For the development of reentry technology it is essential that the kno
wledge gained from ground test facilities and numerical methods is tes
ted and broadened in real reentry flights. The first of such projects
was the space reentry capsule EXPRESS, which was designed as a German-
Japanese enterprise for both microgravity research and reentry experim
ents. The capsule was built by the Russian company DB Saljut as part o
f the Khrunichev State Research and Production Space Center and modifi
ed by DASA. The capsule was launched from Kagoshima by a Japanese M-3
SII rocket in January 1995. Due to a failure of the rocket, the nomina
l orbital altitude could not be reached, which led to an early reentry
of the capsule in Ghana after two and a half orbits. In the stagnatio
n region of the reentry module an experiment was planned with a fibre
reinforced ceramic tile of 300 mm in diameter integrated in the ablati
ve heat shield. This experiment, called ''CETEX'', was designed by the
German Aerospace Research Establishment (DLR) in Stuttgart. The aim o
f CETEX is to qualify lightweight fibre reinforced ceramics and relate
d structural concepts in terms of heat shield applications for space v
ehicles as well as to compare the erosion behaviour shown in Eight exp
eriments and ground tests. An integral part of the CETEX experiment is
the PYREX experiment of the University of Stuttgart. With PYREX a pyr
ometer shall be qualified, which is designed for high precision temper
ature measurement of heat shield materials made of fibre reinforced ce
ramic compounds during the reentry phase of space vehicles and probes.
A third German experiment, RAFLEX, projected by Hyperschall Technolog
ie Gottingen (HTG), Was also integrated in the CETEX tile. RAFLEX is d
esigned for the measurement of dynamic and static pressures and heat t
ransfer at various positions on the EXPRESS capsule. Two small SiC tub
es are fed through the CETEX tile for the RAFLEX and RTEX experiments.
RTEX is a Japanese spectroscopy experiment which uses the same SiC tu
be as RAFLEX. Other pressure measurement points and the heat transfer
gauges are located in the conical flare of the reentry module. The aim
of these pressure measurements is to verify theoretical flow field mo
dels for different flight altitudes and to determine the angle of atta
ck of the capsule. In addition, the flight qualification of CETEX and
the pressure tube integration are important technological experiments
for future reentry experiments. In this paper the EXPRESS and the MIRK
A missions will be described briefly. The three experiments, CETEX, PY
REX and RAFLEX, in particular their qualification in ground tests, wil
l be dealt with in detail. Copyright (C) 1996 Elsevier Science Ltd