Human Lunar Return study

NASA began its "Human Lunar Return study" in September 1995 to identify ways it could conduct future human spaceflight missions to the Moon. The final Human Lunar Return (HLR) briefing took place on August 7, 1996. The study was seen as laying, "the foundation for human space activity over the next three decades."

It baselined a lightweight architecture including an open-cockpit lunar lander weighing 4565 kg including fuel. Components and crew for the mission would have been transported to the International Space Station (ISS) by two Space Shuttle flights. The HLR schedule called for the first mission to depart from the ISS in August 2001.

The projected cost of the mission over the five year development timeline was $2.5 billion. The mission required two shuttle and three Proton launches to land two astronauts and a small habitat structure at Aristarchus crater.