Silicon ChipWRESAT: Australia’s first satellite – 50 years ago! - October 2017 SILICON CHIP
  1. Outer Front Cover
  2. Contents
  3. Publisher's Letter: Let’s be realistic about an Australian space industry
  4. Mailbag
  5. Feature: WRESAT: Australia’s first satellite – 50 years ago! by Dr David Maddison
  6. Feature: Three of our miniature satellites have gone missing... by Ross Tester
  7. Project: 0.01Hz - 6+GHz touchscreen frequency meter, Part 1 by Nicholas Vinen
  8. Feature: El Cheapo Modules Part 10: GPS receivers by Jim Rowe
  9. Project: One hour project: Kelvin – the very clever cricket by John Clarke
  10. Serviceman's Log: Old-fashioned appliance repairs are still worthwhile by Dave Thompson
  11. Project: 3-way Active Crossover for speakers, Part 2 by John Clarke
  12. Project: Deluxe eFuse, Part 3: using it! by Nicholas Vinen
  13. Feature: Adjust your hot-water thermostat and save $$$$ by Leo Simpson
  14. Subscriptions
  15. Vintage Radio: HMV 1955 Portable Model 12-11 by Associate Professor Graham Parslow
  16. PartShop
  17. Market Centre
  18. Notes & Errata: Automatic NBN/ADSL Router Rebooter / Power Supply for Battery-Operated Valve Radios / Vintage Radio (DKE38)
  19. Advertising Index
  20. Outer Back Cover: Microchip Low-power LCD

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Items relevant to "0.01Hz - 6+GHz touchscreen frequency meter, Part 1":
  • 6GHz+ Touchscreen Frequency Counter PCB [04110171] (AUD $10.00)
  • Short Form Kit for the Micromite Plus Explore 100 (Component, AUD $75.00)
  • Case pieces for the 6GHz+ Frequency Counter (PCB, AUD $15.00)
  • Software for the 6GHz+ Touchscreen Frequency Counter (v1.01) (Free)
Articles in this series:
  • 0.01Hz - 6+GHz touchscreen frequency meter, Part 1 (October 2017)
  • Touch-screen 6GHz+ Frequency Counter, part II (November 2017)
  • Part 3: Finishing our new 6GHz+ Digital Frequency Meter (December 2017)
Items relevant to "El Cheapo Modules Part 10: GPS receivers":
  • VK2828U7G5LF TTL GPS/GLONASS/GALILEO module with antenna and cable (Component, AUD $25.00)
Articles in this series:
  • El Cheapo Modules From Asia - Part 1 (October 2016)
  • El Cheapo Modules From Asia - Part 2 (December 2016)
  • El Cheapo Modules From Asia - Part 3 (January 2017)
  • El Cheapo Modules from Asia - Part 4 (February 2017)
  • El Cheapo Modules, Part 5: LCD module with I²C (March 2017)
  • El Cheapo Modules, Part 6: Direct Digital Synthesiser (April 2017)
  • El Cheapo Modules, Part 7: LED Matrix displays (June 2017)
  • El Cheapo Modules: Li-ion & LiPo Chargers (August 2017)
  • El Cheapo modules Part 9: AD9850 DDS module (September 2017)
  • El Cheapo Modules Part 10: GPS receivers (October 2017)
  • El Cheapo Modules 11: Pressure/Temperature Sensors (December 2017)
  • El Cheapo Modules 12: 2.4GHz Wireless Data Modules (January 2018)
  • El Cheapo Modules 13: sensing motion and moisture (February 2018)
  • El Cheapo Modules 14: Logarithmic RF Detector (March 2018)
  • El Cheapo Modules 16: 35-4400MHz frequency generator (May 2018)
  • El Cheapo Modules 17: 4GHz digital attenuator (June 2018)
  • El Cheapo: 500MHz frequency counter and preamp (July 2018)
  • El Cheapo modules Part 19 – Arduino NFC Shield (September 2018)
  • El cheapo modules, part 20: two tiny compass modules (November 2018)
  • El cheapo modules, part 21: stamp-sized audio player (December 2018)
  • El Cheapo Modules 22: Stepper Motor Drivers (February 2019)
  • El Cheapo Modules 23: Galvanic Skin Response (March 2019)
  • El Cheapo Modules: Class D amplifier modules (May 2019)
  • El Cheapo Modules: Long Range (LoRa) Transceivers (June 2019)
  • El Cheapo Modules: AD584 Precision Voltage References (July 2019)
  • Three I-O Expanders to give you more control! (November 2019)
  • El Cheapo modules: “Intelligent” 8x8 RGB LED Matrix (January 2020)
