Amateur optical tracking in South Africa during 1957-2014.
As mentioned in the first article the MOONWATCH program, for logistical and other reasons, did not in its early years encourage or cater for "lone-wolf" observers, so several other organizations sprang into existence to make use of this untapped potential. Despite several intensive searches, especially on the internet, the author has been unable to locate any history or major documentation on these organisations so has had to rely mainly on his personal experiences and recollections so this is an incomplete record.
If anyone has any additional information on these groups it would be much appreciated.
Western Satellite Research Network
Early in the MOONWATCH program several of the more experienced MOONWATCH teams felt that routine visual observations were of comparatively little value for "well-behaved" satellites and that there was also a need to cater for those excluded from Moonwatch because of SAO's "lone-wolf" discrimination. With financial support from North American Aviations Space and Information Systems Division and the United States Air Defence Command (ADC) the Western Satellite Research Network (WSRN) was formed in July 1959 by two engineers at North American Aviation, namely Gary A. McCue and Richard Angel. They believed that experienced visual observers could make significant contributions to some of the more specialized problems of satellite tracking and history has proved this correct.
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By observing the magnitude and other characteristics such as tumble rate or variability in brightness it is possible to identify the nature and condition of satellites, for example observations of spin rate increase could indicate leaks or ruptures in the satellite's pressurized systems. The flash pattern and magnitude variation enable one to determine the general nature of a satellites surfaces and its orientation--i.e. whether spinning, stabilized or regular or irregular tumbling.
Today this is recognized as the first stage in the evolution of Space Situational Awareness (SSA) which is invaluable for scientific or military use and which lasted from 1957 to 1964 and focussed on the fundamental requirements for detection, tracking and identification of a small but rapidly growing number of artificial earth satellites and associated pieces of space debris.
In 1959 eight WSRN teams contributed more than half of all American visual satellite observations and by mid-1964 the organization had grown to 25 teams with 82 observing sites in North America, Australia, South America, and South Africa (Durban), and later (1966) South Africa (Cape Town).
The observations made were of value primarily when photographic or electronic methods were inadequate, i.e. the satellite was too small, too distant or had poorly determined orbital elements, so consequently WSRN concentrated on recovering lost satellites, tracking faint problem objects, observing unusual launches and satellite decays in the atmosphere, and recording the distinctive optical characteristics of individual objects thus making WSRN an integral part of the US national space surveillance system.
The program was co-ordinated by North American Aviation's SPACE Sciences Laboratory in Downey, California using an IBM 7094 computer which could produce 2000 "look-angle" predictions per minute. Approximately 50000 predictions were distributed each month, either telephoned, telegraphed or air mailed depending on the urgency of the situation.
Observations made were reported to WSRN Headquarters in Downey and telegraphed promptly to the Spacetrack centre in Colorado Springs, Colorado.
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Satellite Optical Characteristics Study SID 65-1176, 1 August 1965, North American Aviation, Inc, Space and Information Systems Division. Contains 11 000 observations of 365 satellites made by 26 teams of the WSRN. 175 pages.
Optical Observations Of Faint Satellites (Final Report), Technical Document Report No ESD-TDR-65-155 July 1964
Satellite Optical Characteristics Catalogue SID68-629. 20 July 1968, North American Rockwell Corporation, Space Division. Contains 7900 observations of optical characteristics of 574 satellites, 356 pages
Optical Characteristics of Artificial Satellites SID 70-55 1 July 1970
The following credits appear in these reports:
Particular thanks must be given to the members of the WSRN teams who have donated a considerable amount of time to this project. Without their unselfish efforts preparation of this report would not have been possible. The contributions of the following individuals are particularly noteworthy (given in order listed):
M. McCants, Austin, Texas; G. Roberts, Durban, South Africa; P. Maley, Edinburgh and San Antonia, Texas; D. Brierley, Poynton, England; A. Beresford, Adelaide, Australia; (after the initial three listed only those still tracking in 2013 are given)
Observations of all the Apollo Spacecraft were made during translunar coast. Six WSRN teams reported observations of Apollo 12 including several sightings at ranges in excess of 280 000 km with magnitudes between +12 and +13. Depending upon the difficulty of the object, the instruments used by WSRN observers ranged in size from the naked eye to the 18-inch refractor at Granby, Massachusetts, or the 20-inch reflector and 26.5-inch Innes refractors at the Republic Observatory, Johannesburg.
