Source4

Computers in Spaceflight: The NASA Experience



l. Interview with Arnold Aldrich, Johnson Space Center, June 13, 1983.

2. Interview with Lynn Killingbeck, IBM, Johnson Space Center, June 7, 1983.

3. For a full discussion of the evolution of Shuttle design concepts, see the first two chapters of the forthcoming Space Shuttle Chronology.

4. NASA, Space Vehicle Design Criteria: Spaceborne Digital Computer Systems, SP-8070, March 1971.

5. Killingbeck interview; In 1967, the Manned Spacecraft Center contracted with IBM for a conceptual study of spaceborne computers; see M. Ball, and F.H. Hardie, "Computer Partitioning Improves Long-term Reliability in Space," Space/Aeronaut.,114-118 (May 1967).

6. F.J. Hudson and J.C. McCall, "Integrated Electronics System for Space Shuttle," AIAA Advanced Space Transportation Meeting, Cocoa Beach, FL, February 4-6,1970.

7. M. Hamilton and S. Zeldin "Higher Order Software Techniques Applied to a Space Shuttle Prototype Program," Programming Symposium, ed. B. Robimet, Springer-Verlag, New York, 1974, pp. 17-32; Higher-Order SoftwareóA Methodology for Defining Software, AIAA Paper 75-593; Higher Order Software Requirements, MIT Draper Laboratory, Cambridge, MA, August 1973.

8. G.A. Vacca et al. "Mission Influences on Advanced Computers," Astronaut. Aeronaut., 36-37 (April 1967).

9. NASA, Space Vehicle Design Criteria, p. 16.

10. R.L. Alonso; and G.C. Randa "Flight-Computer Hardware Trends," Astronautics and Aeronautics, April 1967, pp. 31.

11. B.W. Boehm, "Some Information Processing Implications of Air Force Space Missions: 1979-1980," Memorandum, Rand Corp., January 1970, V.

12. Boehm, "Information Processing Implications," p. 21.

13. H. Kreide and D.W. Lambert, "Computation: Aerospace Computers in Aircraft, Missiles and Spacecraft," Space/Aeronaut., 42, 78 (1964); see also N.H. Herman and U.S. Lingon, "Mariner 4 Timing and Sequencing," Astronaut. Aeronaut., 43 (October 1965).

14. A.E. Cooper, "The Shuttle Computer Complex," Space Transportation System: The IBM Role, IBM Corporation, 1981, p. 3.

15. NASA, Space Vehicle Design Criteria, p. 44.

16. Z. Strickland, "NASA Seeks Ways to Handle Data Flood," Aviation Week, June 22, 1970, p. 135.

17. E.S. Chevers, "Proposed Avionics Baseline for the Shuttle," Memorandum, Manned Spacecraft Center, Houston, TX, August 1971, JSC History Office Archives.

18. Interview with Stan Mann, Johnson Space Center, June 8, 1983.

19. Draper Laboratory, "Computer Hardware," charts, March 1971, Johnson Space Center Archives.

20. Draper Laboratory, "Computer Hardware."

21. P.H. Stakem, "One Step Forward - Three steps Backup: Computing in the U.S. Space Program," BYTE, 114 (September 1981).

22. Draper Laboratory, "Computer Hardware."

23. J. Kernan, "Desirable Computer Features," Memorandum, Cambridge: MIT, March 5, 1971.", JSC History Office; see also Draper Laboratory, "Computer Hardware."

24. Boehm, "Information Processing Implications," p. 19.

25. R.E. Poupard et al., "Design Considerations for Shuttle Information Management," Astronaut. Aeronaut., 53 (May 1973).

26. "Guidance Software Programming Advances," Aviation Week, 73 (November 8, 1976).

27. Interview with Dick Parten, Johnson Space Center, June 16, 1983.

28. Killingbeck interview.

29. "New Family of Computers: Military and Aerospace," Electronics, 42 (October 31, 1966).

