initially intended as a supplementary programme for the german spacelab missions, the first launch of a texus payload took place on december 13, 1977 with a two-stage skylark rocket at esrange. in the following years, up to four texus missions (6 minutes of microgravity) were flown per year, with numerous experiments. in order to meet the ever-increasing number of experiments with different requirements and objectives, the swedish maser programme, the maxus programme (13 minutes microgravity), and the minitexus programme (3 minutes microgravity) were initiated, under the aegis of the european space agency (esa).