The Future That Never Came: The Unflown Mission of Apollo 1

The tragic Apollo 1 fire of January 27, 1967 which killed NASA astronauts Gus Grissom, Ed White and Roger Chaffee was a defining moment in the history of the Apollo program. It forced a reassessment of the manned lunar program and the country’s push to send astronauts to the Moon before the end of that decade. Most reviews today of Apollo 1 (whose official pre-flight designation was “AS-204”) center on remembering the achievements of the mission’s crew or the accident, its investigation and the impact it subsequently had on the Apollo program. But what about the unflown mission of Apollo 1 itself? What was the purpose of this mission and what activities were planned for the crew during their time in orbit with the new Apollo spacecraft?


The New Spacecraft

At this stage of the Apollo program, there were actually two versions of the Apollo spacecraft being built by its prime contractor, North American Aviation (which, after decades of corporate mergers, is now part of Boeing). The first variant, designated Block I, was essentially a prototype meant for test flights in low Earth orbit for the purpose of verifying the basic Apollo CSM (Command-Service Module) design. Lessons learned from constructing and flying these versions would be then incorporated into the improved Block II Apollo CSM which would include all of the equipment required to support a flight to the Moon.


Diagram of the Block I Apollo CSM-012 in its launch configuration for the AS-204 or Apollo 1 mission. Click on image to enlarge. (NASA)

The Apollo CM (Command Module), which carried the astronauts during their mission as well as the recovery systems needed to return them safely to Earth, was conical in shape with a diameter of 3.9 meters and a height of 3.2 meters. The SM (Service Module), which included all the systems and consumables needed to support the astronauts and their mission, was a cylinder with the same diameter. Its appearance was dominated by the 91-kilonewton Aerojet AJ10-137 engine of the Service Propulsion System (SPS) which would be used for all major propulsive maneuvers after the Saturn launch vehicle had finished its task. The total height of the CSM was 11 meters and the Block I version had a nominal mass in excess of 20 metric tons making it the most massive crewed spacecraft to fly up until that time.

The Apollo spacecraft was topped off by the launch escape system (LES) built by the Lockheed Propulsion Company (whose corporate parent is now part of Lockheed Martin). It consisted of a solid rocket motor assembly attached to the top of the CM by means of a truss framework with a total height of 9.9 meters and a mass of 4,200 kilograms. It was designed to pull the CM and its crew to safety in case of an abort situation during the earliest phase of launch and would be jettisoned during the burn of the Saturn second stage when it was no longer needed. The LES included a lightweight boost protective cover (BPC) made of fiberglass and cork which protected the outer hull and windows of the CM during the early phases of ascent and when the LES was jettisoned.

saturn IB launch vehicle, artist concept with callouts. REF: msfc-68-Ind-1125d (MIX FILE)

Artist concept of the Apollo-Saturn IB. Click on image to enlarge. (NASA)

The launch vehicle for the Apollo missions destined for Earth orbit was the Saturn IB. The Saturn IB was a substantially improved version of the Saturn I originally developed by the team led by famed rocket engineer Wernher von Braun based at NASA’s Marshall Space Flight Center in Huntsville, Alabama. The first stage of this new launch vehicle, built by Chrysler and designated S-IB, was an updated version of the S-I stage successfully flown ten times between 1960 and 1965 during the Saturn I test flight program (see “The Last Launch of the Saturn I”). Like the S-I stage, the S-IB structure consisted of a set of eight 1.8-meter in diameter tanks holding LOX and RP-1 derived from the proven Redstone rocket clustered around a single 2.7-meter LOX tank adapted from the Jupiter rocket. A new set of eight swept-back fins as well as a host of other changes to the hardware and fabrication of the S-IB made it 9,000 kilograms lighter than the older S-I. The S-IB was powered by eight improved Rocketdyne H-1 engines whose total thrust at launch was increased from 6,683 to 7,120 kilonewtons.


