Tag Archives: Artificial Satellite

31 January 1958, 03:48:00 UTC

Explorer 1 launch, Launch Complex 26A, Cape Canaveral Air Force Station. (NASA)

31 January 1958, 10:48 p.m., Eastern Standard Time (1 February 1958, 03:48:00 UTC): The United States of America launched its first successful satellite, Explorer 1, from Launch Complex 26A at the Cape Canaveral Air Force Station, Cape Canaveral, Florida. The satellite entered an orbit with a perigee of 224 miles (360 kilometers) and apogee of 1,575 miles (2,535 kilometers). It completed one orbit every 1 hour, 54.9 minutes.

Explorer 1 was designed and built by the Jet Propulsion Laboratory (JPL) at the California Institute of Technology, Pasadena, California. The satellite carried a cosmic ray detector, internal and external temperature sensors, and a micrometeorite detector. Powered by batteries, it transmitted data for 105 days.

Cutaway illustration of Explorer 1 satellite and booster. (NASA)

The satellite was launched aboard a Juno-1 four-stage liquid-fueled rocket, produced by the U.S. Army Ballistic Missile Agency (ABMA). The Juno satellite launch vehicle was developed from the Jupiter-C intermediate range ballistic missile, and externally appears virtually identical. The complete Explorer 1/Juno-1 was 71.25 feet (21.72 meters) tall and weighed 64,080 pounds (29,066 kilograms) at launch.

The Juno-1 first stage was 69 feet, 8 inches (21.234 meters) long and 5 feet, 10 inches (1.778 meters) in diameter. Four stabilizing fins had a maximum span of 12 feet, 8 inches (3.861 meters). The engine was a Rocketdyne A-7, which burned a combination of Hydyne and liquid oxygen. The A-7 was rated at 83,000 pounds of thrust (369.20 kilonewtons) and burned for 2 minutes, 35 seconds.

The second stage consisted of a cluster of 11 JPL “Baby Sergeant” solid-rocket boosters, producing a total of 16,500 pounds of thrust (73.40 kilonewtons) and burned for 6.5 seconds. These were scaled-down version of the Thiokol XM100 Sergeant booster. They were 3 feet, 10 inches (1.168 meters) long and 6.00 inches (15.24 centimeters) in diameter. Each booster contained 50 pounds ( kilograms) of solid fuel. The second stage weighed 1,020 pounds (463 kilograms).

Juno-1 satellite launch vehicle number RS-29, marked UE, ready for launch, 31 January 1958. (NASA)

The third stage was powered by three Baby Sergeant boosters, producing 4,500 pounds of thrust (20.02 kilonewtons). These were clustered inside the second stage boosters, and both the second and third stage were covered by a fiberglass “tub” which could be spun up to 750 r.p.m. to stabilize the rocket after launch. The third stage weighed 280 pounds (127 kilograms).

The fourth stage consisted of the Explorer satellite and a single Baby Sergeant booster. The booster remained attached to the satellite in orbit. The Explorer 1 satellite was 2 feet, 6.75 inches (0.781 meters) long, and 6.50 inches (16.51 centimeters) in diameter. It weighed 30.66 pounds (13.91 kilograms). Including its booster, the fourth stage was 6 feet, 8.75 inches (2.051 meters) long and weighed 80 pounds (36 kilograms). The fourth stage booster produced 1,500 pounds of thrust (6.67 kilonewtons) for 6.5 seconds. This gave the Explorer 1 an orbital velocity of approximately 18,000 miles per hour (28,968 kilometers per hour).

Explorer 1 remained in orbit for 12 years, 2 months and 1 day. On 31 March 1970, its orbit decayed and the satellite re-entered Earth’s atmosphere over the Pacific Ocean and was destroyed.

Explorer 1 artificial satellite. (NASA)

© 2019, Bryan R. Swopes

4 January 1958

Replica of Sputnik 1 satellite at the Smithsonian Institution National Air and Space Museum (NSAM)
Replica of Sputnik 1 satellite at the Smithsonian Institution National Air and Space Museum (NASA)

4 January 1958: After completing 1,440 orbits, Sputnik 1, the world’s first artificial satellite, reentered the Earth’s atmosphere and was destroyed.

Простейший Спутник-1 (Sputnik 1, or Elementary Satellite 1) had been launched 4 October 1957 from Site No. 1 at the Scientific-Research Test Range No. 5, Tyuratam, Kazakh S.S.R. (now, Kazakhstan), aboard a two-stage Sputnik 8K71PS rocket, a variant of the R-7 Semyorka intercontinental ballistic missile.

Mikhail S. Khomyakov
Mikhail S. Khomyakov

The satellite was designed at OKB-1 (the Special Design Bureau) by a team of Mikhail Stepanovich Khomyakov, Maksim Khramov and Oleg Genrikhovich Ivanovsky. It was constructed as a sphere with a diameter of 58.0 centimeters (22.84 inches), made from an aluminum alloy with a thickness of 2 millimeters (0.08 inch). The two halves were joined by 36 bolts and filled with pressurized nitrogen. Four “whip” antennas were equally spaced around the satellite’s shell, angled at 35° from the longitudinal axis. With three silver-zinc batteries and equipment, the Sputnik 1 mass was 83.6 kilograms (184.3 pounds).

