So far the X-Men have only been in space once, but it's been a common feature of the Marvel universe ever since Fantastic Four #1. It seems to be a more routine thing than in the real world - apart from Starcore One, there's Project: Armageddon's secret space station, which is a disused SHIELD base. But still, a short-notice launch is notable enough to get reported in the news.
This is the issue where Colossus's brother, Mikhael is first mentioned. He was one of "Russia's first cosmonauts", which is a bit of a coincidence, but no worse than usual. He died in a rocket explosion, which is making Colossus nervous (Colossus therefore gets himself added to the list of X-Men who have had relatives die in aviation incidents, alongside Alex, Scott and Lorna). Corbaeu can understand - he lost friends in the Apollo I fire.
The shuttle they're in (in 1976) is fairly similar to the actual ones that were being built (OV-101 was rolled out for testing only the next year). It's multi-stage to orbit. But there's another form of space travel in this arc. The sentinels themselves, which appear to be single-stage-to-orbit and are evidently capable of taking people up there as witnessed by them successfully kidnapping various mutants. Furthermore, the Sentinels can be built by one mad scientist, and it only took a billion dollars of black budget to do it (that figure, while it would certainly buy you a lot of comics and ramen, is chickenfeed by the standards of space programs). So why still have space shuttles? I suppose they must be much cheaper too? But more generally, why is Sentinel technology confined only to mutant eradication?
A clue comes in (and I'm skipping ahead here, but I don't care) #100. Trask's notes were essential for this project. That's the six years that was mentioned before - between 1969 and X-Men #57-#59 and 1975. Trask was a solo genius scientist who made an achievement that cannot be replicated properly by people acting from first principles... or perhaps the Sentinels are some kind of alien technology that they're finding it really hard to adapt? So maybe the Master-Mold is not something that was built by Bolivar Trask, but an artefact he found and has been trying to use.
Incidentally, I believe this issue has the first usage of the "Greymalkin Lane" address for the mansion.