Perseverance is one of a few Mars spacecraft carrying laser retroreflectors. The devices could provide new science and safer Mars landings in the future.
PASADENA, Calif. (NASA PR) — When the Apollo astronauts landed on the Moon, they brought devices with them called retroreflectors, which are essentially small arrays of mirrors. The plan was for scientists on Earth to aim lasers at them and calculate the time it took for the beams to return. This provided exceptionally precise measurements of the Moon’s orbit and shape, including how it changed slightly based on Earth’s gravitational pull.
As NASA celebrates the 50th anniversary of manned Apollo flights leading to the first moon landing in July 1969, the number of astronauts from the program is slowly dwindling away.
Of the 29 men who flew in the Apollo lunar program, 15 are still alive while 14 others have passed away. When the Skylab and Apollo-Soyuz programs are included, there are 21 Apollo-era astronauts still with us while 17 have died.