ISS Spacewalk Cut Short
RobertB-DC writes "The spacewalk that was intended to replace a balky power supply ended almost before it started, according to Spaceflight Now's Mission Status Center play-by-play. The Russian Orlan spacesuit worn by US astronaut Mike Fincke developed a problem with its oxygen supply (!), forcing both spacewalkers back to the airlock after less than 15 minutes. Mission control and the ISS crew are still debating what to do next."
The American suits have been used and are preferred for spacewalks (the US airlock recycles the air which is useful).
Unfortunately when they tested the US suits shortly after getting onboard they found problems (air bubbles in the cooling system IIRC) so they had to use the Russian equipment. This meant a much more dangerous/risky spacewalk but it was the only working kit they had.
Now it is a question of which kit they can fix/replace first.
As for jet packs, the airlocks are not able to handle them. They would need to be mounted outside, but they would deteriorate, so they would need a locker.....and the problems keep mounting.
I stole this sig.
You're probably confusing the backup system (SAFER) with the MMU. The backup system is a small backpack, it's not the big flying chair you may be thinking of (which hasn't been used since the 80's IIRC.)