@NASASpaceflight Sub lightspeed is all that’s needed to be interstellar. Intergalactic is tough.
@NASASpaceflight亚光速是星际飞行所需的全部。星系际是困难的。
@NASASpaceflight Sub lightspeed is all that’s needed to be interstellar. Intergalactic is tough.
@NASASpaceflight亚光速是星际飞行所需的全部。星系际是困难的。