XPost: alt.astronomy, alt.fan.heinlein

Wayne Boyd
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Philosopher, published author, science writer.Updated Mar 23
Why is the Apollo Reflector experiment still operating 54 years later?

Those weird looking things they left behind when astronauts left the
Moon are still working.

The Apollo Reflectors are reflective panels that were placed on the Moon
during the Apollo missions. They are still working today and can reflect
laser beams from Earth back to the source with high accuracy. These
reflectors help scientists measure the distance between the Earth and
the Moon using laser beams and study the Moon's orbit and rotation.
There are five such reflectors on the Moon. It is worth noting for Moon
hoaxers that the presence and functionality of these reflectors on the
Moon serve as compelling evidence against the notion that the lunar
landings were faked.

Although bouncing a laser off the Apollo Reflectors is difficult, it is possible with specialized equipment and knowledge. Even professional observatories find it challenging, and amateurs need a powerful laser
and a telescope with high magnification to accurately aim the beam at
the reflector's location. After the laser beam hits the reflector, a
sensitive detector is used to detect the reflected light. Despite its difficulty, bouncing a laser off the Apollo Reflectors has been
accomplished by both professionals and amateurs. It was even portrayed
once on the Big Bang Theory television show. The episode is called “The
Lunar Excitation” and it is the twenty-third and final episode of the
third season of The Big Bang Theory. It first aired on Monday, May 24, 2010.

The Apollo reflectors have lasted all this time, since they were first
placed there a half century ago by Apollo astronauts. They managed to
remain operational because:

The Moon's environment has no wind or water erosion to damage the
reflectors.
The reflectors were built to withstand extreme temperatures and resist corrosion.
There has been no human activity on the Moon to damage the reflectors.
The reflectors are small and low-profile, so they are less likely to be
hit by objects.
That’s why, as of the time of writing, the Apollo Reflector experiment
is still operating 53 years and 8 months after being placed on the Moon
by Apollo astronauts.

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Peter Lohmann
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Peter Lohmann
· Mar 13
If I remember correctly, these laser reflections were also used to
measure (and prove) the slow movement of Earth’s tectonic plates.

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Michael Schmidt
· Mar 14
They have no moving parts so the only reason they would stop working
would be if they were to become covered with enough dust to obscure the mirrors. There is no wind to carry dust so it would require enough close impacts to throw rock dust over them. That is going to take a long long
long time.

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Wayne Boyd
· Mar 14
What about the UV light from the Sun? That’s a destructive force.

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Michael Schmidt
· Mar 14
Depends on the actual materials the unit is made from.

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C V Britton
Optical Glass can handle UV with not problem. Total Internal Reflection
is used. No ‘Silvering’ of the glass is required.
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Ken Hecker
· Apr 5
Also fortunate that it has never been hit by a falling piece of rock,
such as a meteorite. Small chance of that happening, but it could happen.

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