They did not, so the question is misguided.
None. No astronaut or man-made object has ever gotten close to the speed of light. It is impossible for an object to actually travel at the speed of light.
Nobody has ever traveled at the speed of light, and I can promise you that nobody ever will.
Sails that are pushed by light is one concept.
According to NASA, there are two reasons why astronauts wear white. First, white helps keep astronauts cool. Dark colors absorb a lot of light, which changes from light energy to heat energy.
Roemer was the first to measure the speed of light.
First of all, you would have to be dead to go to heaven or hell. So basically, the answers is no.
Light pollution does not affect astronauts, it affects astronomers.
Are you asking when the speed of light was first estimated, or are you asking when the speed of light was first actually measured?
he was revering to a high speed light that passed by them while in orbit around earth . I believe they were going twice the speed of sound at the time. there's been several astronauts reports of UFOs' while orbiting earth not just US. astronauts. Russian astronauts for instance.
Perhaps this will change with future advancements, but given our current knowledge no astronauts would ever reach the speed of light or even get close. One possibility for very extended journies would be something like the particle engines that are being developed. These engines (that put out a stream of sub-atomic particles) produce almost no thrust, but they can produce their low thrust non-stop for very long periods of time. After a few years, the results could be spectacular with fuel requirements that might be manageable. Then, coming to a stop would be the challenge. Imagine a massive engine failure, and watching your destination fly by at perhaps ten or twenty percent the speed of light. Disheartening to say the least.
The speed of light was first measured in 1676 by Danish astronomer Ole Rømer using observations of the moons of Jupiter. Rømer's work provided the first quantitative estimate of the speed of light.
Astronauts