  • El Cheapo modules: 8-channel USB Logic Analyser (February 2020)
  • New w-i-d-e-b-a-n-d RTL-SDR modules (May 2020)
  • New w-i-d-e-b-a-n-d RTL-SDR modules, Part 2 (June 2020)
  • El Cheapo Modules: Mini Digital Volt/Amp Panel Meters (December 2020)
  • El Cheapo Modules: Mini Digital AC Panel Meters (January 2021)
  • El Cheapo Modules: LCR-T4 Digital Multi-Tester (February 2021)
  • El Cheapo Modules: USB-PD chargers (July 2021)
  • El Cheapo Modules: USB-PD Triggers (August 2021)
  • El Cheapo Modules: 3.8GHz Digital Attenuator (October 2021)
  • El Cheapo Modules: 6GHz Digital Attenuator (November 2021)
  • El Cheapo Modules: 35MHz-4.4GHz Signal Generator (December 2021)
  • El Cheapo Modules: LTDZ Spectrum Analyser (January 2022)
  • Low-noise HF-UHF Amplifiers (February 2022)
  • A Gesture Recognition Module (March 2022)
  • Air Quality Sensors (May 2022)
  • MOS Air Quality Sensors (June 2022)
  • PAS CO2 Air Quality Sensor (July 2022)
  • Particulate Matter (PM) Sensors (November 2022)
  • Heart Rate Sensor Module (February 2023)
  • UVM-30A UV Light Sensor (May 2023)
  • VL6180X Rangefinding Module (July 2023)
  • pH Meter Module (September 2023)
  • 1.3in Monochrome OLED Display (October 2023)
  • 16-bit precision 4-input ADC (November 2023)
  • 1-24V USB Power Supply (October 2024)
  • 14-segment, 4-digit LED Display Modules (November 2024)
  • 0.91-inch OLED Screen (November 2024)
  • The Quason VL6180X laser rangefinder module (January 2025)
  • TCS230 Colour Sensor (January 2025)
  • Using Electronic Modules: 1-24V Adjustable USB Power Supply (February 2025)
Items relevant to "One hour project: Kelvin – the very clever cricket":
  • Kelvin the Cricket PCB [08109171] (AUD $7.50)
  • PIC12F675-I/P programmed for Kelvin the Cricket [0810917B.HEX] (Programmed Microcontroller, AUD $10.00)
  • Firmware (HEX and ASM) file for Kelvin, the Very Clever Cricket [0810917B.HEX] (Software, Free)
  • Kelvin the Clever Cricket PCB pattern (PDF download) [08109171] (Free)
Items relevant to "3-way Active Crossover for speakers, Part 2":
  • 3-Way Adjustable Stereo Active Crossover PCB [01108171 RevD] (AUD $12.50)
  • 3-Way Adjustable Stereo Active Crossover prototype PCB [01108171 RevC] (AUD $5.00)
  • 3-Way Adjustable Stereo Active Crossover PCB [01108171 RevE] (AUD $20.00)
  • Set of four 8-gang potentiometers with knobs for the 2/3-Way Active Crossover (Component, AUD $55.00)
  • SMD parts for the 3-way Adjustable Active Stereo Crossover (Component, AUD $30.00)
  • 3-Way Adjustable Stereo Active Crossover simulation file (Software, Free)
  • 3-Way Adjustable Stereo Active Crossover PCB pattern (PDF download) [01108171] (Free)
  • 3-Way Adjustable Stereo Active Crossover front & rear panel artwork (PDF download) (Free)
Articles in this series:
  • Fully adjustable, 3-way active loudspeaker crossover Pt.1 (September 2017)
  • 3-way Active Crossover for speakers, Part 2 (October 2017)
Items relevant to "Deluxe eFuse, Part 3: using it!":
  • Deluxe Touchscreen eFuse PCB [18106171] (AUD $12.50)
  • PIC32MX170F256B-50I/SP programmed for the Deluxe Touchscreen eFuse [1810617A.HEX] (Programmed Microcontroller, AUD $15.00)
  • 2.8-inch TFT Touchscreen LCD module with SD card socket (Component, AUD $25.00)
  • IPP80P03P4L-07 high-current P-channel Mosfet (Component, AUD $2.50)
  • LT1490ACN8 dual "Over-the-Top" rail-to-rail op amp (Component, AUD $10.00)
  • IPP80N06S4L-07 high-current N-channel Mosfet (TO-220) (Component, AUD $2.00)
  • Matte Black UB1 Lid for the Deluxe Touchscreen eFuse (PCB, AUD $7.50)
  • Software for the Deluxe Touchscreen eFuse (Free)
  • Deluxe Touchscreen eFuse PCB pattern (PDF download) [18106171] (Free)
Articles in this series:
  • Deluxe Touchscreen eFuse, Part 1 (July 2017)
  • Deluxe Touchscreen eFuse, Part 2 (August 2017)
  • Deluxe eFuse, Part 3: using it! (October 2017)

Purchase a printed copy of this issue for $10.00.

