Skip to main content

An Assessment of Space Shuttle Flight Software Development Processes (1993) / Chapter Skim
Currently Skimming:

1. Overview of the Study
Pages 17-28

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.


From page 19...
... This was long before the current 386/486 and 68000 series of computer chips were available. At the time, there did not exist a high-level language tailored for digital avionics applications, and structured programming techniques were just beginning to be applied outside the research environment.
Read the entire page →
From page 20...
... The IV&V function had been ~nshtu~, in part, as a result of a recommendation of a previous NRC committee evaluating post-Challenger Space Shuttle risk assessment and management. When the Committee began its investigations, the Shuttle Program Office believed that the flight software and the processes that were use to develop and verify updates were sufficiently mature to permit a phase-out of the contractors Cat perform IV&V.
Read the entire page →
From page 21...
... Since the Committee began its ~nvestigabons in January of 1992, the Shuttle Program Office has agreed, based on recommendations Cat were made in He Commiaee's Interim Report (see Appendix C) , to maintain the IV&V function In its current form.
Read the entire page →
From page 22...
... PREVIOUS STUDIES Following the Challenger accident in 1986, a number of assessments were made of the overall safety of the Shuttle program, many of which addressed verification and validation and He general software process as part of their investigations. These included evaluations by the Rogers Commission; an NRC committee; the House of Representatives' Committee on Science, Space, and Technology; and the General Accounting Office (GAO)
Read the entire page →
From page 23...
... software steering group, 8 and NASA-wide guidance, and ensure that the independent V&V organization is outside the control of He Shuttle Program Office. 6 Post Challenger Evaluation of Space Shuttle Risk Assessment awl Management, National Research Council Committee on Shuttle Criticality Review and Hazard Analysis Audit (Washington, D.C.: National Academy Press, 1988)
Read the entire page →
From page 24...
... Change Requests x Source: Intermetrics, Inc. In requesting the current review of the Shuttle flight software development process, the Shuttle Program Office has stated that if funding were not an issue they would continue with a robust IV&V program.
Read the entire page →
From page 25...
... Instead, the IV&V contractors report to the Shuttle Program Office directly, but at the same level as the software development contractors. THE FLIGHT SOFTWARE CHALLENGE Digital flight control systems of varying sophistication, and the software that ties them together, have existed on aerospace vehicles for decades, including digital flight control on the Apollo spacecraft.
Read the entire page →
From page 26...
... Operation of Me Shuttle Avionics Integration I laboratory, which is used to test Me flight software, requires approximately $24 million per year. This total does not include costs for software reconfiguration, development and maintenance of Space Shuttle Main Engine software, and other support contractors.
Read the entire page →
From page 27...
... OVERV1FW OF 17] E STUDY TABLE 1-2 Operational Increment Change History Operational I Year of I Lines of code I Increment Description Incorporation changed OI-2 Rendezvous software, SpaceLdb soRw~e 1983 10,600 OI-3 Redesi ~ 1983 8,000 OI-4 | Payload ret s capabilities | 1984 | 11,400 OI-S ~ _ _ ~ 198 , OI-6 | Experimentalorbit .utopilot,~nced 1 1985 1 12,200 l gm_l~ OI-7 ~ Western test range, chanced propellant ~ 1985 ~ 8,800 dm~s OI-7C 1 C~r 1 1985 1 6,600 1 OI-8A _ ~ 1987 6,300 OI-8B ~ __ 1988 1,100 OI-8C _ = ~ ~ 1988 7,200 OI-8D ~ _ ~ ~ 1989 12,000 OI-8F ~ 1989 1,700 tes,Tn~ Adantic abort | 1990 1 28,000 code OI-21 ~~ ~ 1991 32,000 condngency aborts, hardware changes for new Orbiter Source: NASA Office of Space Flight 27
Read the entire page →

Key Terms

  • software development
  • shuttle flight
  • shuttle program
  • space shuttle
  • space center

  • shuttle software
  • johnson space
  • challenger accident
  • development contractors
  • previous studies

  • complete description
  • office believed
  • current form
  • house committee
  • shuttle risk

  • space flight
  • rogers commission
  • hardware certification
  • studies described
  • shuttle challenger

  • software process
  • software verification
  • safety issues
  • independent oversight
  • space transportation

  • software steering
  • overall quality
  • presidential commission
  • validation requirements
  • independent verification


    • This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
    More information on Chapter Skim is available.