Tag Archives: National Aeronautics and Space Administration

16 March 1966, 16:41:02.389 UTC, T plus 0.389

Gemini VIII lifts off from Launch Complex 19, Kennedy Space Center, 17:41:02 UTC, 16 March 1966. (NASA)
Gemini VIII lifts off from Launch Complex 19, Cape Kennedy Air Force Station, 16:41:02 UTC, 16 March 1966. (NASA)

16 March 1966: At 16:41:02.389 UTC (12:41:02 p.m. Eastern Standard Time), forty years to the day after the launch of Dr. Robert Goddard’s first liquid-fueled rocket, Gemini VIII, with command pilot Neil Alden Armstrong and pilot David Randolph Scott, lifted off from Launch Complex 19 at the Cape Kennedy Air Force Station, Cape Kennedy, Florida, aboard a Titan II GLV booster. Their mission was to rendezvous and dock with an Agena Target Vehicle launched earlier aboard an Atlas rocket.

Gemini VIII/Titan GLV-8 accelerates toward Low Earth Orbit, 16 March 1966. (NASA, MSCF-9141927)

Gemini VIII entered a 86.3  × 146.7 nautical mile (99.3 × 168.8 statute miles/160 × 271.7 kilometers) elliptical orbit. The spacecraft was traveling at 17,549 miles per hour (28,242 kilometers per hour).

The Gemini Agena Target Vehicle seen from Gemini VIII, 16 March 1966. (David R. Scott, NASA)

The docking, the first ever of two vehicles in Earth orbit, was successful, however after about 27 minutes the combined vehicles begin rolling uncontrollably. The Gemini capsule separated from the Agena, and for a few minutes all seemed normal. But the rolling started again, reaching as high as 60 r.p.m.

The astronauts were in grave danger. Armstrong succeeded in stopping the roll but the Gemini’s attitude control fuel was dangerously low.

David R. Scott and Neil A. Armstrong, flight crew of Gemini VIII. (NASA)

The pilots’ report reads:

     Shortly after sending encoder command 041 (recorder ON), roll and yaw rates were observed to be developing. No visual or audible evidence of spacecraft thruster firing was noted, and the divergence was attributed to the GATV.

     Commands were sent to de-energize the GATV ACS, geocentric rate, and horizon sensors, and the spacecraft Orbital Attitude and Maneuver System (OAMS) was activated.

     The rates were reduced to near zero, but began to increase upon release of the hand controller. The ACS was commanded on to determine if GATV thruster action would help reduce the angular rates. No improvement was noted and the ACS was again commanded off. Plumes from a GATV pitch thruster were visually observed, however, during a period when the ACS was thought to be inactivated.

     After a period of relatively stable operation, the rates once again began to increase. The spacecraft was switched to secondary bias power, secondary logics, and secondary drivers in an attempt to eliminate possible spacecraft control-system discrepancies. No improvement being observed, a conventional troubleshooting approach with the OAMS completely de-energized was attempted, but subsequently abandoned because of the existing rates.

     An undocking was performed when the rates were determined to be low enough to precluded any recontact problems. Approximately a 3 ft/sec velocity change was used to effect separation of the two vehicles.

     Angular rates continued to rise, verifying a spacecraft control-system problem. The hand controller appeared to be inactive. The Reentry Control System (RCS) was armed and, after trying ACME-DIRECT and then turning off all OAMS control switches and circuit breakers, was found to be operative in DIRECT-DIRECT. Angular rates were reduced to small values with the RCS B-ring. Inspection of the OAMS revealed that the no. 8 thruster had failed to open. Some open Attitude Control and Maneuver Electronics (ACME) circuit breakers probably accounted for the inoperative hand controller noted earlier. All yaw thrusters other than number 8 were inoperative. Pitch and roll control were maintained using the pitch thrusters. . .

      All four retrorockets fired on time. . . .

