SOLRAD 3

Last updated

SOLRAD 3
Transit-4A Injun-1 Solrad-3.jpg
Transit 4A, Injun 1 and SOLRAD 3 satellites
NamesGRAB 2
SOLar RADiation 3
SR 3
GREB 2
Mission type Solar X-rays
Operator United States Naval Research Laboratory (USNRL)
Harvard designation1961 Omicron 2
COSPAR ID 1961-015B OOjs UI icon edit-ltr-progressive.svg
SATCAT no. 00117
Mission duration62 years, 5 months and 11 days (in orbit)
Spacecraft properties
Spacecraft typeSOLRAD
Manufacturer Naval Research Laboratory (NRL)
Launch mass25 kg (55 lb)
Dimensions51 cm (20 in)
Start of mission
Launch date29 June 1961, 04:22 GMT
Rocket Thor-Ablestar
Launch site Cape Canaveral, LC-17B
Contractor Douglas Aircraft Company
Orbital parameters
Reference system Geocentric orbit [1]
Regime Low Earth orbit
Perigee altitude 882 km
Apogee altitude 999 km
Inclination 66.82°
Period 103.90 minutes
←  SOLRAD 2
SOLRAD 4  →
 

SOLRAD (SOLar RADiation) 3 was a solar X-ray satellite, the third in the SOLRAD program. Developed by the United States Navy's Naval Research Laboratory (USNRL), it shared satellite space with and provided cover for the Navy's GRAB 2 (Galactic Radiation And Background), a secret electronic surveillance program.

Contents

The satellite was launched atop a Thor-Ablestar rocket on 29 June 1961 along with Transit 4A and the University of Iowa's Van Allen Belts Injun 1 satellite. After reaching orbit, SOLRAD 3/GRAB 2 and INJUN 1 separated from Transit 4A but not from each other. Though this reduced SOLRAD 3's data-transmission ability by half, the satellite still returned valuable information regarding the Sun's normal levels of X-ray emissions. The SOLRAD experiment package also established that, during solar flares, the higher the energy of emitted X-rays, the more disruption caused on the Earth's thermosphere (and radio transmissions therein). The GRAB mission was also highly successful, returning so much data on Soviet air defense radar facilities that an automated analysis system had to be developed to process it all.

Background

The United States Navy's Naval Research Laboratory (NRL) established itself as a player early in the Space Race with the development and management of Project Vanguard (1956–1959), [2] America's first satellite program. After Vanguard, the Navy's next major goal was to use the observational high ground of Earth's orbit to survey Soviet radar locations and frequencies. This first space surveillance project was called "GRAB", later expanded into the more innocuous backronym, Galactic Radiation and Background. [3] As American space launches were not classified until late 1961, [4] [5] a co-flying cover mission sharing satellite space was desired to conceal GRAB's electronic surveillance mission from its intended targets. [3]

The field of solar astronomy provided such cover. Since the invention of the rocket, astronomers had wanted to fly instruments above the atmosphere to get a better look at the Sun. The Earth's atmosphere blocks large sections of sunlight's electromagnetic spectrum, making it impossible to study the Sun's X-ray and ultraviolet output from the ground. Without this critical information, it was difficult to model the Sun's internal processes, which in turn inhibited stellar astronomy in general. [6] : 5–6  On a more practical level, it was believed that solar flares directly affected the Earth's thermosphere, disrupting radio communications. The U.S. Navy wanted to know when its communications were going to become unreliable or compromised. [3] Sounding rockets had shown that solar output was unpredictable and fluctuated rapidly. A long-term, real-time observation platform above the Earth's atmosphere – in other words, a satellite – was required to properly chart the Sun's radiation, determine its effects on the Earth, and correlate it with ground-based observations of the Sun in other wavelengths of light. [6] : 63 

Thus, the SOLRAD project was conceived to address several NRL goals at once:

A dummy SOLRAD was successfully launched on 13 April 1960, and SOLRAD 1 went into orbit on 22 June 1960, becoming both the world's first surveillance satellite (as GRAB 1) and the first satellite to observe the Sun in X-ray and ultraviolet light. SOLRAD 2, a duplicate of SOLRAD 1, [10] was launched on 30 November 1960, but was lost when its booster flew off course and had to be destroyed. [11]

