4th ANNUAL ASRI CONFERENCE 12 - 14th December 1994 CONFERENCE SUMMARY Written by Michael Leske (4th Yr Adelaide Uni. Mech Eng.) INTRODUCTION This report provides a brief summary of the student project presentations at the 4th Annual ASRI Conference which was held at the Australian National University in Canberra from the 12-14th December 1994. The conference presented a broad over view of all the ASRI programs currently being worked on. Invited speakers included: * Dr. Brian Embleton (Head COSSA, ASRI Research Director) "Opening Presentation" * Mr. David Large (Policy Coordinator, Australian Space Office) "Australian Space Office - 5 Year Plan" * Mr. Mark Blair (ASRI Chairman) "ASRI - Year in Review" * SQNLDR G. Wren (Force Development (Air), Space Systems) "Space Systems Applications in the Defence of Australia" * Mr. Ken Stone (Public Relations, Australian Space Office) "Australian Space Office - Public Awareness Program" * Mr. Chris Deakin (Director Space Communications, ASO) "Satellite Services for Australia" * Mr. Ed Roberts (Major Projects Manager, Auspace) "LightSats and Australia" * Dr. Sarjal Pilot (University of Canberra) "Joint DCA - Uni. of Canberra Satellite Comms. Facility" ASRI PROGRAM OBJECTIVES The main objectives of ASRI are to: * Develop and advance space technology. * Conduct encourage and promote space related R and D. * Provide educational project opportunities to students. * Coordinate programs in support of the above. The involvement of Universities around Australia are: Adelaide Uni, Monash Uni, Uni NSW, U.T.S., Uni of SA, Sydney Uni, U.S.Q., Q.U.T., Queensland Uni and R.M.I.T., all of which are working together on different projects. The Ausroc projects include Ausroc I - IV, there are projects involved with the Scramjet Program, the Sighter Rocket Program and also the Australis Program. ASRI program sponsors includes the following: * Ardebil Pty. Ltd. * Australian Space Insurance Group (ASIG) * Australian Space Office (ASO) * Davidsons Pty. Ltd. * Department of Defence (DOD) * Explosives Factory Maribyrnong (EFM) * Hawker De Havilland (HdH) * Royal Australian Air Force (RAAF) * South Australian Economic Development Authority (EDA) * CSIRO Office of Space Science and Applications (COSSA) * Defence Science and Technology Organisation (DSTO) PROGRAM UPDATES Caratel Program Update The goal for the Caratel Rocket is to be finished by May 1995. There have been improvements to the nitric acid and alcohol valves by experimenting with different types of valves and seals. It was found that simple bike valves were inadequate and stainless steel valves are required with teflon seals. The recovery system will be electronically activated by pressure transducers and will release the parachute by the use of a solenoid. Ausroc II-2 Program Update There have been many improvements to Ausroc II-2 to ensure that it does not have the same tragedy as Ausroc II-1. These improvements include: * Check valves in the tank pressurisation lines to ensure no back flow. * 3 fins instead of original four fin design. * Nylon pneumatic lines replaced with stainless steel lines. * 3 piece Kerosene valve replaced with Apollo stainless steel ball valve. * 3 piece LOX valve replaced with Apollo stainless steel ball valve. * LOX valve actuator replaced with piston/cam assembly. * Convoluted LOX braided pipes replaced with solid stainless steel tubes. * Push-lock pneumatic fittings replaced with swagelok fittings. * Customised fittings, to reduce joints between components. * Longer fairing spigots machined onto tank ends. * Larger fairing hatches with removable backing plates. * Umbilical connector moved up to payload section. * Launch rail stiffened with a truss frame. * The payload has also been revised as follows: Sensors: 3 accelerometers 2 pressure sensors (measuring altitude, mach #) 4 pressure sensors (on tanks and chamber) valve position sensors (for testing) supply voltage measurement temperature sensor on board video camera Telemetry: via wire link (pre flight) via radio (during flight) Store sensor data on board (using EPROMS) Improved deployment logic for recovery system These improvements have been carried out in order to achieve a safe and successful launch in May 1995. Ausroc III Program Update Ausroc III has a goal to lift a 150kg payload to an altitude of approximately 450km it will then be recovered intact. The guidance and control of the rocket will be by the use of roll control gas thrusters, and a hydraulically activated gimbal system. The Ausroc III program involves student projects from five universities around Australia. The projects are: Adelaide University: Simulation and Roll Control System. Hydraulic Gimbal System. Liquid Rocket Motor Design. Filament Winding of a closed ended Pressure Vessel. Sydney University: Payload Fairing Design. Intertank Fairing Design. Nose Cone Design. Autopilot Simulation. University of Southern Queensland: LOX/KERO Loading System. Hold Down Clamps. Water Deluge System. Launch Stand. Service Tower/Transporter. University of South Australia: Sensor Conditioning Module. Data Acquisition Module. Telemetry