Shocking news. My thoughts go out to the families of the astronauts. We don't have a TV and haven't heard the radio today so this was a terrible thing to find on logging on tonight. I have been involved in the UK space industry since a kid when my father took me to see Blue Streaks being built right up to now working on comms satellites. Tomorrow will be a sombre day at work.
One thing to consider is that one of the tasks of the shuttle when visiting the ISS is orbit raising. Probably not the only way but perhaps the easiest. I don't have the ISS links at hand.