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Abort Guidance System
Auxiliary Power Unit
Abort to Orbit
Russian Micropurification Unit (Russian)
Carbon Dioxide Removal System
Colony Forming Unit
Control Moment Gyroscope
Cell Performance Monitor
Compound Specific Analyzer-Combustible Products
Extravehicular Mobility Unit
Electrical Power System
Fuel Cell Monitoring System
Functional Cargo Block (Russian)
Flight Safety Office
Galley Iodine Removal Assembly
Guidance, Navigation, and Control
General Purpose Computer
Global Positioning System
Inertial Measurement Unit
International Space Station
Internal Thermal Control System
Launch Control Officer
Low Iodine Residual System
Loss of Crew
Loss of Vehicle
Minimum Duration Flight
Master Events Controller
Main Landing Gear
Micro-Meteoroid Orbital Debris
Marshall Space Flight Center
NASA Standard Initiator
Office of Safety & Mission Assurance (NASA HQ)
Protuberance Air Load
Precision Approach Path Indicator
Primary Avionics Software System
Pyrotechnic Initiator Controller
Partial Pressure of CO2
Reaction Control System/Subsystem
Remote Manipulator System
Russia or Russian
Return to Launch Site
Safety & Mission Assurance
Solid Fuel Oxygen Generator
Solid Rocket Booster
Condensate Water Processor Unit (Russian)
Space Shuttle Main Engine
Space Shuttle Program
Thermal Protection System
Loss of Crew
Skylab 4 2/8/1974
Mercury MA-9 5/16/1963
Apollo 11 7/21/1969
Soyuz 18-1(18a) 4/5/1975
X-15 3-65-97 | 11/15/1967 | Crew: 1 | Loss of Crew
Electrical short and crew error led to loss of control at 230,000 feet. First U.S. spaceflight fatality.
On November 15, 1967 an electrical short and crew error led to loss of control of the X-15 at 230,000 feet. During re-entry of the vehicle, the aircraft deviated off course due to a combination of the pilot's distraction, misinterpretation of instrumentation display, and possible vertigo. An electrical disturbance that occurred early in the flight had degraded the overall effectiveness of the aircraft's control system and further added to pilot workload. The aircraft entered into a high Mach spin.
The pilot was able to break free from the spin, but the aircraft was in a high-speed inverted dive. While the aircraft was still at sufficient altitude to recover from the dive, the hand controller began forcing the horizontal stabilizers to oscillate. Because of the buffeting in the spin and dive, the pilot likely lost consciousness and the aircraft broke apart.
This was the first United States spaceflight fatality.
Skylab 4 | 2/8/1974 | Crew: 3
Incorrect circuit breakers opened, resulting in the loss of the automatic control.
On February 8, 1974 while preparing foar entry, the crew inadvertently opened the stabilization and control system (SCS) pitch and yaw circuit breakers instead of the service propulsion system pitch and yaw circuit breakers. The vehicle was in an apex forward configuration for service module jettison. The commander attempted to orient the vehicle to the proper heat shield forward attitude for entry. The control commands produced no effect due to the SCS being inadvertently unpowered, and the vehicle failed to change attitude. The crew switched to “manual reaction control system direct” and oriented the vehicle to the proper attitude. The circuit breakers being in close proximity and similarly labeled, increased the potential for human error.
The failure to orient the heat shield forward would have caused loss of crew.
Navy Chamber | 11/17/1962 | Crew: 4 | Crew Injury (4)
Fire started in a 100% oxygen environment at 5 psi. Four officers injured.
On November 17, 1962 four Navy officers were injured, two seriously, when a fire started in the altitude chamber they were occupying in a 20 day experiment at the U.S. Navy Air Crew Equipment Laboratory as part of a NASA atmosphere validation program.
The chamber contained 100% oxygen at 5 psi. The fire started when one officer changed a light bulb in an energized 24 volt DC light fixture. One wire in the fixture became disconnected resulting in arcing. A cotton towel was used in an attempt to smoother the fire. The towel caught fire, and the flames spread to the officers' clothes.
