Tag Archives: Rocketdyne J-2

16 July 1969, 16:16:16 UTC, T + 02:44:16.2

This 1966 illustration depicts the J-2 engine of the S-IVB third stage firing to send the Apollo spacecraft to the Moon. (NASA)
This 1966 illustration depicts the J-2 engine of the S-IVB third stage firing to send the Apollo spacecraft to the Moon. (NASA)

16 July 1969: At 16:16:16 UTC, T+02:44:16.2, the Apollo 11 S-IVB third stage engine reignited for the Trans Lunar Injection maneuver.

One of the necessary features of the Rocketdyne J-2 engine was its ability to restart a second time. The third stage was first used to place the Apollo 11 spacecraft into Earth orbit and was then shutdown. When the mission was ready to proceed toward the Moon, the J-2 was re-started. Using liquid hydrogen and liquid oxygen for propellant, Apollo 11′s S-IVB burned for 5 minutes, 41.01 seconds, with the spacecraft reaching a maximum 1.45 Gs just before engine cut off. The engine was shut down at T+02:50:03.03. Trans Lunar Injection was at 16:22:13 UTC.

© 2015, Bryan R. Swopes

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14 May 1973, 17:30:00 UTC, T plus 000:00:00.22

SA 513/Skylab 1 (SL-1) launch from LC 39A, 17:30:00 UTC, 14 May 1973. (NASA)

14 May 1973: At 12:30:00 p.m. Eastern Standard Time, America’s first orbital space station, Skylab, was launched by a Saturn V Launch Vehicle, SA-513, from Launch Complex 39A at the Kennedy Space Center, Cape Canaveral, Florida. First motion was detected at T + 000:00:00.22.

After first stage separation, the S-IC/S-II interstage connector failed to separate from the second stage. because of this, orbital insertion occurred at T + 000:09:59.0; 0.64 seconds later than planned, and 0.6 meters per second faster than predicted. The S-II stage followed the Skylab into Earth orbit. Skylab’s orbit was almost perfectly circular, with an apogee of 234.2 nautical miles (433.7 kilometers), and perigee of 233.0 nautical miles (431.5 kilometers). The orbital period was 93.23 minutes, with a velocity of 17,111 miles per hour (27,537 kilometers per hour).

Skylab was unmanned at launch. Three 3-man crews were carried to the station aboard Apollo command/service modules launched by the smaller Saturn IB rocket.

Skylab’s mission was to demonstrate that humans could live and work in orbit for extended periods of time, and that they could also perform useful work and research. The first crew had to make repairs in orbit to extend a damaged solar array and to use a spare solar panel as a shade to prevent sunlight from overheating the station. This was the first orbital repair mission. Astronauts occupied Skylab for 171 days, 13 hours and conducted over 300 scientific projects.

Cutaway illustration of Skylab. (NASA)
Cutaway illustration of Skylab. (NASA)

The Skylab was built from an empty Saturn V third stage, S-IVB number 213, modified by McDonnell Douglas. The launch vehicle consisted of the first two stages of a Saturn V rocket, an S-IC first stage and an S-II second stage.

The total vehicle weight at engine ignition was 6,297,336 pounds (2,856,424 kilograms). Post-launch analysis determined that the five Rocketdyne F-1 engines of SA-513’s S-IC first stage generated 7,551,000 pounds of thrust (33,588.52 kilonewtons) at Sea Level.

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 (8,200 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 33 feet (10.058 meters) in diameter. Its empty weight was 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).

The S-IC was propelled by five Rocketdyne F-1 engines, producing 1,522,000 pounds of thrust, each, for a total of 7,610,000 pounds of thrust at Sea Level. 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, Inc., 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, and combined, 1,161,250 pounds of thrust.

The unmanned space station’s orbit decayed and it reentered on 11 July 1979. It broke up and parts landed in the Indian Ocean and near Perth, Australia.