WRESAT: Australia joins the space race... fifty years ago! Launch of WRESAT, 29th of November 1967. Note the kangaroo logo on the side of the rocket. There is also a woomera (Aboriginal spear thrower). The rocket had been painted white (brushed, not sprayed, apparently!) to assist tracking but beneath that paintwork remained the greenish US Army colour scheme, some of which is visible on the recovered Stage 1 vehicle (see page 21). Photo courtesy Defence Science and Technology Group, Department of Defence. Most people would not be aware that Australia was just the seventh country to put a satellite of its own design into orbit. Just ten years after the launch of Sputnik, Australia successfully launched “WRESAT” from the Woomera Rocket Range in South Australia. On the 50th Anniversary, Dr David Maddison takes a look at what, for the time, was a remarkable achievment. siliconchip.com.au Celebrating 3030 Years Celebrating Years O October ctober 2017  13 2017  13 A fter the Soviet Union launched “Sputnik” in 1957, the United States launched Explorer 1 in 1958, then the United Kingdom followed in 1962. Canada (also in 1962), Italy (1964) and France (1965) had also launched satellites. Australia followed when it launched its first satellite, WRESAT, in 1967. Its name (pronounced “reesat”) is a shortened form of the Australian Weapons Research Establishment (WRE) SATellite. Incidentally, Australia was just the third country to launch a satellite from its own territory, after the USSR and USA. (France is often claimed to be the third country to launch from its own soil but their launch was from post-colonial Algeria). This satellite gave Australia membership of the then-exclusive “space club” which at the time only had the six members mentioned above. It also gained wide publicity in Australia and worldwide. The entire project was one of exploiting available opportunities such as the availability of a largely US-built rocket providing the launch vehicle, a “can do” attitude, government support with minimal interference and a rapid build of the satellite which took only 11 months and was done on a small budget. The USA had been using rockets 14 Silicon Chip at the Woomera Rocket Range (as it was then known) in South Australia, in a collaborative research program with Australia and the UK called Project SPARTA (SPecial Antimissile Research Tests, Australia). The purpose of the project was to test the various physical effects involved in high speed re-entry of nuclear warheads into the upper atmosphere. Ten rockets had been shipped to Australia but only nine were used. The options were to return the tenth rocket to the USA at great expense or alternatively, according to an idea put forward by the Australians, the rocket could be used to launch a small satellite. The Americans thought the idea was excellent and offered a team to prepare the rocket as well. The gift of the rocket was a reward for the great Australia-US friendship and longterm involvement in NASA tracking. There was a challenge, however: the Americans and their team would be leaving Woomera in 12 months hence, which meant that a satellite had to be designed, built, tested and launched within that timeframe. This wasn’t the first offer the USA had made for Australia to use one of their rockets. According to a biographical article about University of Adelaide’s Professor John H. Carver, there had been a previous offer Celebrating 30 Years (Above): “The Canberra Times” of 30th November, 1967 – “All systems go!” (Below): Australia joins the “Exclusive Space Club”, a cartoon of the time. Unfortunately, many have forgotten or don’t know that Australia was ever a member. There is an error in the cartoon where it says we were the fourth nation to launch a satellite – we were seventh overall, although the third to launch a satellite from our own soil. siliconchip.com.au A photo from the Adelaide Advertiser, November 14, 1967, showing key WRESAT personnel: (L-R) Project Manager Des Barnsley (WRE), Professor John H. Carver (UA), Bryan Rofe (Scientific officer in charge, from WRE) and WRE Director Dr Don Woods. Note the antennas about one third of the way up the body. Photo courtesy of Professor John A. Carver, son of Professor John H. Carver. in 1960 but there was no interest in space research by the Australian Government at the time and so the offer was declined. Prior to that, Australian scientists had tried to get access to rockets being launched at Woomera as part of the Australian contribution to the International Geophysical Year in 1957–58 but they could not; one of several very disappointing missed opportunities. The proposal for an Australian satellite received high-level approval from the government at the end of 1966 and with a minimum of bureaucratic interference the project was initiated. One of the reasons cited for approval was national prestige, others being the relatively low cost of the project and also giving staff at Woomera experience in satellite launches. NASA agreed to provide tracking and data acquisition services for the project via their Satellite Tracking and Data Acquisition Network (STADAN) while Britain also offered support by the use of their facilities. NASA also donated the data tapes. There were a lot of very smart and committed people involved in this project but in this article, we will focus on the science and technology rather than the people within the team and their specific involvement. siliconchip.com.au This has been documented elsewhere such as in the book “Fire across the Desert: Woomera and the AngloAustralian Joint Project, 1946-1980” by Peter Morton. Designing and building the satellite The WRESAT