18 December 1958

Project SCORE, the world’s first communications satellite, is launched.

SCORE
Atlas-B with Score payload.jpg
The Atlas-B with SCORE on the launch pad; the rocket (without booster engines) constituted the satellite.
Mission typeCommunications
OperatorU.S. Army / ARPA
Harvard designation1958 Zeta 1
COSPAR ID1958-006A
SATCAT no.00010
Mission duration12 days
Spacecraft properties
ManufacturerU.S. Army / ARPA
Launch mass3980 kg [1]
PowerBatteries
Start of mission
Launch date18 December 1958
23:02:00 GMT
RocketAtlas-B 10B
Launch siteCape Canaveral, LC-11
End of mission
Last contact30 December 1958
Decay date21 January 1959
Orbital parameters
Reference systemGeocentric [2]
RegimeLow Earth
Perigee altitude185 km
Apogee altitude1484 km
Inclination32.3°
Period101.4 minutes
Epoch18 December 1958
Instruments
Signal Communication by Orbiting Relay Equipment
 
The message recorded of Eisenhower.

SCORE (Signal Communications by Orbiting RElay) was the world's first purpose-built communications satellite. Launched aboard an American Atlas rocket on December 18, 1958, SCORE provided the second test of a communications relay system in space (the first having been provided by the USAF/NASA's Pioneer 1,[3] the first broadcast of a human voice from space, and the first successful use of the Atlas as a launch vehicle. It captured world attention by broadcasting a Christmas message via shortwave radio from U.S. President Dwight D. Eisenhower through an on-board tape recorder.[4] The satellite was popularly dubbed "The Talking Atlas". SCORE, as a geopolitical strategy, placed the United States at an even technological par with the Soviet Union as a highly functional response to the Sputnik 1 and Sputnik 2 satellites.

Background

The six-month effort was the first endeavor of the then-new Advanced Research Projects Agency (ARPA) headed by Roy Johnson, and proved that a small, highly focused and versatile research group with appropriate resources was an ideal method to achieve the scientific and technological advances necessary to succeed in the emerging global space race.[5]

SCORE's technical objectives were two-fold. In addition to showing that an Atlas missile was capable of satellite payload launch, the payload itself was a hundred times more massive than any previous US satellite. The program demonstrated the feasibility of transmitting messages through the upper atmosphere from one ground station to one or more ground stations. The result of the program, which used both real-time and store and forward techniques, was a major scientific breakthrough which proved that active communications satellites could provide a means of transmitting messages from one point to any other on Earth.[6]

Spacecraft

The SCORE (Signal Communication by Orbiting RElay) satellite of US ARMY was an 24.3 metres (80 ft) of long, and 3.1 metres (10 ft) of diameter Atlas missile used as a platform for the communications relay experiment. The spacecraft body served as antennae. This satellite was to demonstrate the feasibility and explore problems associated with, operation of a satellite communication system. It carried messages on a tape recorder which was used at one point to carry a Christmas greeting from President Eisenhower. The performance was nominal with experiment operation for 12 days, planned orbit lifetime 20 days, actual orbit lifetime 34 days. The tracking beacon operated at 108 MHz.[1]

The SCORE communications package was designed and built by Kenneth Masterman-Smith, a military communication research engineer, along with other personnel with the U.S. Army Signal Research and Development Laboratory (SRDL) at Fort Monmouth, New Jersey.[7] The overall program was conducted in such secrecy that only 88 people were aware of its existence. Before the date of the SCORE launch, 53 of the 88 people had been told the program had been canceled and they were not to mention to anyone that it had ever existed. That left only 35 people who knew of the mission of Atlas 10B with the rest of the engineering crew, including the launch crew, under the impression that they were working solely on a test launch of the rocket.[8]:236 The night before launch, however, Rear Adm. John E. Clark, deputy director of ARPA, was asked at a news conference whether he could deny that Eisenhower's voice was on the recorder. He replied, "No", and news reports that day suggested the voice might well be the president's.[9]

Signal Communication by Orbiting Relay Equipment

This first communications satellite experiment consisted of 2 identical communications repeater terminals mounted in the guidance pods along the sides of the launch vehicle. The experiment was to test the feasibility and explore problems associated with, using satellites for communications purposes. No modulation was received on the carrier wave from experiment package no. 1. Voice and teletype messages were sent and returned in real-time, and also from experiment tape recorder no. 2. The tape recorder was loaded with new material 28 times and failure finally was due to battery depletion. The experiment receiver and transmitter operated at 150 to 132 MHz, respectively.[10]

