Slide 38 of 99
Notes:
NASA radically changed its Space Station baseline design in October 1985 following frequent complaints from users and astronauts. The new "Dual Keel" Station was largely based on Lockheed and McDonnell-Douglas designs and its structure was much stiffer and hence easier to stabilize. It would offer additional space for external instruments plus a better microgravity environment than the previous gravity gradient-stabilized "Power Tower.” The number of crewmembers was increased to 8 astronauts because scientists were concerned that a crew of six would be too busy with assembly & maintenance tasks and have no time for research.
“Dual Keel” Space Station illustration from the 1986 “Pioneering the Space Frontier” report. Note Hubble Space Telescope at upper left. NASA's target date for the launch of the first element was now January 1993 while the initial operational capability had slipped to January 1994 mainly because the Fiscal 1986 budget was reduced from $280 million to just $200 million.
This diagram shows the distribution of work between the four NASA centers and international partners during Phase B in April 1985-87.
Rockwell's “Dual Keel” proposal at various stages of the assembly process. 11 Shuttle flights would be required for initial assembly. Officially, the estimated cost of the Station had only increased by $400 million but there were concerns that NASA was once again hiding the true cost of the larger, more complex “Dual Keel” design.
