History

Throughout the first few years of NERO, priority was given to the development of rocket motors. It was decided to concentrate on Zinc-Sulfur propellant, which was, and still is, a combination much used by many amateurs at that time. This was probably inspired by an America booklet by Capt. Bertrand M. Brinley called "A guide to Amateur Rocketry". Black gunpowder was also considered as propellant because it had resulted in some good results before. However, the Zinc-Sulfur combination propellant is a prominent for 25 years now and has shown to be a very reliable propellant in those years.

In the summer of 1969, this working group was able to get accommodation at the model airplane society "Anthony Fokker" in the Vogellaan in Heemstede. This accommodation proved to be an ideal place to experiment with small solid propellant rockets. After a while, the working group really felt at home with "Anthony Fokker", so they decided to join this society collectively. The working group Technics from the Karel van Manden Lyceum thus became the rocket section of "Anthony Fokker".

Besides the test motors, the  facilities to test them were also developed. Two different methods for measuring the rocket thrust were developed: the 'spinning disk' and the 'pendulum rig' methods.

In the spinning disk method, the rocket is attached tangentially to a horizontal disk. This method is equivalent to the spinning disk displayed in some Chinese fireworks. Upon ignition of the rocket, the disk starts spinning. Both the total number of revolutions as the revolution time is a measure for the exhaust velocity of the gasses and thus for the efficiency of the rocket motor. The number of revolutions is determined mechanically and the total burning time is measured with a stopwatch. This method is particularly suitable for comparative research.

The pendulum rig is a platform which is cardanically suspended on four chains and on which a rocket motor can be mounted. By measuring the excursion of the platform, the rocket thrust can be determined. A glass plate covered with soot is used to generate a thrust curve (thrust as a function of time).

Besides the above devices, the group was equipped with a wooden test rig, which could be placed in a pit below the ground level to minimise the risk accompanied with explosions. A rocket motor was placed upside down in the pit and subsequently tested. This test set-up was particularly suitable for testing the more powerful rocket motors. A battery was used to electrically ignite the motors.

All these activities finally resulted in the launch of the first Haarlem rockets, designated H1 and H2 (H for Haarlem). For the launch of the third rocket, H3, an adjustable launch tower proved to be necessary. In 1974 the wooden test rig was replaced by a steel one.

The H3 launch was conducted from the newly built 5 meter launch tower and took place at the end of March 1974.  The rocket reached an altitude of nearly 1 kilometre and landed on a sand bank just off-shore. After this success, the group more or less disintegrated because of high study demands and the rocket activities were reduced to a very low level. The launch tower was put into storage at the "Anthony Fokker" society.

An important change in those days was the society of the Young Researchers group (in Dutch: De Jonge Onderzoekers - DJO). The DJO department Haarlem had accommodation in 'the Egelantier' in the centre of Haarlem. Members of the rocket section of "Anthony Fokker" played an important role in the foundation of DJO-Haarlem. It was therefore logical that the rocket activities were to be continued within the DJO-Haarlem.

Because of all these activities, the working group progressively attained a more professional character. An unfortunate accident with rocket propellant gave rise to an investigation into the possibility of covering these type of activities by an insurance policy.  This proved to be financially unattainable for the group. However, it was found that the Dutch Federation for Rocket Research (in Dutch: Nederlandse vereniging voor Raket Onderzoek - NERO) had already such an insurance policy. In 1980 it was therefore decided that the rocket activities would be continued within the NERO, resulting in the foundation of the department Haarlem of the NERO.

A public nuisance act license was requested and issued by the authorities in order to build and use a static test bench, which was to be used below ground level only. Furthermore, the electrical ignition equipment was modernised and two small test motors were manufactured. In between these projects, a test series was completed which was required for the future conversion from nozzle exhaust ignition to top bulk head ignition.

During the following years the Haarlem department of NERO became active nationally and some international contacts were also made. This resulted in the delivery of parts of the instrumentation for the so-called Interim project to NERO department Drechtsteden. A lot of experience was gained in measuring pressures and temperatures on-board a rocket. In the mean time, several members participated in a NERO working group in order to develop more efficient and powerful rocket motors.

Around 1986 the construction of a totally new rocket, the H5, was started which would have to result in the launch at the first Dutch Launch Campaign in 1987. It was decided to take a quite powerful Yugoslavian motor and to build the rocket around that motor. The launch date, 30 May 1987 was just attained, thanks to the dedication of many people in the final days before launch. The flight itself took place in heavy fog, which meant that the rocket could not be tracked with the naked eye. The flight was not successful due to a fault in the electrical system which caused the deployment of the parachutes just 3 seconds after launch. Because of the high velocity, the parachute were completely torn off and the rocket continued its flight ballistically up to the highest point and down to Earth, making a lot of noise. The rocket was totally shattered upon impact with the ground and virtually nothing could be recovered, this included all the data recorded by the instruments on-board.

After the first Dutch Launch Campaign, the activities regarding rocket construction within the department slowed down somewhat. NERO Haarlem published a bi-monthly bulletin and the contacts with other clubs, both national and international were numerous. The construction of the follow-up rocket (H6) however, did not fully materialise. During the year 1989, in which NERO celebrated its 6th lustrum, several 'political' troubles caused the construction of rockets to come to almost a complete halt. Out of 'political' considerations the NERO society was reformed in 1992 into a federation with separate, independent departments. Since 1 June 1992 NERO Haarlem is an independent society with its own regulations, which is affiliated with the Dutch Federation for Rocket Research (in Dutch: NEderlandse federatie voor Raket Onderzoek - NERO).

The increase of activities accompanied with the change-over of the society made it possible to organise the second Dutch Launch Campaign (in Dutch: Nederlandse Lanceer Campagne - NLC-II) in September 1992. Despite the late start of the construction of the H6 rocket is proved to be possible to launch it during this NLC-II. The H6 was originally intended as an improved version of the H6, but in the end it was completely designed from scratch. The launch of this rocket (designated H6A, because it was the first flight of the H6) took place on 26 September 1992 and was a complete success, with full recovery of the rocket, which did not sustain any damage. The H6 flew a second time as the H6B, before crashing - due to wind gusts - as the H6c. The extensive on-board electronics however made it possible to provide us with a wealth of information concerning the flight of the rocket, its behaviour during flight and its performance.

The success of the H6 project formed the basis of the H7 project. The H7 is based on the H6 technology, but has two stages instead of one. The H7 is - with five successful launches - one of the most successful rockets ever. With the H8, NERO Haarlem launched the first amateur canard controlled rocket in the world. With the H10 we will break the European altitude record for amateur rockets. read more about these projects on the project pages.

At this moment, NERO Haarlem has about 20 members. Besides these people, NERO Haarlem can rely on the ad-hoc technical support from a group of people for our projects. These people manufacture parts and/or assemblies on request or provide valuable advise and/or calculations. Because of the geographical dispersion of its members, NERO Haarlem does not have a permanent accommodation. The work for projects is mainly done at home, while the Free University (in Dutch: Vrije Universiteit - VU) of Amsterdam provides accommodation for group meetings and work.