137-687: The Apollo command and service module ( CSM ) was one of two principal components of the United States Apollo spacecraft , used for the Apollo program , which landed astronauts on the Moon between 1969 and 1972. The CSM functioned as a mother ship , which carried a crew of three astronauts and the second Apollo spacecraft, the Apollo Lunar Module , to lunar orbit, and brought the astronauts back to Earth. It consisted of two parts:
274-471: A high gain antenna . The oxygen was also used for breathing, and the fuel cells produced water for drinking and environmental control. On Apollo 15, 16 and 17 it also carried a scientific instrument package, with a mapping camera and a small sub-satellite to study the Moon. A major portion of the service module was taken up by propellant and the main rocket engine. Capable of multiple restarts, this engine placed
411-545: A 400 Ah auxiliary battery was added to the SM for emergency use. Apollo 13 had drawn heavily on its entry batteries in the first hours after the explosion, and while this new battery could not power the CM for more than 5–10 hours it would buy time in the event of a temporary loss of all three fuel cells. Such an event had occurred when Apollo 12 was struck twice by lightning during launch. Apollo (spacecraft) The Apollo spacecraft
548-442: A fire in the cockpit." After 6.8 seconds of silence, a second, badly garbled transmission was heard by various listeners (who believed this transmission was made by Chaffee ) as: The transmission lasted 5.0 seconds and ended with a cry of pain. Some blockhouse witnesses said that they saw White on the television monitors, reaching for the inner hatch release handle as flames in the cabin spread from left to right. The heat of
685-467: A flashing rendezvous beacon visible from 54 nautical miles (100 km) away as a navigation aid for rendezvous with the LM. The SM was connected to the CM using three tension ties and six compression pads. The tension ties were stainless steel straps bolted to the CM's aft heat shield. It remained attached to the command module throughout most of the mission, until being jettisoned just prior to re-entry into
822-476: A great deal of risk, especially in initial operations, regardless of planning. You just can't forecast all the things that could happen, or when they could happen. "I suppose that someday we are going to have a failure. In every other business there are failures, and they are bound to happen sooner or later", he added. Grissom was asked about the fear of potential catastrophe in a December 1966 interview: You sort of have to put that out of your mind. There's always
959-498: A large pressurized auxiliary orbital module where the crew would live and work for weeks at a time. They would perform space station-type activities in the module, while later versions would use the module to carry cargo to space stations. The spacecraft was to service the Project Olympus (LORL), a foldable rotating space station launched on a single Saturn V . Later versions would be used on circumlunar flights, and would be
1096-684: A mechanically operated one for the Gemini and Apollo programs. Before the fire, the Apollo astronauts had recommended changing the design to an outward-opening hatch, and this was already slated for inclusion in the Block II command module design. According to Donald K. Slayton 's testimony before the House investigation of the accident, this was based on ease of exit for spacewalks and at the end of flight, rather than for emergency exit. The board noted that
1233-506: A parachute recovery system. It was the only part of the Apollo/Saturn space vehicle that returned to Earth intact. The service module was unpressurized and contained a main service propulsion engine and hypergolic propellant to enter and leave lunar orbit, a reaction control system to provide attitude control and translational capability, fuel cells with hydrogen and oxygen reactants, radiators to dump waste heat into space, and
1370-479: A pore seal, a moisture barrier (a white reflective coating), and a silver Mylar thermal coating that looks like aluminum foil. The heat shield varied in thickness from 2 inches (5.1 cm) in the aft portion (the base of the capsule, which faced forward during reentry) to 0.5 inches (1.3 cm) in the crew compartment and forward portions. The Total weight of the shield was about 3,000 pounds (1,400 kg). The 1-foot-11-inch (0.58 m)-tall forward compartment
1507-509: A possibility that you can have a catastrophic failure, of course; this can happen on any flight; it can happen on the last one as well as the first one. So, you just plan as best you can to take care of all these eventualities, and you get a well-trained crew and you go fly. The launch simulation on January 27, 1967, on pad 34, was a "plugs-out" test to determine whether the spacecraft would operate nominally on (simulated) internal power while detached from all cables and umbilicals. Passing this test
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#17327908134191644-402: A so-called 'soft dock' state and enabled the pitch and yaw movements in the two vehicles to subside. Excess movement in the vehicles during the 'hard dock' process could cause damage to the docking ring and put stress on the upper tunnel. A depressed locking trigger link at each latch allowed a spring-loaded spool to move forward, maintaining the toggle linkage in an over-center locked position. In
1781-541: A spacecraft–LM adapter (SLA) designed to shield the LM from the aerodynamic stress of launch and to connect the CSM to the Saturn launch vehicle and a launch escape system (LES) to carry the crew in the command module safely away from the launch vehicle in the event of a launch emergency. The design was based on the lunar orbit rendezvous approach: two docked spacecraft were sent to the Moon and went into lunar orbit. While
1918-503: A total of six hours and fifteen minutes, two and a half hours longer than it had been during the plugs-out test. The review board cited "many types and classes of combustible material" close to ignition sources. The NASA crew systems department had installed 34 square feet (3.2 m ) of Velcro throughout the spacecraft, almost like carpeting. This Velcro was found to be flammable in a high-pressure 100% oxygen environment. Astronaut Buzz Aldrin states in his book Men From Earth that
2055-568: Is that both bodies were at the lower edge of the hatch. They were not in the seats. They were almost completely clear of the seat areas." As a result of the in-flight failure of the Gemini 8 mission on March 17, 1966, NASA Deputy Administrator Robert Seamans wrote and implemented Management Instruction 8621.1 on April 14, 1966, defining Mission Failure Investigation Policy And Procedures . This modified NASA's existing accident procedures, based on military aircraft accident investigation, by giving
2192-441: The g -force experienced by the astronauts, permitted a reasonable amount of directional control and allowed the capsule's splashdown point to be targeted within a few miles. At 24,000 feet (7,300 m), the forward heat shield was jettisoned using four pressurized-gas compression springs. The drogue parachutes were then deployed, slowing the spacecraft to 125 miles per hour (201 kilometres per hour). At 10,700 feet (3,300 m)
2329-566: The Aerojet-General company to start developing the engine, resulting in a thrust level twice what was needed to accomplish the lunar orbit rendezvous (LOR) mission mode officially chosen in July of that year. The engine was actually used for mid-course corrections between the Earth and Moon, and to place the spacecraft into and out of lunar orbit. It also served as a retrorocket to perform
