REXUS 3 Experiment overview
Project ARCHIMEDES is a joint effort of the Mars Society Germany, the University of the German Federal Armed Forces in Munich, the University of Stuttgart and others with the goal to built a spacecraft capable of probing the atmosphere of planet Mars from its thin outermost layers down to the surface. This goal will be achieved by deploying a spherical super-pressure - type balloon prior to atmospheric entry.
The flight on a sounding rocket can close an important gap between previous parabolic flight and orbit, namely by putting the system in space just long enough for the balloon package to be ejected and to start expanding under the pressure of its own protective gas filling. The experiment starts when the payload section of the rocket enters 0-g. It should be mounted at a free end of the payload section, preferably at the opposite end of the recovery system. After entry into the 0-g phase the separation mechanism is triggered, and in a safe distance the deployment mechanism. Cameras that are left in the payload section record the separation and deployment, and can be recovered with the other payload.
Combined mass: Approx. 30kg incl. batteries and structure.
The T-Rex project at the Institute of Astronautics started in April 2005 as a part of the practical course “Space Technology”. The task was to develop and construct an experiment that can be placed on the Rexus-Rocket. Soon it was clear that the main focus of the experiment existed in finding accelerometers, which are really cheap but still able to survive in space. Three main requirements where found:
• Measure accelerations as best as possible
• Use low cost elements
• Assure a safe operation
Several acceleration sensor principles have been considered and led to the selection of capacitive accelerometers. In the end, accelerometer choice was mainly based on low cost and thus, summing all up, T-Rex now fly with 3 x 3 Freescale accelerometers. The chosen products are:
• Freescale MMA3201D 2 channels +/- 40g
• Freescale MMA1250D 1 channel +/- 5g
• Freescale MMA6233Q 2 channels +/- 10g
As within these chosen sensors are no three-dimensional units, measuring all three axes will be achieved through appropriate set-up on the circuit boards. Three independent circuit boards will be used, each carrying three different sensors and a complete set of data processing units. The sampling rate is 2 kHz per channel. The data is stored in solid flash devices and will be partially transmitted over downlink for redundancy.
The goal of this experiment is to test the sensors and in particular the optics during supersonic flight and measure the interconnected heating of the hardware. The Camera Hardware is capable of storing the temperature of the rocket casing. This information is added to the picture data. Because of unpredictable changing illumination ratios during the flight, the camera is recording pictures with cyclical changing exposure times. The picture data will be ordered by different brightness values after the flight and processed for colour matching. Maybe equalization will be also applied. After this process the data will be assembled to an animation.
The experiment is operated by the University of Berlin.
TUPEX is an experimental platform to design and test components especially used in pico satellites. The experiment is operated by the Technical University of Berlin.
The objective is to test the functionality of solar cells, several commercial sensors and a self-developed sun sensor for attitude determination in respect to the sun.
TUPEX consists of a main box and two solar boards. The main box includes a measurement value logging unit and several sensors (3 gyros, 2 two-axis accelerometers, 1 three-axis magnetometer, 5 temperature sensors). The solar boards include a triple junction GaAs solar cell, a sun sensor and a temperature sensor.
During flight all acquired values are stored on flash memory and transmitted to ground station via rocket communication link simultaneously.
IAP Particle detector
The instrument package for the REXUS-sounding rocket campaign at the ESRANGE in April 2006 provided by the Leibniz Institute of Atmospheric Physics at the University of Rostock consists of a total of 4 instruments: The two simple particle detectors are flat electrode surfaces mounted flash with the rocket payload skin. Strong NeFeBo-magnets (field strength ~0.4 T) are embedded into the electrode structure to prevent electrons and ions from contributing to the measured signal.
The two fixed biased Langmuir sondes have a similar geometry, however, instead of using magnets in order to shield the electrodes from the ambient plasma, the electrode surfaces are biased at +4.5 V (-4.5V) in order to measure electrons (positive ions).
Hard Disc Drive, Rexus Rocket of Rymdgymnasiet
Upper secondary space school, Kiruna
The purpose of the experiment is to analyze how a micro hard drive in a modern MP3-player is affected by the environment in space. Is it possible for a hard drive to function after it has been exposed to high acceleration, low gravity and no air pressure?
The micro hard drive MP3-player Iriver H10, sponsored by Iriver Nordic and encouraged by the Swedish tech magazine M3.
The player can maybe expose electromagnetic fields but it will be reduced by the protective box, the box shields frequencies from 5 Hz up to 1800 MHz.
The player will be examined prior to launch that it functions correctly. An error check will be done on the hard drive using the error check tool in Windows for hard drives. Hard drive info will also be obtained from another application not yet decided, probably Partition Magic.
During the flight the built in FM radio will provide static noise to be recorded on the hard disc.
The examinations after the trip to space will be first of all controlling if the player starts and can play the recorded noise. After that an error check will be performed in Windows followed by a more detailed scan by a proper application, probably Partition Magic. In any case if the player starts or does not start, I will through eventual sponsorship agreements try to send the player to computer laboratories or technical universities for further technically advanced examinations, if needed.
The MEMS experiment, built by a Norwegian team.
The use of MEMS (Micro Electro Mechanical System) is one step forward towards the miniaturization of electronic systems used in space. Angular rate sensors and accelerometers based on different MEMS technologies are today available from several companies. We will focus on sensors from SensoNor, Analog Devices and MEMSIC which are all using different sensing technologies. These sensing technologies are based on vibrating silicon structure (gyro), capacitive comb structure (accelerometer) and natural heat convection (accelerometer) respectively.
MEMSIC accelerometers do not depend on moving mechanical parts. The principle of operation of the accelerometers is based on heat transfer by natural convection, and they measure internal changes in heat transfer caused by acceleration. This new technology provides shock survival up to 50.000g and eliminates stiction and particle failures that commonly exist in all traditional capacitive sensors.
The SensoNor SAR10 angular rate gyro is a silicon bulk micromachined capacitive device, consisting of a vibrating silicon structure sensor element and an ASIC integrated in a SOIC package. The principal of operation of the sensor is based on the detection of Coriolis force. Excellent gyroscopic scale factor, offset and vibration sensitivity is achieved due to anti phase operation.
The Analog Devices accelerometers are a well proven capacitive technology and are frequently used nowadays.
To achieve the most accurate measurements possible, these sensors will be placed at different angles and positions inside the payload. Several of the sensors will be running in parallel during the flight so a direct comparison of the different sensor outputs should be easily achievable. A number of microcontrollers will collect all the information from the sensors and direct it to the encoder unit.
The primary objective of the experiment is to investigate our sensors behavior in the harsh environment of the interior of a sounding rocket. The goal is to determine if they are good enough to be considered for future space applications. Different sensors are set up to measure the spin and coning of the rocket, acceleration in the longitudinal direction and the vibration subjected to the circuit box. If the experiment proves successful, these sensors can make up a measurement system witch can be used to evaluate the behavior of the rocket during its flight