Apollo 11 astronauts Neil Armstrong and Buzz Aldrin first set foot on the moon's surface on July 20, 1969. Astronauts Eugene Cernan and Harrison Schmitt, as members of the Apollo 17 crew, completed the series of manned explorations of the lunar surface in December 1972. Lunar exploration by man was replaced by robotic technology during the post-Apollo years and manned flights were limited to the development of the International Space Station (ISS). The launch vehicles and spacecraft for this were the Space Transport System (STS) and the space shuttle. However, the STS program is soon to be terminated and it is being replaced by a new program - the Constellation program. The new program will incorporate two rockets - one to transport a crew to orbit (Ares I) and one to transport cargo Ares V). In future missions to the moon, the two will meet in Earth orbit and combine components which will then travel on to the moon. One of these components will, of course, be a lunar lander.

The photograph above is a scale model of the Space Transportation System (STS) and Ares I and Ares V. Ares I is the Crew Launch Vehicle (CLV) and consists of a two-stage in-line rocket configuration topped by the Orion crew vehicle. Ares V is an in-line rocket configured to lift cargo to orbit. To learn much more about the Constellation project and NASA's new spacecraft and launch vehicles, Orion and Ares, visit NASA's website given to that program. Click right here on CONSTELLATION. Join the engineers, scientists and astronauts as they begin their journey back to the moon!