Spacecraft

Like its two predecessors, SOLRAD 1 and SOLRAD 2, SOLRAD 3/GRAB 2 was a 51 cm diameter sphere based on the Vanguard 3 satellite. Unlike SOLRAD 1 and the abortive SOLRAD 2, the satellite's scientific package did not include Lyman-alpha photometers. This is because it had been discovered since SOLRAD 2's failed launch that the ultraviolet radiation level remained constant during solar flares. Instead, SOLRAD 3 carried two X-ray photometers designed to cover a greater range of wavelengths than the first SOLRAD. In addition to a photometer that, covered the same 2-8 Å range as the earlier SOLRAD, SOLRAD 3 also carried one that measured the bandwidth from 8-14 Å. [12]

As was the case with most early automatic spacecraft, SOLRAD 2, though spin stabilized, [3] lacked attitude control systems and thus scanned the whole sky with no source in particular. [6] : 13  So that scientists could properly interpret the source of the X-rays detected by SOLRAD 2, the spacecraft carried a vacuum photocell to determine when the sunlight was striking its photometers and the angle at which it hit them. [6] : 64 

SOLRAD 3/GRAB 2 was significantly heavier than its predecessors (25 kg versus 19 kg for SOLRAD 1, 18 kg for SOLRAD 2) as its GRAB package included equipment for monitoring two radar frequencies rather than just one, as in prior flights. [13] In addition to monitoring Soviet air defense radars in the S-band (1,550-3,900 MHz), GRAB 2 could also detect long-range air surveillance radars operating in the Ultra high frequency (UHF) band at around 500 MHz. [14]

Mission and science results

SOLRAD 3's Thor-Ablestar takes off Thor Able Star with Transit 4A, Solrad 3 and Injun 1 (Jun. 29, 1961).jpg
SOLRAD 3's Thor-Ablestar takes off

SOLRAD 3/GRAB 2 was launched on 29 June 1961 at 04:22 GMT on a Thor-Ablestar rocket, along with Transit 4A and the University of Iowa's Van Allen radiation belt Injun 1 satellite from Cape Canaveral, LC-17B. [15] Its course to orbit was more northerly than that of its predecessors to avoid the possibility of fragments falling on Cuba in the event of a mission failure (as had happened with SOLRAD 2). [13]

After reaching orbit, SOLRAD 3/GRAB 2 and Injun 1 separated from Transit 4A but not from each other, causing them to rotate more slowly than planned. [12] Moreover, because electro-magnetic interference generated by the spacecraft prevented ground controllers from requesting data from both spacecraft at the same time, [13] SOLRAD 3/GRAB 2's transmissions were limited to odd-numbered days, Injun's to even-numbered days; thus, data was only recovered for half of each satellite's lifetime. [16]

Nevertheless, the SOLRAD package on the satellite made several important findings. It established the Sun's normal X-ray radiation levels during times of inactivity at levels below 14 Å in wavelength (less than 5×10−3 ergs/cm2/sec). The satellite also found that the higher the hardness (energy level) of X-rays emitted during solar flares, the greater the disturbances and microwave bursts in the thermosphere, both affecting radio communications. [6] : 67–68 

GRAB results

The GRAB 2 portion of the satellite began transmission of information on Soviet radars starting 15 July 1961, returning a large volume of information over the next fourteen months. [17] As opposed to the cautious approach exercised by former President Eisenhower, President Kennedy did not require personal authorization for the satellite to receive and transmit collected data. [14] As a result, data was collected quicker than analysts could process, and by October 1961, a new automated analysis system was implemented not only to process the backlog of existing data but also data from upcoming electronic surveillance flights and even the Air Force's SAMOS reconnaissance satellites. [13]

Legacy and status

The SOLRAD/GRAB series flew twice more (both unsuccessful missions), finishing with the SOLRAD 4B mission launched 26 April 1962. [18]

In 1962, all U.S. overhead reconnaissance projects were consolidated under the National Reconnaissance Office (NRO), which elected to continue and expand the GRAB mission starting July 1962 [19] with a next-generation set of satellites, code-named POPPY. [16] With the initiation of POPPY, SOLRAD experiments would no longer be carried on electronic spy satellites; rather, they would now get their own satellites, launched alongside POPPY missions to provide some measure of mission cover. [15] Starting with SOLRAD 8, launched in November 1965, the final five SOLRAD satellites were scientific satellites launched singly, three of which were also given NASA Explorer program numbers. The last in this final series of SOLRAD satellites flew in 1976. In all, there were thirteen operational satellites in the SOLRAD series. [3] The GRAB program was declassified in 1998. [13]

As of 2024, SOLRAD 3 (COSPAR ID 1961-015B [20] ) is still in orbit, and its position can be tracked. [21]

See also

Related Research Articles

<span class="mw-page-title-main">Laboratory for Atmospheric and Space Physics</span> Research organization at the University of Colorado Boulder

The Laboratory for Atmospheric and Space Physics (LASP) is a research organization at the University of Colorado Boulder. LASP is a research institute with over one hundred research scientists ranging in fields from solar influences, to Earth's and other planetary atmospherics processes, space weather, space plasma and dusty plasma physics. LASP has advanced technical capabilities specializing in designing, building, and operating spacecraft and spacecraft instruments.