GEMINI PROGRAM MISSION REPORT, GEMINI VIII, Gemini Mission Evaluation Team, National Aeronautics and Space Administration, Manned Spacecraft Center, Houston, Texas, , MSC-G-R-66-4, Section 7 at Pages 7-21 and 7-22

The mission was aborted and the capsule returned to Earth after 10 hours, 41 minutes, 26.0 seconds, landing in the Pacific Ocean at N. 25° 12′, E. 136° 05′. U.S. Air  Force pararescue jumpers (“PJs”) parachuted from a Douglas C-54 transport and attached a flotation collar to the Gemini capsule. The astronauts were recovered by the Gearing-class destroyer USS Leonard F. Mason (DD-852), about three hours later..

The Gemini VIII spacecraft is displayed at the Neil Armstrong Air and Space Museum, Wapakoneta, Ohio.

Gemini VIII with flotation collar. (NASA)

The two-man Gemini spacecraft was built by the McDonnell Aircraft Corporation of St. Louis, Missouri, the same company that built the earlier Mercury space capsule. The spacecraft consisted of a series of cone-shaped segments forming a reentry module and an adapter section. It had an overall length of 18 feet, 9.84 inches (5.736 meters) and a maximum diameter of 10 feet, 0.00 inches (3.048 meters) at the base of the equipment section. The reentry module was 11 feet (3.353 meters) long with a maximum diameter of 7 feet, 6.00 inches (2.347 meters). The Gemini re-entry heat shield was a spherical section with a radius of 12 feet, 0.00 inches (3.658 meters). The weight of the Gemini spacecraft varied from ship to ship. Gemini VIII weighed 8,351.31 pounds (3,788.09 kilograms) at launch. Spacecraft 8 was shipped from the St. Louis factory to Cape Kennedy on 2 January 1966.

Artist’s concept of Gemini spacecraft, 3 January 1962. (NASA-S-65-893)

The Titan II GLV was a “man-rated” variant of the Martin SM-68B intercontinental ballistic missile. It was assembled at Martin’s Middle River, Maryland plant so as not to interfere with the production of the ICBM at Denver, Colorado. Twelve GLVs were ordered by the Air Force for the Gemini Program.

Titan II GLV, (NASA Mission Report, Figure 3-1, at Page 3–23)

The Titan II GLV was a two-stage, liquid-fueled rocket. The first stage was 70 feet, 2.31 inches (21.395 meters) long with a diameter of 10 feet (3.048 meters). It was powered by an Aerojet Engineering Corporation LR87-7 engine which combined two combustion chambers and exhaust nozzles with a single turbopump unit. The engine was fueled by Aerozine 50, a hypergolic 51/47/2 blend of hydrazine, unsymetrical-dimethyl hydrazine, and water. Ignition occurred spontaneously as the components were combined in the combustion chambers. The LR87-7 produced approximately 430,000 pounds of thrust (1,912.74 kilonewtons). It was not throttled and could not be shut down and restarted. Post flight analysis indicated that the first stage engine of GLV-8 had produced an average of 461,080 pounds of thrust ( kilonewtons).

The second stage was 25 feet, 6.375 inches (7.782 meters) long, with the same diameter, and used an Aerojet LR91 engine which produced approximately 100,000 pounds of thrust (444.82 kilonewtons), also burning Aerozine 50. GLV-7’s LR91 produced an average of 102,735 pounds of thrust ( kilonewtons).

The Gemini/Titan II GLV VIII combination had a total height of 107 feet, 7.33 inches (32.795 meters) and weighed 345,359 pounds (156,652 kilograms) at ignition.

The Atlas-Agena Target vehicle takes off at Launch Complex 14, 17:00:00 UTC, 16 March 1966. (NASA)
The Atlas-Agena Target Vehicle takes off at Launch Complex 14, Cape Kennedy Air Force Station, 15:00:03 UTC, 16 March 1966. (NASA)

© 2019, Bryan R. Swopes

10 March 1959

North American Aviation X-15A 56-6670 carried aloft by Boeing NB-52A Stratofortress 52-003. The absence of frost on the fuselage of the X-15 shows that no cryogenic propellants are aboard for this captive flight. The chase plane is a Lockheed F-104A-15-LO Starfighter, 56-0768. This Starfighter suffered an engine failure on take off at Edwards AFB, crashed and was destroyed, 30 June 1959. (NASA)

10 March 1959: With North American Aviation’s Chief Engineering Test Pilot Albert Scott Crossfield in its cockpit, the X-15 hypersonic research rocket plane was airborne for the first time. X-15A 56-6670 was carried aloft under the wing of the Boeing NB-52A Stratofortress drop ship, 52-003, for a series of captive flights. The purpose was to verify that all the systems on both the X-15 and the B-52 were properly functioning up to the point that the drop would occur.