Cutaway diagram showing the major components of the S-IB stage. Click on image to enlarge. (NASA)

By far the biggest change to create the Saturn IB was to the second stage designated S-IVB and built by the Douglas Aircraft Company. Instead of six Pratt & Whitney RL-10 engines which produced a total of 400 kilonewtons of thrust on the original S-IV stage used by the Saturn I, the new and larger S-IVB stage employed a single Rocketdyne J-2 engine to produce 890 kilonewtons of thrust using the same high energy propellant combination of liquid hydrogen and LOX used on the S-IV. The S-IVB stage also included a pair of auxiliary propulsion system (APS) modules which provided roll control during the burn of the J-2 as well as attitude control while coasting in orbit. The stage was topped off by the Instrument Unit (IU) which controlled both stages of the launch vehicle. In addition carrying the CSM or LM (Lunar Module) into Earth orbit for initial test flights, the first launches also allowed flight testing of the nearly identical version of the S-IVB stage that would be employed as the third stage of the Saturn V which would send Apollo to the Moon.

saturn IB second stage (s-IVB) REF: msfc-68-Ind-1190c (MIX FILE)

Cutaway diagram showing the major components of the S-IVB stage. Click on image to enlarge. (NASA/MSFC)

A tapered spacecraft launch adapter consisting of four panels connected the S-IVB stage to the Apollo CSM. During flights of the Saturn V, the LM would also be housed inside this adapter beneath the SM. The Saturn IB, without the payload, was 43.2 meters tall and was capable of placing about 21 metric tons into low Earth orbit. The total height of the Apollo-Saturn IB was 68.3 meters and it had a typical lift off mass of 598 metric tons.


The first Apollo orbital test flight, A-101, on pad B at LC-37 before its launch in May 1964. (NASA)

The Apollo AS-204 mission would not be the first test flight of the Apollo program. Starting with the Apollo A-101 mission on May 28, 1964, NASA launched a total of five Apollo missions into orbit as payloads for Saturn I development flights over the course of 15 months (see “50 Years Ago Today: The First Apollo Orbital Test Flight”). Although the mission hardware consisted of instrumented boilerplate models of the CSM, they gathered vital data on the aerodynamic and structural properties of the Apollo spacecraft during actual flight. The separation of Apollo’s LES during flight was also tested during these missions.


The Apollo A-004 abort test in January 1966 was the first launch of a production Apollo spacecraft, CM-002. (NASA)

Boilerplate models of the Apollo CM were also used in a series of launch abort tests starting in November 1963. These included pad abort tests with just the LES and CM as well as flights using the Little Joe II rocket to test the LES under much more stressing flight conditions (see “50 Years Ago Today: The First Flight of the Apollo Little Joe II”). This flight test program culminated in the Apollo A-004 mission launched on January 20, 1966. For the first time, production Apollo flight hardware was launched on a mission this time to test the LES and CM-002 (Command Module #002) under a stressing power-on, tumbling abort situation (see “The First Launch of Apollo Flight Hardware”). With the successful conclusion of these test flights, it was time to test Apollo program hardware in an actual spaceflight.


The first Apollo-Saturn IB at LC-34 ready for the launch of the AS-201 mission in February 1966. (NASA)

The unmanned Apollo AS-201 mission launched on February 26, 1966 was the first spaceflight of a production model CSM and the first flight of its Saturn IB launch vehicle (see “The First Flight of the Apollo-Saturn IB”). While all the primary mission objectives were met by CSM-009 (Command-Service Module #009), problems encountered during this 37-minute suborbital test flight, especially during the pair of burns of the SM’s SPS, forced a postponement of the follow on AS-202 mission in order to resolve the issues.


SA-203 on Pad B at LC-37 being prepared for launch in July 1966. (NASA)

In the mean time, the AS-203 mission was launched out of the originally intended sequence on July 5.  The objectives of the AS-203 mission, which did not fly with an Apollo spacecraft, concentrated on testing various design features of the S-IVB stage during orbital flight before it was flown on the Saturn V (see “AS-203: NASA’s Odd Apollo Mission”). The final unmanned Apollo-Saturn IB test flight, AS-202, launched CSM-011 on a 93-minute suborbital test flight on August 25 which ended with a splashdown in the Pacific Ocean. The spacecraft met its mission objectives and the CM successfully executed a double-skip reentry profile certifying the CSM for manned orbital flight (see “AS-202: The Last Test Flight Before Apollo 1”).


