Tag Archives: NASA

4 April 1968: 12:00:01.38 UTC, T plus 00:00:00.38

Apollo 6/Saturn V AS-502 launch from LC-39A, 12:00:01.38 UTC, 4 April 1968. (National Aeronautics and Space Administration NASA 68-HC-201)

4 April 1968: At 07:00:01.38 EST (12:00:01.38 UTC), Apollo 6 (AS-502), the second and last unmanned Apollo mission, lifted off from Launch Complex 39A, Kennedy Space Center, Cape Canaveral, Florida. First motion was detected at Range Time 00:00:00.38. The purpose of the flight was to determine that an all-up Saturn V could attain Trans Lunar Injection. Because of engine difficulties, it did not do so, but data from the test gave mission planners confidence to go ahead with manned flights.

Apollo 6/Saturn V AS-502 lifts off from Launch Complex 39A, Kennedy Space Center, Cape Canaveral, Florida, 12:00:01.38 UTC, 4 April 1968. (National Aeronautics and Space Administration)

At T+2:05 the Saturn V experienced a severe “pogo” oscillation, but no structural damage occurred. Next, several structural panels from the lunar module adaptor section were lost due to a manufacturing defect. Finally, during the second stage burn, two of the five Rocketdyne J-2 engines shut down prematurely. Because of this, the planned circular orbit at 175 kilometers altitude was not achieved, instead, the spacecraft entered a 106.9 × 138.6 miles (172.1 × 223.1 kilometers) orbit, circling Earth in 89.8 minutes.

After two orbits, it was planned to send Apollo 6 to the Trans Lunar Injection point, but the third stage engine would not fire. The Service Module engine was used to boost the spacecraft to a peak altitude of 13,810.2 miles (22,225.4 kilometers) and a planned lunar re-entry simulation was carried out. Apollo 6 reached 22,385 miles per hour (36,025 kilometers per hour) as it reentered the atmosphere. 9 hours, 57 minutes, 20 seconds after launch, Apollo 6 splashed down in the Pacific Ocean north of Hawaii and was recovered by USS Okinawa (LPH-3).

Apollo 6/Saturn V AS-502. (National Aeronautics and Space Administration NASA S68-27366)

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).¹ 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.

Apollo 6/Saturn V AS-502 S-/S-II interstage falling away. (NASA 68-HC-193)

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).

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. For more than 50 years, they were the most powerful machines ever built by man.

¹ The five Rocketdyne F-1 engines of the AS-502 S-IC first stage produced a combined thrust of 7,567,000 pounds (33,660 kilonewtons), 15,000 pounds (67 kilonewtons) less than predicted.

© 2025, Bryan R. Swopes

Virgil Ivan Grissom (3 April 1926 – 27 January 1967)

Astronaut Virgil I. Grissom with scale model of Gemini/Titan II launch vehicle. (NASA)
Virgil Ivan Grissom (1944 Gold and Blue)

3 April 1926: Virgil Ivan Grissom was born at Mitchell, Indiana, the second of five children of Dennis David Grissom, an electrician, and Cecile King Grissom. “Gus” Grissom attended Mitchell High School, graduating in 1944. He was a member of the Hi-Y Club, the Camera Club, and the Signal Club.

Upon graduation from high school. Virgil I. Grissom enlisted as an aviation cadet in the Air Corps, United States Army, at Fort Benjamin Harrison, Lawrence, Indiana, 9 August 1944. He was assigned to basic flight training at Sheppard Field, Texas, but the War came to an end before he could graduate as a pilot. Then reassigned as a clerk, he requested to be discharged from the Air Corps, which he was in November 1945.

Grissom married Miss Betty Lavonne Moore at Mitchell, Indiana, 6 July 1945. They wood have two sons, Scott and Mark. (In Korea, Grissom named his F-86 Scotty after his first son.)

After the war, Grissom enrolled at Purdue University, Lafayette, Indiana, and in 1950, graduated with the degree of Bachelor of Science in Mechanical Engineering.