The NB-52A Stratofortress flight crew, left to right: Harry W. ("Bill") Berkowitz, NAA, Launch Panel Operator; Captain John E. ("Jack") Allavie, USAF, Pilot; Captain Charles C. Bock, Jr., USAF, Aircraft Commander, at Edwards AFB, 7 February 1959. (U.S. Air Force)
The NB-52A Stratofortress flight crew, left to right: Harry W. (“Bill”) Berkowitz, NAA, Launch Panel Operator; Captain John E. (“Jack”) Allavie, USAF, Pilot; Captain Charles C. Bock, Jr., USAF, Aircraft Commander, at Edwards AFB, 7 February 1959. (U.S. Air Force via Jet Pilot Overseas)
North American Aviation X-15A 56-6670 carried aloft by Boeing NB-52A Stratofortress 52-003. The absence of frost on the fuselage of the X-15 shows that no cryogenic propellants are aboard for this captive flight. (NASA)

Fully settled in my tiny flight office, I could speak by radio to the B-52 pilot, Charlie Bock, who was about thirty feet away in the nose of the mother plane, out of sight. . .

As we sat, waiting at the end of the long runway while chase planes took off and circled, the clock on the instrument panel of the X-15 showed 0955. . . On signal, B-52 pilot Charlie Bock cobbed the eight engines, standing hard on the brake pedal. As the engines wound up to full military power, the X-15 trembled and the noise was tremendous. Through my radio earphones I heard Bock call a countdown for the benefit of the official movie cameramen who would record  every inch of the takeoff:

“Five . . . four . . . three . . . two . . . one. BRAKE RELEASE.”

One hundred thirty tons of aluminum, fuel, Inconel X, five men and the hope of a nation began rolling down the long runway. . .

As we rolled, the huge runway distance markers flashed by, clocking our path: 14,000 . . . 13,000 . . . 12,000 . . . 8,000. When the X-15 air-speed indicator reached 170 knots, I noted only a minor vibration. We would continue the takeoff. 6,000 . . . 5,000 . . . 4,000, and we broke ground. It was smooth and gentle, like the take-off of an airliner. The air-speed indicator crept up to 260 knots. The parched brown desert fell away. . . .

Always Another Dawn: The Story of a Rocket Test Pilot, by A. Scott Crossfield and Clay Blair, Jr., The World Publishing Company, Cleveland and New York, 1960, Chapters 34 and 35 at Pages 316–321.

X-15A 56-6670 under the wing of NB-52A 52-003 at high altitude. Scott Crossfield is in the cockpit of the rocketplane. Air Force Flight Test Center History Office, U.S. Air Force)
X-15A 56-6670 under the wing of NB-52A 52-003 at high altitude. Scott Crossfield is in the cockpit of the rocketplane. (Air Force Flight Test Center History Office, U.S. Air Force)

The gross weight of the combined aircraft was 258,000 pounds (117,000 kilograms). After a takeoff roll of 6,200 feet (1,890 meters) the B-52/X-15 lifted of at 168 knots (193 miles per hour/311 kilometers per hour). During the 1 hour, 8 minute flight the the B-52 climbed to 45,000 feet (13,716 meters) and reached a speed of 0.83 Mach (548 miles per hour/881 kilometers per hour).

The X-15A rocketplane was designed and built for the U.S. Air Force and the National Advisory Committee for Aeronautics (NACA, the predecessor of NASA) by North American Aviation, Inc., to investigate the effects of hypersonic flight (Mach 5+). Design work started in 1955 and a mock-up had been completed after just 12 months. The three X-15s were built at North American’s Los Angeles Division, at the southeast corner of Los Angeles International Airport (LAX), on the shoreline of southern California.

Test pilot Albert Scott Crossfield with X-15 56-6670 attached to the right wing pylon of NB-52A 52-003 at Edwards Air Force Base. (North American Aviation Inc.)