2466-495: The Apollo command and service module (CSM) to Earth orbit, launched on a Saturn IB rocket. AS-204 was to test launch operations, ground tracking and control facilities and the performance of the Apollo-Saturn launch assembly and would have lasted up to two weeks, depending on how the spacecraft performed. The CSM for this flight, number 012 built by North American Aviation (NAA), was a Block I version designed before
2603-416: The Apollo command and service module . The mission never flew; a cabin fire during a launch rehearsal test at Cape Kennedy Air Force Station Launch Complex 34 on January 27 killed all three crew members—Command Pilot Gus Grissom , Senior Pilot Ed White , and Pilot Roger B. Chaffee —and destroyed the command module (CM). The name Apollo 1, chosen by the crew, was made official by NASA in their honor after
2740-525: The KC-135 weightlessness training aircraft , and had to undergo surgery on January 27. Slayton replaced him with Chaffee, and NASA announced the crew selection on March 21, 1966. James McDivitt , David Scott and Russell Schweickart were named as the backup crew. On September 29, Walter Schirra , Eisele, and Walter Cunningham were named as the prime crew for a second Block I CSM flight, AS-205. NASA planned to follow this with an uncrewed test flight of
2877-474: The Phillips Report . This disclosure embarrassed NASA Administrator James E. Webb , who was unaware of the document's existence, and attracted controversy to the Apollo program. Despite congressional displeasure at NASA's lack of openness, both congressional committees ruled that the issues raised in the report had no bearing on the accident. Crewed Apollo flights were suspended for twenty months while
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#17327908134193014-549: The Thiokol Chemical Company . Abort modes after this point would be accomplished without the LES. The LES was carried but never used on four uncrewed Apollo flights, and fifteen crewed Apollo, Skylab , and Apollo-Soyuz Test Project flights. The disposition of all command modules, and all unflown service modules is listed at Apollo command and service module#CSMs produced . All flown service modules burned up in
3151-466: The fuel cell gauges and controls, the electrical and battery controls, and the communications controls. Flanking the sides of the main panel were sets of smaller control panels. On the left side were a circuit breaker panel, audio controls, and the SCS power controls. On the right were additional circuit breakers and a redundant audio control panel, along with the environmental control switches. In total,
3288-694: The lunar orbit rendezvous landing strategy was chosen; therefore it lacked the capability of docking with the lunar module. This was incorporated into the Block II CSM design, along with lessons learned in Block I. Block II would be test-flown with the LM when the latter was ready. Director of Flight Crew Operations Deke Slayton selected the first Apollo crew in January 1966, with Grissom as Command Pilot, White as Senior Pilot, and rookie Donn F. Eisele as Pilot. But Eisele dislocated his shoulder twice aboard
3425-403: The transposition, docking, and extraction maneuver at the beginning of the translunar coast. The docking mechanism was a non-androgynous system, consisting of a probe located in the nose of the CSM, which connected to the drogue , a truncated cone located on the lunar module. The probe was extended like a scissor jack to capture the drogue on initial contact, known as soft docking . Then
3562-510: The Apollo 204 Review Board, it was decided to terminate the crewed Block I phase and redefine Block II to incorporate the review board's recommendations . Block II incorporated a revised CM heat shield design, which was tested on the uncrewed Apollo 4 and Apollo 6 flights, so the first all-up Block II spacecraft flew on the first crewed mission, Apollo 7 . The two blocks were essentially similar in overall dimensions, but several design improvements resulted in weight reduction in Block II. Also,
3699-530: The Apollo Command and Service Modules. The spacecraft–LM adapter (SLA), built by North American Aviation (Rockwell), was a conical aluminum structure that connected the service module to the Saturn S-IVB rocket stage. It also protected the LM, the service propulsion system engine nozzle, and the launch-vehicle-to-service-module umbilical during launch and ascent through the atmosphere. The SLA
3836-738: The Apollo Lunar Surface Experiment Packages ALSEP , the modularized equipment transporter (MET) (a hand-pulled equipment cart used on Apollo 14 ), the Lunar Rover ( Apollo 15 , 16 and 17 ), a surface television camera, surface tools, and lunar sample collection boxes. The ascent stage contained the crew cabin, instrument panels, overhead hatch/docking port, forward hatch, optical and electronic guidance systems , reaction control system, radar and communications antennas, ascent rocket engine and propellant to return to lunar orbit and rendezvous with
3973-526: The Apollo program, four CSMs were launched on Saturn IBs for three Skylab Earth orbital missions and the Apollo-Soyuz Test Project . The major part of the Apollo spacecraft was a three-man vehicle designed for Earth orbital, translunar, and lunar orbital flight, and return to Earth. This consisted of a command module supported by a service module , built by North American Aviation (later North American Rockwell ). The command module
4110-442: The Apollo spacecraft into and out of lunar orbit, and was used for mid-course corrections between the Earth and the Moon. The service module remained attached to the command module throughout the mission. It was jettisoned just prior to reentry into the Earth's atmosphere. The Apollo Lunar Module was a separate vehicle designed to land on the Moon and return to lunar orbit, and was the first true "spaceship" since it flew solely in
4247-541: The Block I service module propellant tanks were slightly larger than in Block II. The Apollo 1 spacecraft weighed approximately 45,000 pounds (20,000 kg), while the Block II Apollo 7 weighed 36,400 lb (16,500 kg). (These two Earth orbital craft were lighter than the craft which later went to the Moon, as they carried propellant in only one set of tanks, and did not carry the high-gain S-band antenna.) In
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4384-518: The CM and faster break-up on re-entry. The service propulsion system ( SPS ) engine was originally designed to lift the CSM off the surface of the Moon in the direct ascent mission mode, The engine selected was the AJ10-137 , which used Aerozine 50 as fuel and nitrogen tetroxide (N 2 O 4 ) as oxidizer to produce 20,500 lbf (91 kN) of thrust. A contract was signed in April 1962 for
4521-471: The CM reaction control subsystem; water tanks; the crushable ribs of the impact attenuation system; and a number of instruments. The CM-SM umbilical, the point where wiring and plumbing ran from one module to the other, was also in the aft compartment. The panels of the heat shield covering the aft compartment were removable for maintenance of the equipment before flight. The components of the ELS were housed around
4658-440: The CM would land with its parachute recovery system. If the emergency happened on the launch pad, the LES would lift the CM to a sufficient height to allow the recovery parachutes to deploy safely before coming in contact with the ground. In the absence of an emergency, the LES was routinely jettisoned about 20 or 30 seconds after the launch vehicle's second-stage ignition, using a separate solid-fuel rocket motor manufactured by
