The Altair spacecraft, previously known as the Lunar Surface Access Module or LSAM, was the planned lander spacecraft component of NASA's cancelled Constellation program. Astronauts would have used the spacecraft for landings on the Moon, which was intended to begin around 2019. The Altair spacecraft was planned to be used both for lunar sortie and lunar outpost missions. On February 1, 2010, U.S. President Barack Obama announced a proposal to cancel the Constellation program (except the Orion spacecraft), to be replaced with a re-scoped program, effective with the U.S. 2011 fiscal year budget. Name On December 13, 2007, NASA's Lunar Surface Access Module was retitled "Altair", after the 12th brightest star in the northern hemisphere's night sky, Altair in the constellation Aquila. In Latin, means "eagle", providing a connection to the first crewed lunar landing, Apollo 11's Eagle; the name Altair itself is a latinization of the Arabic , meaning "the eagle," "the bird," or "the flyer." Prior to the announcement of the "Altair" name, reports had suggested other names had been considered by NASA, but Altair won in a vote by the design team over Pegasus. Description NASA developed only conceptual designs for Altair. No Altair spacecraft were built—plans called for a first landing on the Moon in 2018. Like the Apollo Lunar Module (LM), Altair was envisioned as having two stages. The descent stage would have housed the astronauts, life-support equipment, and fuel for the ascent-stage motor and steering rockets. Like the Apollo LM, the Altair's crew cabin was based on that of a cylinder. Initially a horizontal cylinder, like that of the LM (despite the "boxy" appearance on the outside), contemporary blueprints and computer simulations showed the use of a vertical cylinder. Unlike its two-man Apollo ancestor, Altair was designed to carry the entire four-person crew to the surface, while the temporarily unoccupied Orion crew module would have remained in lunar orbit. Altair was intended to be capable of operating away from Earth (in space and on the lunar surface) for up to 210 Earth days. Altair would also be capable of flying uncrewed missions, as had been proposed with LM Truck concept during the Apollo Applications Program. Mission planners would have been able to choose among three distinct mission modes for Altair: Crewed sortie mode Crewed outpost mode (with no airlock) Uncrewed cargo mode, capable of transporting up to 15 metric tons to the lunar surface