The first flight took place 8 June 1959, again, with Scott Crossfield in the cockpit of the Number 1 ship, 56-6670.

While earlier rocketplanes, the Bell X-1 series, the the Douglas D-558-II, and the Bell X-2, were airplanes powered by rocket engines, the X-15 was a quantum leap in technology. It was a spacecraft.

Like the other rocketplanes, the X-15 was designed to be carried aloft by a “mothership,” rather than to takeoff and climb to the test altitude under its own power. The carrier aircraft was originally planned to be a Convair B-36 intercontinental bomber but this was soon changed to a Boeing B-52 Stratofortress. Two B-52s were modified to carry the X-15: NB-52A 52-003, The High and Mighty One, and NB-52B 52-008, Balls 8.

From 8 June 1959 to 24 October 1968, the three X-15s were flown by twelve test pilots, three of whom would qualify as astronauts in the X-15. Two would go on to the Apollo Program, and one, Neil Alden Armstrong, would be the first human to set foot on the surface of the Moon, 20 July 1969. Joe Engle would fly the space shuttle. Four of the test pilots, Petersen, White, Rushworth, and Knight, flew in combat during the Vietnam War, with Bob White being awarded the Air Force Cross. Petersen, Rushworth and White reached flag rank.

One pilot, John B. (“Jack”) McKay, was seriously injured during an emergency landing at Mud Lake, Nevada, 9 November 1962. Michael James Adams, was killed when the Number 3 ship, 56-6672, went into a hypersonic spin and broke up on the program’s 191st flight, 15 November 1967.

Scott Crossfield prepares for a flight in the North American Aviation X-15A. Crossfield is wearing a David Clark Co. MC-2 full-pressure suit and MA-3 helmet, which he helped to develop. (NASA)

Flown by a single pilot/astronaut, the X-15 is a mid-wing monoplane with dorsal and ventral fin/rudders and stabilators. The wing had no dihedral, while the stabilators had a pronounced 15° anhedral. The short wings have an area of 200 square feet (18.58 square meters) and a maximum thickness of just 5%. The leading edges are swept to 25.64°. There are two small flaps but no ailerons. The entire vertical fin/rudder pivots for yaw control.

Above 100,000 feet (30,840 meters) altitude, conventional aircraft flight control surfaces are ineffective. The X-15 is equipped with a system of reaction control jets for pitch, roll and yaw control. Hydrogen peroxide was passed through a catalyst to produce steam, which supplied the control thrusters.

The forward landing gear consists of a retractable oleo strut with steerable dual wheels and there are two strut/skids at the rear of the fuselage. The gear is retracted after the X-15 is mounted on the NB-52 and is extended for landing by its own weight.

X-15A cockpit with original Lear Siegler instrument panel. (NASA)

The rocketplane’s cockpit featured both a conventional control stick as well as side-controllers. It was pressurized with nitrogen gas to prevent fires. The pilot wore an MC-2 full-pressure suit manufactured by the David Clark Company of Worcester, Massachusetts, with an MA-3 helmet. The suit was pressurized below the neck seal with nitrogen, while the helmet was supplied with 100% oxygen. This pressure suit was later changed to the Air Force-standardized A/P22S.

The X-15 is 50.75 feet (15.469 meters) long with a wing span of 22.36 feet (6.815 meters). The height—the distance between the tips of the dorsal and ventral fins—is 13.5 feet (4.115 meters). The stabilator span is 18.08 feet (5.511 meters). The fuselage is 4.67 feet (1.423 meters) deep and has a maximum width of 7.33 feet (2.234 meters).

North American Aviation, Inc. X-15A 56-6670 on Rogers Dry Lake, Edwards Air Force Base, California. (NASA)

The X-15s were built primarily of a nickel/chromium/iron alloy named Inconel X, along with corrosion-resistant steel, titanium and aluminum. Inconel X is both very hard and also able to maintain its strength at the very high temperatures the X-15s were subjected to by aerodynamic heating. It was extremely difficult to machine and special fabrication techniques had to be developed.

