Recent financial woes and budgetary constraints have touched many programs at the federal and state level, and Project Constellation is no exception to this rule. Originally initiated by the Bush Administration, this effort seeks to both replace the venerable Space Shuttle as well as do what the Shuttle cannot - return to our nearest celestial neighbor, the Moon. To reduce development costs and time, the hardware used for this program was to be either directly obtained from the Shuttle or derived from it.
Technical problems have plagued it since the beginning; alterations to the design of the crew launch vehicle, the Ares I, have consumed both time and resources that could have been allocated to the Ares V, the portion of the project designed to support a Moon mission. Out of such difficulties came a proposal based on early NASA studies and more directly linked to the Shuttle hardware, hence its name: DIRECT.
The most recent iteration of DIRECT has addressed many, if not all, of the substantial issues and concerns leveled against the program by critics both within and outside of NASA. It has clearly demonstrated that the proposal is a robust and affordable alternative to the current course rather than simply a back-of-the-envelope effort taken on by amateurs with no understanding of the realities of spaceflight, or the organizational capacity of NASA. In this iteration, they have presented the additional option of retaining the Space Shuttle Main Engines for reduced development cost and risk, as well as enumerating more of the 2,532 different combinations possible with hardware available off the shelf at the present as well as components in development for Ares I and V. The major advantage of the new “officially recommended” configurations is the fact that they all involve readily available technology and would minimize the delay between the last Shuttle and first follow-on flights.
DIRECT is gaining attention, as well; the McNeil/Lehrer News Hour and the Augustine Commission organized to review NASA’s human spaceflight program have both taken a look at the concept, and, with larger budgetary clouds looming on the horizon, DIRECT 3.0 makes the alternative to Ares look better than ever.