Of course, "宇宙" (Uchu) means "universe", but it's also very often also used just with the meaning of space/outer space instead of meaning the entirety of a universe or something like that. In fact, I'm almost sure that is machine translation and you can notice that because it says first "outer space" and then "universe" for the same kanji.
If one would specify outer space, in general, they could use "宇宙空間" (Uchū kūkan), but even that can get into the problem of general meaning because it literally means "space of the universe", so it could also be used to describe all of the universe's space other than the astronomical use of merely "outer space". This just goes on to show how important context is (In fact, although Uchū by definition means all of time and space,
most Japanese general astronomers would say that they just never use it to include time anymore, and is just used to describe generic outer space).
In that text, it could be something to discuss if it's called "宇宙" (Uchu) because they went to a generic outer space with stars and not something to say it's a literal universe-sized construct. (Japanese really be fun to discuss if "universe" really means universe).