Encoder. Telemetry Recording. Computer Acquisition and Display. Queensland Uni. of Technology: Range Networking. Flight Safety Systems I-II. Trajectory Calculation. Australis Program Update The Australis Program commenced in 1991 and involves the design and construction of a Microsatellite. The payload will be an Infrared Imaging System (IRIS) and/or an Amateur Band Communications System. The payload is to be 30kg and occupy an area of 0.4m cube and will use GA Solar cells. It is proposed to be launched on an Ariane ASAP or Shuttle GAS Can and possibly in Ausroc IV. Scramjet Program Update The Scramjet Program is involved with the design and development of hypersonic combustion vehicles, and is being coordinated by both ASRI and Queensland University. There are two vehicles being considered firstly the UQ Scramjet and secondly the ASRI Hypersonic Test Vehicle (HTV). Both vehicles require a minimum speed of mach 5 to start operating. Since these vehicles will operate at such high speeds very high precision and accurate tolerancing of the vehicles components is required. Also the materials used in the construction of the vehicle must be resistant to both high temperatures and very large aerodynamic forces. These vehicles need to be boosted initially to their operating speed and this will be done by using a booster rocket motor which will reach a high enough speed so as to allow the hypersonic vehicle to operate. Sighter Rocket Program Update The Sighter Rocket Program commenced in 1993 and involves the use of surplus 3.5" Sighter and 5" Zuni RAAF rockets. The program is aimed at secondary and tertiary students to provide an introduction to rocket technology. The main goal of the project is to gain student involvement and to provide a successful and reliable launching and recovery method for payloads weighing between 5-10 kg. There are many potential sighter rocket projects such as: The design and implementation of recovery systems. Simple telemetry systems. Camera payloads. Wind and weather recording systems. Aerodynamic dart designs. The sighter rocket will use a standard fin design and will have a 3.5" payload fairing, these rockets will achieve an altitude between 6000-7000m and will have an approximate acceleration of 50G. The rockets will be launched from sites in NSW, Queensland and S.A. and it is hoped that this project will involve students from all over Australia. PROPULSION Ausroc III Rocket Motor Design This project involves the design and manufacture of the Ausroc III rocket motor. Because the rocket motor will have a long burn time a regenerative cooling system was chosen, this also enables both pre-flight and multi use capabilities. The coolant used will be the fuel (Kerosene) this is because it is readily available within the rocket also because it has good heat transfer characteristics. The cooling is achieved by utilising single pass vertical coolant slots which will have a low pressure drop. Both the internal and external surfaces of the motor will be CNC machined from a solid steel billet. The coolant slots will be CNC milled and then filled with wax, the outer surface will then be chemically cleaned and electroplated using copper or nickel. The external surface will then be filament wound with carbon fibre to withstand the internal pressures associated with the motor operation. The wax is removed by heat and solvents to reveal the finished slots. Once the motor is completed it will be pressure tested to 4MPa and then static fired to determine its performance. Ausroc IV Solid Propellant Development Ausroc IV is a proposed three stage satellite launch vehicle. It will be based upon the existing design of Ausroc III using four liquid fuelled Ausroc III rockets for the first stage, one Ausroc III for the second stage and a solid fuelled Waxwing rocket motor for the third stage. Waxwing motors were developed in the UK and used in the Black Arrow satellite launch vehicle. Seven Waxwing motors will be obtained from the UK and will be refilled with a new composite solid propellant which will be theoretically and experimentally matched to the original propellant. The propellant has been matched theoretically using the NASA-Lewis code which calculates, amongst other data, the maximum temperatures, pressures, and specific impulses produced for different composite propellants for given expansion ratios. Upon initial theoretical matching small scale mixes are carried out and tested experimentally. This enables the physical properties such as viscosity, pot life, mechanical properties and burn rate to be studied. The mixes are cast and then machined into strands which are burnt in a strand burner at different temperatures and pressures. The burn rate must be accurately matched and will be varied by using iron oxide and amminium perchlorate particle size distribution as a burn rate catalyst. The mounting system must adapt the Waxwing to the existing Ausroc III dimensions and must be such that the Waxwing may be spun up, released and then fired. The mounting system must be of minimum weight without sacrificing strength and reliability. STRUCTURES