|astronautix.com||All-battery Apollo LEM decision - replaces fuel cells|
MSC decided in favor of an "all-battery" LEM (i.e., batteries rather than fuel cells in both stages of the vehicle) and notified Grumman accordingly. Pratt and Whitney's subcontract for fuel cells would be terminated on April 1; also, Grumman would assume parenthood of GE's contract (originally let by Pratt and Whitney) for the electrical control assembly.
MSC ordered an immediate cessation of all other efforts involved in the fuel-celled configuration. During the next several weeks, Grumman issued study contracts to Yardney Electric and Eagle-Picher for cost proposals. On April 1, the spacecraft manufacturer presented its proposal for an all-battery LEM; MSC's concurrence followed two weeks later.
A portable life support system (PLSS) battery charger would no longer be required, but three additional nonrechargeable PLSSs would be carried to provide for extravehicular activities. This change would now require a total of six nonrechargeable batteries.
On this same date, MSC ordered Grumman to end its work on a supercritical helium system for the LEM's ascent stage, and to incorporate an ambient mode for pressurization. All work on a supercritical system for the stage should be halted. However, Grumman should maintain the supercritical approach for the descent stage, while continuing parallel development on the ambient system. To permit the incorporation of either approach into the final design of the descent stage, components must be interchangeable. References: 16 .