Liquid rocket engine test facility engineering challenges

Liquid rocket engines for launch vehicles and space crafts as well as their subsystems need to be verified and qualified during hot-runs. A high test cadence combined with a flexible test team helps to reduce the cost for test verification during development/qualification as well as during acceptance testing for production. Test facility intelligence allows to test subsystems in the same manner as during complete engine system tests and will therefore reduce development time and cost.This paper gives an overview of the maturing of test engineering know how for rocket engine test stands as well as high altitude test stands for small propulsion thrusters at EADS-ST in Ottobrunn and Lampoldshausen and is split into two parts:

• Part 1 gives a historical overview of the EADS-ST test stands at Ottobrunn and Lampoldshausen since the beginning of Rocket propulsion activities in the 1960s.

• Part 2 gives an overview of the actual test capabilities and the test engineering know-how for test stand construction/adaptation and their use during running programs.

Examples of actual realised facility concepts are given to demonstrate cost saving potential for test programs in both cases for development/qualification issues as well as for production purposes.

Article Outline

1. Introduction

2. Historical overview

2.1. Ottobrunn

2.1.1. Air-breathing propulsion

2.2. Lampoldshausen

2.2.1. Attitude control systems

2.2.2. Launcher Propulsion

3. Today's status of hot firing test facilities at Lampoldshausen

4. Test facility engineering know how

5. Conclusion and outlook

References

1. Introduction

Test facilities are an indispensable element for the development and acceptance of space systems/subsystems and components. Hot-test facilities especially with environment simulation (e.g., altitude simulation) are very unique and are specifically designed to their needs.In Germany rocket propulsion developments were started during the 1950s in Ottobrunn near Munich. Beginning in the 1960s developments of attitude control engines and thruster for space crafts were started in Lampoldshausen. In addition to these two plants with test facilities and test capabilities, a third centre with test facilities operated by ERNO in Trauen was built up for the development of the ELDO Launcher (Europa III).In the frame of the consolidation of the different Space Propulsion activities within Dasa (Daimler-Benz Aerospace) in the 1990s as well as the creation of EADS-Space, all test activities were concentrated to the Lampoldshausen site, concluded in 2000.Main reasons for this concentration to one test site were:

• One EADS-ST test-centre in Germany.

• One EADS-ST Test and Engineering Team at one location.

• Multi-use of the three EADS test fields in Lampoldshausen instead of 10 facilities.

• Experts with test engineering know how for development and production programs at one location.

• Synergy effects for test facility modification/maintenance and field support together with DLR.

In addition, cost aspects, especially for test conductions have to be reduced. Therefore, the facility and test requirements have been changed by:

• Using more intelligence in the design and features of the facility (e.g., several test objectives to be tested during one hot-firing test).

• Use of test data for computer simulations as code calibration and therefore reduction of the total number of needed tests.

• Multi-function of test specialists with the main goal to reduce the test team size.

• Computer aided test set-up, firing sequencing and online documentation.

2. Historical overview

2.1. Ottobrunn

A complete overview of all technologies created since the mid of the 1950s is given by Hopmann in 1]. Within this chapter the focus was set on technologies and know how generated in the frame of the Ariane cyrogenic developments at P 59 and air-breathing propulsion 2] and 3].The start of the ARIANE 1 programme and the contract for the development of the HM7-A thrust chamber called for a new facility complex. The erection of the P 59 Test facility was the first high-pressure thrust chamber facility in Europe with a storage level of 800 bars. This high pressure gas was needed to feed the 400 bar LH2 and LOX vacuum insulated run-tanks. For this facility also a special valve test facility was erected in order to test the facility valves in advance to their integration into the test bench (Fig. 1).