Since the X-15 was built of steel rather than light-weight aluminum, as are most aircraft, it is a heavy machine, weighing approximately 14,600 pounds (6,623 kilograms) empty and 34,000 pounds (15,422 kilograms) when loaded with a pilot and propellants. The X-15s carried as much as 1,300 pounds (590 kilograms) of research instrumentation, and the equipment varied from flight to flight. The minimum flight weight (for high-speed missions): was 31,292 pounds (14,194 kilograms) The maximum weight was 52,117 pounds (23,640 kilograms) at drop (modified X-15A-2 with external propellant tanks).

Initial flights were flown with a 5 foot, 11 inch (1.803 meters)-long air data boom at the nose, but this would later be replaced by the “ball nose” air sensor system. The data boom contained a standard pitot-static system along with angle-of-attack and sideslip vanes. The boom and ball nose were interchangeable.

Two Reaction Motors Division XLR11-RM-5 four-chamber rocket engines installed on an X-15. (NASA)

Delays in the production of the planned Reaction Motors XLR99 rocket engine forced engineers to adapt two vertically-stacked Reaction Motors XLR11-RM-5 four-chamber rocket engines to the X-15 for early flights. This was a well-known engine which was used on the previous rocketplanes. The XLR11 burned a mixture of ethyl alcohol and water with liquid oxygen. Each of the engines’ four chambers could be ignited individually. Each engine was rated at 11,800 pounds of thrust (58.49 kilonewtons) at Sea Level.

The Reaction Motors XLR99-RM-1 rocket engine was throttleable by the pilot from 28,500 to 60,000 pounds of thrust. The engine was rated at 50,000 pounds of thrust (222.41 kilonewtons) at Sea Level; 57,000 pounds (253.55 kilonewtons) at 45,000 feet (13,716 meters), the typical drop altitude; and 57,850 pounds (257.33 kilonewtons) of thrust at 100,000 feet (30,480 meters). Individual engines varied slightly. A few produced as much as 61,000 pounds of thrust (271.34 kilonewtons).

The XLR99 burned anhydrous ammonia and liquid oxygen. The flame temperature was approximately 5,000 °F. (2,760 °C.) The engine was cooled with circulating liquid oxygen. To protect the exhaust nozzle, it was flame-sprayed with ceramic coating of zirconium dioxide. The engine is 6 feet, 10 inches (2.083 meters) long and 3 feet, 3.3 inches (0.998 meters) in diameter. It weighs 910 pounds (413 kilograms). The Time Between Overhauls (TBO) is 1 hour of operation, or 100 starts.

Thiokol Reaction Motors Division XLR99-RM-1 rocket engine. (U.S. Air Force)

The XLR99 proved to be very reliable. 169 X-15 flights were made using the XLR99. 165 of these had successful engine operation. It started on the first attempt 159 times.

The highest speed achieved during the program was with the modified number two ship, X-15A-2 56-6671, flown by Pete Knight to Mach 6.70 (6,620 feet per second/4,520 miles per hour/ kilometers per hour) at 102,700 feet (31,303 meters). On this flight, the rocketplane exceeded its maximum design speed of 6,600 feet per second (2,012 meters per second).

The maximum altitude was reached by Joe Walker, 22 August 1963, when he flew 56-6672 to 354,200 feet (107,960 meters).

The longest flight was flown by Neil Armstrong, 20 April 1962, with a duration of 12 minutes, 28.7 seconds.

North American Aviation X-15A-1 56-6670 is on display at the Smithsonian Institution National Air and Space Museum. X-15A-2 56-6671 is at the National Museum of the United States Air Force.

North American Aviation Inc./U.S. Air Force/NASA X-15A 56-6670 hypersonic research rocketplane on display at the National Air and Space Museum. (NASM)

© 2019, Bryan R. Swopes

21 February 1961

Project Mercury astronauts with Convair F-106B-75-CO Delta Dart 59-0158. (NASA)
Project Mercury astronauts with Convair F-106B-75-CO Delta Dart 59-0158. (NASA)

21 February 1961: Final training begins for Mercury 7 astronauts. Alan Shepard, Gus Grissom and John Glenn are selected for the initial flights. Left-to-Right: Scott Carpenter, Gordon Cooper, John Glenn, Gus Grissom, Wally Schirra, Alan Shepard and Deke Slayton.

