NASA awarded the contract for constructing the lunar modules to Grumman Aerospace in Bethpage, NY. Altogether Grumman built 14; each one being given a different number as it was assembled. LM's 10 through 14 were called the "extended stay" lunar modules because they were modified to allow the Apollo astronauts to spend several days on the lunar surface and to carry a great deal of equipment--including the lunar rover. The original lunar modules, LM's 1 through 9, were all nearly identical to one another. The first two were assigned to unmanned flights to test the performance of the lunar module in space. However, the flight of LM1 onboard Apollo 5 was so successful that a second flight was considered unnecessary. Instead, LM2 was used in drop tests to insure proper performance of the landing gear. Later, it became part of the Smithsonian's collection.