The propulsion system for the "Ludion" one-man hopper, an anglo-french rocket engine cooperation 40 years ago

Paper number

IAC-08.E4.3.6

Author

Mr. Christophe Rothmund, Snecma, France

Year

2008

Abstract

The Ludion ("cartesian diver") was a concept for a military "one-man hopper" aimed at giving troopers the ability to cross rivers or trenches using a simple rocket-powered backpack. The backpack design having quickly proven its impracticability, it was replaced by a skeleton structure supporting the rocket system and the "pilot". Following studies initiated in 1965, Sud Aviation was awarded the development contract together with Bertin (for the jet pumps) and SEPR was to develop the rocket propulsion system.

The propulsion system selected for the "Ludion" was based on british monopropellant engines designed by the Plessey company and integrated by SEPR with a complex jet pump (designed by Bertin) and hand-guided by the pilot through a gimbal for easy steering. The main challenges laid in the successful integration of all components and the management of a multi-partners program and in the design of a highly efficient thermal insulation protecting the "pilot" from the intense heat generated by the catalytic decomposition of isopropyl alcohol (used as a propellant).

The first ground test of a Ludion with its rocket propulsion system took place forty years ago, on January 24, 1968, on the test airfield of Villaroche. 

Although the powered flights were deemed to be successful, the Ludion was abandoned as it was too impractical due to its sheer size and the "bulky" protective clothing its operations required. The first prototype still resides at the Paris Le Bourget air & space museum today.

Abstract document

IAC-08.E4.3.6.pdf

Manuscript document

IAC-08.E4.3.6.pdf (🔒 authorized access only).

To get the manuscript, please contact IAF Secretariat.