satellite itself was designed and built as a joint project between the Weapons Research Establishment (WRE) of the Department of Supply and the Physics Department of the University of Adelaide. They were already cooperating on a research program with the use of locally developed sounding rockets and payloads for upper atmosphere measurements for climate research. Given the short time frame available, it was logical to build upon the existing work and expertise of these upper atmospheric measurements. A satellite offered many advantages over sounding rockets (rockets carrying instruments to perform experiments during sub-orbital flights), such as measurements over a much larger time scale than the few minutes permitted by sounding rockets, plus the ability to make measurements at any point on the earth’s surface. As mentioned above, the launch vehicle and vehicle preparation team were provided by the USA, specifically the Advanced Research Projects Agency of the Department of Defense (DARPA) through the US Army Missile Command. This team included private contractors from Thompson Ramo Wooldridge Systems (most recently known as TRW, Inc. but defunct as of 2002, when it was acquired by Northrop Grumman). WRESAT was built in the form of a cone which formed the top of the rocket, rather than the traditional design which was contained within a jettisonable fair- Vacuum chamber at the University of Adelaide in which WRESAT was tested to ensure its systems would tolerate a vacuum. Photo courtesy of Professor John A. Carver. Celebrating 30 Years October 2017  15 The main instrument packages and components of WRESAT. Images courtesy Defence Science and Technology Group, Department of Defence. ing. Presumably this was done for space efficiency and simplicity. The mechanical construction was in the form of a ring and stringer design, meaning the round shape was established by a series of rings connected by a series of long strips or “stringers”, a typical aerospace type of construction.This was covered by an aluminium skin 1.2mm thick. This is about two to three times the thickness of the skin of a light aircraft. Three satellite cones were built. The first was used as a model for the structural design, the second was used for checking the internal arrangement and accessibility of components and the third was the actual working one launched into space. The exterior of the satellite was painted mostly black and the interior was white, both colours chosen to aid in thermal management. On the exterior, there was also some silver striping to give a balance between heat absorbed on the sunlit side and radiated on the shadow side. An interesting anecdote is that what was thought to be a special aerospace grade white paint was imported at great expense from the USA and 15 coats had to be applied in a marathon 48 hour painting session. But it turned out that the wrong paint was sent and it was the equivalent of house paint. 16 Silicon Chip Despite this, it worked fine. WRESAT itself was 159cm long with a base diameter of 76cm and a weight of 45kg without the stage three motor. Including the third stage, it weighed 72.5kg and had an overall length of 217cm. After burn out, stage three (including its motor) remained attached to the satellite by design. In comparison, the Soviet Sputnik 1 weighed 83.6kg and had a diameter of 58cm and the US Explorer 1 weighed 13.97kg and was 205.1cm long and 15.2cm diameter. Those satellites were the first for both countries. Part of the satellite testing included placing it in a vacuum chamber at the University of Adelaide, to ensure its systems would tolerate the vacuum of space. Static, vibration and shock testing was also done to ensure the satellite would tolerate the shock of launch and high acceleration forces. Shock testing was done to 40g. As the satellite was to spin, it also needed to be properly balanced and this was done on commercial Repco equipment used for engine balancing. Radio testing was also done to determine that the antennas and telemetry worked correctly along with the tracking transponder. Temperature cycling was done between -15°C and +50°C. WRESAT structural model undergoing vibrational testing. Photo courtesy Defence Science and Technology Group, Department of Defence. Celebrating 30 Years siliconchip.com.au WRESAT was powered by batteries (one mission battery and one for the tracking transponder) rather than solar panels, as back then they were not off-the-shelf items and an array would have to have been designed and built which would also have also complicated the design. There was not enough time to do this. The battery type is not disclosed in the available literature but looking at spacecraft battery technology of the period, we speculate that they may have been silver-zinc batteries with a potassium hydroxide electrolyte, such as were used on the Apollo Lunar Module which had a battery voltage of 28V, the same as the battery on WRESAT. The batteries were intended to last about 10 days and the orbital life was expected to be 40 days. The satellite had two sensor ports, one at the apex of the satellite and one at the side. These were protected by covers during ascent and were later released by explosive nuts. There were also telemetry antennas external to the body of the craft. Instruments and sensors The measurement sensors in the forward port were three ion chambers, an ozone sensor and an aspect sensor. The side port had three ion chambers, a Lyman a (alpha particle) telescope The initial spin axis of WRESAT was along the long axis but for the sensors to operate as desired this had to be changed to rotation about an axis at right angles to this. and