4795-530: The CSM umbilical cables . The command module was built in North American's factory in Downey, California , and consisted of two basic structures joined together: the inner structure (pressure shell) and the outer structure. The inner structure was an aluminum sandwich construction consisting of a welded aluminum inner skin, adhesively bonded aluminum honeycomb core, and outer face sheet. The thickness of
4932-555: The CSM and LM together on a Saturn V (AS-503) to an elliptical medium Earth orbit (MEO), to be crewed by Frank Borman , Michael Collins and William Anders . McDivitt, Scott and Schweickart had started their training for AS-258 in CM-101 at the NAA plant in Downey, California, when the Apollo 1 accident occurred. Once all outstanding CSM-012 hardware problems had been fixed,
5069-581: The CSM away, rotated it through 180 degrees, and came back for docking. The LM was connected to the SLA at four points around the lower panels. After the astronauts docked the CSM to the LM, they blew charges to separate those connections and a guillotine severed the LM-to- instrument-unit umbilical. After the charges fired, springs pushed the LM away from the S-IVB, and the astronauts were free to continue their trip to
5206-481: The Deputy Administrator the option of performing independent investigations of major failures, beyond those for which the various Program Office officials were normally responsible. It declared, "It is NASA policy to investigate and document the causes of all major mission failures which occur in the conduct of its space and aeronautical activities and to take appropriate corrective actions as a result of
5343-486: The Earth's atmosphere at termination of the missions. The disposition of all lunar modules is listed at Apollo Lunar Module#Lunar modules produced . Apollo 1 Apollo 1 , initially designated AS-204 , was planned to be the first crewed mission of the Apollo program , the American undertaking to land the first man on the Moon. It was planned to launch on February 21, 1967, as the first low Earth orbital test of
5480-458: The Earth's atmosphere. At jettison, the CM umbilical connections were cut using a pyrotechnic-activated guillotine assembly. Following jettison, the SM aft translation thrusters automatically fired continuously to distance it from the CM, until either the RCS fuel or the fuel cell power was depleted. The roll thrusters were also fired for five seconds to make sure it followed a different trajectory from
5617-555: The LM (AS-206), then the third crewed mission would be a dual flight designated AS-278 (or AS-207/208), in which AS-207 would launch the first crewed Block II CSM, which would then rendezvous and dock with the LM launched uncrewed on AS-208. In March, NASA was studying the possibility of flying the first Apollo mission as a joint space rendezvous with the final Project Gemini mission, Gemini 12 in November 1966. But by May, delays in making Apollo ready for flight just by itself, and
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5754-415: The LM separated and landed, the CSM remained in orbit. After the lunar excursion, the two craft rendezvoused and docked in lunar orbit, and the CSM returned the crew to Earth. The command module was the only part of the space vehicle that returned with the crew to the Earth's surface. The LES was jettisoned during launch upon reaching the point where it was no longer needed, and the SLA remained attached to
5891-401: The Moon if we can't talk between two or three buildings?" The simulated countdown was put on hold again at 5:40 pm while attempts were made to troubleshoot the communications problem. All countdown functions up to the simulated internal power transfer had been successfully completed by 6:20 pm, and at 6:30 the count remained on hold at T minus 10 minutes. The crew members were using
6028-500: The Moon. The Apollo launch escape system (LES) was built by the Lockheed Propulsion Company . Its purpose was to abort the mission by pulling the CM (the crew cabin) away from the launch vehicle in an emergency, such as a pad fire before launch, guidance failure, or launch vehicle failure likely to lead to an imminent explosion. The LES included three wires that ran down the exterior of the launch vehicle. If
6165-412: The SLA panels during docking and extraction of the LM in a lunar mission. Wally Schirra compared it to the "angry alligator" from Gemini 9 . This led to a redesign using a spring-loaded hinge release system which released the panels at the 45-degree angle and pushed them away from the S-IVB at a velocity of about 5 mph (8 km/h), putting them a safe distance away by the time the astronauts pulled
6302-410: The astronauts pressed the 'CSM/LV Sep' button on the control panel to separate the CSM from the launch vehicle. Detonating cord was ignited around the flange between the SM and SLA, and along the joints between the four SLA panels, releasing the SM and blowing apart the connections between the panels. Dual-redundant pyrotechnic thrusters at the lower end of the SLA panels then fired to rotate them around
6439-516: The astronauts to breathe while reducing the fire risk. The Apollo 1 crew had successfully tested this procedure with their spacecraft in the Operations and Checkout Building altitude (vacuum) chamber on October 18 and 19, 1966, and the backup crew of Schirra, Eisele and Cunningham had repeated it on December 30. The investigation board noted that, during these tests, the command module had been fully pressurized with pure oxygen four times, for
6576-587: The astronauts was detected by the spacecraft's inertial measurement unit and the astronauts' biomedical sensors, and also indicated by increases in oxygen spacesuit flow, and sounds from Grissom's stuck-open microphone. The stuck microphone was part of a problem with the communications loop connecting the crew, the Operations and Checkout Building , and the Complex 34 blockhouse control room. The poor communications led Grissom to remark: "How are we going to get to
6713-569: The base, and a height of 11 feet 5 inches (3.48 m) including the docking probe and dish-shaped aft heat shield. The forward compartment contained two reaction control system thrusters, the docking tunnel, and the Earth Landing System. The inner pressure vessel housed the crew accommodation, equipment bays, controls and displays, and many spacecraft systems. The aft compartment contained 10 reaction control engines and their related propellant tanks, freshwater tanks, and
6850-425: The basis for a direct ascent lunar spacecraft as well as used on interplanetary missions. In late 1960, NASA called on U.S. industry to propose designs for the vehicle. On May 25, 1961 President John F. Kennedy announced the Moon landing goal before 1970, which immediately rendered NASA's Olympus Station plans obsolete. When NASA awarded the initial Apollo contract to North American Aviation on November 28, 1961, it
6987-495: The board, and was replaced by Robert W. Van Dolah of the U.S. Bureau of Mines . The next day North American's chief engineer for Apollo, George Jeffs, resigned as well. Seamans ordered all Apollo 1 hardware and software impounded, to be released only under control of the board. After thorough stereo photographic documentation of the CM-012 interior, the board ordered its disassembly using procedures tested by disassembling
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#17327908134197124-426: The cabin, beginning the second phase. The third phase began when most of the oxygen was consumed and was replaced with atmospheric air, essentially quenching the fire, but causing high concentrations of carbon monoxide and heavy smoke to fill the cabin, and large amounts of soot to be deposited on surfaces as they cooled. It took five minutes for the pad workers to open all three hatch layers, and they could not drop
