Первый беспилотный испытательный полет лунного модуля Apollo 5.

Uncrewed first test flight of the Apollo Lunar Module

As with Apollo 4, there were significant delays for Apollo 5. The primary cause of the Apollo 5 delays was the LM, which was behind schedule. Apollo Program Manager Major General Samuel C. Phillips had originally hoped that the uncrewed test flight of LM 1, the first lunar module, would launch in April 1967. Anticipating six months for checkout and testing of the vehicle, NASA asked Grumman to have LM 1 delivered to Kennedy Space Center in Florida by September 1966, but due to difficulties in manufacturing LM 1, delivery was repeatedly delayed. The delivery date was still uncertain when AS 206, the Saturn IB launch vehicle planned to boost LM 1 to orbit, was erected at Launch Complex 37 in January 1967. After the fire that month that killed the Apollo 1 crew, the launch vehicle planned for Apollo 1, AS 204, was moved from Launch Complex 34 to Launch Complex 37 and replaced AS 206. This was done because AS 204 was the last Saturn IB with full research and development instrumentation, and, with crewed flight on hold, NASA wanted to use that booster for the first flight of the LM. With no LM yet available, Grumman built a plywood mockup of one at Launch Complex 37 to aid in facilities verification. On May 12, 1967, Apollo Program Spacecraft Manager George M. Low informed NASA headquarters that Grumman was committed to a June 28 delivery of LM 1, though Low noted that the goal would be hard to meet. On June 23, LM 1 arrived at Cape Kennedy on board Aero Spacelines' Super Guppy; the stages were mated to each other four days later. A 400 person team under John J. Williams, a veteran of launch operations for both Mercury and Gemini, checked to see that LM 1 met specifications, after which they supervised Grumman technicians, who tested and modified the vehicle. Due to leaks in the LM's ascent stage, the two stages were demated in August, and after these were fixed and the stages remated, another leak developed and the stages were demated again in September. During this time, several pieces of equipment were removed for repair by Grumman; the stages were remated again in October. As of September 6, 1967, Apollo 5 was running about 39 days behind the plan established on July 18, but all known issues were being dealt with, with the exception of some leaks from the propulsion system. Most mission documents were ready by late 1967; Mission Director William C. Schneider issued mission rules on November 18, 1967. The following day, LM 1 was mated to its launch vehicle, and the space vehicle readiness test was completed in December. In early January 1968, the office of NASA Administrator James E. Webb announced that Apollo 5 would be launched no earlier than January 18, 1968. Minor faults such as clogged filters led to some additional delays. The countdown demonstration test concluded on January 19 and an abbreviated 22 hour countdown began on January 21.

Apollo 5 was intended to verify the operation of the subsystems of the LM. During the flight, the ascent and descent engines would be fired. A "fire in the hole" test would be conducted to verify that the ascent stage could still fire while attached to the descent stage, a procedure that would be used on the lunar surface and in the event of an aborted lunar landing. It involved shutting down the descent stage, switching control and power to the ascent stage, and starting the ascent engine while the two stages were still mated. The term "fire in the hole" derived from a term used in mining when explosives are about to be used. Additional testing was to check that the LM engines could be restarted after initial use. In addition to testing LM systems, Apollo 5 was to test the Instrument Unit in its Saturn V configuration. It was expected that the ascent stage of LM 1 would remain in orbit for about two years before re entering the atmosphere and disintegrating, and the descent stage for about three weeks.

Apollo 5 was launched into orbit by the Saturn IB, designated SA 204R, which had been assigned to Apollo 1. Originally brought to Cape Kennedy in August 1966, it had survived the fire unscathed, having been inspected after the fire for corrosion or other damage. Ignition weight for the launch vehicle, including the spacecraft and propellant, was
The space vehicle for this mission was tall but had a stubby appearance since it had neither a CSM nor a launch escape system. Instead, the LM was housed within the spacecraft lunar module adapter (SLA) at the top of the vehicle stack. The SLA, numbered as SLA 7, was just below the nose cap in the stack, and had four panels that would open once the nose cap was jettisoned in orbit, allowing the LM room to separate and move away. The LM, designated as LM 1, was the first flight ready Apollo lunar module. To save weight, and because they would not be necessary during the test mission, LM 1 had no landing legs. After one of the windows of LM 5 (which would fly on Apollo 11) broke during testing in December 1967, NASA officials decided to replace the windows of LM 1 with aluminum plates out of concern a window might fail in flight. Since there would be no astronauts aboard, LM 1 had a mission programmer installed, which could control the craft remotely. Not all LM 1 systems were fully activated nor was it given a full load of consumables: for example, its primary batteries were partially discharged to avoid over voltage complications, and the oxygen tanks for the environmental control systems were only partially full.