Space: Kindergarten Gemini

The Gemini two-men-in-space program, already nine months behind schedule, got off the ground last week. A Martin Marietta Titan II rode from Cape Kennedy trailing orange smoke from its two engines, an unmanned dummy capsule fitted into its nose. The first stage burned for 21 minutes, then the second stage ignited and accelerated to orbital speed. In six minutes the word came back from the tracking system: Gemini was in orbit with a perigee of 99.6 miles and an apogee of 204 miles, almost exactly as planned.

The delay-free smoothness of the launch was largely because Titan II, a practical, dependable military rocket, does not use troublesome liquid oxygen. Instead it burns storable liquid fuels (a mixture of hydrazine and unsymmetrical dimethylhydrazine with nitrogen tetroxide as oxidizer) that are "hyper-golic," ignited spontaneously on contact. It is much more powerful than the Atlas that launched the manned Mercury capsules, having 430,000 Ibs. of thrust at takeoff instead of 360,000, and 100,000 Ibs. of thrust in its second stage. The dummy Gemini capsule, weighted with ballast and instruments, was more than twice as heavy (6,950 Ibs.) as a manned Mercury capsule, though lighter than the 8,200-lb. warhead that the Titan II normally carries on a ballistic flight.

Last week's Gemini was expected to burn up in the atmosphere in a few days. It was sacrificed chiefly to find out whether Titan II had been successfully modified for the man-in-space program. It used a different guidance system and many safety devices to protect the lives of the astronauts whom it will carry later in the program. The Titan's engines were modified to reduce its characteristic "pogo-stick" (up-and-down) vibration, which might incapacitate a human crew. Reports came back that everything worked fine.

The Gemini capsules, whose two-man crews will experiment with rendezvous in orbit, are an essential part of the Apollo moon project. The kindergarten schooling of earth orbit maneuvers is intended to train astronauts for the infinitely more difficult moon landing. Next Gemini launch, which is scheduled for late this summer, will test the capsule's re-entry behavior. Unless the program falters, the first two-man flight will come toward the end of this year.