TYPICAL LUNAR LANDING MISSION

The jumping-off place for a trip to the moon is NASA’s Launch Complex 39 at the Kennedy Space Center. After the propellants are loaded, the three astronauts will enter the spacecraft and check out their equipment.

While the astronauts tick off the last minutes of the countdown in the command module, a large crew in the launch control center handles the complicated launch operations. For the last two minutes, the countdown is fully automatic.

At the end of countdown, the five F-l engines in the first stage ignite, producing 7.3 million pounds of thrust. The holddown arms release the vehicle, and three astronauts begin their ride to the moon.

Turhopumps, working together with the strength of 31) diesel locomotives, force 15 tons of fuel per second into the engines. Steadily increasing accel­
eration pushes the astronauts back into their couch­es as the rocket generates 1-1, If times the force of earth gravity.

After 2,5 minutes, the first stage has burned its

4,192,0 pounds of propellants and is discarded at about 38 miles altitude. The second stage’s five,1-2 engines are ignited. Speed at this moment is 5,330 miles per hour.

The second stage’s five 4-2 engines burn for about (5 minutes, pushing the Apollo spacecraft to an altitude of nearly 115 miles and near orbital velocity of 15,300 miles per hour. After burnout the second stage drops away and retrorockets slow it for its fall into the Atlantic Ocean west of Africa.

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The single 4-2 engine in the third stage now ignites and burns for 2.75 minutes. This brief burn boosts the spacecraft to orbital velocity, about 17,500 miles an hour. The spacecraft, with the third stage still attached, goes into orbit about 12 minutes after liftoff. Propellants in the third stage are not depleted when the engine is shut down. This stage stays with the spacecraft in earth orbit, for its en­gine will be needed again.

Подпись: SATURN V NEWS REFERENCE
Подпись: K-107P-66P-258 Throughout the launch phase of the mission, telem­etry systems are transmitting continously, track­ing systems are locked on, and voice communica­tions are used to keep in touch with the astronauts. All stage separations and engine thrust terminations are reported to the Mission Control Center at Houston.

The astronauts are now in a weightless condition as they circle the earth in a “parking orbit” until the timing is right for the next step to the moon.

The first attempt at a lunar landing is planned as an “open-ended” mission with detailed plans at every stage for mission termination if necessary. A comprehensive set of alternate flight plans will be laid out and fully rehearsed for use if such a de­cision should prove necessary. For example, a de­cision might be made in the earth parking ortm not to continue with the mission. At every stage of the mission, right up to touchdown on the moon, this termination decision can be made and an earth flight plan initiated.

During the one to three times the spacecraft circles the earth, the astronauts make a complete check of the third stage and the spacecraft. When the precise moment comes for injection into a trans­lunar trajectory, the third stage J-2 engine is re­ignited. Burning slightly over 5 minutes, it acceler­ates the spacecraft from its earth orbital speed of 17,500 miles an hour to about 24,500 miles an hour in a trajectory which would carry the astronauts around the moon. Without further thrust, the space­craft would return to earth for re-entry.

If everything is operating on schedule, the astro­nauts will turn their spacecraft around and dock with the lunar landing module. After the docking maneuver has been completed, the lunar module will be pulled out of the forward end of the third stage, which will be abandoned. Abandonment com­pletes the Saturn V’s work on the lunar mission.