7261-443: The cabin, which both astronauts and technicians found convenient for holding tools and equipment in place. Although Shea gave the spacecraft a passing grade, after the meeting they gave him a crew portrait they had posed with heads bowed and hands clasped in prayer, with the inscription: It isn't that we don't trust you, Joe, but this time we've decided to go over your head. Shea gave his staff orders to tell North American to remove
7398-505: The center piston. In a temperature degraded condition, a single motor release operation was done manually in the lunar module by depressing the locking spool through an open hole in the probe heads, while release from the CSM was done by rotating a release handle at the back of the probe to rotate the motor torque shaft manually. When the command and lunar modules separated for the last time, the probe and forward docking ring were pyrotechnically separated, leaving all docking equipment attached to
7535-451: The command module panels included 24 instruments, 566 switches, 40 event indicators, and 71 lights. The three crew couches were constructed from hollow steel tubing and covered in a heavy, fireproof cloth known as Armalon. The leg pans of the two outer couches could be folded in a variety of positions, while the hip pan of the center couch could be disconnected and laid on the aft bulkhead. One rotation and one translation hand controller
7672-484: The command module's hazards were addressed. However, the development and uncrewed testing of the lunar module (LM) and Saturn V rocket continued. The Saturn IB launch vehicle for Apollo 1, AS-204, was used for the first LM test flight, Apollo 5 . The first successful crewed Apollo mission was flown by Apollo 1's backup crew on Apollo 7 in October 1968. AS-204 was to be the first crewed test flight of
7809-500: The conclusion of the Apollo program and during 1973–1974, three CSMs ferried astronauts to the orbital Skylab space station. Finally in 1975, the last flown CSM docked with the Soviet craft Soyuz 19 as part of the international Apollo–Soyuz Test Project . Concepts of an advanced crewed spacecraft started before the Moon landing goal was announced. The three-person vehicle was to be mainly for orbital use around Earth. It would include
7946-401: The conical command module, a cabin that housed the crew and carried equipment needed for atmospheric reentry and splashdown ; and the cylindrical service module which provided propulsion, electrical power and storage for various consumables required during a mission. An umbilical connection transferred power and consumables between the two modules. Just before reentry of the command module on
8083-452: The cover until the excess pressure was vented. Emergency procedure called for Grissom to open the cabin vent valve first, allowing White to remove the cover, but Grissom was prevented from doing this because the valve was located to the left, behind the initial wall of flames. Also, while the system could easily vent the normal pressure, its flow capacity was utterly incapable of handling the rapid increase to 29 psi (200 kPa) caused by
8220-401: The crew were not believed to be major factors, and it was concluded that most of them had occurred postmortem. Asphyxiation occurred after the fire melted the astronauts' suits and oxygen tubes, exposing them to the lethal atmosphere of the cabin. The review board identified several major factors which combined to cause the fire and the astronauts' deaths: The review board determined that
8357-460: The decision to design two versions of the CSM: Block I was to be used for uncrewed missions and a single crewed Earth orbit flight ( Apollo 1 ), while the more advanced Block II was designed for use with the lunar module. The Apollo 1 flight was cancelled after a cabin fire killed the crew and destroyed their command module during a launch rehearsal test. Corrections of the problems which caused
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#17327908134198494-407: The deorbit burn for Earth orbital flights. The propellants were pressure-fed to the engine by 39.2 cubic feet (1.11 m) of gaseous helium at 3,600 pounds per square inch (25 MPa), carried in two 40-inch (1.0 m) diameter spherical tanks. The exhaust nozzle measured 152.82 inches (3.882 m) long and 98.48 inches (2.501 m) wide at the base. It was mounted on two gimbals to keep
8631-441: The drogues were jettisoned and the pilot parachutes, which pulled out the mains, were deployed. These slowed the CM to 22 miles per hour (35 kilometres per hour) for splashdown. The portion of the capsule that first contacted the water surface contained four crushable ribs to further mitigate the force of impact. The command module could safely parachute to an ocean landing with only two parachutes deployed (as occurred on Apollo 15 ),
8768-486: The electrical power momentarily failed at 23:30:55 GMT, and found evidence of several electric arcs in the interior equipment. They were unable to conclusively identify a single ignition source. They determined that the fire most likely started near the floor in the lower left section of the cabin, close to the Environmental Control Unit. It spread from the left wall of the cabin to the right, with
8905-491: The environmental control system). On the flight of Apollo 13 , the EPS was disabled by an explosive rupture of one oxygen tank, which punctured the second tank and led to the loss of all oxygen. After the accident, a third oxygen tank was added to obviate operation below 50% tank capacity. That allowed the elimination of the tank's internal stirring-fan equipment, which had contributed to the failure. Also starting with Apollo 14 ,
9042-500: The environmental control unit in the command module was found to have a design flaw, and was sent back to the manufacturer for design changes and rework. The returned ECU then leaked water/glycol coolant, and had to be returned a second time. Also during this time, a propellant tank in another service module had ruptured during testing at NAA, prompting the removal from the KSC test chamber of the service module so it could be tested for signs of
9179-498: The event of a launch abort. The boost hatch cover was partially, but not fully, latched in place because the flexible boost protective cover was slightly distorted by some cabling run under it to provide the simulated internal power (the spacecraft's fuel cell reactants were not loaded for this test). After the hatches were sealed, the air in the cabin was replaced with pure oxygen at 16.7 psi (115 kPa ), 2 psi (14 kPa) higher than atmospheric pressure. Movement by
9316-519: The extra time needed to incorporate compatibility with the Gemini, made that impractical. This became moot when slippage in readiness of the AS-204 spacecraft caused the last-quarter 1966 target date to be missed, and the mission was rescheduled for February 21, 1967. In October 1966, NASA announced the flight would carry a small television camera to broadcast live from the command module. The camera would also be used to allow flight controllers to monitor
9453-641: The findings and recommendations." Immediately after the fire NASA Administrator James E. Webb asked President Lyndon B. Johnson to allow NASA to handle the investigation according to its established procedure, promising to be truthful in assessing blame, and to keep the appropriate leaders of Congress informed. Deputy Director Seamans then ordered the establishment of the Apollo 204 Review Board chaired by Langley Research Center director Floyd L. Thompson , which included astronaut Frank Borman , spacecraft designer Maxime Faget , and six others. On February 1, Cornell University professor Frank A. Long left