In addition a regular newsletter was issued giving current priorities and recent achievements as well as papers of interest to observers. Meetings were held for geographically suited members.
It was primarily as a result of a paper entitled Space Surveillance Technical Memorandum No 68-4, issued by the 1st Aerospace Control Squadron, ENT Air Force Base, Colorado on "A Preliminary Analysis of Molniya orbits" and specifically sent to the author with the comment "I'm sure you will find it very informative" that the author acquired his interest in tracking high altitude faint satellites which has lasted to the present day.
Over the approximately ten years that WSRN operated it acquired a total of over 22 000 optical observations and provided a comprehensive summary of optical appearance data that would serve in future years as a valuable aid for the identification of the nature or condition of a satellite.
A write-up about WSRN appeared in Sky and Telescope Vol XXX No 2, August 1965 Western Satellite Research Network, Pages 88-90.
The Phototrack program was set up to provide valuable support to the operation of the twelve Baker-Nunn cameras that formed the prime optical tracking network since even if the Baker Nunn cameras operated at maximum efficiency they were restricted by weather and other problems.
It was set up by the Society of Photographic Scientists and Engineers in the United States and encouraged volunteers to obtain photographic records of satellite tracks against a background of stars. Negatives had to be ideally at least 4 in. by 5 in. and taken with a lens of at least 5-in. focal length and show the track of the satellite orbit against a fixed starfield background with the trace containing two gaps, or displacements, timed to an accuracy of 0.1 sec using time signals broadcast by station WWV on 5,10,15,20,25 or 30 Mhz.
The programme was directed by Norton Goodwin., by profession a tax lawyer and a keen amateur photographer. Norton appears to have been a man of many talents and the writer did not know where he found the time to practice as a lawyer but it is believed he was financially quite well off (and single!) so could indulge in other activities. It appears to have been a limited staff project and operated with a grant from the Office Of Research Grants, NASA.
All negatives were to be accompanied by a form listing all the required technical information and forwarded to the Secretary-Treasurer of the Society of Photographic Scientists and Engineers at 826 Connecticut Avenue, Washington 6, D.C. USA which was the address of Norton's legal practice.
In addition Norton Goodwin established Project Moonbeam in conjunction with the American Amateur Relay League (ARRL) for the radio tracking of satellites by radio amateurs and other electronic enthusiasts. These amateur stations provided tracking data that could be used for inquisitional purposes, the resolution of small perturbations in the orbit due to localized gravitational anomalies, the influence of the ionosphere upon radio signals and supplementary data in case of premature failure of the satellite transmitter or short life of the satellite. The program was similar to Moonwatch with general headquarters at the United States Naval Research Laboratory with the Jet Propulsion Laboratory of the California Institute of Technology assisting and providing a Moonbeam information office. The ARRL assisted by publishing design information and other related information in its monthly publication "QST". Although this series of articles will concentrate on optical tracking some brief mention will be made in future articles where South Africa was involved in Moonbeam.
Volunteer Satellite Tracking Program--later renamed the Independent Tracking Coordination Program (ITCP)
Norton Goodwin also established the Volunteer Satellite Tracking Program (VSTP) at about the same time as the Phototrack and Moonbeam programs. It is not known how large an organisation VSTP was but many of the members were well known names in the satellite "profession" so it did enjoy considerable support and played a major role in several organizations.
This organisation had a major influence on the author when he was contacted by one of the leading observers--Wilcox Overbeck--and asked if he was interested in providing optical observations from the southern hemisphere and as a result a close friendship and collaboration developed, ably assisted by Norton Goodwin, which lasted for several years until contact was lost.
