AUSROC II-2 Status Report 20 February 1995 Mark Blair (mnb@dstos3.dsto.gov.au) The launch date for the Ausroc II-2 launch vehicle has been shifted from the week starting 1st May 1995 to the week starting 22nd May 1995. This delay was enforced by the RAAF as a result of a slippage in one of their trials scheduled in April. At a meeting held with RAAF-ARDU on the 9th Feb., RAAF indicated that they will require a copy of the insurance policy for the trial at least 6 weeks prior to the scheduled launch date. They also indicated that an identical policy to that obtained for the original Ausroc II trial would be adequate. A list of major system changes is as follows: 1. Cruciform fin unit replaced with Tri-fin arrangement using Aerohigh sounding rocket fins. This results in higher fin stiffness while maintaining essentially the same vehicle stability. 2. Replacement of all nylon pneumatic hoses with stainless steel or copper tube with swagelok fittings. 3. Installation of check valves downstream of both lox and kerosene regulators to prevent backflow of gaseous oxygen into the kerosene tank. 4. Replacement of the seam welded 5083 aluminium fairings with seamless extruded 6061-T6 tube (250 mm OD) resulting in a large strength and stiffness increase. 5. Body segment spigot adaptors increased from 25 mm to 40 mm length with dual rows of M4 contersunk bolts for improved joint stiffness. 6. Electrical umbilical connecter has been relocated from the base of the vehicle to the electronics fairing approximately 1 m from the nose tip to prevent severing by the motor exhaust. 7. Installation of an aft firewall bulkhead between the motor nozzle and the fin unit. 8. 10 kg reduction in propellant load due to a 10 kg increase in rocket dry weight. This results in an identical launch weight to the original vehicle. 9. Addition of a 2D truss frame to the back of the launch rail to improve rail stiffness. 10. Ground wiring in the vicinity of the launcher is to be enclosed in copper tubing for protection. 11. The 3 piece Lox and Kerosene valves have been replaced with stainless steel Apollo ball valves. 12. The Lox rotary vane actuator has been replaced by a linear pneumatic piston and cam arrangement which is thermally isolated from the lox valve unit. 13. Ground software has been provided for real time display of tank pressures and system status in the blockhouse and Instrumentation building. Thus greatly assisting in the determination of abort criteria. 14. Lox tank relief valve exhaust is vented directly to the atmosphere through a wall port, thus avoiding oxygen buildup inside the vehicle. These represent the major changes to the vehicle. They have been incorporated to avoid a recurrence of events that destroyed the original vehicle and prevent the possibility of failure due to other identified flaws.