<span class="mw-page-title-main">Space weather</span> Branch of space physics and aeronomy

Space weather is a branch of space physics and aeronomy, or heliophysics, concerned with the time varying conditions within the Solar System, including the solar wind, emphasizing the space surrounding the Earth, including conditions in the magnetosphere, ionosphere, thermosphere, and exosphere. Space weather is distinct from, but conceptually related to, the terrestrial weather of the atmosphere of Earth. The term "space weather" was first used in the 1950s and came into common usage in the 1990s. Later, it was generalized to a "space climate" research discipline, which focuses on general behaviors of longer and larger-scale variabilities and effects.

<span class="mw-page-title-main">TIMED</span> American Weather Satellite

The TIMED mission is dedicated to study the influences energetics and dynamics of the Sun and humans on the least explored and understood region of Earth's atmosphere – the Mesosphere and Lower Thermosphere / Ionosphere (MLTI). The mission was launched from Vandenberg Air Force Base in California on 7 December 2001 aboard a Delta II rocket launch vehicle. The project is sponsored and managed by NASA, while the spacecraft was designed and assembled by the Applied Physics Laboratory at Johns Hopkins University. The mission has been extended several times, and has now collected data over an entire solar cycle, which helps in its goal to differentiate the Sun's effects on the atmosphere from other effects. It shared its Delta II launch vehicle with the Jason-1 oceanography mission.

<span class="mw-page-title-main">Solar Radiation and Climate Experiment</span> NASA experiment to measure radiation from the Sun

The Solar Radiation and Climate Experiment (SORCE) was a NASA-sponsored satellite mission that measured incoming X-ray, ultraviolet, visible, near-infrared, and total solar radiation. These measurements specifically addressed long-term climate change, natural variability, atmospheric ozone, and UV-B radiation, enhancing climate prediction. These measurements are critical to studies of the Sun, its effect on the Earth's system, and its influence on humankind. SORCE was launched on 25 January 2003 on a Pegasus XL launch vehicle to provide NASA's Earth Science Enterprise (ESE) with precise measurements of solar radiation.

<span class="mw-page-title-main">Galactic Radiation and Background</span> First US orbital surveillance program

Galactic Radiation and Background (GRAB) was the first successful United States orbital surveillance program, comprising a series of five Naval Research Laboratory electronic surveillance and solar astronomy satellites, launched from 1960 to 1962. Though only two of the five satellites made it into orbit, they returned a wealth of information on Soviet air defense radar capabilities as well as useful astronomical observations of the Sun.

<span class="mw-page-title-main">SOLRAD</span> Series of American satellites

SOLRAD was an American series of satellites sponsored by the US Navy in a program to continuously monitor the Sun. SOLRAD was the Naval Research Laboratory's first post-Vanguard satellite.

<span class="mw-page-title-main">OSO 7</span>

OSO 7 or Orbiting Solar Observatory 7, before launch known as OSO H is the seventh in the series of American Orbiting Solar Observatory satellites launched by NASA between 1962 and 1975. OSO 7 was launched from Cape Kennedy on 29 September 1971 by a Delta N rocket into a 33.1° inclination, low-Earth orbit, and re-entered the Earth's atmosphere on 9 July 1974. It was built by the Ball Brothers Research Corporation (BBRC), now known as Ball Aerospace, in Boulder Colorado.

<span class="mw-page-title-main">SOLRAD 4B</span> American surveillance satellite

SOLRAD 4B was a solar X-ray, ultraviolet, and electronic surveillance satellite. Developed by the United States Navy's United States Naval Research Laboratory, it was the fifth in both the SOLRAD and the GRAB programs.

<span class="mw-page-title-main">X-ray astronomy satellite</span> Satellite involved in X-ray astronomy

An X-ray astronomy satellite studies X-ray emissions from celestial objects, as part of a branch of space science known as X-ray astronomy. Satellites are needed because X-radiation is absorbed by the Earth's atmosphere, so instruments to detect X-rays must be taken to high altitude by balloons, sounding rockets, and satellites.

