Science: Reaching for the Moon

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the two-man Gemini* capsules. Shortly before the astronauts take off in one, an Atlas will shoot an unmanned Agena-B rocket into a circular orbit 300 miles above the earth. When the orbit has been carefully determined by ground observers, a Titan II will toss a manned Gemini capsule into a 150-mile orbit in the same plane. Being nearer the earth, the Gemini will move slightly faster than its Agena target. When the two craft reach the proper relative positions, the astronauts, having made their calculations, will fire small rockets just long enough to boost their capsule into an elliptical orbit that will carry it up toward the target.

If all goes well, the astronauts will locate the target by radar or by spotting its flashing strobe light. Though they will be circling the earth at enormous speed (18,000 m.p.h.) the two vehicles will be approaching each other at a relatively low rate, perhaps 35 m.p.h. After carefully measuring the target's relative speed by Doppler radar, the astronauts will fire small bursts from their rockets, gradually slowing their approach to a few feet per second, the speed of a slow walk. At some point they will give their craft "a kick in the apogee" to turn its elliptical orbit into a circular path matching the curve of the target.

During early rendezvous practice, Gemini crews will probably depend on guidance from the ground. Later, crews will make their own calculations; they will also actually "dock" the two satellites, bringing together interlocking parts that ''mate" firmly. At the end of each mission, the target rocket will be abandoned and the Gemini capsule will head back to the earth's surface. NASA hopes to land it on the comparatively friendly land instead of the unfriendly sea. The landing area has not yet been selected, but it will probably be set in the Plains states east of the Rocky Mountains. The Gemini may make its final touchdown suspended under the airy-looking Rogallo wing,* an inflated combination of parachute and glider (see diagram) that can be steered to a favorable spot.

After quite a number of Gemini crews have been trained in basic rendezvous techniques, they will graduate to larger, more complicated Apollo capsules, which will contain all the apparatus needed for a landing on the moon, including the "bug," more formally called the Lunar Excursion Vehicle. While circling around the earth, the astronauts will enter the bug, detach it, take short space rides in it, and finally return to earth in the parent vehicle. These operations will be almost exactly the same as those the astronauts will have to perform when making a rendezvous on an orbit around the moon. No landing on the moon will be attempted until several crews are proficient and all predictable operating difficulties have been eliminated.

DESTINATION MOON

At last the great C-5 rockets will be ready. The first that goes to the moon may not attempt to land; instead, it may merely cruise around to give its crew a good look. Later trips may go into brief lunar orbits, but not land either. If all goes well, before the end of President Kennedy's promised decade, will come the moment of truth. A C-5 with a tightly trained crew and full supplies will take off from Canaveral. After its first two stages have burned, it will swing into a parking orbit around the earth. After making sure that all is