maca2kx
Rookie
I'm guessing you've not read the books, the Spartans learned how to make basic field repairs of their MJOLNIR armour and do so various times. James (one of the Spartans) had to repair a valve to allow his suit to reach peak efficiency after crashing to Reach and John himself has had to carry out minor repairs. They take their suits off several times during the books and don't forget every single one of the Spartans was recruited as part of the Spartan-II project at the age of six thanks to Dr Halsey and Captain Keyes. They're humans, just incredibly superior humans.
Sam
Sam