Raketenfahrt.

The fifth edition of the work first published in 1924 as the brochure Der Vorstoß in den Weltenraum (the second edition, 1925, also in this collection), retitled Raketenfahrt for this printing — whose body pages still carry running headers crediting the earlier “4. Auflage” typesetting.

In a preface dated Friedrichsbrunn am Harz, 5 September 1928, Valier explains the repeated delays and the change of title: after his December 1927 contract with Fritz von Opel, work on the revision kept being overtaken by the pace of the rocket-car and rocket-plane trials it was meant to describe, so that, as he put it, we had in fact already entered the age of Raketenfahrt.

The resulting new chapters, with technical detail largely supplied by Valier himself, document the unmanned Opel-Rak rail cars built December 1927–August 1928 — Rak 1–2; Rak 3, which reached a record 281 km/h at Kleinburgwedel on 23 June 1928; and Rak 4–5, both destroyed in explosions — then Valier’s own split from Opel and new partnership with the pyrotechnics firm J. F. Eisfeld of Silberhütte, whose resulting Eisfeld-Valier-Rak I is estimated to have topped 300 km/h before derailing on 26 July 1928, ending the test series without injury.

A separate technical report reprinted from the Rhön-Rossitten-Gesellschaft covers the first rocket-powered flight of a piloted aircraft, flown by Friedrich Stamer in the glider Ente at the Wasserkuppe on 11 June 1928, a day after an aborted first attempt caught fire in the air. Closing chapters sketch liquid-fuelled successors and a projected Berlin–New York rocket-plane service.

The Russian edition (1936) is also available in this collection.