OTD in Space – July 27: First Zero-G Cosmonaut Training on Soviet Jetliner

On July 27, 1962, two Russian cosmonauts boarded a Soviet airliner and experienced weightlessness without going to space. [‘On This Day in Space’ Video Series on Space.com](https://www.space.com/39251-on-this-day-in-space.html) This was the first time cosmonauts completed zero-G training on an airplane. The Tupelov Tu-104 was a type of jetliner originally designed to transport 50 passengers. It was modified to accommodate cosmonauts who needed to train in an environment that simulated weightlessness. By flying in a parabolic arc, passengers could experience 6 to 25 seconds of weightlessness on each maneuver. Cosmonauts Andriyan Nikolayev and Pavel Popovich were on this flight to prepare for their upcoming orbital missions Vostok 3 and Vostok 4.