PARIS — The German-Swedish Texus suborbital sounding rocket program on April 12 successfully completed its 50th flight, carrying four German experiments to an altitude of 261 kilometers and offering six minutes and 20 seconds of microgravity conditions, the German and Swedish space agencies announced.

Operating from Sweden’s Esrange facility, the 12-meter-long Texus vehicle climbed through the atmosphere for about 30 seconds, at which point its engines cut off and it continued its ascent in free flight.

After the exposure to microgravity conditions, the rocket’s parachutes opened and it landed some 28 kilometers north of the Esrange facility, where it was picked up by helicopter and its experiment packages delivered to their respective teams at Esrange.

Texus began flying in 1977 and has carried 300 experiments, mainly in biology and materials sciences. Some 70 percent of the payloads were designed and flown under contract to the German Aerospace Center, DLR, with the remaining 30 percent conducted for the 20-nation European Space Agency (ESA).

In the April 12 flight, the principal experiment was an electromagnetic levitation facility to study metal alloy compounds nickel-zirconium and aluminum-nickel, according to DLR.

DLR and ESA use sounding rocket flights as precursor missions for some experiments intended for the international space station, at which Europe has a habitable laboratory called Columbus. DLR also is a lead supporter for a drop tower in Bremen, Germany.

“Texus is an essential component for fundamental research in microgravity, and hence also for the preparation of long-term space experiments,” said Otfried Loop, Texus project manager at DLR.

The 51st Texus mission is scheduled to occur April 19.

Peter B. de Selding was the Paris Bureau Chief for SpaceNews.