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词条 Telstar
释义

  1. Description

  2. In service

  3. Newer Telstars

  4. Satellites

  5. See also

  6. References

  7. External links

{{Use mdy dates|date=June 2018}}{{Other uses|Telstar (disambiguation)}}{{Infobox spacecraft class
| image = File:Telstar satellite-CnAM 35181-IMG 5408-gradient.jpg
| caption = Model of a Telstar satellite, on display at Conservatoire national des arts et métiers
| name = Telstar
| manufacturer = Hughes, EADS Astrium, Space Systems/Loral, Airbus Defense and Space
| country = United States
| bus = HS-376, AS-7000, Eurostar-2000, Spacebus-4000B3, SSL-1300
| applications = Communications
| orbits = Medium Earth / Geostationary
| operator = AT&T
| lifetime =
| derivedfrom =
| derivatives =
| Preceded =
| Succeeded =
| status = In service
| built =
| orders =
| launched = 21
| operational =
| retired =
| failed =
| lost =
}}Telstar is the name of various communications satellites. The first two Telstar satellites were experimental and nearly identical. Telstar 1 launched on top of a Thor-Delta rocket on July 10, 1962. It successfully relayed through space the first television pictures, telephone calls, and telegraph images, and provided the first live transatlantic television feed. Telstar 2 launched May 7, 1963. Telstar 1 and 2—though no longer functional—still orbit the Earth.[1]

Description

{{refimprove|section|date=July 2017}}{{External media |width=210px |float=right |audio1=Felker Talking Telstar, 1962, Dr. Jean Felker's speech starts at 4:20, WNYC[2] }}

Belonging to AT&T, the original Telstar was part of a multi-national agreement among AT&T (USA), Bell Telephone Laboratories (USA), NASA (USA), GPO (United Kingdom) and the National PTT (France) to develop experimental satellite communications over the Atlantic Ocean. Bell Labs held a contract with NASA, paying the agency for each launch, independent of success.{{citation needed|date=July 2012}}

Six ground stations were built to communicate with Telstar. One each in the US, France, the UK, Canada, Germany and Italy. The American ground station—built by Bell Labs—was Andover Earth Station, in Andover, Maine. The main British ground station was at Goonhilly Downs in southwestern England. The BBC, as international coordinator, used this location. The standards 525/405 conversion equipment (filling a large room) was researched and developed by the BBC and located in the BBC Television Centre, London. The French ground station was at Pleumeur-Bodou ({{Coord|48|47|10|N|3|31|26|W}}) in north-western France. The Canadian ground station was at Charleston, Nova Scotia. The German ground station was at Raisting in Bavaria. The Italian ground station was at Fucino in Abruzzo

The satellite was built by a team at Bell Telephone Laboratories that included John Robinson Pierce, who created the project;[3] Rudy Kompfner, who invented the traveling-wave tube transponder that the satellite used;[3][4] and James M. Early, who designed its transistors and solar panels.[5] The satellite is roughly spherical, measures {{convert|34.5|in|mm|2}} in length, and weighs about {{convert|170|lb|kg}}. Its dimensions were limited by what would fit on one of NASA's Delta rockets. Telstar was spin-stabilized, and its outer surface was covered with solar cells capable of generating 14 watts of electrical power.

The original Telstar had a single innovative transponder that could relay data, a single television channel, or multiplexed telephone circuits. Since the spacecraft spun, it required an array of antennas around its "equator" for uninterrupted microwave communication with Earth. An omnidirectional array of small cavity antenna elements around the satellite's "equator" received 6 GHz microwave signals to relay back to ground stations. The transponder converted the frequency to 4 GHz, amplified the signals in a traveling-wave tube, and retransmitted them omnidirectionally via the adjacent array of larger box-shaped cavities. The prominent helical antenna received telecommands from a ground station.

Launched by NASA aboard a Delta rocket from Cape Canaveral on July 10, 1962, Telstar 1 was the first privately sponsored space launch. A medium-altitude satellite, Telstar was placed in an elliptical orbit completed once every 2 hours and 37 minutes, inclined at an angle of approximately 45 degrees to the equator, with perigee about {{convert|952|km}} from Earth and apogee about {{convert|5933|km}} from Earth[7] This is in contrast to the 1965 Early Bird Intelsat and subsequent satellites that travel in circular geostationary orbits.[6]