<span class="mw-page-title-main">SOLRAD 8</span>

The SOLRAD 8,Explorer 30 or SE-A satellite was one of the NASA SOLRAD program that began in 1960 to provide continuous coverage of solar radiation with a set of standard photometers. SOLRAD 8 was a spin-stabilized satellite oriented with its spin axis perpendicular to the sun-satellite line so that the 14 solar X-ray and ultraviolet photometers pointing radially outward from its equatorial belt viewed the sun on each revolution. Data were transmitted in real time by means of an FM / AM the satellite's telemetry system and were recorded by the stations on the Spacecraft Tracking and Data Acquisition Network (STADAN) tracking network.

<span class="mw-page-title-main">Student Nitric Oxide Explorer</span> NASA satellite of the Explorer program

Student Nitric Oxide Explorer, was a NASA small scientific satellite which studied the concentration of nitric oxide in the thermosphere. It was launched in 1998 as part of NASA's Explorer program. The satellite was the first of three missions developed within the Student Explorer Demonstration Initiative (STEDI) program funded by the NASA and managed by the Universities Space Research Association (USRA). STEDI was a pilot program to demonstrate that high-quality space science can be carried out with small, low-cost free-flying satellites on a time scale of two years from go-ahead to launch. The satellite was developed by the University of Colorado Boulder's Laboratory for Atmospheric and Space Physics (LASP) and had met its goals by the time its mission ended with reentry in December 2003.

<span class="mw-page-title-main">Miniature X-ray Solar Spectrometer CubeSat</span>

The Miniature X-ray Solar Spectrometer (MinXSS) CubeSat was the first launched National Aeronautics and Space Administration Science Mission Directorate CubeSat with a science mission. It was designed, built, and operated primarily by students at the University of Colorado Boulder with professional mentorship and involvement from professors, scientists, and engineers in the Aerospace Engineering Sciences department and the Laboratory for Atmospheric and Space Physics, as well as Southwest Research Institute, NASA Goddard Space Flight Center, and the National Center for Atmospheric Research's High Altitude Observatory. The mission principal investigator is Dr. Thomas N. Woods and co-investigators are Dr. Amir Caspi, Dr. Phil Chamberlin, Dr. Andrew Jones, Rick Kohnert, Professor Xinlin Li, Professor Scott Palo, and Dr. Stanley Solomon. The student lead was Dr. James Paul Mason, who has since become a Co-I for the second flight model of MinXSS.

<span class="mw-page-title-main">SOLRAD 9</span>

Solrad 9, also known Explorer 37 and Explorer SE-B, was one of the SOLRAD program that began in 1960 to provide continuous coverage of solar radiation with a set of standard photometers.

<span class="mw-page-title-main">SOLRAD 10</span>

Solrad 10, also known Explorer 44, NRL-PL 165 and Explorer SE-C, was one of the SOLRAD series designed to provide continuous coverage of wavelength and intensity changes in solar radiation in the UV, soft and hard X-ray regions. The satellite also mapped the celestial sphere using a high-sensitivity X-ray detector. Information collected was expected to contribute to a better understanding of the physical processes involved in solar flares and other solar activity, and the potential effects of this activity on short-wave communications, as well as on future human space travel. For the period of July 1971 to June 1973, the core memory data of Explorer 44 were used rather than those from Explorer 37. The Explorer 44 core memory failed on 11 June 1973, and Explorer 37 was heavily used until 25 February 1974, when the gas supply of the attitude control system was exhausted.

SOLRAD 7A was the seventh solar X-ray monitoring satellite in the SOLRAD series, and the fourth to successfully orbit the Earth. It was boosted into orbit along with four other military satellites atop a Thor Augmented Delta-Agena D rocket on January 11, 1964. Data returned by SOLRAD 7A dramatically revised scientific models of the solar corona.

<span class="mw-page-title-main">SOLRAD 1</span> U.S. solar X-ray and surveillance satellite

SOLRAD1 is the public designation for SOLRAD/GRAB 1, a combination science and surveillance satellite launched into orbit on 22 June 1960. It was the first satellite to successfully observe solar X-rays, the first to conduct surveillance from orbit, and the first to be launched with another instrumented satellite.

<span class="mw-page-title-main">SOLRAD 2</span> U.S. satellite launched in 1960

SOLRAD 2 was the public designation for a combination surveillance and solar X-rays and ultraviolet scientific satellite, the second in the SOLRAD program developed by the United States Navy's Naval Research Laboratory. The SOLRAD scientific package aboard the satellite provided cover for the GRAB electronic surveillance package, the mission of which was to map the Soviet Union's air defense radar network.

SOLRAD 6 was the sixth solar X-ray monitoring satellite in the United States Navy's SOLRAD series, the third in the series to successfully orbit. It was launched along with POPPY 2, an ELINT surveillance package, as well as three other satellites, boosted into orbit via a Thor Augmented Delta-Agena D rocket on June 15, 1963.

