Apollo 1

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mission emblem
Apollo 1 mission emblem
mission data
Mission: Apollo 1
spacecraft: Apollo
Block I
command module: CM 012
Service module: SM 012
Launcher: Saturn IB
serial number SA-204
Crew: 3
Begin: cancelled
Starting place: CCAFS , LC-34
Landing: —
team photo
Apollo 1 - B.C. l. No. First crew (seated) Ed White, Gus Grissom, Roger Chaffee and second crew (standing) David Scott, James McDivitt, Russell Schweickart
Apollo 1 - B.C. l. No. First crew (seated) Ed White , Gus Grissom , Roger Chaffee and second crew (standing) David Scott , James McDivitt , Russell Schweickart
◄ Before / After ►
Gemini 12
(manned) 		Apollo 4
(unmanned)
Next manned mission:
Apollo 7

Apollo 1 is the subsequently introduced designation for the planned first manned space mission within the framework of NASA 's Apollo program . During a test at Cape Canaveral 's Launch Complex 34 on January 27, 1967, a fire broke out in the capsule, killing the three astronauts nominated as crew . The flight of three crew members with a test version of the new Apollo spacecraft in low Earth orbit , planned under the internal designation AS-204 for February 21, 1967 , was cancelled. The US AmericanThe moon landing program was thoroughly reviewed from a technical and organizational point of view. It was not until October 1968 that NASA's next manned space flight , Apollo 7 , took place with the improved second generation of the Apollo spacecraft.

The team

When NASA's Apollo program became concrete in 1966, it was still assumed that the first manned launch of the three-seat Apollo spacecraft would take place in late 1966 or early 1967 under the project designation AS-204 . On March 21, 1966, it was announced to the public that Virgil Grissom , Edward White and Roger Chaffee had been selected to crew. Grissom was one of the Mercury veterans, White had made the first American spacewalk with Gemini 4 , and Chaffee was a space newcomer from NASA's third astronaut group. At this point four flights of the Gemini program were still pending .

James McDivitt , who had already directed Gemini 4, was nominated as the replacement commander . With him on the backup crew were David Scott , who had undergone the first spaceflight abort on Gemini 8 , and Russell L. Schweickart , one of the few civilian NASA astronauts.

At the end of 1966 the project plans were changed. Flight AS-205, intended to be the second manned Apollo flight, was cancelled, leaving the AS-205 crew as AS-204's backup crew. These were Walter Schirra , Donn Eisele and Walter Cunningham . The previous backup team around James McDivitt became the main team of flight AS-207, which was planned as a test of the lunar module.

The accident

foreplay

Apollo 1 crew in the simulator: (left to right) Roger Chaffee, Ed White, Gus Grissom

The three astronauts Edward H. White, Virgil I. Grissom and Roger B. Chaffee boarded the capsule (S/C 012) on January 27, 1967 for a routine exercise. It was a plugs-out test , removing all connections from the rocket and spacecraft to the supply tower. The rocket and the CM / SM were not refueled, the fuel cells were therefore not ready for operation, they were simulated by a remaining feed. As with the space flights, the atmosphere in the capsule consisted of 100% oxygen, but not at reduced pressure, but at ambient pressure. The plugs-out test was considered uncritical until the accident, no safety measures were taken; so neither the fire brigade was on standby nor the tower crew at the capsule. The test was originally intended to last from startup to completion of the countdown.