an aspect sensor. Other equipment on board included an X-ray counter, telemetry transmitter, a magnetometer, a transponder for tracking, a power supply and the batteries. The ion chambers measured UV light at three wavelengths which strongly affect the atmosphere; one of the wavelengths had never been measured from a satellite before. The same sensors could also be used to measure the temperature of the Sun’s atmosphere and the density of molecular oxygen in the atmosphere. There was also a photodiode sensor to measure ozone in the atmosphere and an X-ray counter. The Lyman a telescope measured UV radiation from hydrogen atoms around the earth. WRESAT telemetry WRESAT transmitted telemetry data at 136.350MHz with a power of 0.1W. There were 29 channels of data, 15 for the scientific instruments plus 14 for housekeeping functions such as battery voltage and internal temperature. Apart from their data content, the signals were also used by NASA’s STADAN network to track WRESAT. Ground stations recorded telemetry signals on tape but were not able to decode the data so the tapes had to be sent back to Australia for analysis. It is not clear how tracking continued after the main battery weakened but we speculate that this was done via the C-band transponder. Science program Preparing WRESAT, showing some detail of the electronics packages. Note part of the third stage rocket motor visible in the lower portion of the vehicle. Image courtesy of Professor John A. Carver. siliconchip.com.au WRESAT was primarily designed to conduct atmospheric research, with a particular emphasis on how atmospheric properties affect weather in Australia, the ability to conduct weather forecasts and even “controlCelebrating 30 Years ling the weather”. This was a topic of significant interest, especially cloud seeding research, as was being done in Australia at the time. It was a natural extension to the collaborative work already being conducted between the University of Adelaide and WRE using sounding rockets to measure parameters of the upper atmosphere and for which expertise had already been developed. Other objectives of the WRESAT program included the development of Australian scientific and technological expertise related to satellite development and management of complex projects of this kind and also assistance to the USA with its research programs. There were four experiments on WRESAT. These were based upon or derived from earlier work that was done with sounding rockets. Two experiments were designed to measure ultraviolet radiation from the sun, one was to measure faint ultraviolet halo from the earth at night and another experiment was to measure X-rays from the sun. Satellite spin and energy dissipation mechanism In order for the satellite to be effective, it had to achieve a certain orientation and rotation. After the burn-out and separation of the first stage, the satellite (with stages two and three still attached) coasted to an altitude of about 185km, the inertial guidance system having placed the spacecraft into a horizontal position with respect to earth. Spin rockets were then ignited to cause the spacecraft to rotate about its long axis like a rifle bullet, with a roll rate of around 2.5 RPM. Stage two was then ignited and was discarded October 2017  17 The front-over-end rotation was needed so that the satellite sensors, which had a field of view of 80°, could scan the Earth and Sun. The launch Woomera Launch Area 6 (LA-6), one of a number of launch facilities that once existed at Woomera. This pad was last used in 1970, most recently by the European Launcher Development Organisation to develop a European rocket although no satellites were ever successfully launched. European satellite launches are now mostly conducted from French Guiana. This pad was not used by WRESAT but is shown to indicate the extensive nature of the launch facilities that were available. Sadly, the historic significance of this pad was not recognised and only the concrete remains today. after burn-out. Stage three was then ignited to insert the satellite into its final orbit, at an initial speed of around 28,500km/h and an altitude of 185km. With ideal balance and no friction, the satellite would continue to spin on its long axis indefinitely (like a rifle bullet) but just as a (non-ideal) spinning top eventually starts to move off axis or “nutate” as it loses energy, so did the satellite. This is because no system is perfectly balanced or rigid and spin energy is lost, causing the axis of rotation to change to the one with the greatest moment of inertia (which in this case was not the long axis). In fact, this behaviour was both expected and desired. The desired spin axis was not the long axis but one at right angles to the long axis, with the head spinning front over end and the axis being parallel to the original spin axis of the satellite at its start of orbit. The new spin rate was 0.5 RPM, as determined by the ratio of the axial mode to tumble mode inertia. The change in spin axes was facilitated by an energy dissipation device in the form of a metal tube containing silicone oil which acted to slow the rotation, removing some spin energy (as with a spinning top that moves off axis), due to the movement of the oil in the tube dissipating energy in the form of heat. 18 Silicon Chip The transition would have happened anyway but purposefully dissipating some of the energy sped up the process which was achieved within one or two orbits, compared with the much longer time that would have been taken if relying on the natural energy dissipation processes on the satellite, such as flexing of the body. The phenomenon of