AUSROC

AUSTRALIA'S AMATEUR ROCKET PROGRAM

M. A. BLAIR
B.E., Grad. I.E.Aust.
AUSROC Program Coordinator

SUMMARY

 	A description of the AUSROC Amateur Rocket Program including past,
present and future projects is presented. The objectives and future program
goals are discussed along with a basic technical description of the rocket
systems.

1. INTRODUCTION

	The AUSROC projects are formulated to achieve a number of prime 
objectives which we believe are beneficial to all parties involved. The first 
and primary objective is:

1. To design, manufacture and launch rocket systems.

	Much of the rocket activity in Australia, based primarily at Woomera, 
died out in the mid 70's and there has since been no commercial or governmental
avenue available for those interested in pursuing rocketry activities or
careers. As a result of this, the experience and technological lead that
Australia once had has all but disappeared.

	Rocket projects, such as those being undertaken by the AUSROC group, 
are beyond the technical and economic means of most individuals. This would
have to be the major impediment that individuals face in their attempts to
undertake such projects. This leads to the second objective of the program:

2. To bring together and combine the resources of many individuals,
institutions and companies to provide the means, both technically and
financially, of successfully undertaking Rocket projects in Australia.

	As mentioned above, much of the experience and technology of the 
Woomera days has been lost through decades of inactivity. If a viable 
commercial or government satellite launcher program is to be established in the 
near future in Australia, people with the required skills are going to
be needed. At current levels, the bulk of these skills will need to be
'imported' from other nations. To avoid this 'un-clever country' scenario,
local people will need to be trained in the required disciplines. This
training should begin in the education system and brings us to the third
objective of the program:

3. To give students the opportunity to undertake research projects in the
aerospace disciplines that may be of use in future national programs and
better prepare themselves for future careers in the same.

	For this reason, the bulk of the AUSROC projects are undertaken within 
the University system, primarily at the undergraduate level.

	Australia currently has a small, but growing, aerospace industry that
generates little public interest and enthusiasm. International aerospace
programs, such as that undertaken in the USA, generate a great deal of
public interest and support and, indeed, America has strong public lobby
groups to promote the benefits and rewards of the aerospace industries. We
see the AUSROC program as one that will stimulate not only academic
interest, but also public interest in Australian aerospace activity. Thus,
the fourth objective of the AUSROC program is:

4. To undertake a high profile amateur Australian rocket program to reveal
joint cooperation between tertiary education centers and industry so as to
awaken public awareness and interest in a local aerospace capability.

	It should be pointed out, at this stage, that the AUSROC program is an
amateur one and, as such, some general concerns have to be realised. First
and foremost is the fact that the program will not have a large budget to
draw on during the program so the systems are being designed in such a way
as to minimise the labour required during manufacture and assembly.
Complicated and labour intensive components can cause numerous delays,
especially with a sponsored project. Secondly, the majority of those that
become involved with the AUSROC program will have little to no prior
experience with rocket systems. It will, therefore, be essential to ensure
that the system will be inherently safe and that every measure be taken to
assure that this will be the case.

	To meet the above 2 concerns it will be essential to have reliable 
systems and, since we will not have the budget to build and test many completed
units, it will be necessary to draw off design information from established
and proven systems wherever possible. This will involve a great amount of
background research but it will reduce the time and budget spent on trial
and error.

2. AUSROC I PROGRAM REVIEW

	The AUSROC Amateur Rocket program commenced in mid 1988 when a group of
Monash University students and amateur rocketeers united to tackle the task
of designing and constructing a liquid fuelled rocket. The group, at this
stage, knew little about designing and manufacturing liquid rocket systems
but had established a commitment to learn.

	To avoid a lengthy development program, it was decided to base the 
design of the first rocket on an established and proven system. To this end a
design report for a small liquid fuelled rocket was located and obtained
from the Pacific Rocket Society (PRS) in the USA and this provided the
basic configuration for what was to become AUSROC I.

	To this basic design the AUSROC team added an electronics module, 
recovery system and modified some of the valving components to arrive at the 
final configuration shown in figure 1. After a series of simulated propellant 
and systems tests at Monash University, AUSROC I was launched from the Graytown
Proof & Experimental Establishment, which is adjacent to the Puckapunyl
Army Base in Victoria, on the 9th February 1989. Table I shows the
specifications and sponsors that participated in the AUSROC I project. The
vehicle velocity and altitude were approximately 600km/hr and 3.5km
respectively. Although the recovery system failed to operate as planned
during this flight, the propulsion system worked very well, as did the
electronics and telemetry system.

