SCORE (satellite)
| SCORE | |
|---|---|
| Type: | Communications satellite |
| Country: |
 United States
|
| Operator: | US Army |
| COSPAR-ID : | 1958-006A |
| Mission dates | |
| Dimensions: | 68 kg (payload), 3970 kg (total with rocket stage) |
| Begin: | December 18, 1958, 23:02 UTC |
| Starting place: | Cape Canaveral , LC-11 |
| Launcher: | Atlas-B 10B |
| Flight duration: | 1 month |
| Status: | out of order from December 30, 1958, burned up on January 21, 1959 |
| Orbit data | |
| Rotation time : | 101.5 min |
| Orbit inclination : | 32.3 ° |
| Apogee height : | 1484 km |
| Perigee height : | 185 km |
SCORE ( Signal Communications by Orbiting Relay Equipment , also Project SCORE ) was the first communications satellite . After starting with a modified Atlas B - intercontinental ballistic missile on 18 December 1958, led the US Army by SCORE transmission experiments. SCORE caused a sensation by broadcasting the Christmas message from American President Dwight D. Eisenhower, which was recorded on a satellite tape recorder before the launch .
construction
In contrast to most other satellites, the SCORE satellite was not a separate, detachable missile, but was completely integrated into the launcher. The missile itself was largely unchanged from the Atlas ICBM test program. Only the re-entry body was replaced with a simple aerodynamic fairing.
The payload was commissioned by the ARPA of the military communications research engineer Kenneth Masterman-Smith in collaboration with a team from the United States Army Signal Research and Development Laboratory (SRDL) led by Hans Ziegler in Fort Monmouth ( New Jersey developed in just six months), and built.
The 68 kg SCORE payload consisted of two redundant systems, each consisting of a receiver, a transmitter and a miniature tape recorder. This communication device could be operated both in store dump mode, in which a sent message was first recorded on tape and later sent again on a command from the ground station, and in direct mode, where the received message was simultaneously re-transmitted by the transmitter . Two transmitting and two receiving antennas attached to the missile were used for signal transmission.
Silver-oxide-zinc batteries with an output of 56 watts, which should be sufficient for the expected 21-day service life of the satellite, served as power supply . The total mass of the SCORE satellite, including the connected Atlas rocket, was 3970 kg, making it the heaviest man-made object of US origin in Earth orbit to date.
mission
The Atlas-B rocket with serial number 10B was launched on December 18, 1958 from Cape Canaveral Air Force Station from launch pad LC-11 . During the ascent, the booster section with two of three main engines was dropped. The remaining engine accelerated the ascending Atlas rocket with the built-in payload until the rocket entered an orbit of 185 km × 1484 km with an orbit inclination of 32.3 °. The satellite launch had been prepared in complete secrecy and a large part of the personnel involved was not informed that the launch was not a test of an ICBM, but a satellite launch. The President's Christmas message was only recorded by the radio system shortly before the start and replaced another text.
During the first flight over the ground station, the primary communication device did not respond to the commands of the ground station, but the secondary device could be activated a little later. All communication tests were performed on the secondary system.
On December 19, 1958, SCORE broadcast the first recording of a human voice from space. The address given by American President Dwight D. Eisenhower read:
- "This is the President of the United States speaking. Through the marvels of scientific advance, my voice is coming to you from a satellite circling in outer space. My message is a simple one: Through this unique means I convey to you and to all mankind, America's wish for peace on Earth and goodwill toward men everywhere. "
- “This is the President of the United States speaking. Through the wonders of scientific advancement, you will hear my voice from a satellite orbiting in space. I have a simple message: By this unique means, I bring you and all humanity America's desire for peace on earth and benevolence towards all human beings. "
In the days that followed, both voice and teletype messages were sent to the satellite, stored, and later broadcast. There were also some live broadcasts. After twelve days in orbit, power failed on December 30, 1958. By then, about eight hours of transmission time had been achieved.
On January 21, 1959, SCORE burned up in the earth's atmosphere.
literature
- Deane Davis: The Talking Satellite: A reminescence of project SCORE , JBIS Vol. 52 No. 7/8, Jul / Aug 99
Web links
- Gunter Dirk Krebs: SCORE. July 6, 2008, accessed July 8, 2008 .
- Donald Martin, Paul Anderson, Lucy Bartamian: The History of Satellites - Chapter 1: Experimental Satellites. February 23, 2013, accessed February 23, 2013 .
- US Army Communications and Electronics Command, Fort Monmouth: PROJECT SCORE ( Memento August 4, 2008 in the Internet Archive ) (English)
Individual evidence
- ↑ Score in the Encyclopedia Astronautica , accessed on August 3, 2012 (English).
- ↑ Steven J. Dick, Steve Garber: A Chronology Of Defining Events In NASA History, 1958-1998. NASA, February 8, 2005, accessed July 8, 2008 .