SUMMARY / RELATED TOPICS

Syncom

Syncom started as a 1961 NASA program for active geosynchronous communication satellites, all of which were developed and manufactured by Hughes Space and Communications. Syncom 2, launched in 1963, was the world's first geosynchronous communications satellite. Syncom 3, launched in 1964, was the world's first geostationary satellite. In the 1980s, the series was continued as Syncom IV with some much larger satellites manufactured by Hughes, they were leased to the United States military under the Leasat program. The three early Syncom satellites were experimental spacecraft built by Hughes Aircraft Company's facility in Culver City, California, by a team led by Harold Rosen, Don Williams, Thomas Hudspeth. All three satellites were cylindrical in shape, with a diameter of about 71 centimeters and a height of about 39 centimeters. Pre-launch fueled masses were 68 kilograms, orbital masses were 39 kilograms with a 25-kilogram payload, they were capable of emitting signals on two transponders at just 2 W. Thus, Syncom satellites were only capable of carrying a single two-way telephone conversation, or 16 Teletype connections.

As of 25 June 2009, all three satellites are still although no longer functioning. Syncom 1 was intended to be the first geosynchronous communications satellite, it was launched on February 14, 1963 with the Delta B #16 launch vehicle from Cape Canaveral, but was lost on the way to geosynchronous orbit due to an electronics failure. Seconds after the apogee kick motor for circularizing the orbit was fired, the spacecraft fell silent. Telescopic observations verified the satellite was in an orbit with a period of 24 hours at a 33° inclination. Syncom 2 was launched by NASA on July 26, 1963 with the Delta B #20 launch vehicle from Cape Canaveral; the satellite kept station at the altitude calculated by Herman Potočnik Noordung in the 1920s. During the first year of Syncom 2 operations, NASA conducted voice and facsimile tests, as well as 110 public demonstrations to show the capabilities of this satellite and invite feedback. In August 1963, President John F. Kennedy in Washington, D. C. telephoned Nigerian Prime Minister Abubakar Tafawa Balewa aboard USNS Kingsport docked in Lagos Harbor—the first live two-way call between heads of government by satellite.

The Kingsport acted as a control uplink station. Syncom 2 relayed a number of test television transmissions from Fort Dix, New Jersey to a ground station in Andover, beginning on September 29, 1963. Although it was low-quality video with no audio, it was the first successful television transmission through a geosynchronous satellite. Syncom 3 was the first geostationary communication satellite, launched on August 19, 1964 with the Delta D #25 launch vehicle from Cape Canaveral; the satellite, in orbit near the International Date Line, had the addition of a wideband channel for television and was used to telecast the 1964 Summer Olympics in Tokyo to the United States. Although Syncom 3 is sometimes credited with the first television program to cross the Pacific Ocean, the Relay 1 satellite first broadcast television from the United States to Japan on November 22, 1963. By the end of 1964, Syncoms 2 and 3 had completed NASA's R&D experiments. On January 1, 1965, NASA transferred operation of the satellites to the United States Department of Defense along with telemetry, command stations, range and rangefinding equipment.

DOD had, in fact, provided the communications ground stations used to relay transmissions via the two Syncoms since their launch. DOD agreed to provide telemetry and ranging data of continuing scientific and engineering interest. In 1965, Syncom 3 was implemented to support the DOD's communications in Vietnam. Turned off in 1969, Syncom 3 remains in geosynchronous orbit as of December 2012. In 40 years it has drifted 8 degrees to the west, to longitude 172; the five satellites of the 1980s Leasat program were alternatively named Syncom IV-1 to Syncom IV-5 and called HS 381 by the manufacturer. These satellites were larger than Syncoms 1 to 3, weighing 1.3 tonnes each. At 4.26 meters, the satellites were the first to be designed for launch from the Space Shuttle payload bay, were deployed like a Frisbee. The satellites are 30 rpm spin-stabilized with a despun communications and antenna section, they were made with a solid rocket motor for initial perigee burn and hydrazine propellant for station keeping and spin stabilization.

The communications systems offers a wideband UHF channel, six relay 25 kHz channels, five narrowband 5 kHz channels. This is in addition to the fleet broadcast frequency, in the military's X-band; the system was used by military customers in the US and in Australia. Most of the satellites were retired in the 1990s, but one would remain operational until 2015. During the First Gulf War, Leasat would be used for personal communications between Secretary of State James Baker and President George H. W. Bush, but was more used by "mobile air, surface and fixed earth stations of the Navy, Marine Corps, Air Force, Army."Hughes was contracted to provide a worldwide communications system based on four satellites, one over the continental United States, one each over the Atlantic and Indian oceans, spaced about 90 degrees apart. Five satellites were ordered, with one as a replacement. Part of the contract were the associated control systems and ground stations; the lease contracts were for 5-year terms, with the lessee having the opportunity to extend the lease or to purchase the equipment outright.

The

Phospholipase

A phospholipase is an enzyme that hydrolyzes phospholipids into fatty acids and other lipophilic substances. There are four major classes, termed A, B, C and D, which are distinguished by the type of reaction which they catalyze: Phospholipase A Phospholipase A1 – cleaves the SN-1 acyl chain. Phospholipase A2 – cleaves the SN-2 acyl chain, releasing arachidonic acid. Phospholipase B – cleaves both SN-1 and SN-2 acyl chains. Phospholipase C – cleaves before the phosphate, releasing diacylglycerol and a phosphate-containing head group. Phospholipase Cs play a central role in signal transduction, releasing the second messenger inositol triphosphate. Phospholipase D – cleaves after the phosphate, releasing phosphatidic acid and an alcohol. Types C and D are considered phosphodiesterases. Endothelial lipase is a phospholipase. Phospholipase A2 acts on the intact lecithin molecule and hydrolyses the fatty acid esterified to the second carbon atom; the resulting products are a fatty acid. Phospholipase A2 is an enzyme present in the venom of bees and viper snakes.

Patatin-like phospholipase Infantile neuroaxonal dystrophy Tappia, Paramjit S. & Dhalla, Naranjan S.: Phospholipases in Health and Disease. Springer, 2014. ISBN 978-1-4939-0463-1.

Anita Snellman

Sini Anita Kyllikki Snellman was a Finnish painter. Snellman was born in Helsinki on September 4, 1924, she studied at the Royal Academy of Arts in Helsinki, the Royal Swedish Academy of Fine Arts in Stockholm and at Académie Julian in Paris. After spending time in Paris, she moved to Ibiza. Snellman taught at the Academy of Fine Arts, Helsinki from 1971 to 1979, she received the Pro Finlandia in 1976. In 1979 she established the Anita Snellman Foundation. Snellman died on February 2006 in Helsinki, she is buried in the Hietaniemi Cemetery in Helsinki. Snellman's work is held in the following public collections in Finland: Ateneum Art Museum Amos Anderson Art Museum Lahti Museum Tampere Museum for Contemporary Art Oulu Museum of Art Joensuu Art Museum Imatra Art Museum Helsinki Art Museum Kuopio Art Museum Wihuri Foundation collection Ahtola-Moorhouse, Leena: Anita Snellman 1924–2006. Helsinki: Anita Snellmanin säätiö, 2014. ISBN 978-952-93-3719-4. Images of Anita Snellman's paintings on Bukowskis Fine Art site