certain rotating objects changing their spin axis in space is shown in the video “Rotating Solid Bodies in Microgravity” at siliconchip.com.au/link/aafz Due to a fault in an umbilical connection to the rocket, WRESAT did not launch on November 28th as planned, causing great disappointment to many dignitaries who had attended. However, the next day, WRESAT was launched at 2:19pm local time. The launch went flawlessly. Two minutes after the launch, stage one burned out and separated. Stages two and three continued and then the spin motors fired, to cause the satellite to spin on its long axis. Stage two was fired and burned out at 30 seconds, separated and fell toward the Gulf of Carpentaria. Stage three fired for nine seconds, finally propelling WRESAT to its orbital velocity. The first incoming telemetry from the rangehead was good and it was confirmed that the instrument port covers were ejected but it was not yet confirmed that WRESAT was in orbit. The next telemetry came in from Gove which was also good. Guam was the first NASA STADAN tracking station to receive telemetry followed by Fairbanks, Alaska. Things were looking good! At Fairbanks, it was noted that the spin rate had decreased from two to 0.7 revolutions per minute, on its way to 0.5, and the change in spin axes was happening faster than expected. The next STADAN stations to receive telemetry were St Johns, New- The ground track of WRESAT for first eight orbits, showing tracking stations as black dots and telemetry recording stations as white dots. Image from http://siliconchip.com.au/link/aaf8 Celebrating 30 Years siliconchip.com.au foundland; Rosman, North Carolina; Quito, Ecuador; Lima, Peru and Santiago, Chile. Twenty-five minutes after the Santiago contact, telemetry was received at Carnavon, WA. This proved that WRESAT had completed an entire orbit and the mission was a success. WRESAT transmitted useful data for 73 orbits each of 98.974 minutes’ duration over five days, until the main battery was too weak. The satellite eventually completed 642 orbits over 42 days, re-entering the earth’s atmosphere on January 10th, 1968 just before 12 noon GMT, between Ireland and Iceland. Note that the number of orbits corresponds to 44 days, not 42; it is not clear why there is a discrepancy. Launch location and trajectory WRESAT was launched over what was arguably one of the finest rocket ranges in the world, which was then known as the Woomera Rocket Range and is now known as the RAAF Woomera Test Range. One of Woomera’s great advantages was the largest overland downrange distance in the Western world of 2250km, from Woomera to the north coast of WA, making parts recovery relatively easy for post flight analysis. Having been established as a joint venture between Australia and the UK, in the 1950s and 1960s it was the sec- ond-busiest rocket range in the world next to Cape Canaveral. WRESAT was launched into a polar orbit so the trajectory was to the north, rather than toward the north coast of Western Australia. There is some variation in the reported orbital parameters of WRESAT but according to Fire Across the Desert, the perigee of the orbit was 169km and the apogee was 1245km. On the other hand, according to the 1968 annual report of the Department of Supply, it was 177km x 1287km. Another figure cited is 198km x 1252km. The most correct figures likely come from NASA’s computed orbital elements for this flight, designated 1967118A and issued on 29th November, which are 170km x 1249km. According to those orbital elements, the orbit was nearly polar with an inclination from the equator of 83.3°. The velocity at apogee was 25,016km/h and at perigee, 29,137km/h. Range safety and satellite tracking Safety over the rocket range was always a top priority at Woomera and while no one would want to do it, if the rocket veered out of control, it would have been necessary to press the self-destruct button. The rocket self-destruct mechanism was called WREBUS. Because of its northerly track, it was not clear whether the self-destruct ra- Planned trajectory for WRESAT launch. Note the first stage estimated landing area in the Simpson Desert. Dick Smith found the stage in 1989. There is speculation that the second stage did not land but burned up on re-entry. The northerly launch corridor was one of two that were possible from Woomera, the other being the launch corridor to the north west. Image courtesy of Defence Science and Technology Group, Department of Defence. siliconchip.com.au Celebrating 30 Years One of the two FPS-16 radars used to track WRESAT at launch. Image source: siliconchip.com.au/link/aaf8 dio signal could reach the rocket or whether it would be attenuated by the second stage rocket flame. A decision was made to install a WREBUS transmitting station at the Oodnadatta Airfield to ensure a signal could get through. To ensure that the rocket remained on track or to detect any deviation from the planned track, its progress was monitored by observers using optical trackers plus a pair of FPS-16 radars which were part of the range facilities. One of the radars was located 40km from the beginning of the range and the other 115km south of Coober Pedy. The radars could track a target out to at least 971km and a ranging error of as little as five metres was possible. These radars operated around 5.5GHz, with up to 1MW of output power. There was also a Digital Impact Predictor which had been developed for the Blue Streak and Europa programs, to predict impact points of the rocket stages or debris. The radars could operate in either the conventional mode, whereby they detected a reflected signal from a target, or in “beacon” mode whereby