On 11 June 1928, the tiny, cramped tailless sweptwing
sailplane named Ente ('Duck') with veteran glider instructor
Fritz Stamer in the cockpit leapt from Germany's Wasser-
kuppe mountains under the thrust of a pair of solid propel-
lant rockets and travelled just over three quarters of a mile
in about sixty seconds. The designers of the little 'Duck'
believed that this modest feat was but the first stage in their
own concept of a space shuttle. They envisioned, firstly,
terrestrially-bound rocket planes for either delivering •
passengers or mail from one continent to another in record
time; then, after the perfection of propulsion and life-
support systems, true spaceships capable of navigating to
other worlds. Their funds and science were not as grand as
their visions. The little craft and others like it saw a brief but
spectacular vogue until they disappeared both from the skys
and the Sunday supplements. Nonetheless, the story of this
dedicated group of enthusiasts has never been adequately
If we discount the fantastic claims of the possibly legendary Chinese official Wan Hu, who is said to have lost his life in an attempt to propel himself by a kite-borne rocket chair in ca. 1500 A.D., and the story of a 1623 manned winged rocket flight by the Turk, Legari Hasan Tchelbi, who wished "to have a talk with the Prophet Jesus," we can safely assume that the first bonafide rocket plane flew in Germany , in 1928. It grew out of Fritz von Opel's rocket car stunts. \/
The idea also took shape in the mind of Antonius Raab, the 32 year old partner of the Raab-Katzenstein-Flugzeug-werk, GmbH, the aeroplane builders of Kassel, in the Spring of 1928. He was determined to fly the machine himself. On 29 April a contract was drawn up between the Opel Automobile Company of Russelsheim and the Raab-Katzenstein Flying Machine Works of Kassel "for the application of the 'rocket' principle to aircraft." Raab, with his partner Diploma Engineer Kurt Katzenstein would apply to their lightest aeroplane the solid-propellant Sander rockets that had proven themselves so well in Fritz von Opel's rocket cars. This machine was the 22 ft. 6 in. (6.85 metres) long, 552 Ib. (1,214 kg) Raab-Katzenstein R.K. 9 Grasmucke ('Warbler'). The two-seat cantilever biplane with a 29 ft. 5 in. (8.96 metre) span, was normally powered by one 40 h.p. Salmson radial engine fed by 42 litres (9 gallons) of fuel from a tank in the top wing. In its new role, the engine, the tank, and some anciliary equipment would be stripped out to accommodate the rockets and lighten the plane as much as possible.
Two batteries of Sander rockets of unspecified thrust and number were to be fitted on each side .of the fuselage between the wings, with electrical ignition from the cockpit, and cross-bracing and welded steel-tube structure of the R.K. 9 were to be specially strengthened "to withstand the high speed expected to be attained." Following Raab's consultations with his "scientific advisor," meteorologist Professor Ludwig Weickmann, Director of the Geophysical Institute at Leipzig University, both the pilot and the plane were to be equipped with parachutes and meteorological instruments also to be taken aboard. The latter included wind-temperature gauges, wind speed and pressure indicators manufactured to order by the famous Zeiss scientific instrument-makers of Jena. Should Raab find himself unable to breath or unable to withstand the cold during the climb towards the estimated maximum altitude of 32,800 ft. (10,000 metres) on the first run, he would bail out leaving
* Research Historian, Astronautics, National Air & Space . Museum, Washington, D.C.
SPACEFLIGHT, Vol. 21,2, Feb. 1979
Zeitschrift des Vereins ffir Raumschiffahrt E. V.
Da» erste bemannte Rafcetenfiugzeug.
Segelflugzeug ,,En!e" Ser Rhon-Rossitlengesellsdlaft.
Breslau, 15. Juli 1928 2, Jahrg.
Title page of Die Rakete 15 July 1928 depicting the flight of the rocketpropelled glider Ente.
Photo: F. I. Ordway Collection
FRITZ STAMER (1897-1969), believed to have been the world's first pilot of a rocket-propelled plane. He flew the Ente glider (above) from the Wasserkuppe Mountains, Germany, on 11 June 1928.
The Smithsonian Institution