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Wilcox P. Overbeck, known as "Bill", was a man of considerable talents. He attended the University of Chicago and worked with Enrico Fermi as part of the Manhattan Project and was one of the 49 scientists that made history on 2 Dec 1942 when Chicago Ile 1 (CP-1) went critical and produced the world's first self-sustaining controlled nuclear chain reaction. He also held 14 patents related to atomic energy and at the time of his involvement with VSTP and ITCP produced numerous scientific papers related to satellite tracking. In his professional capacity he was director of the Savannah River Laboratories of the U.S. Atomic Energy Commission until a brain tumour apparently terminated his career and interest in satellites. He battled cancer for 10 years before dying from arteriosclerosis in 1981.
To assist the writer Bill wrote two publications that for a period served as the "amateur satellite trackers bible" as it described the techniques used by Bill to predict and analyse his observation and was distributed free to all members of the VSTP. This publication was called "A Letter to Gregory Roberts" and described Bill's method of predicting positions of artificial satellites at the point of local culmination. Bill proved that it was possible for an individual to maintain accurate orbital data on a large number of satellites using modest equipment and his own observations--recall that in those days micro-computers did not exist so one had to use mechanical hand calculators, logarithm tables and other computing aids! This "Letter" subsequently resulted in Moonwatch approaching the writer to set up a Moonwatch station, but more of this later.
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In the 20 July Report to the Office of Research Grants and Contract, NASA Norton Goodwin for the period 1 April-30 June 1964 had this to say:
"It will be noted that the mean orbital elements supplied by Gregory Roberts and Arthur Arnold were based solely on observations made at Durban, South Africa. The data obtained by Roberts and Arnold are of use to anyone in the world having an interest in acquiring 1963-14A or 1962 Kappa 1 during a period from 30 to 60 days after issue. The analytical procedure was carried out with the aid of a desk calculator, following methods suggested by W. P. Overbeck's "A Letter to Gregory Roberts", which has been published as part of the ITCP Program. This is the first known instance of amateurs producing satellite orbital data for use by others.
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In addition Bill had access to a computer at his place of work and wrote several FORTRAN programs related to satellite tracking and was the prime motivation for the author to learn how to program a computer when the South African Astronomical Observatory, where the author was employed, acquired its first NOVA mini-computer.
The collaboration with Bill and Norton lasted into the mid 70s and faded out--probably as a result of Bill's failing health which the writer only found out about several decades later from his son. Bill and Norton were the writers mentors and he owes them a deep debt of gratitude for teaching and encouraging an interest in the optical and radio tracking of satellites. Despite an intensive search on the Internet it has not been possible to establish what eventually happened to ITCP and Norton--probably Bill's illness contributed to its eventual closedown as he was the leading "light" of the observers.
British Satellite Tracking
In compiling the short history of the British satellite tracking activities the writer has extracted material from an article written by Desmond King-Hele in September 1987 shortly before he retired from the Royal Aircraft Establishment (RAE). Some information was also obtained from a nearly 11-hour tape recorded interview of King-Hele by the British Library Board in 2010 as part of the series of National Life Stories--An Oral History Of British Science. This is a fascinating transcript as it gives insight into why Britain decided not to develop its own rocket--Blue Streak and Black Night, for example, and decided to go instead for manned V-bomber aircraft, and why Britain never really got into space research or had its own space program, primarily as a result of the opposition of the Astronomer Royal Sir Richard Woolley, who thought space research a waste of money that could be better spent on astronomy. King-Hele also refers to Prime Minister Margaret Thatcher's disastrous dastardly destructiveness (his words!) in closing down the RAE and the Royal Greenwich Observatory. Information was also extracted from several of King-Heles books, principally a "Tapestry of Orbits". As Chairman of the British National Committee for the History of Science, Medicine and Technology and Deputy Chairman of the British National Committee on Space Research he is more than qualified to overview the situation.
