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Preferred LOR. No C-5s are scheduled to fly before 1965, but assembly and launch facilities must be started well ahead. Much of Holmes's attention goes into such planning, but not long ago he had to make a more crucial decision: he had to select the "mode" in which the first men will fly to the moon.
According to present NASA thinking, there are only three possible methods for making a manned moon expedition. The direct approach requires a multistage rocket big enough to fly straight to the moon and land a manned spacecraft there with everything needed for the return trip back to earth. Mode No. 2 is Earth Orbit Rendezvous (EOR), which requires two rockets to meet on an orbit around the earth. One of them fuels itself from the other and departs, replenished, for the moon. In mode No. 3, LOR (Lunar Orbit Rendezvous), a single rocket will proceed to the moon and park its manned upper stage in a lunar orbit. Then a small manned landing craft will descend to the lunar surface, stay there for a short while, and climb up again for orbital rendezvous before returning to earth.
Until recently NASA officially favored Earth Orbit Rendezvous. But now Lunar Orbit Rendezvous has become the most favored mode. Dr. Joseph F. Shea, Holmes's deputy in charge of systems, makes a convincing case for the decision. Each mode, says Shea, was broken down into major elements, starting with takeoff from the earth. To each element was assigned a number expressing its relative hazard as accurately as possible. A very safe element, for instance, might have been given the fraction .9998, while a very dangerous one might have gotten .75, meaning that it would probably fail one out of four times. After all the hazard numbers, from take-off to return, were multiplied together, the result represented the hazard of the whole mode. In the final reckoning, LOR looked best. Chief advantage is the smallness of the lunar landing vehicle, which will be easier and safer to set down on the moon. Shea is sure that rendezvous near the moon will be no more difficult than rendezvous near the earth.
There are still too many unknowns for NASA scientists to make an irreversible decision. But Holmes smiles with a hint of apology, "We have to choose some plan, or we'd better pack up and go home." Then he turns intensely serious. "We can't change too often though. It costs too much money." He picks from his desk a child's china bank in the shape of a rocket. When he puts a nickel in the slot, the coin falls right out through the open bottom. "A friend gave me this," he says, "to keep me thinking about the taxpayers' money."
TRAINING FOR THE MOON
The earth-circling trips of the astronauts and cosmonauts were almost as passive as floating down a river on an oarless raft. Making a rendezvous in space will have to be learned by long, expensive and dangerous practice, The basic trainers will be