At 7:55 a.m.  EST , commissioning began and power was turned on.

the fire

The inside of the capsule after the fire

At 1:00 p.m., the astronauts boarded the capsule. According to NASA documents, as soon as he entered the capsule, Grissom noticed an unpleasant smell of “sour milk”, which also played a role in later investigations. At about 18:20 the countdown was stopped at T-10 min because there was repeated severe interference in the voice connection. At 18:31, an astronaut - believed to be Chaffee - reported a fire on board. Brief voltage dips and current spikes occurred a few seconds before the message. The life support system increased the supply of oxygen as more oxygen was consumed by the fire. As a result of this and the resulting combustion gases, the pressure in the capsule rose rapidly and it was no longer possible to equalize the pressure. The inner hatch could no longer be opened against the pressure as it would have had to be removed inwards. Tower personnel were on their way to the capsule at the time. About 15 seconds after the fire broke out, the capsule between the pressure hull and the heat shield ruptured. All voice and data connections were finally lost. At least up to this point, White had still attempted to open the hatch. Open fire was only now visible in the capsule, recorded by a camera outside a window of the capsule.

Failed rescue and salvage

When the tower personnel arrived at the capsule without adequate respiratory protection , the entire area was already thick with smoke. The work on the capsule often had to be interrupted to catch a breath. When the hatches were opened at 18:36, no more signs of life could be seen on the astronauts, they were probably suffocated 30 seconds after the fire broke out. The fire in the capsule went out by itself, the tower personnel only extinguished small pockets of fire on the tower itself. Although the fire had been extinguished when the fire brigade arrived, it was feared that the rocket's rescue rocket (LES) could still ignite due to the heat. At 18:40 an attempt was made to get White out of his seat. At around 6:45 p.m., a doctor determined the astronauts had died. The bodies could only be recovered from the capsule with some delay, which took over 90 minutes. The corpses, suits and seats were partially strongly fused together.

The investigation

Photo of Block I hatches (outer hatch open)
Sketch of the hatch construction
Astronaut White in a nylon rich spacesuit

Interior and exterior photographs of the capsule were taken before and immediately after the body was recovered. After the corpses had been recovered, the securing and recovery of the capsule began. First, two experts climbed into the capsule and documented switch positions that were still recognizable. On Jan 28, astronaut Frank Borman climbed back into the capsule, documenting and verifying switch settings and circuit breakers that had remained unclear. The capsule was then removed from the undamaged rocket and taken to the pyrotechnics workshop that seemed most appropriate for the study. There, a transparent intermediate floor was built into the capsule so that all built-in parts could be gradually removed without hindrance. The manufacturer North American Aviation delivered the capsule S/C 014, which was almost identical. Both capsules were dismantled synchronously, so to speak, and all the internals were compared with each other. Each damage was evaluated as to whether it was caused by the fire or whether it could have contributed to the outbreak of the fire. This work dragged on for weeks. Comparisons with the factory-new capsule revealed many design flaws. The results were incorporated into the improvement of the Block II capsules. The main shortcomings related to the accident were:

cabling

  • The exact cause of the fire could no longer be determined with certainty. The outbreak of the fire in the area of ​​the life support system to the left of Grissom's place is secured.
  • It is also clear that the fire must have been caused by a failure of the electrical system.
  • The cables were made with polytetrafluoroethylene (PTFE, "Teflon") insulation, which is highly resistant to high temperatures and chemical attack, but is easily damaged mechanically. That turned out to be a weak point.
  • Arc flash damage has been demonstrated in areas where wiring harnesses made contact with the aluminum structure . Damage to the insulation in similar areas was also found on S/C 014.
  • Experiments showed that cable harnesses with Teflon insulation could lead to a fire under mechanical stress (chafing against aluminum parts) in pure oxygen. Even the insulation caught fire, fuses and automatic circuit breakers did not respond, and the current peaks were too short.

cooling system

  • The sour smell Grissom had noticed was most likely from older leaks in the cooling system. Mechanics had sometimes held on to the pipes, which were largely soldered at the time . Smaller leaks and leaks are well documented.
  • The coolant (RS-89) was composed of 62.5% ethylene glycol , 35.7% water and 1.8% stabilizers from ammonium salts not described in detail . It was therefore classified as oxidizing and corrosive .
  • A direct triggering of the fire by a coolant leak could not be proven. However, it is assumed that coolant may have escaped in the area of ​​the life support system. One of the cable harnesses described above also runs there .

