LEX (french: Lithergol EXpérimentale) was a French experimental hybrid-propellant sounding rocket, developed by ONERA.[1][2][3][4] It had the objective of testing a lithergol fueled rocket engine (an hybrid mixture of solid and liquid propellants - Nylon-metatolueneamine as fuel and mixture of nitric acid and nitrogen tetroxide as oxidizer).[1] It was the first rocket in history to use this technology, flying 8 times between 1964 and 1967.[5][6][1]
The rocket had a single stage with a thrust of 10.00 kN (MT.27 hybrid rocket motor), a gross mass of 100 kg, a height of 3.40 m, and a diameter of 0.16 m, reaching an apogee of 130 km.[6][1]
All LEX launches were carried out from CERES Ile du Levant.[1]
The first LEX-01 launch on 25 April 1964 was a partial success, with the payload consisting of a telemetry transmitter.[5][6]
Three LEX-02 rockets were fired on 1 June 1965. One of these rockets, with an initial mass of 78 kg, reached an altitude of 68 km.[5][6]
Four LEX-02-B launches occurred on 1 November 1967. Two were intended as technological tests and two others as actual payload launches.[5][6] These carried the SECT Meteo meteorological payloads, reaching an altitude of more than 100 km, with a parachute ensuring a correct descent for 31 minutes allowing wind measurements over a wide range of altitudes.[5][1]
Flight no. | Version | Launch date (UTC) | Payload(s) | Apogee | Notes |
---|---|---|---|---|---|
1 | LEX-01 | 04/25/1964 | Telemetry transmitter | 1 km | First flight of LEX (partial failure due to residues in the engine) |
2 | LEX-02 | 06/01/1965 | Telemetry transmitter | 68 km | First flight of LEX-02 |
3 | LEX-02 | 06/01/1965 | Telemetry transmitter | 60 km | |
4 | LEX-02 | 06/01/1965 | Telemetry transmitter | 60 km | Last flight of LEX-02 |
5 | LEX-02B | 01/11/1967 | Telemetry transmitter | 101 km | First flight of LEX-02B |
6 | LEX-02B | 01/11/1967 | SECT Meteo | 80 km | |
7 | LEX-02B | 01/11/1967 | SECT Meteo | 115 km | |
8 | LEX-02B | 01/11/1967 | SECT Meteo | 115 km | LEX's last flight |