The aircraft in the photograph is a Convair F-106B-75-CO Delta Dart, 59-0158, a two-place supersonic interceptor trainer.

© 2015, Bryan R. Swopes

31 January 1971, 21:03:02 UTC, T plus 000:00:00.57

The flight crew of Apollo 14, Edgar D. Mitchell, Alan B. Shepard and Stuart A. Roosa, stand in front of their Saturn V rocket, AS-509, at Space Flight Complex 39A, Kennedy Space Center. (NASA)

31 January 1971, 04:03:02 a.m., Eastern Standard Time: Apollo 14 (AS-509) lifted off for The Moon from Space Flight Launch Complex 39A, Kennedy Space Center, Cape Canaveral, Florida. The Mission Commander was Captain Alan Bartlett Shepard, Jr., United States Navy. The Command Module Pilot was Colonel Stuart Allen Roosa, United States Air Force, and the Lunar Module Pilot was Captain Edgar Dean Mitchell, Sc.D., United States Navy. Their destination was the Fra Mauro Highlands.

Apollo 14 was the eighth manned mission of the Apollo Program, and the third to land on the surface of the moon.

Alan Shepard was the first American astronaut. He flew into space aboard a Mercury spacecraft, Freedom 7, launched from Cape Canaveral by a Redstone rocket, 5 May 1961.

Captain Alan B. Shepard, Jr., Mission Commander, Apollo 14. (NASA)
Captain Alan B. Shepard, Jr., Mission Commander, Apollo 14. (NASA)

Mitchell and Roosa had not flown in space before. This would be their only space flight.

The Apollo Command/Service Module was built by the Space and Information Systems Division of North American Aviation, Inc., at Downey, California.

The SPS engine was an AJ10-137, built by Aerojet General Corporation of Azusa, California. It burned a hypergolic fuel combination of Aerozine 50 and nitrogen tetraoxide, producing 20,500 pounds of thrust (91.19 kilonewtons). It was designed for a 750 second burn, or 50 restarts during a flight.

The Saturn V rocket was a three-stage, liquid-fueled heavy launch vehicle. Fully assembled with the Apollo Command and Service Module, it stood 363 feet (110.642 meters) tall. The first and second stages were 33 feet (10.058 meters) in diameter. Fully loaded and fueled the rocket weighed 6,200,000 pounds (2,948,350 kilograms). It could lift a payload of 260,000 pounds (117,934 kilograms) to Low Earth Orbit.

The first stage was designated S-IC. It was designed to lift the entire rocket to an altitude of 220,000 feet (67,056 meters) and accelerate to a speed of more than 5,100 miles per hour (8,280 kilometers per hour). The S-IC stage was built by Boeing at the Michoud Assembly Facility, New Orleans, Louisiana. It was 138 feet (42.062 meters) tall and had an empty weight of 290,000 pounds (131,542 kilograms). Fully fueled with 203,400 gallons (770,000 liters) of RP-1 and 318,065 gallons (1,204,000 liters) of liquid oxygen, the stage weighed 5,100,000 pounds (2,131,322 kilograms). It was propelled by five Rocketdyne F-1 engines, producing 1,522,000 pounds of thrust (6770.19 kilonewtons), each, for a total of 7,610,000 pounds of thrust at Sea Level (33,850.97 kilonewtons). These engines were ignited seven seconds prior to lift off and the outer four burned for 168 seconds. The center engine was shut down after 142 seconds to reduce the rate of acceleration. The F-1 engines were built by the Rocketdyne Division of North American Aviation at Canoga Park, California.

The S-II second stage was built by North American Aviation at Seal Beach, California. It was 81 feet, 7 inches (24.87 meters) tall and had the same diameter as the first stage. The second stage weighed 80,000 pounds (36,000 kilograms) empty and 1,060,000 pounds loaded. The propellant for the S-II was liquid hydrogen and liquid oxygen. The stage was powered by five Rocketdyne J-2 engines, also built at Canoga Park. Each engine produced 232,250 pounds of thrust (1,022.01 kilonewtons), and combined, 1,161,250 pounds of thrust (717.28 kilonewtons).