Mercury MA-9 | 5/16/1963 | Crew: 1 | Manual Entry
Electrical faults caused loss of some systems and need to perform manual entry. Also experienced high PPCO2 levels in suit during entry operations.
During the May 16, 1963 flight electrical faults caused the loss of some systems and the need to perform manual entry. The alternating current power supply for the control system failed to operate, and it was determined that the pilot would have to make a manual retrofire and re-entry. He performed these maneuvers with close precision and landed a short distance from the prime recovery ship in the Pacific Ocean.
The malfunction during re-entry on MA-9 was traced to two connectors in an electrical amplifier.
STS-2 | 11/21/1981 | Crew: 2 | Minimum Duration Flight | Crew Injury
Failure of fuel cell resulted in a MDF being declared. The fuel cell failure also resulted in hydrogen in the drinking water leading to crew dehydration.
During the flight of STS-2, which spanned from November 12 – 14, 1981, fuel cell failure led to the declaration of a minimum duration flight (MDF). In addition to the MDF, the failure of the fuel cell also led to high hydrogen levels in the drinking water. The fuel cells used produce drinking water as a by product. When the crew drank this water it provoked a need to belch. Belching in zero g leads to regurgitation. The crew avoiding drinking the water in order to avoid belching, which caused crew dehydration. Prior to entry, crew members fluid load to offset fluid shift when returning from orbit. The crew dehydration increased the effects of the fluid shift and could have posed a risk during high g entry procedures due to a higher chance for loss of consciousness.
STS-83 | 4/6/1997 | Crew: 7 | Loss of Mission
Failure of fuel cell number 2 resulted in MDF being declared. The 15-day mission was shortened to 3 days.
A failure of fuel cell (FC) number two resulted in a minimum duration flight being declared on April 6,1997. The 16-day mission was reduced to four days due to FC problems encountered on flight day two. During prelaunch operations the differential voltage on FC 2, substack 3 remained above the 150mV limit (defined in the Operations and Maintenance Requirements Specification Document) for an unusually long period of time before dropping below 150 mV. The substack delta voltage began to trend upward shortly after on-orbit operations began at approximately two hours Mission Elapsed Time. FC purges were ineffective at stopping the trend. FC 2 was subsequently shut down and safed to prevent the possibility of a crossover condition, and multiple payloads had to be powered down. FCs 1 and 3 continued to carry the total orbiter load and performed nominally.
Post-flight failure analysis of FC 2 did not identify a root cause for the on-orbit anomaly experienced, but did identify degraded cells and verified the cell performance monitor (CPM) was functioning properly. No foreign material/contaminant was found and the most credible scenario implies an abnormal external event affected a group of cells prior to start–up. It has been hypothesized that this external event was the presence of oxygen in the oxygen side of substack 3 of the FC at a time when the FC was supposed to be inerted with helium. This event over time would cause oxidation of the nickel Electrolyte Reservoir Plate and dissolution of palladium and platinum in the anodes. Migration and plating of the palladium onto the cathode catalyst would cause high open circuit voltage once full reactants are applied to the FC.
As a result of this anomaly and failure analysis, the Launch Commit Criteria was revised to not allow launching with an FC showing similar prelaunch CPM readings. Kennedy Space Center FC purge procedures were also modified to preclude the potential for the presence of oxygen in inerted fuel cells. The program also designed and tested a fuel-cell monitoring system (FCMS) which finally provided individual cell-health monitoring capability (STS-87 first flight). If the FCMS had been available for STS-83, it may have precluded the shutdown of the FC and may have allowed the mission to complete its planned duration.
Apollo 11 | 7/21/1969 | Crew: 2
Engine arm circuit breaker knob broke off. Circuit breaker successfully reset allowing ascent.