He then re-joined the U.S. Air Force in 1950 and was trained at Randolph Air Force Base, Texas, and Williams Air Base, Arizona, where he specialized as a fighter pilot.  He was commissioned as a second lieutenant, U.S. Air Force, in March 1952.

Lieutenant Grissom was assigned to he 334th Fighter Interceptor Squadron, 4th Fighter Interceptor Wing, based at Kenpo Air Base (K-14), in the Republic of South Korea. He flew 100 combat missions in the North American Aviation F-86 Sabre. Grissom was promoted to first lieutenant, 11 March 1952. he requested to fly another 25 combat missions, but that was declined and he returned to the United States. Lieutenant Grissom was then assigned as a flight instructor at Bryan Air Force Base, Texas.

Grissom attended a one year program at the Air Force Institute of Technology at Wright-Patterson Air Force Base, Dayton, Ohio, and earned a second bachelor’s degree in aircraft engineering. He was then sent to the Air Force Test Pilot School at Edwards Air Force Base, California (Class 56D). After completion, he was assigned as a fighter test pilot back at Wright-Patterson.

One of 508 pilots who were considered by NASA for Project Mercury, Gus Grissom was in the group of 110 that were asked to attend secret meetings for further evaluation. From that group, 32 went on with the selection process and finally 18 were recommended for the program. Grissom was one of the seven selected.

Mercury-Redstone 4 (Liberty Bell 7) launch at Pad 5, Cape Canaveral Air Force Station, 12 20 36 UTC, 21 July 1961. (NASA)

Major Grissom was the second American to “ride the rocket” aboard Mercury-Redstone 4. He named his space capsule Liberty Bell 7. The spacecraft reached a maximum altitude of 102.8 nautical miles (118.3 statute miles, 190.4 kilometers) and traveled 262.5 nautical miles (302.1 statute miles, 486.2 kilometers) down range. During the 15 minute, 37 second, flight, Grissom was weightless for 5:00 minutes.

Next he orbited Earth as commander of Gemini III along with fellow astronaut John Young. He was back-up commander for Gemini VI-A, then went on to the Apollo Program.

The flight crew of Gemini III, John W. Young and Virgil I. Grissom. (NASA)

Gus Grissom was selected as the commander for Apollo I in January 1968. This was to be the first manned flight of the Apollo spacecraft. Ed White and Roger Chaffee were the other members of the flight crew.

As commander of AS-204 (Apollo I), LCOL Virgil I. Grissom, USAF was killed along with Ed White and Roger Chafee during a test on the launchpad, 27 January 1967.

The crew of Apollo 1. Left to right, Lieutenant Colonel Virgil I. Grissom, United States Air Force, Lieutenant Colonel Edward H. White II, United States Air Force, and Lieutenant Commander Roger B. Chaffee, United States Navy. (NASA)

Gus Grissom was an Air Force Command Astronaut with over 4,600 hours flight time. He was the first American astronaut to fly into space twice, and logged 5 hours, 7 minutes of space flight. For his military service, Grissom was awarded the Distinguished Flying Cross; the Air Medal with one bronze oak leaf cluster (two awards); the American Campaign medal; the World War II Victory Medal; teh Korean Service Medal; the United Nations Korea medal, and the Korean War Service Medal of the Republic of South Korea. For his NASA service, he was awarded the Congressional Space Medal of Honor (posthumous); the NASA Distinguished Service Medal (two awards); and the NASA Exceptional Service Medal.

Had he lived, it is very possible that Grissom would have commanded the first Apollo mission to land on The Moon.

The remains of Lieutenant Colonel Virgil Ivan Grissom, United States Air Force, NASA Astronaut, are buried at the Arlington National Cemetery, Arlington, Virginia.