a coded signal was transmitted from the radar which triggered a C-band (4-8GHz) transponder on the spacecraft. This then replied with an appropriate signal. The transponder was a special unit, model SST-135C, designed to work with this radar equipment. This allowed a much greater range and the spacecraft could be tracked up to the point of orbital insertion and beyond. In the diagrams of WRESAT, the Cband transponder is visible and it can be seen to have its own battery pack. While not stated anywhere in the literature surveyed for this article, it is assumed that the C-band transponder remained active for the life of the mission, even after the main satellite battery had become weak. October 2017  19 This would have been how the satellite was tracked throughout its orbit (via other radar stations around the world) and its re-entry point determined. That is speculation by the Author, however. The radar system and its various modifications were considered cutting-edge technology for the time. The radar system was also used by NASA to track Mercury and later spacecraft. The launch vehicle While the satellite was of Australian design, as stated earlier, the SPARTA launch vehicle was donated by the United States. It was a three-stage rocket that used a Redstone missile (SRBM) with 416kN thrust as its first stage. This was fuelled with liquid oxygen and Hydyne, a mixture of 60% unsymmetrical dimethylhydrazine (UDMH; similar to hydrazine) and 40% diethylenetriamine (DETA) This is somewhat more powerful but also more toxic than the alcohol/water fuel used in earlier Redstone rockets. The Redstone was America’s first large short-range ballistic missile and was capable of carrying a 3100kg nuclear warhead 280km. In other applications, it had a range of up to 323km. It was a direct descendant of the German V-2 rocket of World War 2 and was mainly designed by German engineers who had been bought to the USA after the war. The rocket was produced from 1952 to 1961 and retired from use by the US Army in 1964 after which many surplus rockets were put to alternative uses such as tests and satellite launches, including WRESAT. The Redstone missile was also modified and used to put America’s first astronaut into space (John Glenn). SPARTA’s second stage was a 93kN Antares 2 (designed by Thiokol, also known as X-259). This was originally the third stage of the USA’s Scout fourstage solid fuel rocket, also designed for launching satellites. The third stage was an Australiandesigned BE-3, by WRE (Weapons Research Establishment), with 34kN thrust. This also used solid fuel. In order to conduct firings of the SPARTA rockets, including the one that launched WRESAT, some equipment that had previously been donated to the Smithsonian Institution for museum display had to be borrowed back. WRESAT was the last launch that utilised a Redstone missile and was considered a great end to the career of this excellent and successful rocket. At launch, the SPARTA rocket with the WRESAT payload weighed around 25.8 tonnes and the Redstone motor developed 34.0 tonnes of thrust for 122 seconds. These figures come from the booklet describing WRESAT from WRE, however, Wikipedia quotes 30.0 tonnes as the mass of a SPARTA launch vehicle with 42.4 tonnes of first stage thrust and a burn time of 155 seconds. It is therefore conceivable that the launch used a lesser fuel load than normal for the WRESAT mission. Dick Smith undertook an expedition in 1989 to find the first stage of the rocket vehicle in the Simpson Desert (see box). The second stage was designed to land in the Gulf of Carpentaria and has not been found (it’s unlikely that it ever will be). The re-entry of the second stage was not observed and it is speculated it may have burned up as it fell back to earth. The third stage remained attached to the satellite. This was intended to eliminate the added complexity of a separation mechanism. Congratulations After the successful launch, congratulations were received from numerous places, including a radio broadcast from Prime Minister Harold Holt, who said it was “a notable sci- Some of the University of Adelaide and Weapons Research Establishment scientists, engineers, technical and support staff involved in the WRESAT project at WRE. Photo courtesy Professor John A. Carver. 20 Silicon Chip Celebrating 30 Years siliconchip.com.au Dick Smith finds the WRESAT Stage 1 rocket Event Cover for WRESAT launch with 5c stamp issued by the Postmaster-General’s Department. Acknowledgement Dr Ross J Smith: siliconchip.com.au/link/aaf9 entific achievement, demonstrating a remarkable advance by Australia”. A notable message from Hubert Humphrey, Vice President of the United States reads “Word that your scientific spacecraft is performing successfully in orbit is a source of satisfaction to all. Congratulations and welcome to the ‘Space Club’.” A summary of congratulations received from around the world appears at siliconchip.com.au/link/aafa Scientific findings and conclusion The findings of WRESAT were published in three sci- Redstone launch vehicle and WRESAT payload. Overall height was almost 21.8m (all dimensions shown here are in feet and inches). Note that the third stage intentionally remained attached to the satellite after motor burn out. Image courtesy of siliconchip. com.au/link/aaf8 siliconchip.com.au In 1989, Dick Smith was reading about the history of the Woomera Range and was inspired to find the remains of the rocket that launched WRESAT. With the cooperation of the Department of Defence, he contacted the Range Safety Officer at Woomera, Bruce Henderson, who used original tracking data from the launch to determine the probable