CM-011 shown following its splashdown in the Pacific Ocean at the end of the successful AS-202 mission. (NASA)


Plans for the AS-204 Mission

NASA’s early planning called for a pair of manned Block I test flights, designated AS-204 and AS-205, before introducing the Block II Apollo. On March 21, 1966 NASA officially announced the crew selection for the AS-204 mission. The command pilot was USAF Lt. Colonel Virgil “Gus” Grissom, the senior pilot was USAF Lt. Colonel Edward H. White, Jr. and the pilot was USN Lt. Commander Roger B. Chaffee. The 40-year old Gus Grissom was one of NASA’s original “Mercury 7” astronauts chosen in 1959 and was already a veteran of two spaceflights. His first was Mercury-Redstone 4 launched on a 15-minute suborbital flight on July 21, 1961 making Grissom only the second American, after Alan Shepard, to fly into space (see “A History of Suborbital Crewed Spaceflights“). Grissom was also the commander of the first manned Gemini mission, Gemini 3, launched on a three-orbit test flight on March 23, 1965 (see “50 Years Ago Today: The Launch of Gemini 3”).


The primary crew of the Apollo 1 mission: (l to r) Ed White, Gus Grissom and Roger Chaffee. (NASA)

Ed White, who would be 36 years old at the time of the AS-204 mission, was a member of NASA’s second astronaut group chosen in 1962. White was also a veteran astronaut who had previously flown as the pilot on the four-day Gemini 4 mission during which he became the first American to perform an EVA on June 3, 1965 (see “The Forgotten Mission of Gemini 4”). Roger Chaffee, who would have just turned 32 years old at the scheduled beginning of the AS-204 mission, was a member of NASA’s third astronaut group chosen in 1963. This would be his first space mission.


The official patch for the Apollo 1 mission. (NASA)

While the official designation of the first manned Apollo mission was originally AS-204, early on the crew and others in the program pushed for the use of the name “Apollo 1” which was informally adopted early by many inside NASA and among the contractors. In June 1966, NASA officially approved the proposed mission patch containing the label “Apollo 1” and there was every expectation that this would become the official designation of the mission come launch which, after many delays over the course of 1966, was set for February 21, 1967 as the end of 1966 approached.


The original backup crew for the Apollo 1 mission: (l to r) Dave Scott, Jim McDivitt and Rusty Schweikart. (NASA)

The original backup crew for the Apollo 1 mission consisted of James A. McDivitt, who had flown as the commander on the Gemini 4 mission with White, David R. Scott, who was the pilot on the Gemini 8 mission (see “Gemini 8: The First Docking in Space”) and rookie astronaut Russell “Rusty” Schweikart. But as NASA’s plans for Apollo evolved over the course of 1966, this would change. On November 15, officials cancelled the second Block I test flight, informally designated “Apollo 2”, after it was found to be redundant. A new “Apollo 2” mission, officially designated AS-205/208, would instead test the first Block II Apollo. The crew would also rendezvous with a Lunar Module launched on a separate Saturn IB rocket to perform the first manned test of this key piece of Apollo hardware.


The new backup crew for the Apollo 1 mission reassigned in early December 1966 shown during a break in training: (l to r) Donn Eisele, Wally Schirra and Walter Cunningham. (NASA)

In early December 1966, NASA reassigned McDivitt, Scott and Schweikart to the new “Apollo 2” mission and substituted the primary crew of the now cancelled second Block I mission as the new backup crew for AS-204. The commander of the new backup crew was now veteran astronaut Walter “Wally” Schirra who had previously flown on the Mercury-Atlas 8 and as commander on the Gemini 6 mission (see the series of articles on Gemini 6) and had pushed for the cancellation of the second Block I mission. He was less than pleased with the reassignment as the backup to the Apollo 1 mission and had hoped to command the new AS-205/208 mission. The two other backup crew members were rookie astronauts Donn F. Eisele (who was originally suppose to be the senior pilot on the primary crew of AS-204 but was replaced because he had to undergo surgery to repair a dislocated shoulder) and Walter Cunningham.