hatch

  • The original hatch on Block I capsules was actually a hatch system of two hatches, one inner and one outer. These were assembled, disassembled and completely removed during opening and closing. The inner hatch was also removed inwards. The internal pressure also served as a seal, but prevented it from opening in the accident.
  • With Block I capsules, an EVA through this hatch was not possible.
  • A third cover lay outside the hatches until the rescue rocket was dropped.

space suits

  • The space suits were advanced suits that still bore close resemblance to the suits from the Mercury and Gemini programs. They originally came from the US Air Force and CIA's U - 2 project , among others .
  • Polyamide ("Nylon") turned out to be unsuitable as a material for space suits. It is too flammable and melts when heated.

Quality assurance, organization

  • When examining the capsule, many defects were found, for example, forgotten materials and tools. A socket of a socket wrench was even found in a wiring harness . However, this wiring harness was not directly involved in the fire.
  • Safety guidelines were far too lax or followed superficially.

Conclusions

After the first investigations, it quickly became clear that many individual defects had led to the accident. They in turn brought about a myriad of corrections and improvements.

Firstly, the spaceship has been fundamentally rebuilt:

  • The hatches were replaced by a single hatch that no longer had to be opened on the inside and could be opened with a simple lever mechanism if necessary against a higher internal pressure.
  • The suits have been completely redesigned using different materials.
  • Polyamide or other combustible materials were no longer used.
  • PTFE was retained as the insulation material, but the cable harnesses were more heavily armored and only laid in such a way that they could no longer come into contact with sharp edges.
  • All electrical connections have been sealed against the ingress of liquids.
  • All pipes were no longer soldered, but connected by screws or welding .
  • The atmosphere inside the capsule was replaced with a nitrogen - oxygen mixture during all pre-launch and launch phase work. In orbit , it was swapped for an atmosphere of pure oxygen at reduced pressure.

On the other hand, there were many organizational changes:

  • The list of "critical" tests was greatly expanded, and the plugs-out test was also a critical test afterwards. From then on, a security team and the fire brigade had to be available for all of these tests.
  • Mechanics were forbidden to push off or hold on to pipes and wires.
  • Another mock-up test was introduced, in which a fully equipped Apollo boilerplate was set on fire.
  • The Scheufelen paper factory developed a flame-retardant paper for future logbooks . 500 grams of paper were required for each log book.

The Saturn IB rocket was unharmed in the fire and was used to launch Apollo 5 a year later .

The numbering

In the predecessor program Gemini, all launches, whether unmanned or manned, were numbered together: after two unmanned launches, the first manned flight took place as Gemini 3 , also with Grissom as commander of the maiden flight.

No numbering scheme had yet been established for the Apollo program. On the one hand, both spaceships and rockets had serial numbers, on the other hand, the rocket serial numbers (here: SA-204; for SA turn) modified (here: AS-204 for A pollo– S aturn) were used internally as mission designations.

Grissom, White, and Chaffee submitted a mission badge that bore the designation "Apollo 1", advocating that only the manned Apollo missions should be numbered. The badge was approved in June 1966, although this did not say anything about the number under which the flight would finally take off.

After the accident, the three widows asked that no other flight be given the designation "Apollo 1" in memory of the dead. NASA managers James E. Webb , Robert Seamans , and George E. Mueller concurred.

At times, the next flight was internally referred to as "Apollo 2". The proposal by Apollo manager George Michael Low in March 1967 to retrospectively rename the previous three unmanned test flights "Apollo 1A", "Apollo 2" and "Apollo 3" was not implemented; it remained with the designations AS-201 (February 1966), AS-203 (July 1966) and AS-202 (August 1966).