location of the first stage. The location was predicted to be 623km north of Woomera and 255km west of Birdsville with an error range of 8km. Dick Smith mounted an expedition to find the remains of the launch vehicle and he found it in the Simpson Desert on the 5th of October. It was recovered by volunteers in April 1990 and returned to Woomera, 600km away. The story of the recovery is very interesting itself and details are to be found in the article by Kerrie Dougherty, listed on page 24. Dick Smith’s wife, Pip, with the wreckage of the WRESAT first stage. Note how where the white paint has weathered off, it has exposed the original US Army colour scheme. Fortunately, the wreck had not been found by souvenir hunters or there might not have been much left! It was returned to Woomera, where it is now on display. Photos courtesy Dick Smith. Celebrating 30 Years October 2017  21 Another early Australian satellite: Australis OSCAR-5 Another satellite produced in Australia at about the same time as WRESAT was the amateur radio satellite Australis-OSCAR 5, built by students at the University of Melbourne. (OSCAR stood for Orbiting Satellite Carrying Amateur Radio). The satellite was completed on June 1, 1967, pre-dating WRESAT, but it required some minor modifications and was finally launched on January 23, 1970 from Vandenberg Air Force Base in California. The satellite was 43cm x 30cm x 15cm in size and weighed 17.7kg. It was the first remotely controlled amateur satellite and the first launched by the new AMSAT organisation. See the following links for more details: siliconchip.com.au/link/aafb (the most detailed site) siliconchip.com.au/ link/aafc Here is a recording of some of its telemetry: siliconchip.com.au/link/aafd Recommended videos and other resources Recollections of Professor John H. Carver on the WRESAT project can be found on pages 87 & 88 of “Space Australia: The Story of Australia’s Involvement in Space” by Kerrie Dougherty and Matthew James, 1993. Available from the Museum of Applied Arts & Sciences, http://siliconchip.com.au/link/aag1; (Powerhouse Publishing), $32.95 plus p&p There is information about WRESAT and other early Australian involvement in the space program at the Honeysuckle Creek website. See siliconchip.com.au/link/aag0 A scan of the original booklet published about WRESAT is also available there. “Weapons Research Establishment Satellite (WRESAT)”, 1967: siliconchip.com.au/link/aafe At 1:35 in this video, you will see the recovered first stage of the WRESAT launch which was found by Dick Smith: siliconchip.com.au/link/aafy Unfortunately, YouTube has removed the audio from this video due to copyright reasons but you can still see some interesting scenes, albeit silent ones. “Woomera Rocket Range”: siliconchip.com.au/link/aaff This video is not directly related to WRESAT but talks about the Island Lagoon Tracking Station at Woomera that received the first images from lunar orbiters that were used to select landing sites for the Apollo missions. It shows how heavily involved Australia was in the early space race. “How Woomera helped to map the moon”: siliconchip.com.au/link/aafg See also: siliconchip.com.au/link/aafh “A small scientific satellite” siliconchip.com.au/link/aafi “Preparation of the satellite” siliconchip.com.au/link/aafj “Launch of the satellite” siliconchip.com.au/link/aafk User “mendahu” on imgur.com has created some graphic reconstructions of aspects of the launch at siliconchip.com.au/link/aafl A biography of Professor John H Carver which also discusses his work on WRESAT: siliconchip.com.au/link/aafm Australian Space History by Colin Mackellar, including WRESAT: siliconchip.com.au/link/aaf8 Re-connecting veterans of WRESAT: siliconchip.com.au/link/aafn and siliconchip.com.au/link/aafo “Old Reliable: The story of the Redstone” with mention of WRESAT: siliconchip.com.au/link/aafp There is a project to build a replica of WRESAT and its rocket, however, the crowd funding link does not appear to be working: siliconchip.com.au/link/aafq entific papers plus a doctoral thesis. One of the findings was a confirmation of a layer of ozone in the atmosphere between 110km and 120km altitude. Another was a refined figure for the temperature of the Sun’s atmosphere which is close to the currently accepted figure. Unfortunately, since the early days when Australia had quite an extensive involvement in space exploration, we have subsequently failed to follow up on numerous space-related opportunities. WRESAT could have been the start of a productive space industry in Australia but unfortunately, that was not SC to be. 22 Silicon Chip There is a display of one of the WRESAT test satellites at the Woomera Heritage Centre. This is a picture of the display. You can see various pictures of the displays, including two of WRESAT at the following link: siliconchip.com.au/link/aafr Australia’s space-related contributions to the International Geophysical Year 195758, from page 29 to 32: siliconchip.com.au/link/aafs “Retrieving Woomera’s heritage: recovering lost examples of the material culture of Australian space activities” by Kerrie Dougherty: siliconchip.com.au/link/aaft For a detailed look at the Redstone missile, go to siliconchip.com.au/link/aafu There are some excellent diagrams and detailed photos. Redstone missile history and firing procedure: siliconchip.com.au/link/aafv Detailed description and US Army manuals for Redstone missile: siliconchip.com.au/link/aafw “Redstone: The Missile That Launched America into Space”: siliconchip.com.au/link/aafx * These SILICON CHIP Shortlinks will take you direct to the appropriate page Celebrating 30 Years siliconchip.com.au