Diagram of the interior of the Block I CM-012 as it was configured for the Apollo 1 mission. Click on image to enlarge. (NASA)

The hardware assigned to the Apollo 1 mission consisted of Apollo CSM-012 and the Saturn IB designated SA-204. Launch would take place from Launch Complex 34 (LC-34) which had supported the earlier AS-201 and AS-202 unmanned test flights. The SA-204 rocket would place the 20,400-kilogram CSM-012 into an initial 140 by 210-kilometer orbit after 11½ minutes of powered flight. For the first two and a half hours in orbit, CSM-012 would remain attached to the S-IVB stage much as a Moon-bound Apollo would do prior to trans-lunar injection. After separation of the CSM, Grissom would perform a station keeping exercise with the spent S-IVB stage so that White and Chaffee could photograph the stage as it vented its residual propellants. This would provide vital observations on the behavior of the S-IVB stage to aid in planning future mission activities.


Among the crew’s first tasks once Apollo 1 got into orbit was to perform a station keeping exercise with the spent S-IVB stage much as was done during the Apollo 7 mission pictured here. (NASA)

At this point, Apollo 1 would perform an open-ended mission which could last for as little as six orbits in order to meet at least the highest priority mission objectives or as long as two weeks, provided that CSM-012 continued to function adequately. The primary objectives of the mission basically centered on testing all the systems of the Block I Apollo spacecraft during ascent, in orbit and during descent. The first pair of firings of the SM’s SPS would take place the day after launch to raise and circularize the orbit of Apollo 1. No attempts would be made to perform a rendezvous with the spent S-IVB stage. Afterwards, burns of the SPS were planned to be performed every other day during the course of the mission with each astronaut taking turns in the left-side commander’s seat – three burns each by Grissom and White as well as two burns by Chaffee. Apollo 1 would carry a television camera which would allow live broadcasts from inside the CM cabin during the mission. The camera would also allow ground controllers to monitor the CM’s control panel during key parts of the flight.


The storage locations of some of the hardware for flight experiments inside the Apollo 1 cabin. Click on image to enlarge. (NASA)

In addition to the laundry list of systems checks, Apollo 1 also carried an array of hardware to perform a total of nine medical, scientific and technological experiments during its long orbital mission. These consisted of the following:

M-3A In-Flight Exerciser: This was simply a pair of bungee cords that would loop around the astronaut’s feet and grasped by the hand via a handle. Each astronaut would spend three ten-minute sessions each day exercising with this device to determine the utility of in-flight exercise to stave off the effects of prolonged weightlessness. A similar M-3 experiment was flown on the Gemini 4, 5 and 7 long-duration missions during 1965.


Diagram showing the M-3A exercise experiment carried by Apollo 1. Click on image to enlarge. (NASA)

M-4A In-Flight Phonocardiogram: The purpose of this experiment was to produce in-flight recordings of the crew’s heartbeat to determine the effects of weightlessness on heart function. Grissom and Chaffee would be the subjects of these tests. This was similar to the M-4 experiment flown on the long-duration Gemini missions.

M-6A Bone Demineralization: The goal of this experiment was to determine the effects of weightlessness on the demineralization of certain bones in the body. This experiment required no special in-flight equipment and would rely on measurements derived from X-rays taken before and after the flight from all three crew members. Once again, this was similar to the M-6 experiment performed during the long-duration Gemini missions.

M-9A Human Otolith Function: The objective of this experiment was to determine the effect of prolonged weightlessness on an astronauts sense of orientation. Each crew member would spend 15 minutes each day in orbit wearing a set of test goggles with their responses recorded by a 16 mm movie camera. A similar experiment was conducted during the Gemini 5 and 7 missions.

M-11 Cytogenetic Blood Studies: This experiment sought to determine if the space environment produced cellular changes in the blood of the crew. No in-flight equipment was required with the necessary data coming from blood samples taken from all three crewmen at set intervals before and after the mission.

M-48 Cardiovascular Reflex Conditioning: In this experiment, one of the astronauts would don a set of vascular support tights one or two hours before the end of the mission to determine if such a garment helps prevent physical fatigue blood pooling in the lower body following return to Earth.

S-5A Synoptic Terrain Photography: This was similar to the S-5 experiment flown on most of the earlier Gemini missions. The crew would use a 70 mm Hasselblad camera to perform near nadir-viewing photography of the Earth during 9 AM to 3 PM local time. Two color film packs with a total of 110 exposures were to be carried on the Apollo 1 mission.