9590-424: The fire fed by pure oxygen caused the pressure to rise to 29 psi (200 kPa), which ruptured the command module's inner wall at 6:31:19 (23:31:19 GMT, initial phase of the fire). Flames and gases then rushed outside the command module through open access panels to two levels of the pad service structure. The intense heat, dense smoke, and ineffective gas masks designed for toxic fumes rather than smoke, hampered
9727-457: The fire were applied to the Block II spacecraft, which was used for all crewed spaceflights. Nineteen CSMs were launched into space. Of these, nine flew humans to the Moon between 1968 and 1972, and another two performed crewed test flights in low Earth orbit , all as part of the Apollo program. Before these, another four CSMs had flown as uncrewed Apollo tests, of which two were suborbital flights and another two were orbital flights . Following
9864-451: The fire. Three minutes after the count was resumed the hatch installation was started. The hatch consisted of three parts: a removable inner hatch which stayed inside the cabin; a hinged outer hatch which was part of the spacecraft's heat shield; and an outer hatch cover which was part of the boost protective cover enveloping the entire command module to protect it from aerodynamic heating during launch and from launch escape rocket exhaust in
10001-499: The fire. Immediately after the fire, NASA convened an Accident Review Board to determine the cause of the fire, and both chambers of the United States Congress conducted their own committee inquiries to oversee NASA's investigation. The ignition source of the fire was determined to be electrical, and the fire spread rapidly due to combustible nylon material and the high-pressure pure oxygen cabin atmosphere. Rescue
10138-454: The flammable material had been removed per the crew's August 19 complaints and Joseph Shea's order, but was replaced before the August 26 delivery to Cape Kennedy. The inner hatch cover used a plug door design, sealed by higher pressure inside the cabin than outside. The normal pressure level used for launch (2 psi (14 kPa) above ambient) created sufficient force to prevent removing
10275-438: The flammables from the cabin, but did not supervise the issue personally. North American shipped spacecraft CM-012 to Kennedy Space Center on August 26, 1966, under a conditional Certificate of Flight Worthiness: 113 significant incomplete planned engineering changes had to be completed at KSC. That was not all; an additional 623 engineering change orders were made and completed after delivery. Grissom became so frustrated with
10412-455: The floor being affected only briefly. The board noted that a silver-plated copper wire, running through an environmental control unit near the center couch, had become stripped of its Teflon insulation and abraded by repeated opening and closing of a small access door. This weak point in the wiring also ran near a junction in an ethylene glycol /water cooling line that had been prone to leaks. Electrolysis of ethylene glycol solution with
10549-431: The forward docking tunnel. The forward compartment was separated from the central by a bulkhead and was divided into four 90-degree wedges. The ELS consisted of two drogue parachutes with mortars , three main parachutes , three pilot parachutes to deploy the mains, three inflation bags for uprighting the capsule if necessary, a sea recovery cable, a dye marker, and a swimmer umbilical. The command module's center of mass
10686-414: The forward heat shield was jettisoned to expose the Earth landing equipment and permit deployment of the parachutes. The 1-foot-8-inch (0.51 m)-tall aft compartment was located around the periphery of the command module at its widest part, just forward of (above) the aft heat shield. The compartment was divided into 24 bays containing 10 reaction control engines; the fuel, oxidizer, and helium tanks for
10823-430: The ground crew's attempts to rescue the men. There were fears the command module had exploded, or soon would, and that the fire might ignite the solid fuel rocket in the launch escape tower above the command module, which would have likely killed nearby ground personnel, and possibly have destroyed the pad. As the pressure was released by the cabin rupture, the rush of gases within the module caused flames to spread across
10960-399: The hatch. Because of the large strands of melted nylon fusing the astronauts to the cabin interior, removing the bodies took nearly 90 minutes. The bodies were only able to be removed after 7.5 hours from the time the incident took place, due to the gasses and toxins present which prevented medical personnel from entering initially. Deke Slayton was possibly the first NASA official to examine
11097-459: The hinges at 30–60 degrees per second. On all flights through Apollo 7 , the SLA panels remained hinged to the S-IVB and opened to a 45-degree angle, as originally designed. But as the Apollo 7 crew practiced rendezvous with the S-IVB/SLA containing a dummy docking target, one panel did not open to the full 45 degrees, raising concern about the possibility of collision between the spacecraft and
11234-404: The honeycomb varied from about 1.5 inches (3.8 cm) at the base to about 0.25 inches (0.64 cm) at the forward access tunnel. This inner structure was the pressurized crew compartment. The outer structure was made of stainless steel brazed-honeycomb brazed between steel alloy face sheets. It varied in thickness from 0.5 inch to 2.5 inches. Part of the area between the inner and outer shells
11371-463: The identical CM-014 and conducted a thorough investigation of every part. The board also reviewed the astronauts' autopsy results and interviewed witnesses. Seamans sent Webb weekly status reports of the investigation's progress, and the board issued its final report on April 5, 1967. According to the Board, Grissom suffered severe third-degree burns on more than one-third of his body and his spacesuit
11508-501: The inability of the training simulator engineers to keep up with the spacecraft changes that he took a lemon from a tree by his house and hung it on the simulator. The command and service modules were mated in the KSC altitude chamber in September, and combined system testing was performed. Altitude testing was performed first uncrewed, then with both the prime and backup crews, from October 10 through December 30. During this testing,
11645-438: The inner hatch to the cabin floor as intended, so they pushed it out of the way to one side. Although the cabin lights remained on, they were unable to see the astronauts through the dense smoke. As the smoke cleared they found the bodies, but were not able to remove them. The fire had partly melted Grissom's and White's nylon space suits and the hoses connecting them to the life support system. Grissom had removed his restraints and
11782-451: The inside of an 8-by-2.75-foot (2.44 by 0.84 m) skin panel. The primary fuel (MMH) tank contained 69.1 pounds (31.3 kg); the secondary fuel tank contained 45.2 pounds (20.5 kg); the primary oxidizer tank contained 137.0 pounds (62.1 kg), and the secondary oxidizer tank contained 89.2 pounds (40.5 kg). The propellant tanks were pressurized from a single tank containing 1.35 pounds (0.61 kg) of liquid helium. Back flow
11919-540: The intense heat of the fire. North American had originally suggested the hatch open outward and use explosive bolts to blow the hatch in case of emergency, as had been done in Project Mercury . NASA did not agree, arguing the hatch could accidentally open, as it had on Grissom's Liberty Bell 7 flight, so the Manned Spacecraft Center designers rejected the explosive design in favor of
