One of the many tests carried out prior to today's hot-firing test

Today the new Vinci cryogenic upper-stage engine was successfully ignited and fired for the first time. This marks a further milestone in developing a more efficient cryogenic upper-stage engine for future upgrades of the Ariane-5 launcher.

Although the test lasted just one second, engineers declared themselves to be “very satisfied with the test-data”. The test results will be evaluated during the next few weeks prior to a decision being made to gradually increase the duration of the test, in a step-by-step process.

Tension ran high among the engineers when the Vinci engine fired, and the hydrogen and oxygen valves opened in sequence for the first time. As the explosive mixture of hydrogen and oxygen ignited, the two turbopumps spun up to speed. Measurements confirmed after shutdown showed that the predicted values had been reached.

The Vinci engine was to have been developed under the Ariane-5 Plus Programme in combination with the development of a new Ariane-5 upper-stage, the ESC-B. Although development of the upper-stage has been put on hold after the initiation of the Ariane-5 recovery plan, the technologies involved in developing this new upper-stage engine are of importance for future developments in the European propulsion sector. As a result, it was agreed to continue a small series of test firings.

Vinci engine thrust chamber

Vinci is a re-ignitable cryogenic upper-stage engine with an expander cycle and does not require a gas generator to drive the two turbo-pumps: one for the liquid hydrogen (LH2) and one for the liquid oxygen (LOX). It will provide 18 tonnes of vacuum thrust with a specific engine impulse of 465 sec.

The successful test firing is the result of work carried out by European industry under the leadership of the prime-contractor SNECMA, and DLR’s new test facilities in Lampoldshausen, Germany. To perform hot-firing tests under near-realistic space conditions, DLR have built a new test-facility, called the P4.1 test stand. This is unique in Europe both for its size and because it allows continuous hot-firing tests of upper-stage engines, capable of providing up to 20 tonnes of thrust at pressure levels below 200 mbar (typically 60 mbar), to be carried out. The maximum test duration is 10 minutes.

The new test facility at Lampoldshausen performed flawless during today’s Vinci hot-firing test. Figure 1: The Vinci thrust chamber, developed by EADS Ottobrunn Figure 2: Vinci thrust chamber test at nominal operating point (63 bar)