NASA's LLCD Tests Confirm Laser Communication Capabilities In Space

An anonymous reader writes "This week, NASA released the results of its Lunar Laser Communication Demonstration's (LLCD) 30-day test carried out by its Lunar Atmosphere and Dust Environment Explorer (LADEE) that is currently in orbit around the Moon. According to the space agency, the LLCD mission proved that laser communications are practical at a distance of a quarter of a million miles and that such a system could perform as well, if not better, than any NASA radio system."

Re:That's Great

[ganjadude]

cat, just because we dont have a large manned space program does not mean we dont have a space program. I would say that we have found out more about space and moons and planets and stars in the previous 10 years than at any time in the past. Sure it is not as flashy as sending an astronaut to the moon or mars, which I am in agreement with you that we need to be working harder on our manned missions, but to say our space program is dead is just simply wrong

Re:SETI

[mysidia]

The earth orbits where the sun is right now. It takes light about 8 minutes to travel from the sun to the earth.

No. It also takes 8 minutes for changes in the gravitational field to travel from the sun to the earth.

The earth orbits, where the Sun appears to be; as the Sun appears to move, the gravitational field changes.

These changes are delayed by 8 minutes.

The constant 'c' from special relativity is not just the speed of light in a vacuum -- it is also the highest possible speed for any physical interaction within nature, and the conversion factor from changing units of time into units of space.

Gravitational waves, Gluons, Photons, and other massless particles travel at a maximum speed of c.

It is impossible to convey information at a speed faster than c.

There are cases where a wave can propagate faster than c, but no information can be conveyed faster than light.