Skylab in Earth orbit over the Amazon River Valley, 28 July 1973. (NASA)

© 2018, Bryan R. Swopes

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15 April 1970, 01:09:40 UTC: T Plus 077:56:40.0

Impact crater of the Apollo 13/Saturn V AS-508 S-IVB third stage, photographed by the Lunar Reconnaissance Orbiter. The crater is approximately 30 meters (98 feet) across. (NASA)

15 April 1970, 01:09:40 UTC: T plus 077:56:40.0: The Apollo 13 Saturn S-IVB-508 third stage impacted the surface of The Moon north of Mare Cognitum. (S. 2° 33′ 00″, W. 27° 52′ 48″)The S-IVB hit the lunar surface at a velocity of 2.58 kilometers per second (5,771 miles per hour). The impact energy was 4.63 x 1017 ergs (1.04 kiloton).

The impact was detected by seismometers placed on the Moon by Apollo 12 astronauts Pete Conrad and Alan Bean. This was part of the Apollo Lunar Surface Experiments Package, or ALSEP.

Seismograph tracings of Apollo 13 S-IVB impact. (NASA)

The Apollo 12 seismometer was located 135 kilometers (83.9 miles) from the Apollo 13 third stage impact. The signals were used to calibrate the instrument package, which was in service from 1969 to 1977.

The Saturn V third stage was designated Saturn 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 (118,841 kilograms). The third stage had one Rocketdyne J-2 engine which used liquid hydrogen and liquid oxygen for propellant. Itproduced 232,250 pounds of thrust (1,033.10 kilonewtons). 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.

A Saturn V S-IVB third stage. (NASA)

© 2017, Bryan R. Swopes

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

Apollo 6 (AS-502) launch, 07:00:01 EST, 4 April 1968 (NASA)
Apollo 6 (AS-502) launch, 07:00:01 EST, 4 April 1968 (NASA)

4 April 1968: At 07:00:01.38 EST, 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.

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).

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.

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. 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.

© 2018, Bryan R. Swopes

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22 January 1968, 22:48:08.86 UTC, T + 00:00:00.86

Apollo 5 Saturn IB (AS-204) lifts off with LM-1 at Launch Complex 37B, Cape Kennedy Air Force Station, Cape Canaveral, Florida, at 22:48:09 UTC, 22 January 1968. (NASA)

22 January 1968: At 22:48:00.86 UTC (5:48:08 a.m., Eastern Standard Time) a Saturn IB rocket lifted off from Launch Complex 37B at the Cape Kennedy Air Force Station, Cape Kennedy, Florida, carrying LM-1, an unmanned Apollo Program lunar lander, into a low-Earth orbit.

AS-204 reached Mach 1 at T + 0:59.8, passing 24,574 feet (7,490.16 meters). First stage separation occurred at T + 02:23.6, at an altitude of 194,228 feet (59,201 meters), with the vehicle accelerating through 7,563 feet per second (2,305 meters per second).

The AS-204 S-IVB engine cut off occurred at T + 09:53 at 536,166 feet (163,423 meters) with the vehicle travelling 25,659 feet per second (7,820 meters per second). Orbital insertion occurred at T + 00:10:03 at an altitude of 88 nautical miles (163 kilometers) with a velocity of 25,684 feet per second (7,828 meters per second). The orbit was elliptical with an apogee of 120 nautical miles (222 kilometers) and perigee of 88 nautical miles (163 kilometers). The orbital period was 88.39 minutes.

Apollo 5 lefts off from Launch Complex (NASA)

The Lunar Module separated from the S-IVB stage at T + 00:53:55.24. It was the allowed to cold-soak for about 3 hours. At T + 03:59.46, the LM’s descent engine was fired but aborted by the guidance computer after 4.0 seconds. A little over 3 hours later, at T + 06:10:42, the descent engine was fired a second time, and burned until T +  06:13:14.7.

The ascent engine fired at  06:12:14.7 while the descent and ascent stages were still joined. The engine burned 60.0 seconds. It was fired a second time at T + 07:44:13.

With the tests completed, the orbits of the separated LM stages were allowed to decay. LM-1 quickly re-entered Earth’s atmosphere and was destroyed.

The purpose of the Apollo 5 mission was to test the Grumman-built Lunar Module in actual spaceflight conditions. Engines for both the descent and ascent stages had to be started in space, and be capable of restarts. Although the mission had some difficulties as a result of programming errors, it was successful and a second test flight with LM-2 determined to be unnecessary and was cancelled.

Apollo 5/Saturn IB (AS-204) clears the tower at Launch Complex 37B, Cape Kennedy Air Force Station, Cape Canaveral, Florida, 22:48 UTC, 22 January 1968. (NASA)

SA-204 ¹ had originally been the scheduled launch vehicle for the Apollo 1 manned orbital flight.

