The Constellation Program is NASA’s over-arching framework for the future of human spaceflight. Under its original vision under the Bush administration, the Constellation Program involved manned flights to the Moon and then Mars using newly designed spacecraft, much more advanced than the Apollo craft which visited the Moon a generation ago. However, the Constellation Program never had adequate funding, and, under the Obama administration, was first scrapped and then revised drastically downward to a single low-Earth-orbit space vehicle for use with the International Space Station.
– Initial Objectives –
The Bush administration’s ambitious if underfunded plans for Constellation called for the construction of a new series of spacecraft – the Ares rocket, the Orion space ship, and the Altair landing module – which would then embark on a series of wide-ranging missions to nearby space objects. By the 2020s, according to the original plans, the Constellation spacecraft would permit long-term missions to the Moon, perhaps resulting in the eventual construction of a permanent station on the Moon.
These would be followed by a possible mission to a nearby asteroid, and, finally, the most ambitious human spaceflight project yet to be attempted: a manned mission to Mars, tentatively slated for somewhere between 2025 and 2030.
– Spacecraft –
The centrepiece of the Constellation Program was the planned Orion spacecraft, a joint project of Lockheed Martin and Boeing which would be the living and working space for the crew as well as a re-entry module and propulsion unit, together capable of at least ten space flights and ocean recoveries before being retired. (This made Orion a compromise between the cheaper but single-use Apollo spacecraft and the fully reusable but appallingly expensive space shuttles.) Obama’s scaled-down plans for Orion call for it to be used solely as a transfer vehicle for astronauts leaving the International Space Station.
A separate landing module, Altair, was to have been devised for use on the Moon, as well as a special propulsion unit called the Earth Departure Stage which would power the ship away from low orbit. Now that the Constellation Program has been mostly cancelled, these units will probably never be designed.
A new family of rockets, Ares, was also designed under the aegis of the Constellation Program. The Ares I and Ares V rockets were intended as full replacements to the ancient but powerful Saturn V rockets. The future of Ares V, which could carry spacecraft (both manned and unmanned) far beyond Earth orbit, is uncertain, but Ares I is still being developed for use with the reduced Orion mission profile.
– Reduction under the Obama Administration –
The Bush administration, when it initially approved the Constellation Program in 2004, provided a low-ball estimate of $230 billion over 20 years as a funding envelope. However, the actual costs would almost certainly be far higher (space program budgets usually rise dramatically over the development process), and there are always critics of the already-high expense of space projects, especially manned ones.
In 2010, president Barack Obama controversially surrendered to these critics, ending – at least for the time being – humanity’s future in deep space. Initially he proposed cancelling the Constellation Program entirely. However, in April 2010 the Orion project was salvaged for use as an escape pod for the International Space Station (essentially a useless function, since the cheaper and already-functioning Russian Soyuz spacecraft already serves the same purpose).