Mission

The payload weighed 68 kilograms (150 lb), and was built into the fairing pods of the Atlas missile. Combined weight of the total on-orbit package was 3,980 kilograms (8,770 lb). SCORE was launched into an orbit with a perigee of 185 kilometres (115 mi), an apogee of 1,484 kilometres (922 mi) from LC-11 at Cape Canaveral Missile Test Annex, Florida, inclined at 32.3°, with a period of 101.4 minutes.[2] Its batteries lasted 12 days and it reentered the atmosphere on 21 January 1959.[11]

The communications repeater installed on the missile would receive a signal, amplify it, and then retransmit it. Two redundant sets of equipment were mounted in the nose of the SCORE missile. Four antennas were mounted flush with the missile surface, two for transmission and two for reception. SCORE's other equipment included two tape recorders, each with a four-minute capacity. Any of four ground stations in the southern United States could command the satellite into playback mode to transmit the stored message or into record mode to receive and store a new message. These redundancies proved invaluable as one of the tape recorders malfunctioned and was rendered inoperable during the 12-day mission.[4]

According to an official history of the Advanced Research Projects Agency (ARPA),[12] SCORE was originally programmed to broadcast a voice message from Army Secretary Wilber M. Brucker. When the President learned this fact, hours before lift-off, he said he would like to provide the message. His tape-recording was hand-carried to Cape Canaveral, but by then the payload was locked and ready for launch. The ARPA program director decided to launch with the Army message, then erase it while in space, and upload the President's message to replace it. This effort was successful, and accordingly SCORE's transmitted message from space to Earth was as follows:

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.[4]

The broadcast signal for Eisenhower's greeting was fairly weak, and only very sensitive radio receivers were able to detect it. Most Americans heard the message as it was rebroadcast on commercial news programs.[8]:243

See also

References

  1. ^ a b "SCORE: Display 1958-006A". nssdc.gsfc.nasa.gov. NASA. 27 February 2020. Retrieved 30 April 2020. This article incorporates text from this source, which is in the public domain.
  2. ^ a b "SCORE: Trajectory 1958-006A". nssdc.gsfc.nasa.gov. NASA. 27 February 2020. Retrieved 30 April 2020. This article incorporates text from this source, which is in the public domain.
  3. ^ Marcus, Gideon. "Pioneering Space II" (PDF). Quest Space Quarterly.)
  4. ^ a b c "SCORE (Signal Communications by Orbiting Relay Equipment)". GlobalSecurity.org. 20 September 2006. Retrieved 2010-12-16.
  5. ^ "Darpa". The Froehlich/Kent Encyclopedia of Telecommunications. CRC Press. 1992. pp. 75–77. ISBN 0-8247-2903-X.
  6. ^ "Project Score". Patterson Army Health Clinic. Archived from the original on 2011-07-22. Retrieved 2010-12-16.
  7. ^ Masterman-Smith, Michael. "12-18-1958 First Communication Satellite". Engineering Pathway. Archived from the original on 2011-07-10. Retrieved 2010-12-16.
  8. ^ a b D'Antonio, Michael (2008). A Ball, a Dog, and a Monkey: 1957 — The Space Race Begins. Simon and Schuster. p. 236. ISBN 0-7432-9432-7.
  9. ^ "Eisenhower's Voice May Be Beamed to Earth Stations from Outer Space" UPI (December 17, 1958) Rome News-Tribune", p. 1
  10. ^ "SCORE: Experiment 1958-006A". nssdc.gsfc.nasa.gov. NASA. 27 February 2020. Retrieved 30 April 2020. This article incorporates text from this source, which is in the public domain.
  11. ^ Encyclopedia Astronautica - Atlas B
  12. ^ The Advanced Research Projects Agency, 1958-1974, Barber Associates, December 1975, pages III-23 to III-24.

17 March 1958

The USA launched the Vanguard 1 satellite.

Vanguard 1 was a small Earth-orbiting satellite designed to test the launch capabilities of a three-stage launch vehicle and the effects of the environment on a satellite and its systems in Earth orbit. It also was used to obtain geodetic measurements through orbit analysis. It was the second satellite launched by the U.S., the first successful satellite of the Vanguard series, and the first satellite to use solar cell power. It is the oldest satellite still orbiting the Earth.