Diagram showing the in-flight stowage of the camera and film packs for the S-5A and S-6A experiments on the inside CM crew hatch. Click on image to enlarge. (NASA)

S-6A Synoptic Weather Photography: Similar to the S-6 experiment conducted on most of the Gemini missions, the purpose of this investigation was to provide orbital photographs of weather phenomena at a much higher resolution than was possible with contemporary weather satellites like NASA’s TIROS or Nimbus satellites. One color and one color-shifted infrared film packet along with an ultraviolet filter for the camera would be carried to support this experiment.

T-3 In-Flight Nephelometer: This experiment used a device to measure the size, concentration and distribution of particles present inside the CM cabin. Measurements would be made every six hours starting two days into the mission.


The Apollo 1 crew shown training inside of the CM. (NASA)

If no vital system failures forced a early end of the Apollo 1 mission, the crew was scheduled to return to Earth on March 7, 1967 for a splashdown in the Pacific Ocean. Assuming Apollo 1 flew for the maximum expected mission time of 13 days, 18 hours and 50 minutes, the crew would set a new spaceflight endurance record beating that set by the crew of Gemini 7 by about quarter of an hour (see the series of articles on Gemini 7). With this successful flight, the way would be clear for the first Block II Apollo mission and manned LM test flight by McDivitt, Scott and Schweikart tentatively set for launch in August 1967.


The Apollo 1 crew shown during water egress training in the Gulf of Mexico on October 27, 1966. (NASA)


Preparations for Apollo 1

The first major piece of flight hardware for the Apollo 1 mission to arrive at Cape Kennedy (which reverted back to its original name of Cape Canaveral in 1973) was the second stage of the SA-204 launch vehicle, designated S-IVB-204, on August 6, 1966. This was followed nine days later by the rocket’s first stage, designated S-IB-4, which arrived at the Cape by barge. Following the successful launch of AS-202 on August 25, LC-34 was quickly refurbished and the S-IB-4 was erected on the pad followed by S-IVB-204 on August 31. The long process of checking out the Saturn IB for its first manned mission then began.


The S-IB-4 stage shown being erected on the pad at LC-34 at the end of August 1966 for the beginning of launch preparations for the Apollo 1 mission. (NASA)

In the mean time, a series of three vacuum thermal tests – one unmanned and two manned – using CSM-008 were concluded at the Space Environment Simulation Laboratory (SESL) at the Manned Space Center in Houston, Texas (today known as Johnson Space Center). The final week-long test was completed on August 9, 1966 carrying a crew of two NASA astronauts and a USAF test pilot with the spacecraft configured to emulate CSM-012. The problems uncovered during these important thermal vacuum tests led to a number of hardware and procedural changes to improve the chances of Apollo 1 succeeding (see “The Apollo Flights to Nowhere: The Testing of CSM-008”).


A view of CSM-008 inside SESL Chamber A as it was being prepared for vacuum thermal testing. (NASA)

On August 19, NASA accepted CSM-012 for delivery with 113 engineering orders still pending. A problem with the CM environmental control unit forced it to be switched with that from CM-014 delaying arrival of CM-012 until August 26. Three days later, SM-012 arrived at the Cape to begin prelaunch testing as well as completion of unfinished work. The two modules were mated inside of the high altitude chamber at the Cape to begin combined systems checks which uncovered additional problems with CSM-012. NASA headquarters certified the design as flightworthy on October 7 pending satisfactory resolution of the yet to be completed work.


The primary crew shown entering CM-012 during a high altitude chamber test on October 18, 1966. (NASA)

Unmanned altitude chamber tests were performed between October 11 and 15 with the first in a series of manned tests starting on October 18 with the prime crew. Following a high altitude chamber test with the original Apollo 1 backup crew on October 21, the environmental control system regulator was pulled after it had failed again due to a design flaw. As engineers struggled with this and a litany of other issues with CSM-012 uncovered during testing, the propellant tanks on SM-017 under construction at North American Aviation ruptured due to corrosion forcing engineers to check the tanks on SM-012 to ensure they would not fail as well. Through November and into December, CM-012 had its third environmental control system removed and replaced with a fourth unit which then proceeded to malfunction leaking its water-glycol coolant mixture on at least six instances saturating a nearby bundle of wires. With the repaired unit reinstalled on December 16, further vacuum chamber tests were conducted starting on December 27.


