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Other stages of the flight had been —and would be—dangerous enough. At any point during the eight-day journey, a massive failure of the electrical or oxygen systems, or a collision with a large meteor would almost surely result in tragedy. But lift-off was the most nerve-racking part of the mission. If the ascent engine had failed to start, Eagle would have been stranded on the lunar surface. Too short a burn would have tossed the module into a trajectory that would send it smashing back onto the lunar surface. Had the LM achieved an orbit with an apocynthion (high point) much less than 50,000 ft., Columbia would have been unable to reach it. As it turned out, departure from the moon was triumphantly smooth. Of course, even after lift-off and redocking, there were still the dangers of the homeward trip. Control failures could cause the spacecraft to re-enter the earth's atmosphere at too steep an angle and burn to a cinder, or at so flat an angle that it would bounce off the outer fringes of the atmosphere far into space. There its oxygen would be exhausted before it could loop back to the earth.
The Beginning
The early part of Apollo 11 's epic journey had been as uneventful as the later part was suspenseful. Lift-off was nearly perfect. Rising Phoenix-like above its own exhaust flames, a scant 724 milliseconds behind schedule, the giant rocket shook loose some 1,300 Ibs. of ice that had frozen on its white sides. Although it was the heaviest space vehicle ever fired aloft—6,484,289 Ibs. at ignition—it cleared the launch tower in twelve seconds.
Less than twelve minutes after liftoff, a brief boost from the S-4B third stage placed Apollo into a circular 119-mile orbit at a velocity of 17,427 m.p.h. Over the Pacific for the second time, just 2½ hrs. after launch, the spacecraft was cleared by Houston for "translunar insertion" (TLI). Firing for five minutes, the reliable S-4B engine accelerated the ship to 24,245 m.p.h., fast enough to tear it loose from the earth's gravitational embrace and send it toward the moon. At a point 43,495 miles from the moon, lunar gravity exerted a force equal to the gravity of the earth, then some 200,000 miles distant. Beyond that crest, lunar gravity predominated, and Apollo was on the "downhill" leg of its journey.
Through the remainder of the outbound flight, Apollo 11 astronauts were less talkative than their Apollo 10 predecessors. "It's all dead air and static," said an official in Mission Control.
The astronauts compensated for the uninspiring conversations with Houston during several performances in front of their color television camera—something that apparently can bring out the ham in any man. At one point, Collins said: "O.K., world. Hang onto your hat. I'm going to turn you upside down." As Collins rotated his camera, keeping it pointed toward the earth, the blue and white planet took an erratic 180° turn on earth-based TV screens. "I'm making myself seasick," Collins called to Houston. "I'm going to put you right side up." The earth promptly performed another lazy turn on the TV screens.
Snakes in the Lake Bed