Mission Profile

Vanguard 1 launched on 17 March 1958 at 12:15:41 UT from the Atlantic Missile Range in Cape Canaveral Florida. At 12:26:21, the third stage of the launch vehicle injected Vanguard 1 into a 654 x 3969 km, 134.27 minute orbit inclined at 34.25 degrees. Original estimates had the orbit lasting for 2000 years, but it was discovered that solar radiation pressure and atmospheric drag during high levels of solar activity produced significant perturbations in the perigee height of the satellite, which caused a significant decrease in its expected lifetime to only about 240 years. The battery powered transmitter stopped operating in June 1958 when the batteries ran down. The solar powered transmitter operated until May 1964 after which the spacecraft was optically tracked from Earth.

Spacecraft and Subsystems

The spacecraft was a 1.46-kg aluminum sphere 16.5 cm in diameter. A cylinder lined with heat shields mounted inside the sphere held the instrument payload. It contained a set of mercury-batteries, a 10-mW, 108-MHz telemetry transmitter powered by the batteries, and a 5-mW, 108.03-MHz Minitrack beacon transmitter, which was powered by six square solar cells mounted on the body of the satellite. The cells were single crystal silicon and produced a total of about 1 Watt with 10% efficiency at 28 C. Six 30-cm long, 0.8-cm diameter spring-actuated aluminum alloy aerials protruded from the sphere. The aerial axes were mutually perpendicular and passed through the center of the sphere. The transmitters were used primarily for engineering and tracking data, but were also used to determine the total electron content between the satellite and ground stations. Vanguard also carried two thermistors which measured the interior temperature over 16 days in order to track the effectiveness of the thermal protection.

A cylindrical separation device kept the sphere attached to the third stage prior to deployment. At deployment a strap holding the satellite in place released and three leaf springs separated the satellite from the cylinder and third stage at a relative velocity of about 0.3 m/s.

Launch Vehicle

Vanguard was the designation used for both the launch vehicle and the satellite. The first stage of the three-stage Vanguard Test vehicle was powered by a GE X-405 28,000 pound thrust liquid rocket engine, propelled by 7200 kg of kerosene and liquid oxygen, with helium pressurant. It also held 152 kg of hydrogen peroxide. It was finless, 13.4 m tall, 1.14 m in diameter, and had a launch mass of approximately 8090 kg.

The second stage was a 5.8 m high, 0.8 m diameter Aerojet-General AJ-10 liquid engine burning 1520 kg Unsymmetrical Dimethylhydrazine and White Inhibited Fuming Nitric Acid with a helium pressurant tank. It produced a thrust of 7340 pounds and had a launch mass of approximately 1990 kg. This stage contained the complete guidance and control system.

A solid-propellant rocket with 2350 pounds of thrust was developed by the Grand Central Rocket Co. to satisfy third-stage requirements. The stage was 1.5 m high, 0.8 m in diameter, and had a launch mass of 194 kg. The thin steel casing for the third stage had a hemispherical forward dome with a shaft at the center to support the satellite and an aft dome fairing into a steel exit nozzle.

The total height of the vehicle with the satellite fairing was about 21.9 meters. The payload capacity was 11.3 kg to a 555 km Earth orbit. A nominal launch would have the first stage firing for 144 seconds, bringing the rocket to an altitude of 58 km, followed by the second stage burn of 120 seconds to 480 km, whereupon the third stage would bring the satellite to orbit. This was the same launch vehicle configuration, with minor modifications, as used for Vanguard TV-3 and all succeeding Vanguard flights up to and including Vanguard SLV-6.

5 April 1958

Ripple Rock, an underwater threat to navigation in the Seymour Narrows in Canada is destroyed in a controlled explosions.

Ripple Rock, an underwater mountain within Seymour Narrows near Campbell River BC, was a marine hazard responsible for more than 20 large vessels and at least 100 smaller vessels sinking or being damaged. Before its destruction in 1958, Ripple Rock claimed at least 114 lives.

A Marine Commission’s findings brought a recommendation to remove Ripple Rock as early as 1931, but it was 1942 before this was finally authorized. Despite the extreme hazard the rock created, its removal was bitterly opposed by some, who had envisioned it as a bridge support for a railroad connecting Vancouver Island to the mainland.

The following year, a drilling barge 46 metres long was floated over the rock, held in place by one and half inch steel cables attached to six concrete anhors totaling 1,100 tons.The plan was to drill holes into the top of the rock, fill it with explosives and blast Ripple Rock away bit by bit. The enormous drilling barge quivered and tossed in the violent water, the anchor lines vibrating continually. The attempt failed as anchor lines broke at an average of one every 48 hours.