Ausroc III Composite Structures This project involves the design and manufacture of the carbon fibre composite inter tank fairings, the payload fairing and the nose cone. The method of construction was by utilising a three stage process. Firstly a solid male plug was manually constructed and shaped. Over this a thick female mould was made from glass fibre and high temperature resin and cured. The male plug was then removed to reveal the internally smooth female mould. The final fairing is made from pre-impregnated carbon fibre mat which is layed up on the inside of the female mould and cured. The composite is cured inside a vacuum bag with external pressure applied at 20C increasing to 200C (at 20C intervals) and usually takes approximately 1 hour to cure at the upper temperature. Filament Winding of Closed Ended Pressure Vessels Upon familiarisation of the winding machine a new resin bath was designed and is being constructed at the Adelaide University workshop. Both hoop and helical test windings were carried out on an open ended 100mm pipe to determine test procedures and the best type of fibre and resin to use. It was found that glass or carbon fibres used with the vinyl ester resin (Derekane 411-45) was best suited because of its extensive local industry use, superior curing and properties to polyesters and its proven cryogenic temperature characteristics. The final closed ended pressure vessels will have an internal metallic tank as a liner to prevent leakage through the fibre walls. GUIDANCE AND CONTROL Guidance Tracking Schemes To track the flight path of Ausroc III a suitable tracking simulation controller is required. Two such controllers were looked at which were the Classical Tracker and a LQ Tracker. It was found that the LQ Tracker was more robust and had better damping than the Classical Tracker however the LQ Tracker had an unstable response to the Ausroc III gust requirement of 18m/s. This implies that the gust requirement must be reduced to 9m/s or the guidance tracker must be redesigned. Ausroc III Stability and Control The stability of Ausroc III depends greatly on the wind conditions at the time of launch. There have been over 1500 weather balloons released from Woomera in the past in order to attain wind speed and direction data. This data was taken at varying altitudes to gain knowledge of the changing conditions throughout the atmospheric levels. The critical winds have been extracted from this data and applied to the Ausroc III simulation. Data from the Southern Launch Vehicle design study is also analysed and modified for Ausroc III. This data forms a basis for the design of the attitude and direction control systems. Simulation and Roll Control System Firstly the Flight Simulation Model utilised a 6-degree of freedom simulation using the Matrix-X computer program. This simulation was required to predict the stability of the autopilot and determine the hydraulic fluid and roll thruster gas requirements. The roll of Ausroc III will be controlled by the use of horizontally mounted gas thrusters. It was found that the maximum roll inertia would be 27.9kg/m^2 and the gas thrusters would have to produce enough thrust to counter act this roll. The first problem associated with this was to produce 30N of force from each thruster. This was done by redesigning the throat of the thrusters from a previous year's project, to enable the required thrust to be produced. In order to actually simulate the roll of Ausroc III a full scale test rig was built with representative roll inertia and 4 thrusters and successfully tested. The software used a dead band system in which the thrusters would only be activated once the rocket exceeded the dead band limits. Hydraulic Gimbal System This project consisted of two parts: firstly the design of a method of transferring the thrust developed by the motor to the rocket structure and secondly the design and development of a closed loop control system to gimbal the motor. The method used to transfer the thrust load to the kerosene tank structure incorporated a thrust frame and strong ring system. The moly-steel thrust frame will be bolted to a 7075-T6 aluminium strong ring which will be attached to the kero tank composite flange by 60 high tensile steel bolts. The control system was simulated on a test rig and was tested in two dimensions only. A single Moog servovalve and piston actuator was implemented and it was found that the particular valve used did not have a high enough slew rate to be successfully used in Ausroc III, hence a better valve will be required in the follow-on project. Hardware in the Loop Simulation By using Hardware in the Loop (HWIL) simulation methodologies, the actual flight of a rocket may be simulated and fine tuned. The probability of a flight failure can be minimised without the use of expensive flight test hardware. The key segments of a HWIL simulation are a 6 DOF Rocket simulation program running in real time, a 3 axis rotary table for the inertial reference unit and the actual flight control apparatus of the rocket operating and providing feedback. However, the HWIL