“Leave no man behind” isn’t the official policy of our armed forces, but they do their best to bring every soldier, pilot, and crewman home that they can.
The obvious exception is when they get vaporized by nuclear weapons, as what happened when the North Koreans tried to reunify with the South.
Or when the Russians let ISIS acquire a pan-dimensional energy source and they sent most of Libya to a parallel dimension. Ain’t nobody coming back.
So, go ahead. Test this new light-speed spacecraft.
If it works, great. If it doesn’t, you get an empty coffin at Arlington, okay?