Newsgroups: sci.space,rec.models.rockets
Subject: AUSROC II Launch Campaign Review
From: etssp@levels.unisa.edu.au
Date: 2 Nov 92 14:33:37 +1030
Reply-To: steven@sal.levels.unisa.edu.au
Distribution: world
Organization: University of South Australia

26th October 1992

AUSROC II LAUNCH CAMPAIGN REVIEW

        On Friday 16th October the AUSROC II rocket system and
launch crew left Adelaide for the Woomera Rocket Range. The
AUSROC launch crew consisted of the following personnel:

                Mark Blair                      Tzu-pei Chen
                Andrew Cheers                   John Colemen
                Norbert Leidinger               Robert Graham
                Warren Williams                 Richard Bromfield
                Ian Bryce                       Grant Waldram
                Peter Grounds                   David Emery
                Denis Robb                      Colin Biggs
                Brendan Coleman                 John Balatsas
                Peter Kantzos

        After arrival at the Rangehead, the rocket hardware and
support equipment was unloaded in Test Shop 1. For the duration
of the campaign the launch crew resided at the Travellers Village in
the Woomera Township.

        On Saturday the injector, engine and fin unit were attached
along with the pneumatic and electrical umbilical lines in Test Shop
1. At this stage the 3 ball valves on-board the rocket were tested
and found to be operating successfully. The ground cabling and
wiring loom layout was commenced to connect the launcher with
the launch sequencer in Equipment Centre 2 where the firing was to
be initiated from. The on-board electronics was in its final stages of
preparation but the flight software still required some further work
and was being worked on intensively for the majority of the
campaign period.

        The system pressure tests, with nitrogen gas, were
undertaken on the Sunday and about 4 leaks were discovered.
Three of these leaks were associated with connectors, which may
have been loosened during transit, and were re-sealed quite easily.
A small leak between the sections of the kerosene ball valve proved
to be more resistant to our attempts to seal it. Eventually, with
much effort, the leak was reduced to an apparently negligible rate .

        The telemetry antennas were installed onto the rocket on the
Monday and tested. These tests revealed that the antennas were
operating extremely well with quite a high level of efficiency. The
parachute recovery system was prepared for installation and the
launcher services were installed. These services included the
nitrogen purge system, the nitrogen actuation supply lines, the
electrical umbilicals and the fuelling equipment and scaffold. Since
the software still required more time, a 1 day hold was enforced to
allow further time for correction. Thus the nominal launch time
was delayed until 10.00 am Thursday morning.

        The rocket was rolled out of Test Shop 1 on the Tuesday
morning and installed horizontally on the 10m launcher rail. The
electrical and pneumatic circuits were attached and 3 dummy firing
sequences were performed to validate the ignition and valve
operations. These trials were also successful. A pre-flight brief was
held in the Instrumentation Building conference room for visitors,
sponsors and media in mid afternoon and this covered details of the
Ausroc program to date as well as future plans.

        Throughout Wednesday, further testing was performed on
the ground based telemetry receiving and recording equipment as
well as the flight electronics and software. Several changes were
made to the flight electronics and software and the package was
finally loaded into the rocket on the launcher around mid
afternoon. Several telemetry checks revealed that the video signal
was being transmitted well but the telemetry channel data would
require post flight processing to be useable. With the electronics
secured, the recovery system, complete with deployment
pyrotechnics, was installed.

        The launch day commenced with arrival at the range at
5.00am. Two more dummy launch sequence checks were performed
without fault. The helium pressure tank was loaded to 20 MPa and
checked for leaks. No leaks were detected so the upper valve fairing
hatch was replaced and the launcher was elevated to its nominal 70
degree launch angle. A series of telemetry checks were then
performed to check the transmitter and ground based receiving
equipment.

        The kerosene was then loaded and it was observed that there
were no leaks present from the kerosene ball valve while the tank
was at ambient filling pressure. The lower valve fairing hatch was
then replaced in preparation for the lox fuelling. A spray pack of
freon was used to remove any kerosene spillage around and within
the intertank fairing. A dry nitrogen gas purge operation was
conducted to ensure that no water vapour was present in the lox
system that could cause freezing problems. The lox fill line was
attached to the rocket from the cryogenic storage canister located
on the back of a transport truck. The lox fuelling went much
smoother than we had anticipated and the uninsulated external
walls of the tank only had a light frost buildup when the tank was
full. The lox tank bleed plug was replaced, the scaffold was
removed and the ignition flare leads were connected.