CSM-012 shown on January 4, 1967 being prepared to be moved from its test stand for mating with its launch adapter. (NASA)

Following the removal of CSM-012 from the altitude chamber at the conclusion of the test program, the modules were mated to each other on January 4, 1967 and subsequently stacked on the spacecraft launch adapter the next day. On January 6, CSM-012 was moved to LC-34 and stacked on top of the waiting SA-204 launch vehicle. The first “plugs in” test was conducted on January 20 followed by the second five days later.


CSM-012 and its adapter shown being lifted into place atop of SA-204 at LC-34 on January 6, 1967. (NASA)

The first “plugs out” test for a thorough countdown demonstration with the primary crew was set for Friday, January 27, 1967. Grissom, White and Chaffee started entering the CM at 1:00 PM EST. The simulated countdown was halted twenty minutes later when a strange smell was noted in the oxygen supplied to the suits by the environmental control system. After analysis showed there to be no problem, the simulated countdown was resumed at 2:45 PM and the CM’s multi-piece side crew hatch was installed. The CM cabin was then purged with pure oxygen and the pressure raised to 1.1 atmospheres.


Chaffee, White and Grissom shown inside the transfer van on their way to LC-34 for the second “plugs in” test on January 25, 1967. (NASA)

As the astronauts and ground crew struggled with communications systems issues with the simulated countdown held at T-10 minutes, an electrical arc near the troublesome environmental control system at 6:30:55 PM EST ignited nylon webbing and Velcro inside the CM cabin which produced a quickly spreading fire due to the pressurized pure oxygen atmosphere. Nine seconds later, the crew reported a fire in the cabin as they began their evacuation procedures. Before the astronauts had a chance to open the cumbersome crew hatch or ground crews could respond, the fire with its accompanying rise in pressure caused the hull of the CM to burst resulting in the conflagration spreading almost instantly throughout the cabin. It is estimated that by 6:31:30 PM that the CM cabin atmosphere had become lethal asphyxiating the three astronauts as they were attempting to follow procedures to open the crew hatch. With difficulty, the ground crew finally opened the CM’s hatch at 6:36 PM to find the crew had perished.


The fire-damaged CM-012 shown being removed from LC-34 on February 17, 1967. (NASA)

With this tragic accident, the mission of Apollo 1 ended before it ever got off the ground. As the somber task of investigating the accident began, the detailed plans to test Apollo in the push towards the Moon were put on hold and NASA’s ability to reach the Moon before the end of the decade was questioned. While it was not known at the time, it would be 21 months before the problems with NASA’s Apolloprogram were resolved and the Apollo 1 backup crew of Schirra, Eisele and Cunningham would finally test the spacecraft in Earth orbit during the Apollo 7 mission.


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Related Video

Here is a collection of silent NASA video clips documenting the preparations for the Apollo 1 mission and the investigation of the accident which killed its crew.



Related Reading

“AS-202: The Last Test Flight Before Apollo 1”, Drew Ex Machina, August 25, 2016 [Post]

“The Apollo Flights to Nowhere: The Testing of CSM-008”, Drew Ex Machina, October 26, 2016 [Post]


General References

David Baker, The History of Manned Space Flight, Crown Publishers, 1981

“’We’ve got a Fire in the Cockpit!’ – The Tragic Story of Apollo 1”, Quest, Vol. 9, No. 5, pp. 20-32, 2002

Alan Lawrie, Saturn I/IB The Complete Manufacturing and Testing Records, Apogee Books, 2008

Richard W. Orloff and David M. Harland, Apollo: The Definitive Sourcebook, Springer-Praxis, 2006

“Apollo Operations Handbook: Command and Service Module Spacecraft 012”, SM2A-03-SC012, North American Aviation, November 12, 1966

“Report of the Apollo 2014 Review Board”, TM-84105, NASA, 1967

“Tracing Apollo 1: A Spacecraft Chronology”, Quest, Vol. 5, No. 4, pp. 10-11, 1996