Tag Archives: Elliptical Orbit

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 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. It 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). Radiation from this test, combined with residual radiation from the Soviet Union’s  57 megaton detonation over Novaya Zemlya Archipelago (RDS-220, known as “Big Ivan,” or “Tsar Bomba”) on 21 October 1961, damaged the satellite’s circuitry and it went out of service in December 1962.

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)

© 2016, Bryan R. Swopes

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19 November 1999, 22:30 UTC

An unidentified Shenzhou/Long March 2F launch from the Jiuquan Sateliite Launch Area. (CNSA)
An unidentified Shenzhou/Long March 2F launch from the Jiuquan Satellite Launch Area. (CNSA)

19 November 1999, 22:30 UTC: The China National Space Administration ( 国家航天局 ) launched 神舟一號 (Shenzhou 1), an unmanned Project 921-1 spacecraft, from the Jiuquan Satellite Launch Area aboard a 长征二号F火箭, (Changzheng or “Divine Arrow”) two-stage rocket. Shenzhou 1 was placed into a Low Earth Orbit ranging from 195 kilometers (121 miles) to 315 kilometers (196 miles).

The vehicle completed 14 orbits. It successfully deorbited and reentered Earth’s atmosphere. The Shenzhou reentry module landed in Inner Mongolia, 20 November at 19:41 UTC. The duration of the flight was 21 hours, 11 minutes.

The Shenzhou 1 spacecraft was not fully operational and it differed in several ways from the manned space vehicles that followed. The primary purpose of this flight was a test of the man-rated Long March 2F rocket.

The Shenzhou spacecraft is similar to the Russian Federation’s Soyuz from which it was developed, although it is larger. Shenzhou vehicles are 9.25 meters (30 feet, 4.2 inches) long and 2.80 meters (9 feet, 2.2 inches) in diameter. The spacecraft has a mass of 7,840 kilograms (17,284 pounds). There are three modules: the orbital module, reentry module and service module. The vehicle is designed for three people for flights of up to 20 days duration.

The Changzheng is known as the Long March 2F in the West. It is a two-stage liquid-fueled rocket with external boosters.

The first stage is 23.7 meters (77 feet, 9.6 inches) long with a diameter of 3.35 meters (10 feet, 11.9 inches). It is powered by four YF-20B engines (clustered as a YF-21B unit) which use hypergolic fuels. The four “strap-on” boosters use the same engines. The boosters are 15.6 meters (51 feet, 2.2 inches) long and 2.25 meters (7 feet, 4.6 inches) in diameter. With all eight engines running, the total rated thrust is 1,331,140 pounds (5,921.206 kilonewtons) at Sea Level. The boosters’ burn time is 2 minutes, 8 seconds, while the primary engines burn for 38 seconds longer.

The second stage is 15.52 meters (50 feet, 11 inches) long and the same diameter as the first stage. It uses one YF-24B unit, consisting of one YF-22B and four YF-23B engines. The second stage uses the same hypergolic fuel as the first stage. This stage is rated at 177,240 pounds of thrust (788,403 kilonewtons) at Sea Level and burns for 5 minutes. The Long March 2F is capable of lifting a 8,400 kilograms (18,519 pounds) payload into Low Earth Orbit.

JIUQUAN SLC, INNER MONGOLIA, CHINA-DECEMBER 18, 2012: This December 18, 2012, image provides an overview of JSLC’s South Launch Complex just 11 hours prior to the launch of the G?kt?rk 2, a remote sensing satellite for the Turkish government. In addition to the vertical assembly building, the SLS-1 (921) launch pad and the SLS-2 (603) launch pad, various other support buildings are visible. (Photo DigitalGlobe via Getty Images)
Satellite image of the Jiuquan Satellite Launch Area, Inner Mongolia, 18 December 2012. The vertical assembly building is in the lower half of the photograph, with two launch pads in the upper half.  (Bloomberg/DigitalGlobe via Getty Images)

© 2016, Bryan R. Swopes

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