	The AUSROC I project was undertaken as a private project, although
assistance was given by several members of the Monash Uni. Mechanical
Engineering staff. Even at this early stage in the program, the importance
of sponsorship by both industry and individuals cannot be disputed. The
success of the projects is very much dependant on the support provided by
the sponsoring companies and persons.

3. AUSROC II PROGRAM REVIEW

	The success of AUSROC I paved the way for a much more ambitious project,
AUSROC II.  In 1989, 3 4th year Monash Uni. Engineering students, 2
Mechanical and 1 Electrical, commenced an official project to design, build
and test launch a bi-propellant Lox/Kero rocket system. AUSROC II, when
complete, will be one of the largest amateur liquid fuelled rockets ever
constructed. Figure 2 shows a schematic of the AUSROC II vehicle. Table 2
shows the specifications and sponsors for AUSROC II. As with AUSROC I,
AUSROC II has been highly dependant on industry sponsorship as well as
sponsorship from Monash Uni.

	The AUSROC II regeneratively cooled, rocket motor was static test fired 
at the Ravenhall Test Facility in Deer Park, Melbourne, on three occasions
during 1991-92. These trials were performed to validate the system
performance and familiarise the launch crew with operating and safety
procedures associated with liquid fuel rocketry. As of this writing, the
launch of AUSROC II is planned for the second half of 1992.

4. AUSROC III SYSTEM DESCRIPTION

	The interest and support shown for AUSROC II and the undying enthusiasm 
of those involved, led the AUSROC team to set forward a plan for the future of
the AUSROC series of rockets. The successful completion of any further
AUSROC projects would, no doubt, require the interaction between Tertiary
Education Centers and Industry and the commitment of many engineers,
scientists and technicians, working as a team, to see the projects through.

	In late 1990 the AUSROC Team discussed some possible objectives for the
next generation rocket system, AUSROC III. This section discusses these
objectives and provides an outline for the next generation AUSROC vehicle.

	To date, both AUSROC vehicles have been demonstrational rocket 
propulsion systems undertaken to gain experience with rocket and associated 
systems designs. The payload capacity of both these vehicles was negligible. 
Useful payload capacity was not an initial objective of the projects. Rocket
payloads have, traditionally, been utilised to fulfil a variety of tasks
including: upper atmospheric sounding, delivery of nuclear warheads and
satellite launching.

	The ultimate goal of the AUSROC projects group is to develop a 
satellite launch vehicle capable of placing a microsatellite (20-50kg) into a 
polar low earth orbit. This goal encompasses many technical aspects which have
not yet been addressed in the previous projects. Therefore, it was decided
to develop an intermediate rocket system that could be used as a technology
demonstrator for the satellite launcher

The primary objective of the third generation AUSROC system is:

To carry a useful scientific payload of 100 kg mass to an altitude of 500
km on a predetermined and controlled, suborbital trajectory and recover it
intact.

	Achieving this objective will require the development of many new
subsystems. This new vehicle, AUSROC III, would, if completed, be
the largest amateur rocket ever built and would be a useful instrument for
performing research in fields such as; atmospheric physics, microgravity
materials processing, high altitude observations, hypersonics research and
evaluation of space and launch vehicle hardware.

	This new project represents a challenge that encompasses a diverse 
range of science and engineering topics that must be integrated to develop a
workable piece of hardware. The complete AUSROC III system, as described
below, has been sub-divided into a number of smaller subprojects that can
be undertaken by groups of science and engineering students at Universities
and Institutes around Australia. Groups of amateurs, outside the tertiary
education system are also invited to take part, as the AUSROC program is
open to all those who would like to see the fruition of these rocket
systems and their associated benefits.

	In meeting our primary objective of lofting a 100 kg payload to 500 km, 
we started by determining the type of rocket propulsion that would be used as
this would, undoubtedly, determine the size of the vehicle and the required
subsystems. Three types of propulsion were initially considered for this
project: Solid Fuelled Motors, Liquid Fuelled Motors & Hybrid Rocket
Motors.

	Our preliminary calculations, using a trajectory simulation program and 
an iterative approach, indicated that approximately 1200 kg of propellant,
assuming a specific impulse around 250 sec, will be required to meet the
objective. Australia does not yet have the capacity to cast this amount of
solid propellant from one mix. It would be necessary to cast the grain in a
number of segments and cartridge load them into the rocket casing. Either
way, the mixing, storing and transportation of solid propellant is a
hazardous operation that requires strict process control and safety
supervision.  These requirements would result in increased project cost.