simulation can only be as accurate as the data provided to the simulation program. Thus, realistic and accurate aero and control data is vital. GROUND SUPPORT Flight Safety Systems Flight Safety Systems and Flight Termination Systems are essential for any guided rocket. The method of flight termination systems depends on the type, size and range of the rocket as well as the location of the launch site. In the case of Ausroc II the use of a termination system is unnecessary because of its fixed fins and inherent stability. Due to its active guidance Ausroc III does require a termination system which will be a Robust System with a > 99.9% reliability. Launch Infrastructure The Launch Infrastructure consists of five parts: Transport Tower: Will carry Ausroc to launch site. Erect Ausroc on stand. Provide access for service. Support during preparation. Provide umbilical connection. Recover Ausroc if aborted. Launch Stand: Hold and support Ausroc. Provide a suitable means of aligning Ausroc. Contain flame deflector. Hold Down Clamps: Will hold down Ausroc until all systems are okay and full thrust is built up. Release when Ausroc is ready to be launched. LOX/KERO System: Load LOX/KERO. Dump LOX/KERO if aborted. Water Deluge: Flood launch pad if there are any spills. Cool flame deflector. Activate if a fire results. Range Networking The range networking project involved the identification and electronic networking of the various flight safety systems including: 2 x Adour Radars 2 x Contraves Kinetheodolites Impact Prediction Computer Range Communications and Timing Networks Mission Control Displays Flight Termination System The optical trackers are manual and have a speed of 40 frames/second. They have both azimuth and elevation tracking functions. However, they are only useful up to an altitude of 10km. The adour radar system which will be used has 15 bits for azimuth and altitude tracking and uses 18 bits for range calculations. The maximum range of this system is 468km, so the radar will quite adequately track Ausroc III during its powered flight up to 80 km. PC's will be used for all operations and will operate in real time. TELEMETRY Signal Conditioning Module (SCM) This module converts the raw signal data from the sensors within Ausroc III into 5V to enter the Data Acquisition module for Analogue to Digital conversion. The signals then enter a PDU Telemetry Encoding Unit and are finally transmitted back to the ground station via radio transmission. There will be many different sensors on board Ausroc III including: Thermocouples, Pressure Transducers, Flow Meters, Position Sensors, Strain Gauges, General Analogue Inputs and other input sensors. The amplification of the raw sensor data is by a filtered, variable gain (110000) amplifier which adapts to varying signal levels. The module was designed within specified size limitations. Data Acquisition Module (DAM) The function of the Data Acquisition Module is for the signals A/D conversion, multiplexing of the signals, low pass filtering and the offset and gain adjustment. The module has 16 analogue inputs and uses a 12 bit A/D converter. The Communications Protocol (RS-485) has multiple transmitters and receivers with a distance capability of 1200m and a rate of 10Mb/second. Telemetry Encoder Unit (TEU) The purpose of the Encoder Unit is to sequence the acquisition of parameters (signal data) and to format this data. The encoder produces a serial bit address for the transmission of the data and has a direct interface with the on board flight management computer. After the signals exit this unit they are transmitted back to the ground station. Telemetry Data Recording System (TDRS) Once the ground station receives the signal transmissions they pass through a Telemetry Decoder Unit (TDU) and are displayed on PC screens and stored on hard disk for post flight analysis. The TDRS records the flight data, as backup, onto video tape since video recording has a large data bandwidth and a high data storage rate capability. The TDRS input is a 2Vp-p and this is converted into an output of 300mVp-p for recording purposes. SATELLITE SYSTEMS Onboard 145 Mhz Rx System The objective was to design, implement and test a FM Superheterodyne receiver module prototype for the Australis-1 Microsatellite. The carrier frequency is between 144-146 Mhz and has a bit rate of 4800b/second. The system was designed considering the worst case of available signal level, the noise figure of the system, the number of mixing stages and the redundancies of such systems. The considerations for the design of the hardware were the power consumption, weight, thermal noise, component variations due to temperature changes, the impossibility of maintenance and any impedance mismatch. By considering that the ideal components must have a low profile, be multifunctional, require little external circuitry, have low noise, be thermally stable and readily available the following components were chosen: Pre amp: MAR - 6 First mixing stage: NE602 Second/third mixing stages: MC3362 Store and Forward System This project is concerned with the method of