The Modular Common Spacecraft Bus (MCSB) is a fast-development, low-cost, general purpose spacecraft platform. Its modular design is intended to reduce the cost, complexity, and lead time on missions by providing a reliable, well-characterized system that can carry a variety of payloads. According to NASA, "the spacecraft is roughly one tenth the price of a conventional unmanned mission and could be used to land on the Moon, orbit Earth, or rendezvous with near-Earth objects."
NASA's Ames Research Center in Moffett Field, California, designed, developed, built, integrated, tested and controlled the spacecraft.
The MCSB supervisor, Alan Weston, obtained from NASA Ames Research Center $4 million in internal funding to get the project started. Using that money, the prototype was built in about 15 months during 2007—2008. The fast concept development time is due in part to the preliminary use of repurposed SCUBA air tanks and an engine that uses cold gas, in place of a conventional rocket engine. This allowed the team to perform indoor flight tests as fast as every 40 minutes in their laboratory, rather than waiting weeks or months for a time slot at an appropriate rocket testing facility. After a flight demonstration to top NASA officials, the system was selected as the bus for the planned Lunar Atmosphere and Dust Environment Explorer (LADEE) mission to the Moon, and the project awarded $80 million for further development and construction. When the team switched to a conventional engine, most of the flight control software was modified at minimum cost.
In October 7, 2014, the MCSB design received the Popular Mechanics 2014 Breakthrough Award for innovation in science and technology.
The modular MCSB spacecraft bus structure has a versatile octagonal shape that can carry up to 50 kg (110 lb) of instruments so long as they can fit inside. The bus is made of a lightweight carbon composite and has the ability to perform on various kinds of missions, including voyages to the Moon and Near-Earth objects, with different modules or applicable systems. This modular concept is an innovative way of transitioning away from custom designs and toward multi-use designs and assembly-line production, which could dramatically reduce the cost of spacecraft development. It can be adapted as an orbiter or a lander.