	Liquid fuelled rockets offer a safety advantage over solid propellant
rockets in that the propellants are only loaded into the vehicle at the
launch site. This way, the rocket is safe and easy to store and transport.
However, in the case of a malfunction during fuelling or firing, the 2
liquid propellants may have the opportunity to mix, ignite and explode.
This hazard presents problems from a range safety point of view and can
complicate the pre-launch operations.

	A hybrid rocket has a solid fuel grain and a liquid oxidiser. The fuel 
is, generally, no more dangerous than a block of rubber and the oxidiser can be
loaded at the launch site. With this system there are no storage or
transportation problems and in the case of a malfunction there is no
opportunity for the 2 propellants to intimately mix and explode.  Of the 3
rocket types described, the hybrid rocket is the safest. Hybrid rocket
performance generally falls midway between  the lower performing solid
fuelled rockets and higher performing liquid fuelled rockets. Hybrids,
however, have not had the same extensive development history as solid and
liquid rockets. For this reason there is onlya limited amount of published
data available on hybrid rocket propulsion.

	The AUSROC team has chosen to pursue the bi-propellant liquid 
propulsion concept for AUSROC III, primarily due to the vast amount of data and
experience already in existence that we can draw off to minimise the
development time and technical risks. The Liquid Oxygen and Kerosene
propellant combination provides relatively high performance, abundant
supply and the associated costs are minimal.

	Due to the complexities involved in designing and manufacturing
turbopumps, we decided to implement a pressure feed system to deliver the
Lox and Kerosene to the combustion chamber. This system would involve using
compressed helium to expel the propellants. The helium would be stored at
high pressure, 30MPa, and regulated down to the propellant tank pressures
of approximately 3 MPa. The rocket motor would be designed to deliver
around 35 kN thrust at sea level for a time duration of 80 seconds

	To meet the objective of a predetermined and controlled trajectory, it
will be necessary to include the following:

	1. An Inertial Navigation Unit (INU) to determine the position and
attitude of the vehicle, in free space, at all times. Current INU systems
consist of 3 accelerometers, 3 gyros and associated software algorithms to
provide the position and attitude data.

	2. An Autopilot Control system which, when given the aerodynamic
properties of the vehicle and current attitude and position information,
determines the optimum control response for the steering system to maintain
the predetermined trajectory.

	3. A Thrust Vector Control (TVC) system which takes the autopilot 
control signal and alters the thrust vector to maintain the correct position 
and attitude of the vehicle during flight. The thrust vector can be controlled
by a number of methods. Those considered were Gimballed Nozzle,  Liquid
Injection and Nozzle Jet Vanes.

	Nozzle Jet Vanes, which are located in the exhaust stream to redirect 
the thrust vector, generally cause a thrust loss due to friction and the vanes
suffer from severe erosion. This necessitates the use of heavy refractory
materials or bulky ablatives. Liquid injection involves injecting a liquid
into the nozzle to cause a divergence in the thrust vector. This
system  requires needle valves to be attached to the nozzle exit cone and a
supply of liquid injectant. Utilising a reactive liquid injectant  can
produce side force specific impulses up to 400 sec. Thus, there is no
thrust loss with this system. Integrating a Liquid Injection TVC (LiTVC)
system to a rocket nozzle is easier than integrating a comparative
gimballed chamber but the system response is not linear, nor is it as
weight efficient as a hydraulic chamber gimballing system.

	It is for this reason that we chose to initiate the development of a
chamber gimballing system for the AUSROC III configuration. This method
utilises 2 linear actuators and a 2 axis pivot to gimball the motor in 2
axes (pitch & yaw). The third axis, roll, can be controlled by a system of
small thrusters. These thrusters could be fuelled by a cold gas supply, a
monopropellant such as hydrazine or a bi-propellant mixture such as
hydrazine and nitrogen tetroxide.

	The performance of a rocket structure is usually determined by its mass
ratio. The mass ratio is the ratio of propellant weight to total weight
excluding payload. The AUSROC team has set a target mass ratio of 0.85 for
the AUSROC III system. This means that for a propellant mass of 1200 kg as
mentioned above, the structure weight will be approximately 212 kg. This
target mass ratio is very optimistic and  extensive use of strong,
lightweight materials will be essential to achieve it. For this reason it
was decided to develop the system around the use of high strength and
lightweight filament wound and composite layup structures wherever
possible.

	A microprocessor based control system will need to be developed to 
monitor and control all onboard functions including the telemetry system, INU 
and Autopilot. An essential range safety item for all guided rockets is a self
destruct or flight termination system. This is necessary in the case of a
system malfunction during flight and such a system will be included in the
AUSROC III vehicle. The telemetry system will require the inclusion of both
uplink (for the termination system) and downlink data transmitters and
associated antennae. It will be essential that an accurate track be kept of
the vehicles' flight path for both safety and post flight analysis
purposes. This will require the use of a radar and/or GPS system in
conjunction with an impact prediction computer.