12056-413: The launch vehicle's upper stage. Two uncrewed CSMs, one uncrewed LM, and one crewed CSM were carried into space by Saturn IB launch vehicles for low Earth orbit Apollo missions. Larger Saturn Vs launched two uncrewed CSMs on high Earth orbit test flights, the CSM on one crewed lunar mission, the complete spacecraft on one crewed low Earth orbit mission, and eight crewed lunar missions. After conclusion of
12193-460: The lunar module. In the event of an abort during launch from Earth, the same system would have explosively jettisoned the docking ring and probe from the CM as it separated from the boost protective cover. The central pressure vessel of the command module was its sole habitable compartment. It had an interior volume of 210 cubic feet (5.9 m) and housed the main control panels, crew seats, guidance and navigation systems, food and equipment lockers,
12330-468: The module's pressure vessel. The fused silica outer pane served as both a debris shield and as part of the heat shield. Each pane had an anti-reflective coating and a blue-red reflective coating on the inner surface. Sources: The service module was an unpressurized cylindrical structure with a diameter of 12 feet 10 inches (3.91 m) and 14 feet 10 inches (4.52 m) long. The service propulsion engine nozzle and heat shield increased
12467-431: The most efficient way to keep the program on track was to proceed with the development in two versions: By January 1964, North American started presenting Block II design details to NASA. Block I spacecraft were used for all uncrewed Saturn 1B and Saturn V test flights. Initially two crewed flights were planned, but this was reduced to one in late 1966. This mission, designated AS-204 but named Apollo 1 by its flight crew,
12604-419: The pressure between the tunnel and the CM so the hatch could be removed. The unified crew hatch (UCH) measured 29 inches (74 cm) high, 34 inches (86 cm) wide, and weighed 225 pounds (102 kg). It was operated by a pump handle, which drove a ratchet mechanism to open or close fifteen latches simultaneously. Apollo's mission required the LM to dock with the CSM on return from the Moon, and also in
12741-637: The primary flight controls, and the main FDAI (Flight Director Attitude Indicator). The CM pilot served as navigator, so his control panel (center) included the Guidance and Navigation computer controls, the caution and warning indicator panel, the event timer, the Service Propulsion System and RCS controls, and the environmental control system controls. The LM pilot served as systems engineer, so his control panel (right-hand side) included
12878-471: The probe cylinder body engaged and retained the probe center piston in the retracted position. Before vehicle separation in lunar orbit, manual cocking of the twelve ring latches was accomplished. The separating force from the internal pressure in the tunnel area was then transmitted from the ring latches to the probe and drogue. In undocking, the release of the capture latches was accomplished by electrically energizing tandem-mounted DC rotary solenoids located in
13015-411: The probe was retracted to pull the vehicles together and establish a firm connection, known as "hard docking". The mechanism was specified by NASA to have the following functions: The probe head located in the CSM was self-centering and gimbal-mounted to the probe piston. As the probe head engaged in the opening of the drogue socket, three spring-loaded latches depressed and engaged. These latches allowed
13152-488: The reaction control system (RCS) computer, power distribution block, ECS controller, separation controller, and components for the high-gain antenna, and included eight EPS radiators and the umbilical connection arm containing the main electrical and plumbing connections to the CM. The fairing externally contained a retractable forward-facing spotlight ; an EVA floodlight to aid the command module pilot in SIM film retrieval; and
13289-504: The reassembled spacecraft completed a successful altitude chamber test with Schirra's backup crew on December 30. According to the final report of the accident investigation board, "At the post-test debriefing the backup flight crew expressed their satisfaction with the condition and performance of the spacecraft." This would appear to contradict the account given in the 1994 book Lost Moon: The Perilous Voyage of Apollo 13 by Jeffrey Kluger and astronaut James Lovell , that "When
13426-526: The return home, the umbilical connection was severed and the service module was cast off and allowed to burn up in the atmosphere. The CSM was developed and built for NASA by North American Aviation starting in November 1961. It was initially designed to land on the Moon atop a landing rocket stage and return all three astronauts on a direct-ascent mission, which would not use a separate lunar module, and thus had no provisions for docking with another spacecraft. This, plus other required design changes, led to
13563-512: The signals from any two of the wires were lost, the LES would activate automatically. Alternatively, the Commander could activate the system manually using one of two translation controller handles, which were switched to a special abort mode for launch. When activated, the LES would fire a solid fuel escape rocket and open a canard system to direct the CM away from, and off the path of, a launch vehicle in trouble. The LES would then jettison and
13700-660: The silver anode of the wire was discovered at the Manned Spacecraft Center on May 29, 1967, to be a hazard capable of causing a violent exothermic reaction , igniting the ethylene glycol mixture in the Command Module's pure oxygen atmosphere. Experiments at the Illinois Institute of Technology confirmed the hazard existed for silver-plated wires, but not for copper-only or nickel-plated copper. In July, ASPO directed both North American and Grumman to ensure no silver or silver-coated electrical contacts existed in
13837-423: The southeastern United States with Florida (the launch point) prominent. The Moon is seen in the distance, symbolic of the eventual program goal. A yellow border carries the mission and astronaut names with another border set with stars and stripes, trimmed in gold. The insignia was designed by the crew, with the artwork done by North American Aviation employee Allen Stevens. The Apollo command and service module
13974-430: The spacecraft was removed from the altitude chamber on January 3, 1967, and mated to its Saturn IB launch vehicle on pad 34 on January 6. Grissom said in a February 1963 interview that NASA could not eliminate risk despite precautions: An awful lot of people have devoted more effort than I can describe to [make] Project Mercury and its successors, as safe as humanly possible ... But we also recognize that there remains
14111-486: The spacecraft's instrument panel in flight. Television cameras were carried aboard all crewed Apollo missions. Grissom's crew received approval in June 1966 to design a mission patch with the name Apollo 1 (though the approval was subsequently withdrawn pending a final decision on the mission designation, which was not resolved until after the fire). The design's center depicts a command and service module flying over
14248-410: The spacecraft's interior. His testimony contradicted the official report concerning the position of Grissom's body. Slayton said of Grissom and White's bodies, "it is very difficult for me to determine the exact relationships of these two bodies. They were sort of jumbled together, and I couldn't really tell which head even belonged to which body at that point. I guess the only thing that was real obvious