<span class="mw-page-title-main">SOLRAD 4</span> US navy surveillance satellite

SOLRAD 4 was a solar X-rays, ultraviolet, and electronic surveillance satellite. Developed by the United States Navy's United States Naval Research Laboratory (USNRL), it was the fourth in both the SOLRAD and the GRAB programs.

<span class="mw-page-title-main">SOLRAD 7B</span> Solar monitoring satellite

SOLRAD 7B was the eighth solar X-Ray monitoring satellite in the SOLRAD series and the fifth to successfully orbit the Earth. It was launched via Thor Augmented Delta-Agena D along with seven other satellites on March 9, 1965. The satellite provided continuous coverage of the Sun during the International Quiet Solar Year from March through October 1965.

References

  1. ↑ "Trajectory: Injun 1 1961-015B". NASA. 14 May 2020. Retrieved 15 January 2021.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  2. ↑ Constance Green and Milton Lomask (1970). Vanguard A History. NASA. ISBN   978-1-97353-209-5.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  3. 1 2 3 4 5 6 7 American Astronautical Society (23 August 2010). Space Exploration and Humanity: A Historical Encyclopedia; in 2 volumes, A Historical Encyclopedia. Santa Barbara, California: ABC-CLIO. pp. 300–303. ISBN   978-1-85109-519-3.
  4. ↑ Day, Dwayne A.; Logsdon, John M.; Latell, Brian (1998). Eye in the Sky: The Story of the Corona Spy Satellites. Washington and London: Smithsonian Institution Press. p.  176. ISBN   978-1-56098-830-4.
  5. ↑ "Space Science and Exploration". Collier's Encyclopedia. New York: Crowell-Collier Publishing Company. 1964. OCLC   1032873498.
  6. 1 2 3 4 5 6 Significant Achievements in Solar Physics 1958–1964. NASA. 1966. OCLC   860060668.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  7. ↑ ""Bonus" Payload Set for Transit 2A Orbit". Aviation Week and Space Technology. McGraw Hill Publishing Company. 20 June 1960. Archived from the original on 9 January 2019. Retrieved 8 January 2019.
  8. ↑ "Chapter 8". Navy's Needs in Space for Providing Future Capabilities, Committee on the Navy's Needs in Space for Providing Future Capabilities, Naval Studies Board, Division on Engineering and Physical Sciences, National Research Council of the National Academies. The National Academies Press. 2005. p. 157. doi:10.17226/11299. ISBN   978-0-309-18120-4. Archived from the original on 7 January 2019. Retrieved 6 January 2019.
  9. ↑ Parry, Daniel (2 October 2011). "NRL Center for Space Technology Reaches Century Mark in Orbiting Spacecraft Launches". U.S. Naval Research Laboratory. Archived from the original on 7 January 2019. Retrieved 12 January 2019.
  10. ↑ "Transit 3A Planned for November 29 launch". Aviation Week and Space Technology. McGraw Hill Publishing Company. 7 November 1960. Retrieved 10 January 2019.
  11. ↑ "Transit Launch Fails". Aviation Week and Space Technology. McGraw Hill Publishing Company. 5 December 1960. Retrieved 10 January 2019.
  12. 1 2 "Transit, Two Small Satellites Work Despite Malfunction". Aviation Week and Space Technology. McGraw Hill Publishing Company. 10 July 1961. Retrieved 8 January 2019.
  13. 1 2 3 4 5 LePage, Andrew. "Vintage Micro: The First ELINT Satellites". Drew Ex Machina. Retrieved 18 January 2019.
  14. 1 2 "NRO Lifts Veil On First Sigint Mission". Aviation Week and Space Technology. McGraw Hill Publishing Company. 22 June 1998. Retrieved 6 March 2019.
  15. 1 2 McDowell, Jonathan. "Launch Log". Jonathon's Space Report. Retrieved 15 January 2021.
  16. 1 2 "History of the Poppy Satellite System" (PDF). National Reconnaissance Office. 14 August 2006. Retrieved 15 January 2021.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  17. ↑ "GRAB AND POPPY: America's Early ELINT Satellites" (PDF). Retrieved 15 January 2021.
  18. ↑ "Vintage Micro: The First ELINT Satellites". DrewExMachnica. 30 September 2014. Retrieved 16 December 2022.
  19. ↑ "Review and Redaction Guide" (PDF). National Reconnaissance Office. 2008. Retrieved 15 January 2021.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  20. ↑ "Injun 1". NASA. Retrieved 15 January 2021.
  21. ↑ "SOLRAD 3 (GRAB 2)". N2YO.com. Retrieved 15 January 2021.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.