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NERO Projects H6 rocket

The H6 rocket

- Design
- Flightdata
a H6a
b H6b
c H6c

The development of the H6 rocket in the years 1988 to 1994. The rocket was designed to comply with the requirement to be as light as possible. Achieving this goal enabled us to fly a completely equipped rocket faster than the speed of sound (Mach 1). The rocket was equipped with an advanced on-board computer, which collected the measurement data from several instruments and sensors and was able to show this in real-time on a monitor at the ground control station. Besides real-time data transmission, the data was also recorded in the so-called IRM (Impact Resistant Module). As a consequence of this method of data acquisition, the on-board computer itself was able to indicate what the best moment for launch would be.

The recorded sensor data resulting from the H6b flight was checked later on with extensive simulation software, which provided us with insight into the physics of such a rocket flight. For the H6, a lot of systems and concepts were developed, which could be used later in the H7 rocket. An important disadvantage of the rocket turned out to be the complexity of the (software of the) on-board computer. This eventually resulted in the search for more simple solutions, like the Finite State Machine (FSM).


Design [Top] [Contents]

Mass minimisation was the most important design driver for the mechanical and structural design of the H6. On the one hand, we enjoy the challenge of trying to save mass wherever possible, but on the other hand it is simply a necessity if you want to achieve the goals we had set ourselves for the rocket performance, using the TG-10 motor. For this reason, we have made the principal choice for a construction concept in which the rocket body itself has load-carrying capabilities, which was already implemented for the H5 rocket. Since we have to mount electronics, a recovery system and a motor, the rocket is divided into three compartments which are connected to each other with Aluminium joint rings.

Theoretically, this construction is an ideal construction for several reasons. First, the rocket is much stiffer for buckling, bending and torsion than a rocket with an internal load-carrying frame (at the same structural mass). The tube can therefore be very thin. Furthermore, the internal structures, e.g. the sub-structure for the electronics, can be designed with minimum mass since they don't have to carry large loads.

Just as important as the above, is the principle that the load exerted on a rocket will follow the shortest route possible. This means that unnecessary structural mass can be left out. In the H6 rocket, all non-structural parts, such as the motor, the attachment for the parachute cords and the de-blocking device, are therefore mounted on one of the joints between the compartments.

To the right of the figure below you'll find links to some of the subjects which give an impression of what is relevant for the design and the launch of the H6 rocket.

Blue=new Red=visited Parachutes
Blue=new Red=visited Pyros
Pyrotechnical devices
Blue=new Red=visited Skin
Blue=new Red=visited Sub-structure
Blue=new Red=visited Electronics
Blue=new Red=visited Downlink
Blue=new Red=visited Motor
Blue=new Red=visited Boat tail
Boat tail with antenna

Blue=new Red=visited Take a look at a cut-out drawing of the initial design of the H6 rocket.
Blue=new Red=visited H6 launch procedures Read the launch procedures of the H6..
Blue=new Red=visited H6 photographs Take a look at the photographs of the H6 and its launches.
Blue=new Red=visited H6 animation View a simple animation of the H6 flight.


H6 Flightdata and viewer [Top] [Contents]

With the help of this viewer the flight of the H6b and H6c can be recoinstructed. You can feel the same tension as we did when we saw the H6c make it's fatal crash.

Beware: This program is not fully windows compatible and can only be started using an open MS-DOS window. Put the RMSse an data files in the same directory. Open a MS-DOS window. and make the directory active (CD-command). Start the program.

Download the ground station software and the data files of the H6b and H6c flights and experience the flights 'life'. At start-up of the program, enter the name of the data file. The read-me file will provide brief help information. You will then see real the information screen, which allowed us to follow the flights, despite the fact that the rocket disappeared into a thick cloud cover.


The H6a flight [Top] [Contents]

The H6a launch on 26 September 1992 was the first flight of the H6 rocket. The main goal of the flight was to qualify the mechanical components of the rocket. The fact that these components are still used unchanged in the present H7 rocket shows the success of the mechanical design. Although the rocket didn't fly in the originally intended configuration, the flight was a complete success.

Blue=new Red=visited H6A flight report Read the detailed H6a flight report from the flight on 26 September 1992.


The H6b flight [Top] [Contents]

The H6b launch on October 1994 was the most successful flight of the H6 rocket. During this flight, which unfortunately could not be tracked with the naked eye, a wealth of data was gathered. The rocket could only be recovered from the woods after an extensive search. Because the transmitter antenna ended up in wet moss on the ground, the transmitter failed, which explains the radio silence after landing.

No Eglish page Blue=new Red=visited Read the detailed H6b flight report from the flight on 24 October 1994.


The H6c flight [Top] [Contents]

The H6c launch on 20 September 1996 is a flight which led to one of the most extensive post-mortem analyses ever undertaken within NERO Haarlem. Using the RMS we quickly found out that the rocket had crashed during the flight. How could it be possible that a rocket which had flown successfully twice before crashes? We were puzzled by this. Moreover since the rocket could not be found, not even after extensive searches carried out.

Fortunately, help came from photographs taken during the launch. From the photographs it could be deduced that a sudden wind gust had changed the flight direction of the H6 rocket. We now had the task to try to determine which trajectory had been followed by the H6 in order to find the impact location. Using simulation software, the wind profile of that day and the data recorded by the RMS, we were finally able to predict the impact point. The rocket was later recovered from the crash site which turned out to be within 40 meters of the predicted location. The whole trajectory analysis had cost us about 100 man-days of work.

No Eglish page Blue=new Red=visited Read the detailed H6c flight report from the flight on 20 september 1996.