Due to its non-geosynchronous orbit, similar to a Molniya orbit, Telstar's availability for transatlantic signals was limited to the 20 minutes in each 2.5-hour orbit when the satellite passed over the Atlantic Ocean. Ground antennas had to track the satellite with a pointing error of less than 0.06 degrees as it moved across the sky at up to 1.5 degrees per second.{{citation needed|date=July 2012}}

Since the transmitters and receivers on Telstar were not powerful, ground antennas had to be huge. Bell Laboratory engineers designed a large horizontal conical horn antenna with a parabolic reflector at its mouth that re-directed the beam. This particular design had very low sidelobes, and thus made very low receiving system noise temperatures possible. The aperture of the antennas was {{convert|3600|sqft|m2}}. The antennas were {{convert|177|ft|m}} long and weighed {{convert|380|short ton|kg}}. Morimi Iwama and Jan Norton of Bell Laboratories were in charge of designing and building the electrical portions of the azimuth-elevation system that steered the antennas. The antennas were housed in radomes the size of a 14-story office building. Two of these antennas were used, one in Andover, Maine, and the other in France at Pleumeur-Bodou. The GPO antenna at Goonhilly Downs in Great Britain was a conventional 26-meter-diameter paraboloid.

In service

Telstar 1 relayed its first, and non-public, television pictures—a flag outside Andover Earth Station—to Pleumeur-Bodou on July 11, 1962.[7] Almost two weeks later, on July 23, at 3:00 p.m. EDT, it relayed the first publicly available live transatlantic television signal.[8] The broadcast was shown in Europe by Eurovision and in North America by NBC, CBS, ABC, and the CBC.[8] The first public broadcast featured CBS's Walter Cronkite and NBC's Chet Huntley in New York, and the BBC's Richard Dimbleby in Brussels.[8] The first pictures were the Statue of Liberty in New York and the Eiffel Tower in Paris.[8] The first broadcast was to have been remarks by President John F. Kennedy, but the signal was acquired before the president was ready, so engineers filled the lead-in time with a short segment of a televised game between the Philadelphia Phillies and the Chicago Cubs at Wrigley Field.[8][9] The batter, Tony Taylor, was seen hitting a ball pitched by Cal Koonce to the right fielder George Altman. From there, the video switched first to Washington, DC; then to Cape Canaveral, Florida; to the Seattle World's Fair; then to Quebec and finally to Stratford, Ontario.[8] The Washington segment included remarks by President Kennedy, talking about the price of the American dollar, which was causing concern in Europe. When Kennedy denied that the United States would devalue the dollar it immediately strengthened on world markets; Cronkite later said that "we all glimpsed something of the true power of the instrument we had wrought."[8][10]

That evening, Telstar 1 also relayed the first satellite telephone call, between U.S. vice-president Lyndon Johnson and the chairman of AT&T, Frederick Kappel. It successfully transmitted faxes, data, and both live and taped television, including the first live transmission of television across an ocean from Andover, Maine, US, to Goonhilly Downs, England, and Pleumeur-Bodou, France.[11]

{{Clarify|date=November 2009}} (An experimental passive satellite, Echo 1, had been used to reflect and redirect communications signals two years earlier, in 1960.) In August 1962, Telstar 1 became the first satellite used to synchronize time between two continents, bringing the United Kingdom and the United States to within 1 microsecond of each other (previous efforts were only accurate to 2,000 microseconds).[12]

Telstar 1, which had ushered in a new age of the commercial use of technology, became a victim of technology during the Cold War. The day before Telstar 1 launched, a U.S. high-altitude nuclear bomb (called Starfish Prime) had energized the Earth's Van Allen Belt where Telstar 1 went into orbit. This vast increase in a radiation belt, combined with subsequent high-altitude blasts, including a Soviet test in October, overwhelmed Telstar's fragile transistors.[13][14][15] It went out of service in November 1962, after handling over 400 telephone, telegraph, facsimile and television transmissions. It was restarted by a workaround in early January 1963.[16] The additional radiation associated with its return to full sunlight{{Clarify|date=November 2009}} once again caused a transistor failure, this time irreparably, and Telstar 1 went out of service on February 21, 1963.

Experiments continued, and by 1964, two Telstars, two Relay units (from RCA), and two Syncom units (from the Hughes Aircraft Company) had operated successfully in space. Syncom 2 was the first geosynchronous satellite and its successor, Syncom 3, broadcast pictures from the 1964 Summer Olympics in Tokyo. The first commercial geosynchronous satellite was Intelsat I ("Early Bird") launched in 1965.

