Dutch English
Home page Organizational Structure Launches Projects Rocket motors Pictures NERO History Join NERO Definitions Safety Research Links Sitemap Search
NERO Projects    H5 rocket
Logo  

The H5 rocket
Contents
- Design
a H5a

The H5 is the first rocket which is actually recorded in the archives of NERO Haarlem. The development of this rocket took place during the years 1987-1988. Although it crashed during its first flight, this rocket laid the basis for the development of all rocket projects thereafter. For example, the current rocket body diameter of
10 cm was first used for the H5 and it was found that the weight distribution of the components within the rocket was far from ideal.

 

Design [Top] [Contents]
For the purpose of saving weight, the following philosophy was applied during the design of the H5:
  1. Use of materials which have a high specific strength (ultimate load/mass).
  2. Optimum system design with respect to strength (i.e. not stronger than necessary) to achieve the final goal.

This meant that it was necessary to perform rather lengthy and complicated stress analyses in order to arrive at an appropriate design. Compared to a conventional NERO rocket the following points are noticed:

  • The entire outer body of the rocket is fabricated out of glass fibre epoxy laminate with a thickness of 2 mm. The body is composed of three section, one for each compartment.
  • The joints between the different compartments are made out of Aluminium. Each joint is composed of three parts: the base platform, the upper connection ring (bonded to the compartment above the joint) and the lower connection ring (bonded to the compartment below the joint).
  • The complete instrument section of the rocket is suspended to platform no. 2 (see figure). This made it possible to reduce its mass since it doesn't have to support its own weight.
  • The pyrotechnical device for the release of the main parachute is mainly made out of Aluminium. At some places use is made of materials which can withstand high temperatures or which are wear resistant (e.g. stainless steel - CRES).
  • The electronics are designed to reduce the amount of current required as much as possible in order to reduce the mass of the batteries.
  • The nose cone is made out of fibre reinforced plastics. The shape of the nose cone is the von Karmann shape, which is ideal for sub-sonic and trans-sonic velocities.
Blue=new Red=visited Pictures Take a look at the pictures of the H5 and its launch.
Dutch annotations only Blue=new Red=visited
39.0 KB		 Take a look at the design drawing of the H5 (Dutch annotations only).
Blue=new Red=visited Read more about the pyrotechnical devices of the H5.
 

The H5a flight [Top] [Contents]
 
During the first flight of the H5 on 30 May 1987 things went totally wrong. Later, we were able to reconstruct what actually went wrong and we found out that the vibrations in the rocket were unexpectedly severe. The high dynamic loads caused resonance in the Printed Circuit Boards (PCB), which actually came into contact with each other. Since the tracks on the PCBs were not electrically insulated, a short-circuit resulted. Because of this short-circuit, the drogue parachute was deployed at a high velocity (Mach 0.8). The drogue parachute was subsequently completely torn off and this induced a change in the flight direction of the rocket. As a result, the H5 rocket did not reach the expected altitude, crashed and was later recovered from about half a meter below the ground level.
Blue=new Red=visited H5A flight report Read the complete H5a flight report.
Top