United States Air Force]], reportedly said that year that he would have canceled the shuttle.<ref name="cassutt">{{Cite magazine |last=Cassutt |first=Michael |date=August 2009 |title=The Secret Space Shuttles |url=https://www.airspacemag.com/space/secret-space-shuttles-35318554/ |magazine=Air & Space |language=en |access-date=2021-06-19}}</ref>

In order to get the Shuttle approved, NASA over-promised its economies and utility. To justify its very large fixed operational program cost, NASA initially forced all domestic, internal, and [[United States Department of Defense|Department of Defense]] payloads to the shuttle.{{cn|date=February 2023}} When that proved impossible (after the ''Challenger'' disaster), NASA used the [[International Space Station]] (ISS) as a justification for the shuttle.<ref>{{cite news|url=https://www.theguardian.com/science/2011/jul/21/space-shuttle-programme|title=The space shuttle programme has been a multi-billion-dollar failure|author=Krauss, Lawrence|date=2011-07-21|newspaper=The Guardian|access-date=2013-08-19}}</ref> [[NASA administrator]] [[Michael D. Griffin]] argued in a 2007 paper that the [[Saturn (rocket family)|Saturn program]], if continued, could have provided six crewed launches per year – two of them to the Moon – at the same cost as the Shuttle program, with an additional ability to loft infrastructure for further missions: {{quote|If we had done all this, we would be on Mars today, not writing about it as a subject for "the next 50 years." We would have decades of experience operating long-duration space systems in Earth orbit, and similar decades of experience in exploring and learning to utilize the Moon.<ref>{{cite magazine|url=http://aviationweek.typepad.com/space/2007/03/human_space_exp.html|title=Human Space Exploration:The Next 50 Years|date=2007-03-14|magazine=Aviation Week|access-date=2009-06-18}}</ref>}}

Some had argued that the Shuttle program was flawed.<ref>{{cite news|url=https://www.usatoday.com/tech/science/space/2005-09-27-nasa-griffin-interview_x.htm|title=NASA administrator says space shuttle was a mistake |last=Watson|first=Traci|date=2005-09-30|newspaper=USA Today|access-date=2008-09-26}}</ref> Achieving a reusable vehicle with early 1970s technology forced design decisions that compromised operational reliability and safety. Reusable main engines were made a priority. This necessitated that they not burn up upon atmospheric reentry, which in turn made mounting them on the orbiter itself (the one part of the Shuttle system where reuse was paramount) a seemingly logical decision. However, this had the following consequences:{{Citation needed|date=January 2018}} * a more expensive "clean sheet" engine design was needed, using more expensive materials, as opposed to existing and proven off-the-shelf alternatives (such as the [[Saturn V]] mains); * increased ongoing maintenance costs related to keeping the reusable SSMEs in flying condition after each launch, costs which in total may have exceeded that of building disposable main engines for each launch. {{np}}{{pb}} A concern expressed by the 1990 [[Advisory Committee on the Future of the United States Space Program|Augustine Commission]] was that "the civil space program is overly dependent upon the Space Shuttle for access to space." The committee pointed out, "that it was, for example, inappropriate in the case of ''Challenger'' to risk the lives of seven astronauts and nearly one-fourth of NASA's launch assets to place in orbit a communications satellite."<ref>{{cite web |url=https://history.nasa.gov/augustine/racfup2.htm |title=Report of the Advisory Committee On the Future of the U.S. Space Program, Executive Summary |date = December 1990|publisher=NASA}}</ref>

There are some [[NASA spin-off technologies]] related to the Space Shuttle program which have been successfully developed into commercial products, such as using heat-resistant materials developed to protect the Shuttle on reentry in suits for municipal and aircraft rescue firefighters.<ref name=Spinoff1978>{{cite book | author = NASA | title = Spinoff | location = Washington, DC | publisher = U.S. Government Printing Office | date = 1978 | url = http://www.sti.nasa.gov/tto/back_issues_archives/1978.pdf | archive-url = https://web.archive.org/web/20080706162618/http://www.sti.nasa.gov/tto/back_issues_archives/1978.pdf | url-status = dead | archive-date = 2008-07-06 }}</ref>

==See also== {{portal|Spaceflight}} *[[Buran (spacecraft)]] *[[Skylab 4]]

==References== {{Reflist|2}}

==External links== * [https://web.archive.org/web/20061018192222/http://www.colonyfund.com/Reading/papers/phys_econ_leo2.html When Physics, Economics, and Reality Collide: The Challenge of Cheap Orbital Access] * [http://www.spaceref.com/news/viewnews.html?id=301 Review of ELV cost-to-orbit per pound] {{Webarchive|url=https://web.archive.org/web/20211001053313/http://www.spaceref.com/news/viewnews.html?id=301 |date=2021-10-01 }} *[https://web.archive.org/web/20110711061933/http://www.futron.com/upload/wysiwyg/Resources/Whitepapers/Space_Transportation_Costs_Trends_0902.pdf Space Transportation Costs: Trends in Price Per Pound to Orbit]  * [https://books.google.com/books?id=tE0idc3G364C&pg=PA69 ''Popular Science'' November 1974, "Reusable space shuttle"] by [[Wernher von Braun]]

{{DEFAULTSORT:Criticism Of The Space Shuttle Program}} [[Category:Criticisms|Space Shuttle]] [[Category:Crewed spacecraft]] [[Category:Space Shuttle program]] [[Category:Criticism of science|Space Shuttle program]]