STS-131: Discovery to ISS
Sunday, April 4, 2010 at 11:30AM 
Mission Patch for STS-131
Tomorrow morning at 6:21am EDT the space shuttle Discovery will make its penultimate sojourn to space and the International Space Station. This mission will bring one of the final major elements of the station online and carry the largest payload of any shuttle mission since the doomed STS-107 that saw the Columbia destroyed during re-entry. The space station is now just a few missions away from being complete. USA Today put together an excellent piece by piece reconstruction infographic of the station that gives some sense of the scale of this massive international project.
With just a few shuttle missions left before the program is set to be mothballed, these final missions will focus on prepping the space station for service without regular visits from the shuttle, with only the Russian Soyuz craft capable of making manned trips to the station to ferry crew on and off. The European Space Agency (ESA) and the Japanese Aerospace Exploration Agency (JAXA) both have unmanned cargo transfer vehicles which will help keep the space station supplied for the rest of it's still undetermined lifespan. Originally slated for deorbit as early as 2016, the recent NASA budget proposals under the Obama administration have recommended extending the operation of the space station to 2020, and with continued international support potentially out to 2028. The loss of the shuttle as a ferry for crew and cargo will be significant to the ISS's operational abilities, however it is possible that commercial space flights in the coming years will be able to mitigate this loss.
As always, if you'd like to follow along with the Discovery's final preparations for flight and launch, the best place to do that is SpaceVidCast.com where they re-broadcast NASA's HD satellite feed, which also allows you to listen in to the KSC ground loop. If you're a new iPad owner (or on an iPhone) you should go here for an HD stream that doesn't use Flash. At the moment they are covering the docking of the Soyuz vehicle to the ISS. You will also be able to catch the launch on most of the cable news networks as well. Weather looks good and as of this writing NASA has no technical issues they need to work through, so an on-time launch looks very likely.
Also, don't ever let it be said that NASA lacks a sense of humor:
Movie Poster for STS-131