Telstar was considered a technical success. According to a US. Information Agency (USIA) poll,{{when|date=February 2018}} Telstar was better known in Great Britain than Sputnik had been in 1957.[17]

Newer Telstars

Subsequent Telstar satellites were advanced commercial geosynchronous spacecraft that share only their name with Telstar 1 and 2.

The second wave of Telstar satellites launched with Telstar 301 in 1983, followed by Telstar 302 in 1984 (which was renamed Telstar 3C after it was carried into space by Shuttle mission STS-41-D),[18] and by Telstar 303 in 1985.

The next wave, starting with Telstar 401, came in 1993; which was lost in 1997 due to a magnetic storm, and then Telstar 402 was destroyed shortly after launch in 1994.[19] It was replaced in 1995 by Telstar 402R, eventually renamed Telstar 4.

Telstar 10 was launched in China in 1997 by APT Satellite Company, Ltd.

In 2003, Telstars 4–8 and 13—Loral Skynet's North American fleet—were sold to Intelsat. Telstar 4 suffered complete failure prior to the handover. The others were renamed the Intelsat Americas 5, 6, etc. At the time of the sale, Telstar 8 was still under construction by Space Systems/Loral, and it was finally launched on June 23, 2005, by Sea Launch.

Telstar 18 was launched in June 2004 by sea launch. The upper stage of the rocket underperformed, but the satellite used its significant stationkeeping fuel margin to achieve its operational geostationary orbit. It has enough on-board fuel remaining to allow it to exceed its specified 13-year design life.

Telesat launched Telstar 12 Vantage in November 2015 on a H2A204 variant of the H-IIA rocket,[20] and it commenced service in December 2015.[21]Telstar 18V was launched on 10 September 2018.[22]

Satellites

Name Manufacturer Launch date Launch vehicle Launch place Orbital position Bus Mass
Telstar 1 Bell Laboratories July 10, 1962 Delta-DM19 Cape Canaveral LC-17B {{n/a}} Telstar Bus77|kg|lb|abbr=on}}
Telstar 2 Bell Laboratories May 7, 1963 Delta B Cape Canaveral LC-17B {{n/a}} Telstar Bus79|kg|lb|abbr=on}}
Telstar 301 Hughes July 28, 1983 Delta-3920 PAM-D Cape Canaveral LC-17A 76° W HS-376625|kg|lb|abbr=on}}
Telstar 302 Hughes August 30, 1984 Discovery STS-41D Kennedy LC-39A 125° W HS-376625|kg|lb|abbr=on}}
Telstar 303 Hughes June 17, 1985 Discovery STS-51G Kennedy LC-39A 76° W HS-376630|kg|lb|abbr=on}}
Telstar 401 Lockheed Martin December 16, 1993 Atlas IIAS AC-108 Cape Canaveral LC-36B 97° W AS-70003375|kg|lb|abbr=on}}
Telstar 402 Lockheed Martin September 9, 1994 Ariane 42L Kourou ELA-2{{small>planned}} AS-70003485|kg|lb|abbr=on}}
Telstar 4 Lockheed Martin September 24, 1995 Ariane 42L Kourou ELA-2 89° W AS-70003410|kg|lb|abbr=on}}
Telstar 5 Space Systems/Loral May 24, 1997 Proton-K/Block-DM4 Baikonur 81/23 97° W SSL 13003600|kg|lb|abbr=on}}
Telstar 6 Space Systems/Loral February 15, 1999 Proton-K/Block-DM3 Baikonur 81/23 93° W SSL 13003763|kg|lb|abbr=on}}
Telstar 7 Space Systems/Loral September 25, 1999 Ariane 44LP Kourou ELA-2 127° W SSL 13003790|kg|lb|abbr=on}}
Telstar 8 Space Systems/Loral June 23, 2005 Zenit-3SL Sea Launch 89° W SSL 1300S5493|kg|lb|abbr=on}}
{{small>(not launched)}} Space Systems/Loral {{n/a}} {{n/a}} {{n/a}} {{n/a}} SSL 1300S5493|kg|lb}}
Telstar 10 Space Systems/Loral October 16, 1997 Long March 3B Xichang 3B 76,5° E SSL 13003700|kg|lb|abbr=on}}
Telstar 11 Matra Marconi Space November 29, 1994 Atlas IIA Cape Canaveral LC-36A 37,5° W Eurostar-20002361|kg|lb|abbr=on}}
Telstar 11N Space Systems/Loral February 26, 2009 Zenit-3SLB Baikonur 45/1 37,5° W SSL 13004012|kg|lb|abbr=on}}
Telstar 12 Space Systems/Loral October 19, 1999 Ariane 44LP Kourou ELA-2 15° W SSL 13003814|kg|lb|abbr=on}}
Telstar 12V EADS Astrium November 24, 2015 H-IIA-204 Tanegashima YLP-1 15° W Eurostar-30005000|kg|lb|abbr=on}}
Telstar 13 Space Systems/Loral August 8, 2003 Zenit-3SL Sea Launch 121° W SSL 13004737|kg|lb|abbr=on}}
Telstar 14 Space Systems/Loral January 11, 2004 Zenit-3SL Sea Launch 63° W SSL 13004694|kg|lb|abbr=on}}
Telstar 14R Space Systems/Loral May 20, 2011 Proton-M/Briz-M Baikonur 200/39 63° W SSL 13005000|kg|lb|abbr=on}}
Telstar 18 Space Systems/Loral January 29, 2004 Zenit-3SL Sea Launch 138° E SSL 13004640|kg|lb|abbr=on}}
Telstar 18V Space Systems/Loral September 10, 2018 Falcon 9 B5 Cape Canaveral SLC-40 138° E SSL 13007060|kg|lb|abbr=on}}
Telstar 19V Space Systems/Loral July 22, 2018 Falcon 9 B5 Cape Canaveral SLC-40 63° W SSL 13007076|kg|lb|abbr=on}}

