Monday, February 20, 2012

John Glenn and Friendship 7- 50 Years Ago Today

Mercury-Atlas 6 (MA-6) was a human spaceflight mission conducted by NASA, the space agency of the United States. As part of Project Mercury, MA-6 was the successful first attempt by NASA to place an astronaut into orbit. The MA-6 mission was launched February 20, 1962. It made three orbits of the Earth, piloted by astronaut John Glenn, who became the first American to orbit the Earth. The event was named an IEEE Milestone in 2011.

The Mercury spacecraft, named Friendship 7, was carried to orbit by an Atlas LV-3B launch vehicle lifting off from Launch Complex 14 at Cape Canaveral, Florida. After four hours and 56 minutes in flight the spacecraft re-entered the Earth's atmosphere, splashed down in the Atlantic Ocean and was safely taken aboard the USS Noa.

John Glenn boarded the Friendship 7 spacecraft at 11:03 UTC on February 20, 1962. The hatch was bolted in place at 12:10 UTC. Most of the 70 hatch bolts had been secured, when one was discovered to be broken. This caused a 42 minute delay while all the bolts were removed, the defective bolt was replaced and the hatch was re-bolted in place.

At 14:47 UTC, after two hours and 17 minutes of holds and three hours and 44 minutes after Glenn entered Friendship 7, engineer T.J. O'Malley pressed the button in the blockhouse launching the spacecraft. At liftoff Glenn's pulse rate climbed to 110 beats per minute (bpm).

Thirty seconds after liftoff the General Electric-Burroughs guidance system locked onto a radio transponder in the booster to guide the vehicle to orbit. As the Atlas and Friendship 7 passed through Max Q Glenn reported, "It's a little bumpy about here." After Max Q the flight smoothed out. At two minutes and 14 seconds after launch, the booster engines cut off and dropped away. Then at two minutes and twenty-four seconds, the escape tower was jettisoned, right on schedule.

After the tower was jettisoned, the Atlas and spacecraft pitched over still further, giving Glenn his first view of the horizon. He described the view as "a beautiful sight, looking eastward across the Atlantic." Vibration increased as the last of the fuel supply was used up. At sustainer engine cut-off it was found that the Atlas had accelerated the capsule to a speed only 7 ft/s (2 m/s) below nominal. At 14:52 UTC, Friendship 7 was in orbit. Glenn received word that the Atlas had boosted the MA-6 into a trajectory that would stay up for at least seven orbits. Meanwhile, computers at the Goddard Space Flight Center in Maryland indicated that the MA-6 orbital parameters appeared good enough for almost 100 orbits.

No comments:

Post a Comment