A second plan was made in 1945 that attempted to hold the drill barge in position by attaching it to two enormous steel overhead lines, each weighing 11 tons. The 3,500 foot cables were stretched across Seymour Narrows 135 feet above high water. Again, water turbulence severely hindered the operation; of the estimated 1,500 drill holes needed only 139 were drilled and 93 blasted, before the contract was terminated.

Eight years later the National Research Council directed a feasibility study on tunnelling to the rock. The idea was to sink a shaft from Maud Island, go under Seymour Narrows, and up into the peaks of Ripple Rock. The underground approach was recommended and Dolmage and Mason Consulting Engineers were retained to plan the project.

17 March 1958

The USA launches the Vanguard 1 satellite.

Vanguard 1 was the first satellite to have solar electric power. Although communication with the satellite was lost in 1964, it remains the oldest man-made object still in orbit, together with the upper stage of its launch vehicle. It was designed to test the launch capabilities of a three-stage launch vehicle as a part of Project Vanguard, and the effects of the space environment on a satellite and its systems in Earth orbit. It also was used to obtain geodetic measurements through orbit analysis. Vanguard 1 was described by the Soviet Premier, Nikita Khrushchev, as “the grapefruit satellite”.

Spacecraft design
The spacecraft is a 1.47 kg aluminum sphere 16.5 cm in diameter. It contains a 10 mW, 108 MHz transmitter powered by a mercury battery and a 5 mW, 108.03 MHz transmitter that was powered by six solar cells mounted on the body of the satellite. Six short antennas protrude from the sphere. The transmitters were used primarily for engineering and tracking data, but were also used to determine the total electron content between the satellite and the ground stations. Vanguard also carried two thermistors which measured the interior temperature over sixteen days in order to record the effectiveness of the thermal protection.

A backup version of Vanguard 1 is on display at the Smithsonian National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Virginia.

Mission
On March 17, 1958, the three-stage launch vehicle placed Vanguard into a 654-by-3,969-kilometer , 134.2 minute elliptical orbit inclined at 34.25 degrees. Original estimates had the orbit lasting for 2,000 years, but it was discovered that solar radiation pressure and atmospheric drag during high levels of solar activity produced significant perturbations in the perigee height of the satellite, which caused a significant decrease in its expected lifetime to only about 240 years. Vanguard 1 transmitted its signals for nearly seven years as it orbited the Earth.

Radio beacon
A 10 mW transmitter, powered by a mercury battery, on the 108 MHz band used for International Geophysical Year scientific satellites, and a 5 mW, 108.03 MHz transmitter powered by six solar cells were used as part of a radio phase-comparison angle-tracking system. The tracking data were used to show that the shape of the Earth has a very slight north-south asymmetry, occasionally described as “pear-shaped” with the stem at the North Pole. These radio signals were also used to determine the total electron content between the satellite and selected ground-receiving stations. The battery-powered transmitter provided internal package temperature for about sixteen days and sent tracking signals for twenty days. The transmitter powered by solar cells transmitted for more than six years. Its signal gradually weakened and was last received at Quito, Ecuador, in May of 1964. Since then the spacecraft has been tracked optically from Earth, via telescope.

15 May 1958

The Soviet Union launches Sputnik 3.

On May 15, 1958, the USSR launched its Third Artificial Satellite. While two previous Soviet orbiters were propelled into space by mostly political considerations, Sputnik-3, as it became known in the West, was designed to be a true scientific laboratory. According to original plans, it was supposed to be the first Soviet satellite, but, as it transpired decades later, it became the fourth, after its sibling crashed in a botched launch less than three weeks earlier.

A 8A91 rocket No. B1-1 with the second copy of Object D lifted off on the morning of May 15, 1958. This time, the ride to orbit went without a hitch. (473) A total of four objects were detected by Western radars after the launch: the satellite itself, the core stage of the R-7 rocket and two halves of a payload fairing, while the front tip of the fairing was probably too small to be registered.

On May 29, a press-release dedicated to the mission revealed general dimensions of the satellite and boasted that the third Soviet spacecraft was 2.5 times heavier than the second satellite and 16 times heavier than the first. (199)

As it transpired decades later, most systems onboard the third satellite functioned for more than two weeks, even though its data recorder failed earlier. The onboard system for orbit tracking was misbehaving in the first days of the mission.