Stuart A. Roosa wearing an ILC Dover A7L full-pressure suit, 31 January 1971. (NASA)

The Saturn V third stage was designated S-IVB. It was built by Douglas Aircraft Company at Huntington Beach, California. The S-IVB was 58 feet, 7 inches (17.86 meters) tall with a diameter of 21 feet, 8 inches (6.604 meters). It had a dry weight of 23,000 pounds (10,000 kilograms) and fully fueled weighed 262,000 pounds. The third stage had one J-2 engine and also used liquid hydrogen and liquid oxygen for propellant. The S-IVB would place the Command and Service Module into Low Earth Orbit, then, when all was ready, the J-2 would be restarted for the Trans Lunar Injection.

Eighteen Saturn V rockets were built. They were the most powerful machines ever built by man.

Apollo 14 lifts off from Launch Complex 39A, Kennedy Space Center, 4:03:02 a.m., EST, 31 January 1971. (NASA)

© 2019, Bryan R. Swopes

28 January 1986, 16:39:13 UTC, T+1:13.162

Space Shuttle Challenger (STS-51L) was launched from Launch Complex 39B, Kennedy Space Center, at 16:38 UTC, 28 January 1986. (Thom Baur/AP)

28 January 1986, 11:38:00 a.m. (EST): The Space Shuttle Challenger (OV-99) lifted off from Launch Complex 39B at the Kennedy Space Center, Cape Canaveral, Florida, on Mission STS-51L.

At liftoff, an O-ring seal between segments of the right Solid Rocket Booster (SRB) began leaking. Superheated gases breached the seal and began to burn laterally.

“At 58.778 seconds into powered flight, a large flame plume is visible just above the SRB exhaust nozzle indicating a breach in the motor casing.” (NASA)

The venting rocket exhaust burned through the SRB attachment strut and into the liquid hydrogen tank in the lower section of the External Tank. The aft portion of the liquid hydrogen tank failed and drove the tank vertically upward into the liquid oxygen tank. Both tanks ruptured and the propellants detonated.

1 minute, 13 seconds after liftoff, Challenger was accelerating through Mach 1.62 (1,069 miles per hour, 1,720 kilometers per hour) at approximately 46,000 feet (14,020 meters) when the explosion of the external tank caused the space shuttle to suddenly veer away from its flight path. The shuttle was subjected to aerodynamic forces far beyond its design limits and it was torn apart.

Challenger’s external tank, containing liquid hydrogen and liquid oxygen, exploded 1 minute 13 seconds after liftoff. The two solid rocket boosters flew off in different directions. (Bruce Weaver/AP)
Challenger’s external tank, containing liquid hydrogen and liquid oxygen, exploded 1 minute 13 seconds after liftoff. The two solid rocket boosters flew off in different directions. (Bruce Weaver/AP)

The crew cabin, with its seven astronauts aboard, broke away from the disintegrating shuttle assembly and continued upward for another 25 seconds to approximately 65,000 feet (19,080 meters), then began a long fall to the ocean below.

2 minutes 45 seconds after the explosion, the cabin impacted the surface of the Atlantic Ocean at 207 miles per hour (333 kilometers per hour). The entire crew was killed.

The crew cabin of Space Shuttle Challenger is visible near the end of the smoke plume at the upper center of this photograph, still climbing at supersonic speed. (NASA)
The crew cabin of Space Shuttle Challenger is visible near the end of the smoke plume at the upper center of this photograph, still climbing at supersonic speed. (NASA)

I watched this terrible tragedy as it happened, live on television. I will never forget.

The explosion occurred 1 minute, 13 seconds after liftoff. (NASA)
The explosion occurred 1 minute, 13 seconds after liftoff. (NASA)

AD ASTRA PER ASPERA

Space Shuttle Challenger STS-51L Flight Crew. Front Row, left to right, Captain Michael J. Smith, U.S. Navy; Lieutenant Colonel Francis R. Scobee, U.S. Air Force; Ronald Ervin McNair. Back Row, left to right: Lieutenant Colonel Ellison S. Onizuka, U.S. Air Force; Sharon Christa McAuliffe; Gregory Bruce Jarvis; Judith Arlene Resnick. (NASA)

© 2019, Bryan R. Swopes