14385-414: The spacecraft's oxygen and communication systems. Grissom immediately noticed a strange odor in the air circulating through his suit which he compared to "sour buttermilk", and the simulated countdown was put on hold at 1:20 pm, while air samples were taken. No cause of the odour could be found, and the countdown was resumed at 2:42 pm. The accident investigation found this odour not to be related to
14522-522: The specifications given below, unless otherwise noted, all weights given are for the Block II spacecraft. The total cost of the CSM for development and the units produced was $ 36.9 billion in 2016 dollars, adjusted from a nominal total of $ 3.7 billion using the NASA New Start Inflation Indices. The command module was a truncated cone ( frustum ) with a diameter of 12 feet 10 inches (3.91 m) across
14659-529: The tank problem. These tests were negative. In December the second Block I flight AS-205 was canceled as unnecessary; Schirra, Eisele and Cunningham were reassigned as the backup crew for Apollo 1. McDivitt's crew was now promoted to prime crew of the Block II/LM mission, re-designated AS-258 because the AS-205 launch vehicle would be used in place of AS-207. A third crewed mission was planned to launch
14796-542: The third parachute being a safety precaution. The command module attitude control system consisted of twelve 93-pound-force (410 N) attitude control thrusters, ten of which were located in the aft compartment, plus two in the forward compartment. These were supplied by four tanks storing 270 pounds (120 kg) of monomethylhydrazine fuel and nitrogen tetroxide oxidizer, and pressurized by 1.1 pounds (0.50 kg) of helium stored at 4,150 pounds per square inch (28.6 MPa) in two tanks. The forward docking hatch
14933-786: The thrust vector aligned with the spacecraft's center of mass during SPS firings. The combustion chamber and pressurant tanks were housed in the central tunnel. Four clusters of four reaction control system (RCS) thrusters (known as "quads") were installed around the upper section of the SM every 90°. The sixteen-thruster arrangement provided rotation and translation control in all three spacecraft axes. Each R-4D thruster measured 12 inches (30 cm) long by 6 inches (15 cm) diameter, generated 100 pounds-force (440 N) of thrust, and used helium-fed monomethylhydrazine (MMH) as fuel and nitrogen tetroxide (NTO) as oxidizer. Each quad assembly measured 2.2 by 2.7 feet (0.67 by 0.82 m) and had its own fuel, oxidizer, and helium tanks mounted on
15070-591: The time to run through their checklist again, when a momentary increase in AC Bus 2 voltage occurred. Nine seconds later (at 6:31:04.7), one of the astronauts (some listeners and laboratory analysis indicate Grissom) exclaimed "Hey!", "Fire!", or "Flame!"; this was followed by two seconds of scuffling sounds through Grissom's open microphone. This was immediately followed at 6:31:06.2 (23:31:06.2 GMT) by someone (believed by most listeners, and supported by laboratory analysis, to be Chaffee) saying, "[I've, or We've] got
15207-575: The total height to 24 feet 7 inches (7.49 m). The interior was a simple structure consisting of a central tunnel section 44 inches (1.1 m) in diameter, surrounded by six pie-shaped sectors. The sectors were topped by a forward bulkhead and fairing, separated by six radial beams, covered on the outside by four honeycomb panels, and supported by an aft bulkhead and engine heat shield. The sectors were not all equal 60° angles, but varied according to required size. The forward fairing measured 1 foot 11 inches (58 cm) long and housed
15344-403: The trio climbed out of the ship, ... Schirra made it clear that he was not pleased with what he had seen," and that he later warned Grissom and Shea that "there's nothing wrong with this ship that I can point to, but it just makes me uncomfortable. Something about it just doesn't ring right," and that Grissom should get out at the first sign of trouble. After the successful altitude tests,
15481-411: The upper end of the lunar module tunnel, the drogue, which was constructed of 1-inch-thick aluminum honeycomb core, bonded front and back to aluminum face sheets, was the receiving end of the probe head capture latches. After the initial capture and stabilization of the vehicles, the probe was capable of exerting a closing force of 1,000 pounds-force (4.4 kN) to draw the vehicles together. This force
15618-555: The vacuum of space. It consisted of a descent stage and an ascent stage . It supplied life support systems for two astronauts for up to four to five days on the Apollo 15, 16 and 17 missions. The spacecraft was designed and manufactured by the Grumman Aircraft Company . The descent stage contained the landing gear, landing radar antenna, descent propulsion system , and fuel to land on the Moon. It also had several cargo compartments used to carry, among other things:
15755-582: The vicinity of possible glycol spills in the Apollo spacecraft. The plugs-out test had been run to simulate the launch procedure, with the cabin pressurized with pure oxygen at the nominal launch level of 16.7 psi (115 kPa), 2 psi (14 kPa) above standard sea level atmospheric pressure. This is more than five times the 3 psi (21 kPa) partial pressure of oxygen in the atmosphere, and provides an environment in which materials not normally considered flammable will be highly flammable and burst into flame. The high-pressure oxygen atmosphere
15892-402: The waste management system, and the docking tunnel. Dominating the forward section of the cabin was the crescent-shaped main display panel measuring nearly 7 feet (2.1 m) wide and 3 feet (0.91 m) tall. It was arranged into three panels, each emphasizing the duties of each crew member. The mission commander's panel (left side) included the velocity , attitude, and altitude indicators,
16029-437: Was almost completely destroyed. White suffered third-degree burns on almost half of his body and a quarter of his spacesuit had melted away. Chaffee suffered third-degree burns on almost a quarter of his body and a small portion of his spacesuit was damaged. The autopsy report determined that the primary cause of death for all three astronauts was cardiac arrest caused by high concentrations of carbon monoxide . Burns suffered by
16166-463: Was bolted to a flange at the top of the longer panels, and power to the SLA multiply-redundant pyrotechnics was provided by an umbilical. Because a failure to separate from the S-IVB stage could leave the crew stranded in orbit, the separation system used multiple signal paths, multiple detonators and multiple explosive charges where the detonation of one charge would set off another even if the detonator on that charge failed to function. Once in space,
16303-583: Was composed of four fixed 7-foot-tall (2.1 m) panels bolted to the Instrument Unit on top of the S-IVB stage, which were connected via hinges to four 21-foot-tall (6.4 m) panels which opened from the top similar to flower petals. The SLA was made from 1.7-inch-thick (43 mm) aluminum honeycomb material. The exterior of the SLA was covered by a thin (0.03–0.2 in or 0.76–5.08 mm) layer of cork and painted white to minimize thermal stresses during launch and ascent. The service module
16440-472: Was composed of three parts designed to accomplish the American Apollo program 's goal of landing astronauts on the Moon by the end of the 1960s and returning them safely to Earth . The expendable (single-use) spacecraft consisted of a combined command and service module (CSM) and an Apollo Lunar Module (LM). Two additional components complemented the spacecraft stack for space vehicle assembly:
16577-495: Was essential to making the February 21 launch date. The test was considered non-hazardous because neither the launch vehicle nor the spacecraft was loaded with fuel or cryogenics and all pyrotechnic systems (explosive bolts) were disabled. At 1:00 pm EST (18:00 GMT ) on January 27, first Grissom, then Chaffee, and White entered the command module fully pressure-suited, and were strapped into their seats and hooked up to
16714-450: Was filled with a layer of fiberglass insulation as additional heat protection. An ablative heat shield on the outside of the CM protected the capsule from the heat of reentry , which is sufficient to melt most metals. This heat shield was composed of phenolic formaldehyde resin . During reentry, this material charred and melted away, absorbing and carrying away the intense heat in the process. The heat shield has several outer coverings:
16851-451: Was generated by gas pressure acting on the center piston within the probe cylinder. Piston retraction compressed the probe and interface seals and actuated the 12 automatic ring latches which were located radially around the inner surface of the CSM docking ring. The latches were manually re-cocked in the docking tunnel by an astronaut after each hard docking event (lunar missions required two dockings). An automatic extension latch attached to
16988-529: Was installed on the armrests of the left-hand couch. The translation controller was used by the crew member performing the transposition, docking, and extraction maneuver with the LM, usually the CM Pilot. The center and right-hand couches had duplicate rotational controllers. The couches were supported by eight shock-attenuating struts, designed to ease the impact of touchdown on water or, in case of an emergency landing, on solid ground. The contiguous cabin space
17125-401: Was lying on the floor of the spacecraft. White's restraints were burned through, and he was found lying sideways just below the hatch. It was determined that he had tried to open the hatch per the emergency procedure, but was not able to do so against the internal pressure. Chaffee was found strapped into his right-hand seat, as procedure called for him to maintain communication until White opened
17262-431: Was mounted at the top of the docking tunnel. It was 30 inches (76 cm) in diameter and weighed 80 pounds (36 kg), constructed from two machined rings that were weld-joined to a brazed honeycomb panel. The exterior side was covered with 0.5-inch (13 mm) of insulation and a layer of aluminum foil. It was latched in six places and operated by a pump handle. The hatch contained a valve in its center, used to equalize
17399-443: Was much bigger and far more complex than any previous crewed spacecraft. In October 1963, Joseph F. Shea was named Apollo Spacecraft Program Office (ASPO) manager, responsible for managing the design and construction of both the CSM and the LM. In a spacecraft review meeting held with Shea on August 19, 1966 (a week before delivery), the crew expressed concern about the amount of flammable material (mainly nylon netting and Velcro ) in
17536-409: Was offset a foot or so from the center of pressure (along the symmetry axis). This provided a rotational moment during reentry, angling the capsule and providing some lift (a lift to drag ratio of about 0.368). The capsule was then steered by rotating the capsule using thrusters; when no steering was required, the capsule was spun slowly, and the lift effects cancelled out. This system greatly reduced
17673-551: Was organized into six equipment bays: The CM had five windows. The two side windows measured 9 inches (23 cm) square next to the left and right-hand couches. Two forward-facing triangular rendezvous windows measured 8 by 9 inches (20 by 23 cm), used to aid in rendezvous and docking with the LM. The circular hatch window was 9 inches (23 cm) in diameter located directly over the center couch. Each window assembly consisted of three thick panes of glass. The inner two panes, which were made of aluminosilicate , made up part of
17810-409: Was planned for launch on February 21, 1967. During a dress rehearsal for the launch on January 27, all three astronauts ( Gus Grissom , Ed White and Roger Chaffee ) were killed in a cabin fire, which revealed serious design, construction and maintenance shortcomings in Block I, many of which had been carried over into Block II command modules being built at the time. After a thorough investigation by
17947-528: Was prevented by a series of check valves, and back flow and ullage requirements were resolved by containing the fuel and oxidizer in Teflon bladders which separated the propellants from the helium pressurant. The four completely independent RCS clusters provided redundancy; only two adjacent functioning units were needed to allow complete attitude control. The lunar module used a similar four-quad arrangement of R-4D thruster engines for its RCS. Electrical power
18084-497: Was prevented by the plug door hatch, which could not be opened against the internal pressure of the cabin. Because the rocket was unfueled, the test had not been considered hazardous, and emergency preparedness for it was poor. During the Congressional investigation, Senator Walter Mondale publicly revealed a NASA internal document citing problems with prime Apollo contractor North American Aviation , which became known as
18221-552: Was produced by three fuel cells , each measuring 44 inches (1.1 m) tall by 22 inches (0.56 m) in diameter and weighing 245 pounds (111 kg). These combined hydrogen and oxygen to generate electrical power, and produced drinkable water as a byproduct. The cells were fed by two hemispherical-cylindrical 31.75-inch (0.806 m) diameter tanks, each holding 29 pounds (13 kg) of liquid hydrogen , and two spherical 26-inch (0.66 m) diameter tanks, each holding 326 pounds (148 kg) of liquid oxygen (which also supplied
18358-488: Was similar to that which had been used successfully in the Mercury and Gemini programs. The pressure before launch was deliberately greater than ambient in order to drive out the nitrogen-containing air and replace it with pure oxygen, and also to seal the plug door hatch cover. During the launch, the pressure would have been gradually reduced to the in-flight level of 5 psi (34 kPa), providing sufficient oxygen for
18495-449: Was still assumed the lunar landing would be achieved by direct ascent rather than by lunar orbit rendezvous . Therefore, design proceeded without a means of docking the command module to a lunar excursion module (LEM) . But the change to lunar orbit rendezvous, plus several technical obstacles encountered in some subsystems (such as environmental control), soon made it clear that substantial redesign would be required. In 1963, NASA decided
18632-466: Was the area outside the inner pressure shell in the nose of the capsule, located around the forward docking tunnel and covered by the forward heat shield. The compartment was divided into four 90-degree segments that contained Earth landing equipment (all the parachutes, recovery antennas and beacon light, and sea recovery sling), two reaction control thrusters, and the forward heat shield release mechanism. At about 25,000 feet (7,600 m) during reentry,
18769-422: Was the control center for the Apollo spacecraft and living quarters for the three crewmen. It contained the pressurized main crew cabin, crew couches, control and instrument panel, Primary Guidance, Navigation and Control System , communications systems, environmental control system, batteries, heat shield , reaction control system to provide attitude control , forward docking hatch, side hatch, five windows, and
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