club was founded in september-october 1965.
I.R.A. stands for International Rocket Association. Founder was Claes Frostell and David
Gordon. Small zinc-sulphur rockets was
launched to 200 meters altitude. Much ideas and inspiration from the book:
"Rocket Manuals for Amateurs" by R. Brindley in US.
small workshop was set up. The first primitive testbench
was designed and built INSIDE a little wooden house. This house is
still 'alive' today but outside the club's reach, situated
10 km north of Stockholm. A small military field
was used for many years for launching. This field is only 15 km outside of
test-bunker was built 25 km outside of Stockholm (in Åkersberga). In this
bunker many rockets was tested for the following years. The first 'big'
rocket was successfully launched to an altitude of 700 meters. 1.5 kg of zinc-sulphur
Launching at F2-Hägernäs north of Stockholm 1967
second little and primitive workshop was setup in the cellar of a school.
Only a short time later the club got bigger room in an old building, very
suitable for designing rockets. Plenty of rooms for the club.
Launching at F2-Hägernäs north of Stockholm 1968
very big launching-campaign was organized in the south part of
Stockholm archipelago, on an island named UTÖ
during 3-8 of august. Totally 8 rockets was launched. The first ejected
parachute (1400 meter) and altitude‑record of 2000 meter was obtained
among many other more or less successful experiments.
launching-campaigns was organized: In middle of july in the military-field:
Veckholmen, 60 km from Stockholm.
Three small zinc-sulphur rockets was launched to 600-850 meters
The second launching took place on
the military‑field Villingsberg
(a very big field 260 km West of Stockholm) 11-14 october. 5 rockets
- An 65
kg heavy 2-stagerocket (ZN+S) launched, second stage did not ignite.
50 kg heavy 1-stagerocket (ZN+S), explosion.
3-stage-rocket (ZN+S), 3:rd stage did not ignite.
1-stagerocket with parachutesystem and transmitter worked
1-stagerocket with no parachute and no transmitter worked properly.
Experiments started with more powerful propellants, such as
Potassium perchlorate+asphalt, and similar. No success, many exploded rockets
and destroyed five (!) testbenches completely. Calculations on liquid
propellant rockets was made, but no rocket was built.
and PVC was tested with a little motor containing only 1.1 kg of propellant
with success. A little primitive heatingoven was built, for curing the
of the first successful PVC + Ammoniumperclorate rocket. It was a heavy
reaching 400 meter altitude, 1.3 kg propellant.
Problems with the quality of the Ammoniumperclorate, containing
'anti‑plumbing‑agent' which gives the
propellant unwanted behaving. Different quality each delivery.
A bigger heatingoven was built, for curing the PVC-propellant at
150-155 degree Celsius.
Again the club
had to move to another buildning. Now the club moved for
the last time, so far. Area of 100 sq.m. A very well equipped workshop
could now be setup.
First successful launching of a PVC-composite propellant
contact with Youth and Space. Participating in the 2:nd European conference
in Belgrade, Yugoslavia. One of the IRA
member (Ulf Torberger) participated in the swedish science fair for 'young
scientists', and with a Zinc-sulphur-aluminum project. He
recovered 1:st price, which was a 2-week trip to USA and partition in
the american science-fair for 'young scientists'. The trip also
included a visit to Cape Kennedy and the launching of SKYLAB in May 1973. Two
2-stage Zn+S rockets was launched to 3 km altitude.
with the Italian club CRS from UDINE about a very simple and reliable
parachute-system. This system was tested several times with success.
participating in the science fair (Christian Nissen), recovered 2:nd
price, which gave him a 6-week stay in the 'Weizman institute' in
Israel July 1974.
construction of a strand-burner, also called
This consist of a nitrogen pressurized chamber. Thin strands of propellant
was tested. The aim was to measure the burningrate under different pressure
The workshop 1974--1999
kg Ammoniumperclorate was bough from Japan
(The Japan Carlit Co) for a very good price, and with a
very high and pure quality.
of a new ignitionsystem. Cooperation-project with the Dutch rocketclub
NERO started. Static testing of many PVC-ammoniumperclorate motors with
success, much thanks to the new delivery of ammoniumperclorate and new
ignitionsystem. The new developed rocket ODEN is launched to 4.2
altitude, containing 27 MHz transmitter measuring altitude, flyingtime and
burningtime of the motor.
Launching to 4.2 km altitude. 3kg propellant.
static test in the NERO testbench in Netherlands, all with success.
Annual report 1977
(verksamhetsberättelse) Swedish only, pdf-format.
in the big execution 'SPACE-WEEK' in Stockholm, which over 100,000 people
visited in 7 days. A new launchingtower was designed and built.
rockets was launched to 4.2 km altitude.
Final assembly of the motor in the NERO testbench in Holland.
Static test in Holland was a total success. Measured
specific impulse=185 sec. 3 kg propellant.
test in the NERO testbench, also as demonstration during the Youth and Space
congress in EINDHOVEN arranged by NERO.
Two ODEN-rockets launched to 4.2
- 4.5km similar to the ODEN
launched in 1976.
Presenting the IRA-NERO report from the cooperationproject, also
wellknown as the 'yellow report'.
Acceleration 20 "g".
Altitude 4.5 km. 3 kg propellant.
Acceleration 50 "g". Photo approx. 0.5 second after start
when speed is 900 km/h. Altitude 4.5 km
Max speed is 1900 km/h
Static test "Herkules". Burningtime 5 sec. 8 kg propellant.
Static test. Burning-time=0.54 sec and then explosion
destroying the motor and the testbench.Thrust 1 ton. Measured specific
launching of the biggest PVC-motor ever. 8.5 kg of propellant. Bad casebounding
to the outer wall resulted in a explosion in the tower, which was partially
in december 1979. Enlarged photo to the right.
Final assembly of Herkules in the launchingtower. Herkules is propelled by 8
Antenna for the transmitter vired around the nosecone.
big and stable static testbench was built for test of motors. Electronic
evaluation of chambrepressure and thrust was possible.
of a PVC-rocket. Hangfire and no success. Problems with the home-made
chemicals for the ignitionpowder. Also a static test of a 2 kg PVC-rocket
with 75% oxidizer with success. This mixture however gave a very high
of methods for curing propellant in small tablets. This was a result of the
unsuccessful launching 1978. This method was however never used in real
Many propellantcastings were made with success.
Filling the mold with propellant by pressurized nitrogen,
direct from the vacuummixer.
developing of the HERCULES 2-stage project.
Starshaped coremandrel made in steel and Teflon-coated.
For the first time this starshaped propellant grain was
used with success.
the High-Altitude project. Developing the most sophisticated altitude
computer calculation program, available to amateurs. This program was used
for the final calculation of the 2-stage HERCULES launched at Skillingaryd
(Sweden) in July 1986.
The software was also verified agaist professional calculations, with success.
Assembly of the 2-stagerocket. Total
Instrument included a 450 Mhz transmitter and a computer
the 2:nd stage motor development of the 'High Altitude project'. Start
developing of the motor which will be built in carbonfibre reinforced
epoxy. For this purpose a computerized machine was designed for the
manufacture of the motortube.
analysis of motor-construction, propellant, electronics etc. First
manufacture of motor-tube in carbon-fiber reinforced epoxy. 90-95% of
theoretical strength was obtained during a test. A completely new system for
fastening nozzle and top plug of the motor was also developed, and static
tested with success.
Carbonfibre-reinforced epoxi motorcasing.
first prototype of the core mandrel internal burning star was manufactured in
aluminum. This is to be used in the second stage.
||Workshop was closed down
and club is in heaven.
||The End !