See also

  • Telstar (instrumental)
  • List of communications satellite firsts

References

1. ^{{cite web |url=https://usspaceobjectsregistry.state.gov/Lists/SpaceObjects/DispForm.aspx?ID=90 |title=1962-ALPHA EPSILON 1 |date=2013-06-19 |work=US Space Objects Registry |accessdate=2013-10-02 |deadurl=bot: unknown |archiveurl=https://web.archive.org/web/20131005021146/https://usspaceobjectsregistry.state.gov/Lists/SpaceObjects/DispForm.aspx?ID=90 |archivedate=2013-10-05 |df= }}
2. ^{{cite web |title=Felker Talking Telstar |publisher=WNYC |url=http://www.wnyc.org/story/felker-talking-telstar/ |access-date=2016-10-31}}
3. ^1 {{cite book | title = Something New Under the Sun: Satellites and the Beginning of the Space Age | first= Helen |last=Gavaghan | url = https://books.google.com/books?id=z3bN76jIBjkC&pg=PA180 | isbn = 0-387-94914-3 | publisher = Springer | year = 1998}}
4. ^{{cite book | title = Microwave Tube Transmitters | first= Leo |last=Sivan | isbn = 0-412-57950-2 | publisher = Springer | year = 1994 | url = https://books.google.com/books?id=o2o1R7I8rvEC&pg=PA3 }}
5. ^{{cite web | title = James Early, engineer, 81; Helped Create A Transistor | work = Obituaries | publisher = The New York Times | first= John|last= Markoff | date=2004-01-19 | url = https://query.nytimes.com/gst/fullpage.html?res=9F0DE0D71739F93AA25752C0A9629C8B63}}
6. ^1 [https://books.google.co.uk/books?id=m9sGhgZbmd8C&pg=PA3 An Introduction to Satellite Communications], page 3, D. I. Dalgleish, 1989
7. ^{{cite web|title = IEEE History Center: First Transatlantic Transmission of a Television Signal via Satellite, 1962|work = IEEE History Center |year = 2002|url = http://www.ieee.org/web/aboutus/history_center/telstar_maine.html|accessdate=2009-07-23}}
8. ^1 2 3 4 5 6 {{cite web |author = Walter Cronkite | title = Telstar| publisher = NPR| url = https://www.youtube.com/watch?v=FgplIWibv4Q| accessdate=2009-07-23}}
9. ^{{cite web|url= http://www.baseball-almanac.com/box-scores/boxscore.php?boxid=196207230CHN |title=Philadelphia Phillies vs Chicago Cubs | work=Box Score |publisher= Baseball-Almanac.com |date=1962-07-23 |accessdate=2012-07-15}}
10. ^[https://www.youtube.com/watch?v=FgplIWibv4Q Telstar, Kennedy, and World Gold & Currency Markets], YouTube
11. ^{{cite video| year =1962| title =Video: A Day in History. Telstar Brings World Closer, 1962/07/12 (1962)| url =https://archive.org/details/1962-07-12_A_Day_in_History| publisher =Universal Newsreel| accessdate=2012-02-20}}
12. ^{{cite web|url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19660009169_1966009169.pdf| title=Significant Achievements in Space Communications and Navigation, 1958–1964| year=1966|work=NASA-SP-93|publisher=NASA|pages=30–32|accessdate=2009-10-31}}
13. ^{{cite web | url = http://roland.lerc.nasa.gov/~dglover/sat/telstar.html | title = TELSTAR | work = NASA Experimental Communications Satellites | first = Daniel R. | last = Glover | accessdate=2007-09-01 | date=2005-04-12 | deadurl = yes | archiveurl = https://web.archive.org/web/20070905171036/http://roland.lerc.nasa.gov/~dglover/sat/telstar.html | archivedate=2007-09-05 | df = }}
