Revised memo Challenger Disaster

Revision of First Memo:

July 18, 2009


To: Design groups from Marshall Space Flight Center, Morton Thiokol, Inc., Precision
Rubber Products Incorporated, and Parker Seal Company

From: Marshall Space Flight Center; Engineering and Design Group, Jennifer Furgerson,
Melanie Russell and Gordon Palmer

Subject: O-ring failure and possible explosion of the shuttle during take off

Dear Mr. Robert Boisjoly, Applied Mechanics Division

We understand that you and your group have the same concerns over the o-rings on the Solid rocket Boosters (SRB’s) as we do. The test data demonstrates the possibility of joint failure of the o-rings of the SRB’s. There have been problems since the inception of the program in 1977.
This is established in the November 30th 1977, memorandum. Apparently, the engineering groups could not come to a consensus in ways to solve the problem.

The MTL group had been testing the o-rings since late 1977 with unsatisfactory results. Even at this point in time they did not suggest a hold to the shuttle flights. At this time, Marshall Space flight Center design group wanted to change the specifications of the o-ring material as a possible solution to the problem.

On February 6, 1979, NASA engineers Eudy and Ray took the test results to the suppliers of the o-rings and material used in the manufacture of the o-rings, Precision Rubber Products Incorporated and Parker Seal Company. Both companies had the same reaction about the o-rings. There should be more testing completed in order to solve the problem. Temperature has a great deal to do with the o-ring not reseating at low temperatures. Anything below 50 degrees and the o-ring will not reseat allowing blow-by in the form of hot gases.

NASA, Precision Rubber Products, and Parker Seal want to see more testing completed so the data can be actually more in line with real conditions of lift off. The o-rings and the SRB joints should be mated to reseat at any temperature. The process for doing this is most likely changing the specifications for the material used in the manufacturing process. In the field test the gap between the o-ring and the SRB joint is greater than the allowable tolerances.

NASA engineers also feel that the primary o-ring failure could lead to the failure of the secondary o-ring seal. The MTL group disagrees with that theory and they feel that there is nothing to be concerned about with the secondary o-ring seals. This is a major conflict between the two groups.

Until this matter has been resolved the possibility of a major catastrophe is likely to occur. Not only the lost of the space shuttle but all those on board. This is unacceptable and we recommend that the shuttle flights be put on hold until this serious problem can be solved to the satisfaction of NASA and the o-ring suppliers

Respectfully,
Marshall Space Flight Center, Engineering, and Design Group,
Jennifer Furgerson, Melanie Russell, and Gordon


This is our group’s revised memo for the Challenger Disaster. We each wrote our own memo from our own perspective. As group leader, I took each memo and blended them together and used every ones ideas to revise the memo. Jenn, Melanie, and myself all had good ideas and hopefully I was able to convey those thoughts. We had communicated by e-mail and we eventually got everything in perspective.