30. IBM, Space Shuttle Advanced System/4 Pi Model AP-101 Central Processor Unit, File no. 75-A97-001, 1975, 4.64; see also Cooper, "Shuttle Computer Complex," p. 7.

31. A.J. Macina "Space Shuttle Program," Part I, Memorandum, IBM Federal Systems Division, Houston, p. 16; see also Cooper, "Shuttle Computer Complex," p.5.

32. IBM, Model AP-101 Central Processor Unit., 1.2, 2.8.

33. Marina, "Space Shuttle," Part I, p. 16.

34. Cooper, "Shuttle Computer Complex", p. 4.

35. IBM, Model AP-101 Central Processor Unit, 2.14.

36. IBM, Space Shuttle Model AP-101 C/M Principles of Operation, File no. 624615B, 1974, 2.2.

37. Cooper, "Shuttle Computer Complex", p. 6.

38. IBM, Model AP-101 Principles of Operation, 2.15.

39. IBM, Model AP-101 Principles of Operation, 2.17.

40. NASA, Shuttle Flight Operations Manual: Volume 5-Data Processing System, Flight Operations Directorate, Crew Training and Procedures Division, Johnson Space Center, Houston, TX, November 1978, p. 50.

41. Cooper, "Shuttle Computer Complex," p. 8.

42. IBM, Model AP-101 Central Processor Unit, 5.1.

43. Killingbeck interview.

44. Interview with John R. Garman, Johnson Space Center, June 1, 1983.

45. Killingbeck interview.

46. Interview with Dick Parten, June 3, 1983.

47. Garman interview, June 1, 1983.

48. Parten interview, June 16, 1983.

49. Cooper, "Shuttle Computer Complex," p. 9.

50. IBM, Model AP-101 Central Processor Unit, 4.36.

51. R.E. Poupard, "Redundant Computer Operations," in Space Transportation System, p. 21.

52. IBM, Space Shuttle Advanced System/4 Pi Input/output Processor, File no. 6246556A, 1976, part III, p. 1.

53. IBM, Input/output Processor, part II, p. 1.

54. IBM, Space Shuttle Advanced System/4 Pi Prototype Input/Ouput Processor, File no. 74-A31-016, 1974, p. 1.3.

55. IBM, Prototype input/output, p. 1.1.

56. NASA, Data Processing System Overview Workbook, DPS-OV-2102, 1979, p. 16.

57. A. E. Cooper and E.S. Flanders, "Shuttle Multlfunction CRT Display and Mass Memory Subsystem," in Space Transportation System, p. 11 ;Macina, "Space Shuttle," Part I, p. 24; NASA, Overview Workbook, p. 54.

58. NASA, Shuttle Operations Manual, p. 4.58.

59. "Velocity, Altitude Regimes to Push Computer Limits," Aviation Week, 49 (April 6, 1981).

60. D.C. Fraser and P.G. Felleman, "Digital Fly-by-Wire: Computer Lead the Way," Astronaut. Aeronaut., 12, 24-32 (July-August 1974).

61. Killingbeck interview.

62. For a more complete description see James E. Tomayko, "Digital Fly-By-Wire: A Case of Bidirectional Technology Transfer," in Aerospace Historian, 33 (1), 10.18 (March 1986).

63. B.R.A. Burns, "Control Configured Combat Aircraft," Active Controls in Aircraft Design. P.R. Kurzhals, ed., AGARDograph #234, NATO, London, 1978, p. 3.15.

64. Poupard, "Redundant Computer," p. 20.

65. Mann interview, June 8, 1983.

66. A.D. Aldrich, "A Sixth GPC On-Orbit," Memorandum, Johnson Space Center, Houston, TX, October 13, 1978, JSC History Office.