On July 21, 1969 while preparing for extravehicular activities, the engine arm circuit breaker broke, probably due to an impact from the oxygen purge system. A felt tipped pen was used to successfully depress the circuit breaker when needed. Circuit breaker guards were installed on Apollo 12 and subsequent vehicles to prevent the oxygen purge system from impacting the circuit breakers.
Apollo 13 | 4/13/1970 | Crew: 3 | Loss of Mission
Explosion due to electrical short. Loss of O2 and EPS.
Apollo 13 launched on April 11, 1970. On April 13, 1970 during trans-lunar flight at approximately 56 hours, one of the two Service Module oxygen tanks over-pressurized and exploded. This caused the loss of oxygen in that tank and a leak of oxygen out of the remaining tank. This resulted in the loss of all three fuel cells, loss of the primary oxygen source, and the loss of electrical power to the Command Module (except for the entry batteries). The mission was able to continue with the use of the Lunar Module, and the crew safely returned.
Prior to launch, the following conditions resulted in the oxygen tank failing during the mission: By design the cryogenic oxygen tank required both electrical heaters to maintain pressure, and fans to prevent stratification. The tank was a complex assembly with blind installation of the quantity probe, heater/fan assembly, and fill tube. This design leaves wiring insulation vulnerable to damage during assembly with no way to inspect after installation. The Teflon insulated wiring, which is a combustible material in the oxygen tank, was in close proximity to the heater elements and fan.
The Apollo 13 tanks were originally installed on Apollo 11, but a change required the tanks to be removed. During removal of the oxygen shelf, one bolt was left in place causing the fixture to break and resulting in a two-inch drop of the shelf and tanks. Although a loosely fitting (due to loose specification tolerances) fill tube could have been displaced by this, all testing was passed. No cryogenic tests were performed which would have revealed the problem. During the Count Down Demonstration Test the oxygen tank could not be emptied by the normal means of pressurized oxygen gas due to a leak at the fill tube. Instead, the tank heaters were turned on to boil off the oxygen in the tank. The thermostatic switches were rated for 30 volts direct current, but several years earlier the heater ground power supply voltage was raised to 65 volts to reduce the pressurization time. As the temperature increased the thermostatic switch opened and the higher voltage caused the contacts to weld closed. With the heaters continuously on, the temperature approached 1000 degrees and damaged the wire insulation, setting up the conditions for a short and ignition inside the tank. Ground personnel did not notice the continuous heater operation. During the prelaunch problem solving neither the Apollo Spacecraft Program Manager nor the Kennedy Director of Launch Operations knew the tank had previously been dropped or that the heaters had been on for eight hours.
Soyuz 18-1(18a) | 4/5/1975 | Crew: 2 | Loss of Vehicle/Mission
Electrical fault caused premature firing of half of the 2nd stage separation bolts, resulting in the inability to fire the remaining ones. Staging failure resulted in abort sequence being used at T=295 seconds.
During ascent on April 5, 1975 an electrical malfunction in the Soyuz booster prematurely fired two of the four explosive latches holding the core of the first and second stage together. This severed the electrical connections necessary for firing the remaining two latches. When the core first stage burned out, it could not be cast off as designed.
Ignition of the second stage occurred normally, but the booster was rapidly dragged off course by the weight of the depleted core first stage. When the course deviation reached 10 degrees, the automatic safety system activated, shutting down the booster and separating the Soyuz capsule from the launch vehicle. At the time of separation, the Soyuz was 180 km high and traveling at 5.5 km per second.
The crew endured a 20+ g re-entry and landed in the Altai Mountains. The capsule rolled down a mountain side, and was caught in bushes just short of a precipice. After an hour of waiting in the cold next to the capsule, the crew was discovered by locals speaking Russian.
One crew member suffered internal injuries from the high-g re-entry and downhill fall and never flew again.
Crew Injury/Illness and/or Loss of Vehicle or Mission
Related or Recurring event
LANDING & POSTLANDING