The satellite entered an elliptical Low Earth Orbit, with a perigee of 215.0 kilometers (133.6 miles) and apogee of 939.0 kilometers (583.5 miles). The duration of each orbit was 1 hour, 36 minutes, 12 seconds.

An unidentified engineer with Sputnik 1.
An unidentified engineer with Sputnik 1. (OKB-1)

The Sputnik 8K71PS launch vehicle, serial number 1 M1-PS, was a two-stage, liquid-fueled rocket based on the R-7 Semyorka intercontinental ballistic missile. The R-7 rocket was designed by Sergei Pavlovich Korolev, known as The Chief Designer. It had a length of 29.167 meters (95.69 feet) and maximum diameter of 10.3 meters (33.79 feet) at the base, including stabilizers. Its mass was 267.13 tons (588,921 pounds) at liftoff. The propellant was Kerosene T-1 with liquid oxygen.

The first stage consisted of four “strap-on” boosters surrounding the second, of “core” stage, each with an RD-107 four-chamber rocket engine, for a total thrust of 323.6 tons (713,409 pounds) of thrust. The first stage burn time was 120 seconds.

The second stage (core) was powered by one RD-108 four-chamber engine, producing 93 tons (205,028 pounds) of thrust. Burn time for the second stage was 180 seconds.

Sputnik I launch, Site No. 1, Scientific-Research Test Range No. 5, Tyuratam, Kazakh S.S.R., 19:28:34 4 October 1957 UTC (5 October, Tyuratam). (RKK Energiya/Solaris ID 38466)

Sputnik 1 launched at 22:28:34 Moscow time. After 116.38 seconds, the stages separated. The second stage and satellite entered orbit 295.4 seconds after liftoff at an altitude of 228.6 kilometers (142.05 miles) and velocity of 7,780 meters per second (17,403.36 miles per hour). The satellite separated from the second stage 5 minutes, 14.5 seconds after launch.

The second stage reentered the atmosphere 2 December 1957.

© 2019, Bryan R. Swopes

4 October 1957

Космодром Байконур, 4 октября 1957 года.
Космодром Байконур, 4 октября 1957 года. (“Baikonur Cosmodrome, 4 October 1957.”)

4 October 1957: At 19:28:34 UTC, the world’s first artificial satellite, Простейший Спутник-1 (Sputnik 1, or Elementary Satellite 1) was launched from Tyuratam, Kazakh S.S.R. (now, the Baikonur Cosmodrome) aboard a two-stage Sputnik 8K71PS rocket, a variant of the R-7 Semyorka intercontinental ballistic missile. The satellite entered an elliptical orbit, circling Earth every 96.2 minutes.

Sputnik I launch, Site No. 1, Scientific-Research Test Range No. 5, Tyuratam, Kazakh S.S.R., 19:28:34 4 October 1957 UTC (5 October, Tyuratam). (RKK Energiya/Solaris ID 38466)
Запуск спутника. (The launch.)
Запуск спутника. (“The launch.”)

Sputnik 1 launched at 22:28:34 Moscow time. After 116.38 seconds, the first and second stages separated. The second stage and satellite entered orbit 295.4 seconds after liftoff at an altitude of 228.6 kilometers (142.05 miles) and velocity of 7,780 meters per second (17,403.36 miles per hour). The satellite separated from the second stage 5 minutes, 14.5 seconds after launch.

The second stage reentered the atmosphere 2 December 1957. Sputnik made 1,440 orbits before it reentered the atmosphere, 4 January 1958.

An unidentified engineer with Sputnik 1.

The satellite was designed at OKB-1 (the Special Design Bureau) by a team of Mikhail Stepanovich Khomyakov, Maksim Khramov and Oleg Genrikhovich Ivanovsky. It was constructed as a sphere with a diameter of 58.0 centimeters (22.84 inches), made from an aluminum alloy with a thickness of 2 millimeters (0.08 inch). The two halves were joined by 36 bolts and filled with pressurized nitrogen. Four “whip” antennas were equally spaced around the satellite’s shell, angled at 35° from the longitudinal axis. With three silver-zinc batteries and equipment, the Sputnik 1 mass was 83.6 kilograms (184.3 pounds).

The satellite entered an elliptical orbit, with a perigee of 215.0 kilometers (133.6 miles) and apogee of 939.0 kilometers (583.5 miles). The duration of each orbit was 1 hour, 36 minutes, 12 seconds.

