Tag Archives: Low Earth Orbit

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

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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

20 February 1962, 14:47:39 UTC

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Launch of Friendship 7 from Launch Complex 14, Kennedy Space Center, 14:47:39 UTC, 20 February 1962. (NASA)

20 February 1962: At 9:47:39 a.m., Eastern Standard Time, NASA’s Mercury-Atlas 6 lifted off from Launch Complex 14, Cape Canaveral Air Force Station, Cape Canaveral, Florida. This was the third launch of a manned Mercury spacecraft, and the first time that an Atlas rocket had been used.

Aboard the spacecraft was Lieutenant Colonel John Herschel Glenn, Jr., United States Marine Corps, an experienced fighter pilot and test pilot.

John Herschel Glenn, Jr., NASA Project Mercury Astronaut. (Ralph Morse/LIFE Magazine)

In his post-flight mission report, Glenn wrote,

When the countdown reached zero, I could feel the engines start. The spacecraft shook, not violently but very solidly. There was no doubt when lift off occurred, When the Atlas was released there was an immediate gentle surge to let you know you were on your way.

—Results of the First United States Orbital Space Flight (NASA-TM-108606), Manned Spacecraft Center, National Aeronautics and Space Administration, at Page 120, Column 1

2 minutes, 9.6 seconds after liftoff, the booster engines cut of and were jettisoned. 23 seconds later, the escape tower, no longer needed, was also jettisoned. The Atlas sustainer engine continued to burn until T+00:05:01.4. The spacecraft had now reached 17,544 miles per hour (28,234 kilometers per hour) and was in an elliptical orbit around the Earth. At T+00:05:03.6 the Mercury spacecraft separated from the Atlas booster. During the climb to orbit, John Glenn experienced a maximum acceleration of 7.7 gs.

Glenn’s orbit had an apogee of 162.2 statute miles (261 kilometers) and perigee of 100 miles (161 kilometers). The orbit was inclined 32.54° relative to Earth’s orbital plane. Friendship 7 completed an orbit every 88 minutes, 29 seconds.

Analysis showed that the Atlas had placed Friendship 7 in orbit at a velocity with 7 feet per second (2.1 meters per second) less than nominal. However, computer analysis showed that the orbital trajectory was good enough for nearly 100 orbits.

This photograph of Friendship 7’s cockpit was taken in orbit around the Earth, 20 February 1962. Astronaut John Glenn’s hands and legs are visible at the lower edge of the image. (Ohio State University)

During the 4 hour, 55 minute, 23 second flight, the Mercury capsule orbited the Earth three times. John Glenn was the first American astronaut to orbit the Earth.  (Cosmonaut Yuri Gagarin had orbited the Earth 12 April 1961.)

Friendship 7 is hoisted aboard USS Noa (DD-841). (U.S. Navy)

After re-entry, the capsule parachuted into the Atlantic Ocean, only six miles from the recovery ship, USS Noa (DD-841).

Mercury spacecraft profile with dimensions. (NASA)

The Mercury spacecraft, Friendship 7, was built by McDonnell Aircraft Corporation, St. Louis, Missouri. It was the 13th Mercury capsule built. Designed to carry one pilot, it could be controlled in pitch, roll and yaw by steam thrusters fueled by hydrogen peroxide. The Mercury was 7 feet, 2.83 inches (2.206 meters) long, not including its retro rocket pack. The spacecraft was generally conical, and had a maximum diameter of 6 feet, 2.50 inches (1.885 meters). It weighed 2,700 pounds (1,224.7 kilograms) at launch.

Diagram of Atlas LV-3B (Space Launch Report)

The rocket, a “1-½ stage” liquid-fueled Atlas LV-3B, number 109-D, was built by the  Convair Division of General Dynamics at San Diego, California. It was developed from a U.S. Air Force SM-65 Atlas D intercontinental ballistic missile, modified for use as a “man-rated” orbital launch vehicle.

The LV-3B was 65 feet (19.812 meters) long from the base to the Mercury adapter section, and the tank section is 10 feet (3.038 meters) in diameter. The complete Mercury-Atlas orbital launch vehicle is 93 feet (28.436 meters) tall, including the escape tower. When ready for launch it weighed approximately 260,000 pounds (118,000 kilograms) and could place a 3,000 pound (1,360 kilogram) payload into low Earth orbit.

The Atlas’ three engines were built by the Rocketdyne Division of North American Aviation, Inc., at Canoga Park, California. Two Rocketdyne LR89-NA-5 engines and one LR105-NA-5 produced 341,140 pounds (1,517.466 kilonewtons) of thrust. The rocket was fueled by a highly-refined kerosene, RP-1, with liquid oxygen as the oxidizer.

Friendship 7 is displayed at the Smithsonian National Air and Space Museum.

John Glenn's Mercury spacecraft, Friendship 7, on display at the Smithsonian Institution National Air and Space Museum. (Photo by Eric Long, National Air and Space Museum, Smithsonian Institution.)
John Glenn’s Mercury spacecraft, Friendship 7, on display at the Smithsonian Institution National Air and Space Museum. (Photo by Eric Long, National Air and Space Museum, Smithsonian Institution.)