	The overall system will be analysed so that both its' dynamic and
aerodynamic characteristics are such that it will meet the mission
objectives. This could be accomplished through computer modelling, finite
element methods and wind tunnel testing of scale models. The dynamic data
will be important to determine adequate vehicle stiffness and strength
parameters for a variety of applied loads during operation. The aerodynamic
data will be required to determine characteristics such as the drag, lift,
vehicle stability, aerodynamic heating and the autopilot control algorithm.

	Ground based activities will also require special attention, especially 
to maintain safety at all times. Ground based activities include such areas
as: transportation, assembly, fuelling, the launch pad, launch control
center, film and video systems and vehicle recovery. Figure 3 shows the
general configuration of AUSROC III and table 3 lists the design
specifications.

	As can be seen by the number of systems involved in the AUSROC III
project, it has been necessary to subdivide the project into a number of
smaller sub-projects. Table 4 lists the subprojects that are essential for
the completion of the project and that were forwarded to tertiary students
in 1992. In determining the subprojects, we tried to keep them on a scale
that could be handled by small groups of students and amateurs over a
period of approximately 1 year. However, problems may arise in the course
of the sub projects which will require extra time or extra people to solve.

5. AUSROC IV: ORBITAL CAPABILITY

	As mentioned previously, the ultimate goal of the AUSROC program is to
place a micro-satellite into a low earth orbit. Many of the systems
currently being developed for use within the AUSROC III program will have
direct application to a satellite launch vehicle as well. In this regard,
AUSROC III is considered as the test bed and demonstration vehicle for the
future AUSROC IV program.

	Preliminary stack and trajectory optimisation simulations have been
undertaken and show that a 3 stage vehicle utilising AUSROC III modules can
achieve a 300km polar orbit from Woomera with a 40kg satellite. This stack
would consist of 4 AUSROC III modules, for the first stage, mated to a
central core module which forms the second stage. The third stage would
consist of a spin stabilised solid rocket motor mounted atop the core
module. Figure 4 shows the general stack configuration for the AUSROC IV
system.

	Whether or not the AUSROC IV program takes root, will depend on the 
level of success achieved with AUSROC III and the amount of support received.

6. CONCLUSIONS

	In summary; AUSROC I has been built and flown, AUSROC II is in the 
final stages of preparation for a Woomera launch, AUSROC III is in the design
phase and AUSROC IV is the light at the end of the tunnel. The AUSROC program 
is, no doubt, an ambitious venture but the enthusiasm and commitment of those 
involved is high. To date, the program has managed to meet all of its' initial 
objectives and hopes to continue to do so in the future.

7. ACKNOWLEDGEMENTS

	The author wishes to acknowledge the efforts of all those actively
involved with the AUSROC program; the Ausroc core group, the University
students and supervisors, the technicians and construction personnel and
the sponsoring agencies and companies. The individual names of those
involved are too many to list here but the success of the AUSROC program is
directly attributable to all of them.

TABLE 1

AUSROC I  SPECIFICATION SHEET

	Thrust			1270 N
	Burn Time		8 sec
	Oxidiser		Nitric Acid
	Fuel			Furfuryl Alc.
	Exhaust Velocity	1765 m/s
	Pressurising Gas	Nitrogen
	Pc			1.4 MPa
	Length			2.6 m
	Diameter		0.1 m
	Recovery System		Parachute
	Transmitter		400.5 MHz
	Stabilisation		4 Fins
	Dry Weight		19 kg
	Fuelled Weight		25 kg

AUSROC I SPONSORS

	Able Lemon Co.			Alcan
	Australian Army			Bureau of Meteorology
	C.I.G.				Comalco
	Dawborn Steel			Dorrington Sailmakers
	I.C.I				Measuretech Supplies
	Monash University		Pacific Rocket Society
	Scalar Antennas

TABLE 2

AUSROC II SPECIFICATION SHEET

	Length			6.1 m
	Diameter		0.258 m
	Thrust			11500 N
	Burn Time		20 sec
	Ve (Measured)		1863 m/s
	Fuel			Kerosene
	Oxidiser		LOX
	Pc			3 MPa
	Pressurisation Gas:	Helium
	Dry Weight		126 kg
	Fuelled Weight		225 kg
	Mass Ratio	 	0.44
	Transmitter		444 MHz (20watt)
	Power Supply		Dry Lithium Battery Packs
	Recovery		Ballute + Main
	Rail Length		10 m
	Q.E.			70 deg
	Est. Altitude		12,000 m
	Est. Range		25,000 m
	Est. Burnout Vel.	Mach 1.6

