Extra-vehicular activityExtra-vehicular activity
(EVA) is work done by an astronaut away from the earth outside of the spacecraft
: in space flight
or while on the Moon (see List of lunar astronauts
) or possibly in the future on another planet or moon. In the early days of space flight it was called 'space walk'. The first EVA was carried out by Soviet cosmonaut Aleksei Leonov
on March 18 1965
from the Voskhod 2
spacecraft. The first woman to perform an EVA was Cosmonaut Svetlana Savitskaya
on July 25
while she was aboard the Salyut 7
An EVA is dangerous business for a number of different reasons. The primary one is collision with debris. Orbital velocity at 300km above the Earth (typical for a Space Shuttle mission) is 7.7km/sec. This is 10 times the speed of a bullet, so the kinetic energy of a particle as small as a fleck of paint or a grain of sand is equal to that of a bullet with a mass that is 100 times as large! Every space mission creates more orbiting debris, so this problem will continue to become worse.
Scientists are developing tele-operated robots for outside construction work, to eliminate the need for EVAs.
Also name of mechas
in Neon Genesis Evangelion