14. ^{{cite web| last=Early| first=James M.|title=Telstar I – Dawn of a New Age|url=http://www.smecc.org/james_early___telstar.htm| publisher=Southwest Museum of Engineering, Communications and Computation| accessdate=2012-07-11| year=1990}}
15. ^{{cite journal| last=Mayo| first=J.S. |title=The Command System Malfunction of the Telstar Satellite|journal=Bell System Technical Journal|date=July 1963|volume=42|pages=1631–1657|url=http://www.alcatel-lucent.com/bstj/vol42-1963/bstj-vol42-issue04.html |archiveurl=https://web.archive.org/web/20130810124948/http://www3.alcatel-lucent.com/bstj/vol42-1963/articles/bstj42-4-1631.pdf |deadurl=yes |archivedate=2013-08-10 |accessdate=2016-05-18 |doi=10.1002/j.1538-7305.1963.tb04044.x|display-authors=etal}}
16. ^{{cite book | title = Space Systems Failures: Disasters and Rescues of Satellites, Rocket and Space Probes | first1= Ralph D.|last1= Lorenz | first2=David Michael|last2= Harland | url = https://books.google.com/books?id=g-UOdh34utQC&pg=RA2-PA266&dq=telstar+transistors+radiation+starfish&ei=Cc3ZRsr6FIKmowKO3eySCw&ie=ISO-8859-1&sig=WUcdA_54_3BVeGJNPokAmRrhBYk | isbn = 0-387-21519-0 | year = 2005 | publisher = Springer}}
17. ^{{cite web |url=https://history.nasa.gov/SP-4217/ch6.htm |title=Chapter 6, NASA Experimental Communications Satellites, 1958–1995 |first=Daniel R. |last=Glover |publisher=NASA |access-date=2011-10-23}}
18. ^{{cite web|url=http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/archives/sts-41D.html |title=NASA – STS-41D |publisher=NASA |accessdate=2012-07-15}}
19. ^{{cite web| url= http://www.sat-nd.com/failures/index.html?http://www.sat-nd.com/failures/telstar402.html |title=SAT ND |publisher=SAT ND |accessdate=2012-07-15}}
20. ^{{cite press release |url=https://www.telesat.com/news-events/telesat-orders-high-throughput-satellite-replace-telstar-12-and-expand-capacity-15|title=Telesat orders high throughput satellite to replace Telstar 12 and expand capacity at 15 Degrees west|publisher=Telesat |date=2015-11-24 |access-date=2017-09-04}}
21. ^{{cite press release |title=Telesat's new Telstar 12 VANTAGE satellite now operational three weeks after launch |url=https://www.telesat.com/sites/default/files/news/t12v_operational_-_dec15_final_2.pdf |publisher=Telesat |date=2015-12-15 |access-date=2017-09-04}}
22. ^{{cite web |url=http://www.launchphotography.com/Delta_4_Atlas_5_Falcon_9_Launch_Viewing.html |title=Rocket Launch Viewing Guide for Cape Canaveral |website=Launchphotography.com |first=Ben |last=Cooper |date=2018-08-22 |access-date=2018-08-24}}

}}

External links

  • [https://www.npr.org/ramfiles/atc/20020723.atc.15.ram Walter Cronkite on the first broadcast using Telstar] from the July 23, 2002, episode of All Things Considered
  • May 1962 National Geographic magazine article on Telstar from porticus.org
  • {{YouTube|id=9vdf_Y-zFcM|title=Telstar 1: First Private Communication Satellite – 1963 Educational Documentary}}
  • Stamps and envelopes related to Telstar I from the National Postal Museum
  • Real-Time tracking of Telstar 1 from n2yo.com
  • [https://web.archive.org/web/20140319095654/https://i-m.ch/satellite-services/satellite-coverage/telstar-11n-at-37-6w/ Official provider's page] for Telstar 11N from IMS

3 : Spacecraft launched in 1962|Communications satellites|Telstar satellites
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