© 2018, Bryan R. Swopes

1 April 1959

The Mercury 7: Front row, left to right, LCDR Walter Marty Schirra, USN; CAPT Donald Kent Slayton, USAF; LCOL John Herschel Glenn, Jr., USMC; LT Malcolm Scott Carpenter, USN. Back row, left to right, LCDR Alan Bartlett Shepard, Jr., USN; CAPT Virgil Ivan Grissom, USAF; CAPT Leroy Gordon Cooper, Jr., USAF. (NASA)
The Mercury 7: Front row, left to right, LCDR Walter Marty Schirra, USN; CAPT Donald Kent Slayton, USAF; LCOL John Herschel Glenn, Jr., USMC; LT Malcolm Scott Carpenter, USN. Back row, left to right, LCDR Alan Bartlett Shepard, Jr., USN; CAPT Virgil Ivan Grissom, USAF; CAPT Leroy Gordon Cooper, Jr., USAF. (NASA)

“The selection procedures for Project Mercury were directed by a NASA selection committee, consisting of Charles Donlan, a senior management engineer; Warren North, a test pilot engineer; Stanley White and William Argerson, flight surgeons; Allen Gamble and Robert Voas psychologists; and George Ruff and Edwin Levy, psychiatrists. The committee recognized that the unusual conditions associated with spaceflight are similar to those experienced by military test pilots. In January 1959, the committee received and screened 508 service records of a group of talented test pilots, from which 110 candidates were assembled. Less than one month later, through a variety of interviews and a battery of written tests, the NASA selection committee pared down this group to 32 candidates.

“Each candidate endured even more stringent physical, psychological, and mental examinations, including total body x-rays, pressure suit tests, cognitive exercises, and a series of unnerving interviews. Of the 32 candidates, 18 were recommended for Project Mercury without medical reservations. On April 1, 1959, Robert Gilruth, the head of the Space Task Group, and Donlan, North, and White selected the first American astronauts. The “Mercury Seven” were Scott Carpenter, L. Gordon Cooper, Jr., John H. Glenn, Jr., Virgil I. “Gus” Grissom, Walter M. Schirra, Jr., Alan B. Shepard, Jr., and Donald K. “Deke” Slayton.”

40th Anniversary of the Selection of the Mercury Seven http://history.nasa.gov/40thmerc7/intro.htm

24 March 1960

Joseph Albert Walker in the cockpit of North American Aviation X-15A 56-6670, after a flight, 1960. (NASA)
Joseph Albert Walker in the cockpit of North American Aviation X-15A 56-6670, after a flight, 1960. (NASA)

24 March 1960: After North American Aviation’s Chief Engineering Test Pilot, Albert Scott Crossfield, had made the first flights in the new X-15 hypersonic research rocketplane (one gliding, eight powered), NASA Chief Research Test Pilot Joseph Albert Walker made his first familiarization flight.

The X-15, 56-6670, the first of three built by North American Aviation, Inc., was carried aloft under the right wing of a Boeing NB-52A Stratofortress, 52-003, flown by John E. Allavie and Fitzhugh L. Fulton.

Fitz Fulton and and Jack Allavie with a Boeing NB-52 drop ship. (Jet Pilot Overseas)

The rocketplane was dropped from the mothership over Rosamond Dry Lake at 15:43:23.0 local time, and Joe Walker ignited the Reaction Motors XLR-11 rocket engine. The engine burned for 272.0 seconds, accelerating Walker and the X-15 to Mach 2.0 (1,320 miles per hour/2,124.3 kilometers per hour) and a peak altitude of 48,630 feet (14,822.4 meters). Walker landed on Rogers Dry Lake at Edwards Air Force Base after a flight of 9 minutes, 8.0 seconds.

Joe Walker made 25 flights in the three X-15 rocket planes from 24 March 1960 to 22 August 1963. He achieved a maximum Mach number of 5.92, maximum speed of 4,104 miles per hour (6,605 kilometers per hour) and maximum altitude of 354,200 feet (107,960 meters).

Joe Walker with the Number 2 North American Aviation X-15, 56-6671, on Rogers Dry Lake. (NASA)

Joe Walker was killed in a mid-air collision between his Lockheed F-104N Starfighter and a North American Aviation XB-70A Valkyrie near Barstow, California, 1 June 1966.

