NASA announced today its planned replacement for the Space Shuttle, a new heavy-lift rocket called the Space Launch System (SLS) which is designed to take human crews into deep space for the first time, with primary goals being an asteroid and Mars. It is a sort of hybrid of the old Space Shuttle and (cancelled) Constellation programs, utilizing components of both, such as the Orion Multi-Purpose Crew Vehicle (a larger, updated version of the old Apollo capsules) and Space Shuttle-style side booster rockets. It will use a liquid hydrogen and liquid oxygen fuel system, and will be the first rocket system powerful enough to take humans farther into space than the Moon.
The design will re-focus NASA on deep space missions, while low Earth orbit missions to the International Space Station will be handled by commercial companies. (SLS will also serve as a backup system for trips to the ISS however).
That is a good direction to go in, in my opinion, as the only way we can hope to get to Mars with human crews in the relatively near future (the mid-2030s as outlined by President Obama), is to have NASA focus its energy on what it does best – missions to the inner and outer solar system. The Space Shuttle, while valuable in its own right, was based on 1970s technology and kept NASA stuck in low Earth orbit for far too long. There will certainly be debate now as to whether the SLS system will be better than the previous Constellation system. The many unmanned robotic planetary missions have been incredibly successful, and maybe now we can finally have a manned space program that will inspire people again, to go farther and deeper into space. If you have your own thoughts on this, you can comment below!
The press release itself is here.