When a fire in the command module killed astronauts Virgil I. (“Gus”) Grissom, Edward H. White and Roger B. Chaffee, 27 January 1967, the rocket was undamaged. It was moved from Launch Complex 39 and reassembled at LC 37B for use as the launch vehicle for Apollo 5.

Apollo 5 Saturn IB AS-204 at Launch Complex 37B, 22 January 1968. (NASA)

The Saturn IB was a two-stage, liquid-fueled, heavy launch vehicle. It consisted of a S-IB first stage and S-IVB second stage. The total height of AS-204 was 181 feet, 0.355 inches (55.17782 meters). The Saturn IB rocket stood 141 feet, 8.644 inches (43.19636 meters), without payload. It had a maximum diameter of 22.8 feet (6.949 meters), and the span across the first stage guide fins was 40.7 feet (12.405 meters). Its empty weight was 159,000 pounds (72,122 kilograms) and at liftoff, it weighed 1,296,000 pounds (587,856 kilograms). It was capable of launching a 46,000 pound (20,865 kilogram) payload to Earth orbit.

The S-IB first stage was built by the Chrysler Corporation Space Division at the Michoud Assembly Facility near New Orleans, Louisiana. The first stage was 80 feet, 4.089 inches (24.4878606 meters) long, with a maximum diameter of 21 feet, 8.0 inches (6.604 meters) (21 feet, 5.0 inches across the Redstone tanks). The stage was powered by eight Rocketdyne H-1 engines, burning RP-1 and liquid oxygen. Eight Redstone rocket fuel tanks, with four containing the RP-1 fuel, and four filled with liquid oxygen, surrounded a Jupiter rocket fuel tank containing liquid oxygen. Total thrust of the S-IB stage was 1,666,460 pounds (7,417.783 kilonewtons) and it carried sufficient propellant for a maximum 4 minutes, 22.57 seconds of burn. The first stage of AS-204 was S-IB-4.

Saturn S-IB first stages in final assembly at Michoud, 1967. (NASA GPN-2000-000043)

The McDonnell Douglas Astronautics Company S-IVB stage was built at Huntington Beach, California. The stage was 61 feet, 4.555 inches (18.708497 meters) long, with a maximum diameter of 21 feet, 8.0 inches (6.604 meters). It was powered by a single Rocketdyne J-2 engine, fueled by liquid hydrogen and liquid oxygen. The J-2 produced 229,714 pounds of thrust (1,021.819 kilonewtons), at high thrust, and 198,047 pounds (880.957 kilonewtons) at low thrust). The second stage carried enough fuel for 7 minutes, 49.50 seconds burn at high thrust.

Three-view drawing of the Lunar Module with dimensions. (NASA)

The Lunar Module was a two-stage vehicle designed to transport two astronauts from Lunar Orbit to the surface of the Moon, provide shelter and a base of operations while on the Moon, and then return the astronauts to lunar orbit, rendezvousing with the Apollo Command and Service Module.  It was designed and built by the Grumman Aerospace Corporation at Bethpage, Long Island, New York.

The Descent Stage incorporated extendable landing gear, a hypergolic-fueled rocket engine to brake from orbital speed, establish a landing trajectory, and then decelerate for landing. The TRW Space Technology Laboratories Lunar Module Descent Engine (LMDE) produced a maximum of 10,500 pounds of thrust (46.706 kilonewtons), and could be throttled from 10–100% thrust. The stage also carried support equipment, oxygen, water, etc., needed by the astronauts, and equipment for use during surface activities.

To return to Lunar Orbit, the Descent Stage was left behind, and the Bell Aerosystems Lunar Module Ascent Engine (LMAE) was fired. This engine also used hypergolic fuel and produced 3,500 pounds of thrust (15.569 kilonewtons).

Apollo Lunar Module LM-1 being assembled with upper stage. (NASA)
Apollo Lunar Module LM-1 being assembled with upper stage. (NASA)

¹ The Apollo Program Saturn rockets were designated as both AS-xxx and SA-xxx. The AS-xxx designation was applied to the complete vehicle, or “full stack,” while the SA-xxx designation applied to only the multi-stage rocket assembly.

© 2019, Bryan R. Swopes

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