King-Hele joined the RAE in 1948 where he remained for 40 years and initially worked in the Guided Weapons Department on scram-jets. In the mid 1950's he wrote several papers on artificial satellites so that when Sputnik 1 was launched in October 1957 he was already considered a world authority and was nominally in charge of the RAE prediction Service. In the years that followed he and co-worker Doreen Walker published numerous papers and books dealing with the behaviour of satellite orbits in an atmosphere, which are still regarded today as the textbooks on the subject. One of his books--Observing Earth Satellites, which ran to two editions, is one of the very few good books that deals with this subject and is highly recommended.
The National Prediction service, as it was known, began life at the Royal Greenwich Observatory (RGO) and was set up to basically provide satellite predictions for British observers--professional and amateur, but it only lasted at RGO for three hectic months, which set the pattern for the future. To quote King-Hele "The prediction service at the Royal Greenwich observatory, Herstmonceux, soon ran into a serious obstacle in the form of Dr. Richard Woolley, the Astronomer Royal, who controlled the RGO, and was not at all keen on space. Consequently the service was transferred to the RAE at the beginning of 1958. Woolley's hostility to space was another stroke of luck because it meant the RAE received all the UK Visual and radar observations"
Whilst at RGO, under the Nautical Almanac Office, (Oct 1957 to Jan 1958) the chief predictor was Gordon Taylor who was also a very accurate satellite visual observer. But again it was not thought suitable for RAE and was transferred to the Radio and Space Research Station (RSRS), at Ditton Park, Slough where it remained for 22 years, by which time the RSRS had changed its name to Appleton Laboratory and had then been bodily removed to Chilton.
In 1975 Moonwatch closed down and most of the productive observers were added to the Appleton mailing list so this did not materially affect the flow of optical observations. However the psychological damage is what mattered. To quote King-Hele "Visual observing is an exacting and financially unrewarding activity task: observers need to feel they are wanted if they are to give of their time and to brave the winter weather. The brutal message from the USA was that they were no longer wanted".
Some memorable names from the Appleton Laboratory period are Doreen Walker who was chief predictor (Jan 1958 to Dec 1958), Russell Eberst (1958-1962), Alan Pilkinton (1962-1964) and Pierre Neirinck (1966-1981). Pierre deserves special mention and towards the end at Appleton the staff consisted essentially of two people--Pierre in the day and Pierre at night! (he was always available at any time!)
The Hewitt camera played a major role. This was designed by Joseph Hewitt (1912-1975) of the Royal Radar Establishment, Malvern as it was then called. The purpose of the cameras was to record the re-entry of the British Blue Streak missile and two cameras had already been manufactured by Grubb Parsons when Blue Streak was cancelled. The cameras were considered to be useful for satellite observation and one camera was set up at Sheriffs Lench and was known as the Malvern Hewitt, with the other at Lye Vallets, which was subsequently moved in
1964 to the Royal Observatory Edinburg (ROE) and was known as the Earlyburn Hewittt. It remained in operation till 1975 after which it was placed in storage. The Malvern camera moved to RGO at Herstmonceux around 1982 with the closure of Sheriffs Lench, while the second camera was moved to Siding Spring in Australia. Both cameras were in operation from 1982 to 1990, ending with the closure of the RGO at Herstmonceux. The RGO camera is now in storage whilst the Australian one has been dismantled and the 34-inch diameter primary mirror is now in the possession of an Australian amateur astronomer.
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In 1974 the Earth Satellite Research Unit (ESRU) was set up at the University of Aston and in July 1980 the prediction service was transferred from Appleton to ESRU where it ran until March 1988 when RGO agreed to take over the two Hewitt cameras and the prediction service. The chief predictors at the Earth Satellite Unit were Fiona Lawler, Chris Cooke, Vanda Bennett and Carol Durows.
Kinethodolites also played a major role. Originally used during World War II by the Germans at the Peenmunde test site where the V1 and V2 rockets were developed, they were used after the war for tracking missiles on the test ranges of the RAE and five were converted for satellite tracking in 1957. Russell Eberst worked on one of the camera's when it was at the Royal Observatory, Edinburgh
The RGO Kinetheodolite was moved to the South African Astronomical Observatory, where it was operated most successfully for 12 years, thanks largely to the efforts of Walter Grimwood who accompanied the Kine when it was moved to South Africa after having operated it at RGO, and it provided a wealth of observations on over 40 000 transits and contributed vitally to the accuracy and immeasurability to the reliability of orbit determination.