        With the lox tank bleed plug replaced, the lox tank pressure
increased under its own boil-off vapour pressure to the nominal
tank vent pressure of 4.5 MPa. It was discovered that with the
helium valve closed, there was some back-flow of oxygen vapour
through the lox tank regulator and down into the kerosene tank,
thus increasing the kerosene tank pressure. The early increase in
kerosene tank pressure brought about a slow leak of kerosene
which probably found its way onto the pneumatic supply line. This
was the same leak that had been detected during the pressurisation
tests in Test Shop 1. Further checks should have been made in Test
Shop 1 to ensure that the leak was completely sealed.

        The ignition flare was fired, by the sequencer, at T-5sec. The
flare may have then ignited the leaked kerosene causing a fire
around the pneumatic supply lines. The Helium valve opened
successfully at T-3sec. as did the kerosene valve at T-0.25sec. The
lox valve was to have fully opened at T-0sec. The lox ball valve
opened approximately 10 degrees before it lost its actuation
pressure. This implies that the pneumatic supply lines must have
been severed some instant immediately after the lox valve solenoid
had opened. In this regard the system was about 200 milliseconds
short of successful operation.

        With the lox valve only partially open, the kerosene continued
to rush out and was ignited by the flare producing a very fuel rich
black billowing cloud and no useful thrust. The recovery system was
set to deploy on a timer and since the electrical umbilicals and
remaining pneumatic hose were also severed by the kerosene
flame, it was impossible to abort the sequence. As a result of this,
the nose deployment sequence was initiated very successfully at its
correct time in the launch sequence.

        With the helium and kerosene tanks essentially empty, the
back flow of oxygen through the lox tank regulator continued to
bleed oxygen vapour into the kerosene tank and out through the
kerosene passages to the motor. At around T+4mins, the remaining
small kero flame in the motor initiated the oxygen/kerosene vapour
mixture in the kerosene tank causing it to detonate and rupture at
the intertank end of the lox conduit passage. This event broke the
vehicle in half at the intertank fairing and severed the lox hose. The
resulting expansion of the lox from the base of the lox tank pushed
the forward section of the rocket off the rail and sent it sliding
along the ground where it eventually came to rest next to the 2
ground power supplies.

        The violent nature of the kerosene tank rupture sent a black
kerosene soot through every cavity and conduit in the rocket
making the post-mortem all the more difficult. At this stage it
appears as though the motor, injector and recovery system could be
reused but new tanks and structure will be required.

        Much has been learned from this experience and the majority
of the AUSROC Program objectives have still been achieved. We
are presently reviewing the AUSROC II systems and anticipate
some changes to the vehicle design and launch operations. We have
listed some of these here for your information:

        1. Installation of check valves in both propellant systems.

        2. Re-routing and/or flameproofing pneumatic and electrical
                umbilical lines.

        3. Replacement of all internal plastic pneumatic lines with
                flameproof lines

        4. Review of quality control procedures and standards

        5. Review of launch operations including Abort/Hold criteria,
                program management and media liaison

        6. Review of lox and kero ball valve and actuator operation
                including the effects of ice buildup

        7. Review of vehicle manufacturing techniques to enable a
                more simplified construction of a second vehicle.

        8. Modification and simplification of flight electronics and
                software and simulation of possible flight regimes.

        The launch crew is now more determined than ever to solve
these initial problems and construct a second AUSROC II
derivative for a possible second launch campaign in 1993. For as
little as $30-40,000 a revised and improved system can be
constructed. Design review teams are already being formed and
construction could begin as early as January '93. The media and
sponsor response to the program has been exceptionally positive
and we look forward to working with them again in the future.

                        Regards,
                                                        Mark Blair
                                        AUSROC Program Coordinator


Previous AUSROC updates can be obtained by anonymous ftp to
audrey.levels.unisa.edu.au in directory space/AUSROC

-- 
Steven S. Pietrobon,  Australian Space Centre for Signal Processing
Signal Processing Research Institute, University of South Australia
The Levels, SA 5095, Australia.      steven@sal.levels.unisa.edu.au