Cutaway illustration of the Sputnik I 8K71PS launch vehicle. (RKK Energia via Drew Ex Machina)

The Sputnik 8K71PS launch vehicle, serial number 1 M1-PS, was a two-stage, liquid-fueled rocket based on the R-7 Semyorka intercontinental ballistic missile. The R-7 rocket was designed by Sergei Pavlovich Korolev, known as The Chief Designer. It had a length of 29.167 meters (95.69 feet) and maximum diameter of 10.3 meters (33.79 feet) at the base, including stabilizers. Its mass was 267.13 tons (588,921 pounds) at liftoff. The propellant was Kerosene T-1 with liquid oxygen.

The first stage consisted of four “strap-on” boosters surrounding the second, or “core” stage, each with an RD-107 four-chamber rocket engine, for a total thrust of 323.6 tons (713,409 pounds) of thrust. The first stage burn time was 120 seconds.

The second stage (core) was powered by one RD-108 four-chamber engine, producing 93 tons (205,028 pounds) of thrust. Burn time for the second stage was 180 seconds.

The Chief Designer, Sergei Pavlovich Korolev, (1907–1966)
The Chief Designer, Sergei Pavlovich Korolev (1907–1966)

© 2019, Bryan R. Swopes

10 July 1962

Telstar 1 launches aboard a Thor Delta rocket at Launch Complex 17B, 0835 GMT, 10 July 1962. (NASA)
Telstar 1 launches aboard a Delta rocket at Launch Complex 17B, 0835 GMT, 10 July 1962. (NASA)

10 July 1962: At 0835 GMT (4:35 a.m., EDT) the first communications relay satellite, Telstar 1, was launched into Earth orbit from Launch Complex 17B, Cape Canaveral Air Force Station, Florida. The launch vehicle was a three-stage liquid-fueled Delta rocket.

This was the first commercial space flight, sponsored by a consortium of communications companies and government organizations, including AT&T, Bell Labs, the BBC, NASA, and British and French postal services. The satellite was used to relay live television broadcasts across the Atlantic Ocean. This had never previously been possible.

Telstar weighed 171 pounds (77.5 kilograms). Its weight and size were restricted by the availability of launch vehicles. The satellite was placed in an elliptical orbit, varying from 591 miles (952 kilometers) to 3,686 miles (5,933 kilometers), and inclined at about a 45° angle to Earth’s Equator. The orbital period was 2 hours, 37 minutes. The properties of Telstar’s orbit restricted its use to about 20 minutes during each pass.

In addition to its primary role as a communications relay satellite, Telstar also performed scientific experiments to study the Van Allen Belt.

The Delta was a three-stage expendable launch vehicle which was developed from the Douglas Aircraft Company’s SM-75 Thor intermediate-range ballistic missile.

Designated Thor DM-19, the first stage was 60.43 feet (18.42 meters) long and 8 feet (2.44 meters) in diameter. Fully fueled, the first stage had a gross weight of 108,770 pounds (49,337 kilograms). It was powered by a Rocketdyne LR-79-7 engine which burned liquid oxygen and RP-1 (a highly-refined kerosene rocket fuel) and produced 170,565 pounds of thrust (758.711 kilonewtons). This stage had a burn time of 2 minutes, 45 seconds.

The second stage was an Aerojet General Corporation-built Delta 104. It was 19 feet, 3 inches (5.88 meters) long with a maximum diameter of 4 feet, 6 inches (1.40 meters). The second stage had a gross weight of 9,859 pounds (4,472 kilograms). It used an Aerojet AJ10-104 rocket engine which burned a hypergolic  mixture of nitric acid and UDMH. The second stage produced 7,890 pounds of thrust (35.096 kilonewtons) and burned for 4 minutes, 38 seconds.

The third stage was an Allegany Ballistics Laboratory Altair 1. It was 6 feet long, 1 foot, 6 inches in diameter and had a gross weight of 524 pounds (238 kilograms). This stage used a solid-fuel Thiokol X-248 rocket engine, producing 2,799 pounds of thrust (12.451 kilonewtons). Its burn time was 4 minutes, 16 seconds.

The three stages of the Delta rocket accelerated the Telstar satellite to 14,688 miles per hour for orbital insertion.

The day prior to launch, the United States detonated a 1.45 megaton thermonuclear warhead at an altitude of 248 miles (400 kilometers), near Johnston Island in the Pacific Ocean. (Operation Dominic-Fishbowl Starfish Prime). Between 21 October 1961 and 1 November 1962, the Soviet Union detonated five nuclear warheads in space (Project K), at altitudes ranging from 59 to 300 kilometers (37–186 miles) over a test range in Khazakhstan. High energy electrons from these tests were trapped in the Earth’s radiation belts. This damaged the satellite’s circuitry and it went out of service in December 1962. ¹

Engineers were able to work around the damage and restore service by January 1963, but Telstar 1 failed permanently 21 February 1963.

Telstar is still in Earth orbit.

Telstar 1 communications relay satellite. (Bell Laboratories)

¹ Thanks to regular TDiA reader Steve Johnson for this information.

© 2019, Bryan R. Swopes