Since the Kine was more than 25 years old and was wearing out it finally closed down in 1981 and returned to the UK where it apparently became a museum piece. Wally Grimwood retired and he died in April 1982.
(There is some uncertainty as to when the Kine was actually moved to the Cape as King-Hele states 1969 but this is incorrect as the author observed with it numerous times in 1968 as a part-time Kine satellite tracker).
The Kine at the SAAO will be discussed in greater detail in a future article.
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To quote King-Hele "Throughout the 1980's there was no flagging in enthusiasm, productivity or accuracy among the visual observers who received predictions from, and sent observations, to ESRU. Each year the observers made about 20 000 observations. Russell Eberst had made 100 000 observations by 1980 and David Hopkins reached this target in 1986. Other skilled and prolific British observers in the 1970's and 1980's were David Brierley, Peter Wakelin and Mike Waterman. All these observers, and others, achieved a very high standard of excellence--a higher standard than in most professions."
Special mention has to be made of Bill Hirst, who after retiring as Moonwatch chief in the USA returned to Bergvliet (near Cape Town), South Africa were he became the most prolific observer from the southern hemisphere until Moonwatch closed down in 1975.
King-Hele retired in May 1988 but by then the writing was on the wall. In May 1990 the two Hewitt cameras were shut down. The prediction service for visual observers continued from RGO but most observers had withdrawn, finding their morale undermined by the apparent lack of appreciation for their work. As King-Hele put it so well "If the Hewitt cameras are unwanted, visual observations must be supremely useless".
So ended the era of amateur visual observers reporting scientifically useful data for use by professional space scientists, but was this the end of amateur satellite tracking?
A new direction
Many of the more dedicated observers, after having dedicated several decades of their life, felt the need to do something useful, even if purely for the satisfaction of doing something mentally stimulating, so there was now a new direction--the searching, location and derivation of orbital data for satellites not available in the public domain because the data was classified for one or other reason.
David Hopkins was probably the originator of this mode and by the mid 1980's was already maintaining his own data on about fifty satellites. Several other observers forwarded their observations to him. In Canada Ted Molczan often published these elements on the bulletin board of the Canadian Space Society and in the late 80's the author again became interested in optically tracking satellites but now interested in classified satellites.
In December 1994 the newsgroup called SeeSAT was created on the Internet by Walter Nissen and Bart De Pontieu with the intention of catering for all aspects of visual observing. Initially there was some opposition from some participants on the posting of data on classified satellites, and after the Twin Towers 9/11 event such data ceased to be posted, although a more private newsgroup was created by the main classified satellite trackers. After a short period, posting resumed to SeeSat and in July 2002 Ted Molczan took over the SeeSat newsgroup and its remains active to this day with approximately 1 000 subscribers--most of whom are so-called lurkers.
Today optical observing of classified satellites is the main activity with approximately two dozen active observers at most. Numerous observations are also reported on the optical characteristics of all satellites seen and a large database is maintained, so satellite tracking is alive and well today.
Many of the observers from the Moonwatch and subsequent era, and mentioned by name in this article are still active--mostly from the former WSRN, ITCP and British observers with the fortunate addition of new and younger observers. Technology has changed the way things are done and observations are of professional capability and often surpassing the accuracy that was obtained with some of the prime instruments of the 1960-1990 era.
Russell Eberst continues to observe and remains the world's most prolific observer and expects to reach 250 000 observations in 2015. David Hopkins has retired from satellite tracking, and the oldest tracker is Pierre Neirinck. Several trackers have since passes on--Bill Hirst is one such person.
Next article will start dealing with the amateur satellite tracking stations operated in South Africa during the period 1957 to the present.
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|Publication:||Monthly Notes of the Astronomical Society of Southern Africa|
|Date:||Apr 1, 2014|
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