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no numbers are certain and clearly the qualification testing did not point out the current thermal problems. Currently, plans are being considered and some evaluation testing is being performed to look at stator upgrades. These include a thicker beryllium stator and steel stators. Stiffer axels and hydraulic system orifices are now complete and are in the program. A carbon brake program has been undertaken to provide a major energy improvement and hopefully less dynamic damage due to fewer parts. Recent tests using abort braking procedures and the current brakes achieved over 59 MFP. Tests using the thickened stator for stators number 2 and 3 achieved 65 MFP before all stators failed. This new thickened stator design (stators 2, 3) is currently being certified for use on the next Space Shuttle flight.

It seems clear that, with the current design, the abort brake energy limits in the Flight Rules should be reinvestigated. The 61-C damage resulted from only 34 MFP of energy. If this same brake design is to continue to fly, the STS 61-C damage should be fully understood and the destructive testing should be accomplished to establish the short runway (TAL) rollout capability.

Due to brake problems seen in the program, a series of ad hoc expert reviews has been conducted. The third session will be in the summer
of 1986. The members have reviewed all of the Orbiter brake data and have compared Orbiter problems to industry problems. The Orbiter has had nothing occur that has not been experienced in industry. Improve-ments suggested by these experts have been developed and implemented. Admittedly, the fixes have come very slowly due to the complexity of the fixes and the competition of funds in the program. The concensus [[consensus]] of the Orbiter brake engineers, contractors, and ad hoc committee members is summarized as follows.

1. Brake anomalies are typical of aircraft experience and were
usually incurred in taxi tests and sometimes after aircraft is put into service. They are difficult to simulate in ground tests.

2. Dynamic damage observed is associated primarily with rotors,
which is not significant enough to lock wheels during rollout. This does not significantly affect available brake energy.

3. Thermal/energy failure of stators will occur at low speeds
after significant energy is absorbed during landing.

4. Brake anomalies have been judged to be no threat to flight
safety with current operational restrictions.

5. High priority should be placed on correcting current brake problems. 

6. Brake redesign should proceed for higher energy and torque capacity.

Additionally, since operational braking capability has not yet been demonstrated and a significant number of fixes are yet to be implemented and verified, the National Space Transportation System

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