© 2019, Bryan R. Swopes

19 February 1986

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Mir DOS-7/Proton 8K82K launch at Baikonur Cosmodrome, Site 200, 21:28:23 UTC, 19 February 1986.
Mir DOS-7/Proton 8K82K launch at Baikonur Cosmodrome, Site 200, 21:28:23 UTC, 19 February 1986.

19 February 1986: The core module of the Mir space station (DOS-7) (Dolgovremennaya Orbitalnaya Stanziya) was launched from Site 200 of the Baikonur Cosmodrome aboard a Proton 8K82K rocket. This was the first section of the space station. It consisted of living quarters and environmental systems, engines, and four air locks to which additional modules would be attached.

The Mir was unmanned when it was placed in low Earth orbit. The first two-man crew arrived 15 March 1986 and began bringing the space station systems online. The first expedition stayed aboard for 51 days.

The Mir Core Module was 13.13 meters (43.077 feet) long with a diameter of 4.15 meters (13.616 feet). The solar arrays had a span of 20.73 meters (68.012 feet). The habitable volume of the module was 90 cubic meters (3,178 cubic feet). At launch  it had a mass of 20,400 kilograms (44,974.3 pounds).

The Proton 8K82K was a four-stage liquid-fueled heavy lift rocket. The first stage, Proton K-1, was 21.20 meters (69.554 feet) long with a diameter of 4.15 meters (13.616 feet). Fully fueled, it had a mass of 450,510 kilograms (993,205 pounds). It carried enough hypergolic fuel to power the six RD-253 engines for 124 seconds, producing 67,821.2 kiloNewtons (15,246,812 pounds) of thrust. The second stage, Proton K-2, was 14.00 meters (45.932 feet) long, with the same diameter as the first stage. Its fully-fueled mass was 167,828 kilograms (369,997 pounds). Its four RD-0210 engines burned for 206 seconds, producing 9,596.8 kiloNewtons (2,157,447 pounds) of thrust. The Proton K-3 stage was 6.50 meters (21.326 feet) long, and again, had a diameter of 4.15 meters. The gross mass of the third stage was 50,747 kilograms (111,878 pounds). The single RD-0212 engine burned for 238 seconds, producing 630.2 kiloNewtons (141,675 pounds) of thrust. The final, fourth stage, Proton 11S824, was 5.50 meters (18.045 feet) long with a diameter of 3.70 meters (12.139 feet). Gross mass was 13,360 kilograms (29,454 pounds). It had a single RD-58M engine which burned liquid oxygen and kerosene. It produced 85.02 kiloNewtons (19,113 pounds) of thrust for 610 seconds.

The Proton 8K82K could place a 20,000 kilogram (44,092 pound) payload into low Earth orbit. The rocket was first launched in 1965 and was used until 2003. More than 300 of them were launched.

The Mir space station was continually expanded. It was occupied for 4,592 consecutive days. It remained in orbit until 23 March 2001.

The Mir space station core module (DOS-7) in Earth orbit with solar panel array extended.
The Mir space station core module (DOS-7) in Earth orbit with solar panel array extended.

© 2016, Bryan R. Swopes

8 February 1974, 02:33:12 UTC

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Skylab in Earth orbit, as seen by the departing Skylab 4 mission crew, 8 February 1974. (NASA)
Skylab in Earth orbit, as seen by the departing Skylab 4 mission crew, 8 February 1974. (NASA)

8 February 1974: At 02:33:12 UTC, the Skylab 4/Apollo command module undocked from the Skylab space station in Earth orbit, after 83 days, 4 hours, 38 minutes, 12 seconds. After several orbits, the Apollo capsule reentered the atmosphere and landed in the Pacific Ocean southwest of San Diego California, at 15:16:53 UTC. The crew was recovered by USS New Orleans (LPH-11), a helicopter carrier. Today, the Apollo capsule is displayed at the Smithsonian Institution National Air and Space Museum.

Skylab was an orbital laboratory built from a Saturn S-IVB third stage. It was launched from Cape Canaveral 14 May 1973 as part of a modified Saturn V rocket. The Skylab 4 crew was the third and final group of astronauts to live and the space station. (The mission insignia incorporates the numeral 3.)

Skylab’s orbit gradually decayed and it re-entered the atmosphere near Perth, Australia, 11 July 1979.

The Skylab 4 mission crew, left to right, Mission Commander Gerald P. Carr, Mission Scientist Edward G. Gibson and Pilot William R. Pogue. Pogue and Carr had joined NASA during the Apollo Program and were scheduled for Apollo 19, which was cancelled. This was the only space flight for these three astronauts. (NASA)
The Skylab 4 mission crew, left to right, Mission Commander Gerald P. Carr, Mission Scientist Edward G. Gibson and Pilot William R. Pogue. Pogue and Carr had joined NASA during the Apollo Program and were scheduled for Apollo 19, which was cancelled. This was the only space flight for these three astronauts. (NASA)

© 2019, Bryan R. Swopes