Short answers, pulled from the story.
The Apollo Lunar Module was the spacecraft that carried astronauts between lunar orbit and the Moon's surface during the Apollo program. It remains the only crewed vehicle ever to land anywhere beyond Earth, and it was structurally incapable of flying through Earth's atmosphere.
The Apollo Lunar Module was chiefly designed by Thomas J. Kelly, a Grumman aerospace engineer. Grumman was awarded the construction contract on the 7th of November 1962, and the module was assembled at the company's factory in Bethpage, New York.
The total cost of the Apollo Lunar Module program was $2.29 billion in nominal dollars, which adjusts to $21.65 billion in 2016 dollars using the NASA New Start Inflation Indices.
After an oxygen tank in the Apollo 13 service module ruptured and disabled the main spacecraft, LM-7 Aquarius served as a lifeboat. Designed to support two astronauts for 45 hours, it kept three astronauts alive for 90 hours, using its descent engine for propulsion and its batteries to power the return trip and recharge the command module for reentry. The crew splashed down safely on the 17th of April 1970.
Six Apollo Lunar Modules landed humans on the Moon between 1969 and 1972. Their descent stages remain at the landing sites; the corresponding ascent stages were either crashed into the Moon, left in lunar orbit, or in the case of Apollo 10's Snoopy, sent into a heliocentric orbit around the Sun.
NASA used the Lunar Landing Research Vehicle and Lunar Landing Training Vehicle, contracted from Bell Aerosystems in 1964, to train astronauts. The aircraft used a gimbal-mounted jet engine to simulate the Moon's reduced gravity. Three of the five total aircraft were destroyed in crashes; in each case the ejection seat saved the pilot, including Neil Armstrong.