The TEXUS and Mini-TEXUS (TEXUS-EML) programs The TEXUS Sounding Rocket Program (Technologische EXperimente Unter Schwerelosigkeit) was initiated in 1976 by the German Ministry for Research and Development. Starting with the TEXUS 17 and 18 (launched in May 1988) the TEXUS project was commercialised and Astrium (fomerly ERNO), Bremen, has taken the overall responsibility. The Mini-TEXUS programme was initiated in 1993 to satisfy the demand of investigators for micro-gravity duration in the range of three to four minutes, at lower costs. Skylark VII two-stage solid fuel launchers (first stage: Goldfinch IIC, second stage: Raven XI) manufactured by British Aerospace, are usually employed in the TEXUS programme. With a gross payload weight of typically 360 kg, an apogee of 260 km is reached, and micro-gravity conditions are achieved during 370 seconds. The Mini-TEXUS rockets also employ two-stage solid fuel motors (first stage: Nike, second stage: Orion) from military surplus equipment. They permit launch a 100 kg scientific payload to an altitude of 150 km, thereby providing micro-gravity conditions for 200 seconds. 39 TEXUS and 6 Mini-TEXUS payloads have been launched to date.
The MAXUS program The MAXUS long-duration sounding rocket program is a joint venture of Astrium and the Swedish Space Corporation. This programme was initiated in 1990 to extend the micro-gravity duration capability in Europe to the range of 10-15 minutes. For MAXUS, a single stage solid-fuel rocket motor Castor IVB is used to launch a gross payload of typically 780 kg to an apogee of about 715 km. This corresponds to some 13 minutes of micro-gravity conditions. The first successful MAXUS payload was launched in autumn 1992.
The MASER programme The Swedish Sounding Rocket programme 'MASER' (MAterials Science Experiment Rocket) is managed by SSC (Swedish Space Corporation), Stockholm. SSC has also participated in the TEXUS programme from the very beginning. Up to 1987 one SSC experiment module containing up to 12 independent furnaces was launched with each TEXUS campaign. In the MASER programme, Skylark VII or Black-Brant IX B rocket motors (first stage: Terrier booster, second stage: Black-Brant VB) are used. When required, a guidance system is included in the payload. This system (S19) is a constant lateral-attitude control system which maintains the vehicle in the launcher attitude during the first 18 seconds after lift-off, thereby minimising impact dispersion and wind sensitivity. With MASER 5, a new combination was tested with an improved Terrier booster as first stage and a Black-Brant 5 as second stage. This combination permits launching a gross payload of 500 kg to an apogee of 300 km, corresponding to seven minutes of micro-gravity. The first MASER payload, MASER 1, was launched in March 1987. To date nine MASER payloads were launched successfully.