The number one ship, 56-6670, made 81 of the 199 flights of the X-15 Program. It was the first to fly, and also the last, 24 October 1968. Today, it is in the collection of the Smithsonian Institution National Air and Space Museum.

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

© 2019, Bryan R. Swopes

23 March 1965

Gemini III lifts off at Launch Complex 19, Kennedy Space Center, Cape Canaveral, Florida, 14:24:00.o64 UTC, 23 March 1965. (NASA)
Gemini III lifts off at Launch Complex 19, Cape Kennedy Air Force Station, Cape Canaveral, Florida, 14:24:00 UTC, 23 March 1965. (NASA)

23 March 1965: At 14:24:00.064 UTC, Gemini III was launched aboard a Titan II GLV rocket from Launch Complex 19 at the Cape Kennedy Air Force Station, Cape Canaveral, Florida. Major Virgil Ivan (“Gus”) Grissom, United States Air Force, a Project Mercury veteran, was the Spacecraft Commander, and Lieutenant Commander John Watts Young, United States Navy, was the pilot.

The purpose of the mission was to test spacecraft orbital maneuvering capabilities that would be necessary in later flights of the Gemini and Apollo programs

The spacecraft entered a 100.2 mile (161.2 kilometer) × 139.3 mile (224.2 kilometer) orbit, with an orbital period of 88 minutes, 18 seconds. At the end of the first orbit, Grissom used the Orbital Attitude and Maneuver System (OAMS) to move Gemini III into a 98.2 mile (158 kilometer) × 105 mile (169 kilometer) near circular orbit. During the third orbit, the spacecraft descended to 52 miles (84 kilometers) to allow normal orbital decay should the retro rocket system fail.

Gemini III made three orbits of the Earth, and splashed down after 4 hours, 52 minutes, 31 seconds. Miscalculations of the Gemini capsule’s aerodynamics caused the spacecraft to miss the intended splash down point by 69 miles (111 kilometers). Gemini III splashed down in the Atlantic Ocean at N. 22.43°, W. 70.85°, northeast of the Turks and Caicos Islands. The recovery ship was the Essex-class aircraft carrier USS Intrepid (CVS-11).

Gus Grissom would later command the flight crew of Apollo 1. He was killed with his crew during the tragic fire during a pre-launch test, 27 January 1967.

John Young served as Spacecraft Commander for Gemini 10, Command Module Pilot on Apollo 10, back-up commander for Apollo 13, commander Apollo 16, and back-up commander for Apollo 17. Later, he was commander of the maiden flight of the space shuttle Columbia STS-1 and again for STS-9 and was in line to command STS-61J when it was cancelled following the loss of the Space Shuttle Challenger.

The flight crew of Gemini III, John W. Young and Virgil I. Grissom. (NASA)
The flight crew of Gemini III, Lieutenant Commander John W. Young, U.S. Navy, and Major Virgil I. Grissom, U.S. Air Force. (NASA)

The two-man Gemini spacecraft was built by the McDonnell Aircraft Corporation of St. Louis, the same company that built the earlier Mercury space capsule. The spacecraft consisted of a reentry module and an adapter section. It had an overall length of 19 feet (5.791 meters) and a diameter of 10 feet (3.048 meters) at the base of the adapter section. The reentry module was 11 feet (3.353 meters) long with a diameter of 7.5 feet (2.347 meters). The weight of the Gemini varied from ship to ship but was approximately 7,000 pounds (3,175 kilograms).

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 (2,050.986 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 (456.988 kilonewtons).

The Gemini III/Titan II GLV combination had a total height of 107 feet, 7.33 inches (32.795 meters) and weighed 340,000 pounds (156,652 kilograms) at ignition.

The Gemini III spacecraft is displayed at the Grissom Memorial Museum, Spring Mill State Park, Mitchell, Indiana.

© 2019, Bryan R. Swopes