Apollo 10 Lunar Landing Module
"Houston, this is Snoopy! We is Go and we is down among' em, Charlie!" - Gene Cernan
At 16:49 UTC on the 18th of May, 1969, a Saturn V rocket made a perfect liftoff from the Kennedy Space Centre. The mission was Apollo 10, designed to be a "dry run" for the first lunar landing, testing all the equipment and protocols, without actually effecting a landing. In addition, a close approach to the lunar surface would enable better reconnaisance of potential landing sites.
The Command Service Module was named Charlie Brown, the Lunar Module (perhaps predictably) was called Snoopy. Weighing in at 13,941 kg, Snoopy was fuelled and fully functional for its a vital role in the history of space exploration, being piloted by Gene Cernan. The vessel was also involved in a near-disaster during the mission, which could easily have taken the lives of the crew.
The Mission
The three-day journey to the Moon went right according to plan, the combined CSM/LM achieving a 114 x 109 km (71 x 68 mile) lunar orbit on 21st May 1969 at 20:44 GMT. At On 19:36 on the 22nd, Stafford and Cernan began the process of separating the LM, firing the reaction control thrusters to achieve an independent orbit. Snoopy began a series of low-altitude passes over the lunar surface, "barnstorming" at 14 km (8¾ miles) above the surface, during which time Cernan uttered the words quoted above. All onboard systems were thoroughly checked; communications, propulsion, attitude control, and radar.
The mission profile also required additional photoreconnaisance of planned landing sites, and many close-up photographs and video footage were taken, preparing the way for Apollo 11.
"We've got some wild gyrations"
At the lowest point in their orbit, the crew began the release of the descent stage (the lower part of the LM) from the LM return stage. At this point, the spacecraft began pitching and yawing violently. "We've got some wild gyrations", Cernan announced. The two men fought with the controls for eight long, tense seconds, before Cernan realised the problem. "Hit the AGS!", he yelled to Stafford. The Abort Guidance System switch had for some reason been left in the wrong position, causing the vessel to begin the process of firing the main engines to return to the CSM.
With just two scant seconds remaining, Snoopy was brought under control, the descent stage was jettisoned, and the two-man crew were able to return to rendezvous with Charlie Brown in orbit. Had they failed to isolate the problem then, they would have entered a long dive to the Moon's surface, and would have been beyond rescue. As it was, they succeeded in returning to the CSM, docking at 03:22 on the 23rd May, with much relief.
Snoopy R.I.P.
Later that day, the remainder of Snoopy (the LM ascent stage) was jettisoned into a solar orbit, its work done. On 24th May, at 10:25, Charlie Brown left lunar orbit, to splash down in the Pacific on the 26th May 1969 at 16:52. Charlie Brown is on display at the Science Museum, London. Snoopy is sadly no more.
http://apollo-society.org/shootmoon.html
http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1969-043A