67. Garman interview, June 1, 1983.

68. Mann interview, June 8, 1983.

69. Killingbeck interview; also Parten interview, June 16, 1983.

70. Killingbeck interview.

71. Parten interview, June 16, 1983.

72. NASA, Shuttle Operations Manual, pp. 4.24-4.25.

73. NASA, Shuttle Operations Manual, p. 4.28.

74. Poupard, "Redundant Computer," p. 23.

75. NASA, Shuttle Operations Manual, pp. 4.28-4.29.

76. NASA, Overview Workbook, p. 6; NASA, Shuttle Operations Manual, p. 4.22.

77. Garman interview, June 1, 1983; Killingbeck interview.

78. Mann interview, June 8, 1983.

79. Interview with Kyle Rone, IBM, Johnson Space Center, June 3, 1983.

80. Killingbeck interview.

81. Interview with John Aaron, Johnson Space Center, June 17, 1983.

82. Interview with William Sullivan, Johnson Space Center June 14, 1983.

83. Parten interview, June 3, 1983.

84. Sullivan interview.

85. Parten interview, June 3, 1983.

86. Mann interview, June 8, 1983.

87. Parten interview, June 16, 1983.

88. Parten interview, June 16, 1983.

89. Interview with Anthony Macina, IBM, Houston, TX, June 7,1983.

90. There are widely disparate estimates of how many people actually contributed to the shuttle software. Macina of IBM says 275, but l think he means coders. John Aaron of NASA, head of Spacecraft Software in 1983, estimates 900 contractors and 90 civil servants. Parten said 2,000 but that may include everyone in all contracting organizations working on hardware and software. The figure of 1,000 seems reasonable for software developers, as it is consistent with similar projects.

91. Frederick Brooks, The Mythical Man-Month, Addison-Wesley, Reading, MA, (1975).

92. Parten interview, June 16, 1983.

93. Aaron interview; Sullivan interview.

94. NASA, Development Specification, Volume Five, Book l, pp. 3.72-3.75.

95. Sullivan interview.

96. Parten interview, June 3, 1985.

97. M. Hamilton and S. Zeldin, Higher Order Software Requirements, MIT Draper Laboratory, Cambridge, MA, August 1973.

98. An example would be Draper Lab's, Space Shuttle On-Orbit Flight Control Software Requirements, December 1975.

99. Sullivan interview.

100. Rone interview.

101. Parten interview, June 3, 1983.

102. Killingbeck interview.

103. Sullivan interview.

104. W.A. Madden and K.Y. Rone, Design, Development, Integration: Space Shuttle Primary Flight Software System, IBM Federal Systems Division, Houston, TX 1980, p. 36; also reprinted in the Commun. ACM, 27, (9), 914-925 (September 1984).

105. Aaron interview.

106. NASA, Overview Workbook, p. 52.

107. Killingbeck interview.

108. Mann interview, June 8, 1983.

109. NASA, Space Shuttle Operations, p. 4.32.

110. Macina interview.

111. IBM, Space Shuttle Model AP-101, 2.22.

112. F.H. Martin, "HAL/S The Avionics Programming System for the Shuttle," AIAA, 315 (1977).

113. IBM, Space Shuttle Orbiter Avionics Software Interface Control Document, HAL/S/FCOS, version 5.

114. Macina interview.

115. Killingbeck interview.

116. Garman interview, June 1, 1983.

117. R.F. Thompson, "Minutes of Shuttle System Software Review," Memorandum, Johnson Space Center, Houston, TX, May 29, 1974, JSC History Office.

118. Killingbeck interview.

119. Macina, "Space Shuttle," Part One, p. 30.

120. David Gifford and Alfred Spector, ed., "Case Study: The Space Shuttle Primary Computer System," Commun. ACM, 27,881 (September 1984).

121. Boehm, Information Processing Implications, p. 35.

122. Gifford and Spector, "Case Study," p. 885.

123. J.R. Garman, Managing the Software Development for the Space Shuttle Orbiter, Johnson Space Center, Houston, TX, December 9, 1981, JSC History Office, p.10.

