Spring Awakening and Hairspray ticket question

I'm traveling at the moment and have very limited spotty access to internet and didn't have a chance to look this up before I left....could someone tell me what kind of same day tickets Spring Awakening and Hairspray have? Do either have any student tickets? Rush tickets? How easy has it been to get tickets? I won't be back in London until Friday, and probably won't get over to the Shaftsbury until around 6:00 pm. For Spring Awakening, I have all day Saturday if there is some type of rush. It's the closing show, have ticket sales picked up since the announcement was made or should I still be safe?

Any help would be appreciated!

You are awesome, thank you! One more question, are the Spring Awakening tickets available at any time, or are they released at a certain time?