Wikipedia
In Greek mythology, Astris (or Asteria) was, in Nonnus's Dionysiaca, one of the Heliades, daughters of Helios, either by the Oceanid Clymene or the Oceanid Ceto. She married the river god Hydaspes (the modern Jhelum River) and became mother of Deriades, king in India.
The Astris was a liquid rocket engine burning the hypergolic propellant combination of Aerozine 50 and NO. A single engine powered Astris third stage of the failed Europa rocket.
On November 29, 1968, its inaugural flight, the Astris third stage exploded. On the second attempt on July 1969, the Astris engine failed to start. On the third attempt on June 11, 1970, the stage performed correctly, but the fairing failed to separate. On November 5, 1971, the Europa II launched from CSG ELA-1, had a mishap due to structural failure of the third stage. After this last failure the project was definitely cancelled.
The Astris was an upper stage developed by ERNO Raumfahrttechnik GmbH and MBB as the third stage of the Europa 1 launch vehicle. It was the German contribution to the project and only flew activated four times. Regrettably, the high failure rate of the three and four stage rocket meant that the project was cancelled.
On November 29, 1968, its inaugural flight, the Astris third stage exploded. On the second attempt on July 1969, the Astris engine failed to start. On the third attempt on June 11, 1970, the stage performed correctly, but the fairing failed to separate. On November 5, 1971, the Europa II launched from CSG ELA-1, had a mishap due to structural failure of the third stage. After this last failure the project was definitely cancelled.