AUSROC II SPONSORS

	A.S.T.A				Alcan Aust.
	Ardebil Pty. Ltd.		Australasian Rocket Engineers
	Aust. Space Insurance Group	Bestobell
	B.H.P.				Brathstray Ltd.
	Brown & Dureau			B.T.R Indeng
	C.I.G.				Comalco
	Davidson Pty Ltd		D.S.T.O.  (M.R.L. & A.R.L.)
	Explosives Factory Maribyrnong	Hadland Photonics
	Hawker De Havilland		H.I.Fraser
	Hoppecke			Mobil Aust.
	Monash Uni.			N.E.C.
	Norgren Martonair		Paradynamics
	P.A.Safety Systems		Pacific Rocket Society
	Pendry Pty. Ltd			Philips			
	R.A.A.F.- ARDU			South Australian Government
	Sir Alexander Stewart Award

TABLE 3

  AUSROC III Preliminary Specifications
	
	Propulsion Type: 	Pressure Fed Liquid (Bi-Propellant)
	Fuel: 			Kerosene
	Oxidiser: 		Liquid oxygen
	Mixture Ratio: 		2.4 (Ox./F.)
	Propellant Mass: 	1200 kg
	Combustion Pressure:	2 MPa
	Thrust: 		35 kN (s.l.) - 42 kN (vac.)
	Exhaust Velocity: 	2550 m/s (av.)
	Motor Burn Duration: 	80 sec
	Payload: 		100 kg
	Target Apogee:		500 km
	Vehicle Mass Ratio: 	0.85 (Mass Propellant/Total Mass)
	Diameter: 		0.7 m
	Length: 		9m
	Navigation: 		Strapdown Inertial
	Attitude Control:	Hydraulic Gimballed Nozzle
				Thrusters (Roll)

TABLE 4

AUSROC III - 1992 SUB-PROJECT ALLOCATION LISTING

	Propulsion System
	Rocket Motor			M.Blair (DSTO)
	Injector & Igniter		W.Williams (DSTO)
	Mounts, Valves & Plumbing	(unallocated)
	Roll Control Thrusters		J.Dimaggio (HDHV)
					J.Balatsas (HDHV)
	Static Test Facilities		R. Bromfield (ARE)
					M.Blair (DSTO)

	Composite Structures
	Propellant & Helium Tanks	(unallocated)
	Fairings			(unallocated)
	Nose Cone			Stephen Mitchell

	Control System
	Autopilot 			M.Telfer (Monash)
					A.Burridge (Monash)
					A.Coia (Monash)
	Inertial Navigation System	A.Cheers (Ardebil)
					M.Pszczel (DSTO)
	Motor Gimball System		G.Koennecke (ARL)
					E.Semple (Adelaide Uni.)
	Systems Analysis
	Aerodynamic Analysis 		N.O'shea (RMIT)
	Dynamics			R.Koning (RMIT)
	Trajectory Simulation		A.Cheers (Ardebil)
					P.Wilson (QUT)
					T. Winks (QUT)
	Systems Engineering		M.Blair (DSTO)
	System Reliability Analysis	(unallocated)

	Flight Electronics
	Master Control System		J.Coleman 	
	Sensor Data Aquisition		S.Pietrobon (U.SA)
					S.Kerrisk (U.SA)
					G.Hermann (U.SA)
	Telemetry			(unallocated)
	Power Supply Circuits		(unallocated)

	Experiment Payload
	Microgravity			(unallocated)
	Imaging Remote Sensor		I.French (ASERA)
	Atmospheric Sounding		(unallocated)
	Payload Recovery System		P.Siaw (RMIT)

	Ground Support
	Telemetry			(unallocated)
	Data Reduction & Analysis	D.Kamp	
	Launch Control Sequencer	T.Chen (Ardebil)
	Launcher Infrastructure		P.Pemberton(USQ)
					J.Durack (USQ)
					A.Reid (USQ)
					D.Miller (USQ)
					F.Naseasi (USQ)
					F.Jacobson (USQ)

	Range Safety
	Impact Prediction, Tracking	P.Wilson (QUT)
	Az. El. Optical Tracker		J. Tang (QUT)
	Flight Termination System	M.Blair (DSTO)
	Range Safety Issues		R.Bromfield(ARE)

	Non-Technical Issues
	Legal & Insurance		K.Ikin (GIO)
					W.Jones (ASIG)
	Public Relations
	Information Distribution	M.Blair
					ASERA
	Video & Doc. Archive		K.Dougherty