It’s a busy day for NASA. First up it seems the space agency may finally be getting a new boss (see Bolden tipped for NASA top job, for more on that).

Then there’s the shuttle mission to repair the Hubble telescope. The second of five spacewalks is underway today to swap out old components for new shiny ones to get the telescope back seeing clearly.

NASA has released this rather cool image of the shuttle Atlantis silhouetted against the Sun on Tuesday (photo by NASA/Thierry Legault). More importantly, the first use of Twitter in space has been reported.

Problems with the aging shuttle are also surfacing. NASA says that one of the ‘flash evaporators’ that help cool the shuttle has had to be shut down, although this does not pose “an immediate concern”. This isn’t the first time a shuttle has had this problem either. NASA also says damage one of the shuttle’s wings incurred during launch is no cause for concern (Houston Chronicle).

Once the shuttle and its repair bill is gone, NASA will have another big bill to foot though.

Russia has announced it will be charging America $51 million per return flight for each astronaut that it flies to the space station from 2012, reports Reuters. This is a pretty sharp hike from the $21.8 million that it has charged since 2006 and the $35 million it charges space tourists. No news on how much a one way ticket costs was available.