124. Garman interview, June 1, 1983.

125. Sullivan interview.

126. Macina interview.

127. IBM, SDL Requirements Document. Pt. 2-Hardware Configuration, May 31, 1974, JSC History Office, p. 2.3.

128. C.C. Kraft jr. "Automatic Data Processing Equipment (ADPE) Acquisition Plan for the Software Production Facility (SPF), Memorandum, Johnson Space Center, Houston, TX, April 18, 1980, JSC History Office.

129. Garman, Managing the Software Development, p. 6.

130. Aaron interview.

131. Sullivan interview,

132. J.R. Garman, "Software Production Facility: Management SummaryóConcepts and Schedule Status," NASA Data Systems and Analysis Directorate, Spacecraft Software Division, February 10, 1981, p. 12.

133. Sullivan interview.

134. Macina interview.

135. A.J. Macina, Independent Verification and Validation Testing of the Space Shuttle Primary Flight Software System, IBM, Houston, TX, December 1980, p. 4.

136. Macina, Independent Verification and Validation Testing, p. 8.

137. See IBM, Flight Software Integrated Test Plan, Volume II, #77-SS-3622 for examples of test cases.

138. Macina, "Space Shuttle," Part 2, p. 14.

139. Gifford and Spector "Case Study," p. 884; Hamilton and Zeldin, Software Requirements, p. 39.

140. Macina, Independent Verification and Validation Testing, p. 8.

141. Macina, Independent Verification and Validation Testing, p. 8.

142. Macina interview.

143. Macina interview; Mann interview, June 8, 1983.

144. Garman, Managing the Software Development, p. 3.

145. Macina interview.

146. Parten interview, June 16, 1983.

147. Mann interview, June 8, 1983.

148. Mann interview, June 8, 1983.

149. Mann interview, June 8, 983.

150. Parten interview, June 16, 1983.

151. See NASA, OFTIS-19 Program Notes and Waivers, Houston, November 1983.

152. Macina interview.

153. Mann interview, June 8, 1983.

154. Gifford and Spector, "Case Study," p. 893.

155. Garman, "Managing the Software Development," p. 5.

156. Mann interview, June 8, 1983.

157. Telephone interview with John Young, Johnson Spaceflight Center, March 6, 1984.

158. Interview with Frank Hughes, Johnson Space Center, June 2, 1983.

159. Aaron interview.

160. Hughes interview.

161. Interview with Vance Brand, Johnson Space Center, June 2, 1983.

162. Interview with Henry Hartsfield, Johnson Space Center, June 2, 1983. 41

163. Young interview; Brand interview; Interview with Terry Hart, Johnson Space Center, June 10, 1983.

164. Hart interview.

165. "Main Engine Controller Location," undated charts, no author, obtained from Russ Mattox, Marshall Space Flight Center.

166. Interview with Walt Mitchell, Marshall Space flight Center, June 23, 1983.

167. R.M. Mattox and J.B. White, Space Shuttle Main Engine Controller, NASA Technical Paper 1932, Marshall Space Flight Center, Huntsville, AL, November 1981, p.l.

168. "Main Engine Controller".

169. Interview with Russ Mattox, Marshall Space Center, June 23, 1983.

170. Mattox and White, Space Shuttle Main Engine, p. 6.

171. Mattox and White, Space Shuttle Main Engine, pp. 9,11.

172. Mattox and White, Space Shuttle Main Engine, p. 5.

173. Mattox interview.

174. Mattox and White, Space Shuttle Main Engine, p. 23.

175. Mitchell interview.

176. Mattox and White, Space Shuttle Main Engine, p. 31.

177. Mattox and White, Space Shuttle Main Engine, p. 12.

178. Mitchell interview.

179. Mattox interview.

180. Mitchell interview.

181. Mattox and White, Space Shuttle Main Engine, p. 29.

182. Mattox interview.

183. Telephone interview with Russ Mattox, Marshall Space Center, November 16, 1984.

184. Telephone interview with Gary K. Raines, Johnson Spaceflight Center, November 1, 1985.