Although three Saturn IB launches had already been performed at this point, only the two launches in which an Apollo unmanned spacecraft was tested ( AS-201 with CSM-009 Block I and AS-202 with CSM-011 Block I) were counted. . In addition, two other manned Apollo missions have since been planned, Apollo 2 as a repeat of Apollo 1 (Saturn IB launch with CSM -014 or LM test) and Apollo 3 as a test of the improved CSM Block II prototype ( Saturn IB - or first Saturn V launch), but these missions were canceled during the course of the program . Thus, the names Apollo 2 and Apollo 3 have never been officially used.

In April 1967, Julian Scheer, NASA public relations spokesman, announced that the first unmanned flight of the Saturn V would be called Apollo 4 . Beginning with this flight, unmanned and manned missions were then numbered together, as in the Gemini program. The first manned launch was in October 1968 on Apollo 7 , using the Apollo 1 reserve crew of Schirra, Eisele and Cunningham.

whereabouts

Upon completion of the accident investigation, the Apollo 1 Command Module was placed in a secure storage facility at NASA Langley Research Center in Hampton, Virginia . On February 17, 2007, the parts were moved to a neighboring air-conditioned warehouse. A few weeks earlier, Gus Grissom's brother Lowell had publicly proposed burying the remains of CM-012 permanently in the foundations of Launch Complex 34 .

On January 27, 2017, to mark the 50th anniversary of the accident, NASA displayed the Apollo 1 hatch in the Saturn V Rocket Center Visitor Center at Kennedy Space Center . There it can be seen in a memorial next to parts of the space shuttle Challenger and Columbia that crashed .

reception

The Apollo 1 theme has made its way into popular culture on a number of occasions:

  • In the opening scene of the 1995 drama film Apollo 13 .
  • The accident and its aftermath were the subject of the second episode "Apollo One" of the 1998 HBO miniseries From the Earth to the Moon .
  • The mission and accident are the subject of episodes 8 "Rendezvous" and 9 "Abort" of the 1995 ABC television series The Astronaut Wives Club .
  • The accident is the subject of the song "Fire in the Cockpit" on British band Public Service Broadcasting 's 2015 album The Race For Space .
  • The accident occurs in the 2018 historical film Aufbruch zum Mond (original title: First Man ).

See also

web links

Commons : Apollo 1  - Album with pictures, videos and audio files

itemizations

  1. ↑ Medical History of Spacefarers
  2. ↑ See English Wikipedia: Boilerplate (spaceflight) and Boilerplate prototype in the sense of a prototype
  3. ↑ Andreas Volz: Independent and loyal to the future. Der Teckbote - Kirchheimer Zeitung, September 10, 2005, retrieved February 26, 2013 .
  4. ↑ What Happened to Apollos 2 and 3? Retrieved March 10, 2021 (English).
  5. ↑ NASA Langley Research Center: Apollo 1 (CM-012). Retrieved December 19, 2020 (English).
  6. ↑ Martin Weil: Ill-Fated Apollo 1 Capsule Moved to New Site. In: Washington Post. February 18, 2007, accessed December 19, 2020 (English).
  7. ↑ Diana Tennant: Burned Apollo I capsule moved to new storage facility in Hampton. (No longer available online.) In: Hampton Pilote. June 9, 2012, formerly in the original ; Retrieved December 19, 2020 (English).  ( page no longer available , search in web archives )@1@2Template: Dead link/hamptonroads.com
  8. ↑ 50 years later, NASA displays fatal Apollo capsule. In: The Horn News. 25 January 2019, accessed 19 December 2020 (English).
  9. ↑ From the Earth to the Moon (1998) - Apollo One. In: International Movie Database. Retrieved December 19, 2020 (English).
  10. ↑ Dana Rose Falcone: The Astronaut Wives Club recap: Abortion. 6 August 2015, accessed 19 December 2020 (English).
  11. ↑ Phil Mongredien: Public Service Broadcasting: The Race for Space review – a smart follow-up. In: The Guardian. 22 February 2015, accessed 19 December 2020 (English).