3. Thermal Radiation Forces in Unsteady Conditions Experiment (TRUE-2):

The objective of the TRUE fluid physics experiment, performed by Prof. F.S Gaeta from MARS Center in Naples (Italy), is to measure the effect of Thermal Radiation Forces on a solid disc embedded in a liquid and crossed by a heat flux during a thermal transient. According to the theory of Thermal Radiation Forces the heat flux results in a force on the disc, which is measured by a specially developed highly sensitive force sensor. The interest of the experiment is to reduce the present uncertainty on the value of forces to be expected and to validate the theoretical model. The measurements have to be done under microgravity to eliminate the buoyancy forces and convection, which arise from density gradients under 1g on Earth.

Preparation CIDC experiment for Maser 10 flight

4. Chemically-Driven Interfacial Convection (CDIC):

In many industrial chemical processes two immiscible liquids react at the interface between them. In cases where the reaction product is lowering the interface energy, interesting and complicated interface structures appear and couple back to the process. To understand this complicated and interesting interaction, the elimination of the disturbing influence of gravity is necessary. The CDIC fluid physics experiment required the development of a new experiment module under ESA contract.

The experiment is performed by Dr Eckert from the Technical University of Dresden (Germany), in cooperation with Dr A. De Wit and Dr. P. Boon from the Free University Brussels (Belgium). The main goal of this experiment is a basic understanding of chemically driven interfacial convection, i.e. the convection between two interfacing liquids. It looks in particular into the following aspects: the mass transfer to the interface, the chemical reaction between the two liquids, the generation of concentration gradients, the amplification or damping of concentration perturbation, the generation of interfacial tension gradients and the redistribution of the gradients in concentration, leading again to changes in mass transfer. Special attention is paid to the effect of concentration gradients that can lead to strong deformations of the interface that are called 'fingering' patterns.

Telemetry data

The Service Module, which is part of the payload, handles the communication between the experiment facilities onboard and the scientists in the ground station during the MASER flight. It has been developed by the Swedish Space Corporation (SSC) and the German Space Center DLR on behalf of ESA and has flown two times before, on MASER 8 in 1999 and MASER 9 in 2002. It provides the operators and scientists on the ground with telemetry data from the experiment modules and enables them to send telecommands to control the experiments.

Monitoring experiments during flight

On MASER 10 a digital video system provided compressed realtime video images from seven cameras installed in two of the experiment modules. Thanks to this capability to receive data and send back commands to the experiments in realtime during the flight, the performance and thus the scientific output of the three fluid physics experiments could be optimized by the investigators during the MASER 10 mission. During the ascension flight and the microgravity period of the mission the Service Module has transmitted experiment data to the ground. However, upon reentry it suddenly stopped working. The payload engineer succeeded in restarting the operations for about 30 seconds, but then the transmission of data was discontinued for the rest of the mission.

The data and uncompressed video images stored onboard in memory cards and on video tapes are still readable, despite the shock at impact. However, the experiment facilities themselves, developed by ESA for the scientists participating in sounding rocket missions, have been damaged to an extent that they cannot be repaired and reused for future missions.

The situation for the two biological experiments is different since both experiments do not solely rely on telemetry data, but require the physical recovery of biological experiment samples for the scientific evaluation. Despite the crash landing, 14 out of the 16 ACTIN experiment units were recovered in a state that they can still be analysed scientifically. For the AMUSE experiment the ratio is six out of eight. Unfortunately, two of its microgravity units were destroyed.