storing and transmitting data during the orbit of the Microsatellite. The system will provide full tracking of the satellite, it will also feature a multiple user access to the obtained data during its low earth orbit. Satellite Tracking Platform This project was concerned with the Satellite Tracking Platform and the way in which it will track and receive data from the microsatellite. Reliability of Onboard Equipment and Satellite Communications There were two projects involved with the reliability of communications. Firstly the reliability of the onboard communications equipment was analysed which includes the telemetry hardware and the transmission hardware. Secondly the reliability of the satellite communications link was analysed. SCRAMJET SYSTEMS Student Scramjet Program Scramjets, or supersonic combustion Ramjets, can only operate at velocities > Mach 5. To achieve this starting velocity, a rocket booster will be used as a first stage. Since the operating velocities are high, oblique shock waves and aeroheating can cause severe structural problems. Because of this, ablative composite materials are being used to prevent structural failure. The supporting frame, which connects the scramjet to the solid booster rocket, was required to fit through the center of the six motor exhaust ducts and had to be of sufficient strength to support the scramjet against the aerodynamic loads. A novel space frame was designed to meet this requirement. A structure was designed, developed and simulated and then a 1:1 scale model was manufactured. The model cost around $500 to build and was required to be lightweight, easily transportable and be an exact replica of the actual vehicle. The vehicle has six scramjet modules and will use Ethane as a fuel. Ethane was chosen considering the following points: Storage pressure and temperature Ignition delay and temperature Enthalpy of combustion Heat of vaporisation Cost The ethane fuel will be pressurised by a helium pressurisation storage tank expanding a pressurisation bladder inside the ethane tank. The ethane is stored as a liquid and is expanded to a gas by utilising a heat exchanger. The ethane will be injected via three sets of dual injectors per combustion chamber. Once the initial speed is obtained and the necessary air flow rate is achieved the scramjet has the potential to accelerate to high speeds over mach 5. Hypersonic Test Vehicle Program The Hypersonic Test Vehicle (HTV) Program is primarily involved with obtaining atmospheric free flight data to support scramjet research. The principles of the HTV are the same as the scramjet however the HTV will use pure Silane as a fuel and will use two of the six combustors for non-combustion referencing. It will use a two stage rocket to achieve the required initial speed of Mach 5. The first stage will be a Taurus rocket motor and the second stage will be a Nike rocket motor. QUT/ASRI SIGHTER ROCKET PROGRAM Payload and Mission Planning There are many options for sighter rocket payloads ranging from simple aerodynamic dart experiments to micro gravity and weather experiments. The mission planning involves the overall coordination of events and the planning of such things as the payload selection the fin requirements, safety aspects the launch and recovery procedures etc. Systems and Safety Studies (I-II): Two different launch sites are being considered: Woomera and Wide Bay Army Range. Mt Herman and Mt Easy are the actual launch locations within the Wide Bay site, a computer program was written to determine the approximate impact position at these locations. The program uses the payload mass and angle of launch as the input and calculates the maximum speed, altitude and range expected, it also plots velocity, altitude, range, thrust and drag force curves. A program considering the cross and tail winds was used for both sites however the accuracy is unknown. The launcher specifications are still required and actual launches are required to attain accurate figures. Ground Support and System Integration The proposed launcher will be mobile, lightweight, durable and be of high strength. The launcher will have an adjustable azimuth angle between 0-90 with an accuracy of 1 degree. The method of ignition is via a dual circuit electric ignition system the sequence of events is: T-60 sec. Countdown commencement. T-5 sec. Tracking Flare Ignition signal (2 channel). T-0 sec. Rocket Motor Ignition Signal (1 Channel). A tracking flare will be used in order to aid the recovery of the rockets, the flare will be electrically activated, it must have a low heat output with minimal flame, the smoke emission must be of high volume and density and the burn time must approach, but not exceed, the flight time for fire hazard reasons. Telemetry and Data Acquisition: The aim is to have a multi channel receiver to track and receive flight information, this would aid in the development of better flight simulation programs. Coordination between projects is necessary to plan and combine the projects. Also a suitable antenna was looked at and a crossed pattern dipole antenna was chosen. CONCLUSION