Engine components of potential lunar and planetary landers will be tested by scientists from the Łukasiewicz Institute of Aviation as part of a project for the European Space Agency. Aerospike-type nozzles may be a way to circumvent the limitations of classic bell nozzles, which are currently widely used in the rocket and space industries.
Widely used in the rocket and space industry, bell nozzles are designed for applications in specific pressure conditions, outside of which their efficiency decreases. Meanwhile, aerospike nozzles are characterized by high efficiency in a wide range of ambient pressure. Jest to ważne w przypadku napędów kosmicznych, szczególnie dla lądowników planetarnych. This is important for space propulsion systems, in particular for planetary landers.
The technological challenges
A classic bell nozzle for use in a vacuum (e.g. in a lunar lander) or in a thin atmosphere (e.g. in planetary landers in the Mars mission considered by various countries) would be characterized by considerable dimensions. On the other hand, an aerospike nozzle works differently: while in a bell nozzle, the flow of exhaust gases is limited by the outer jacket of the nozzle, aerospike nozzles utilize a cone-shaped nozzle tip (not a bell-shaped one), which largely compensates for the loss of engine power with pressure changes. The range of pressure changes in which the lander’s engines operate is particularly extensive in the case of planetary landers, because their engines must be able to operate in a vacuum and at different heights in the atmosphere.
Aerospike engines seem to offer the answer to such challenges, but indeed, this design also brings important technological problems that need to be solved. Efficient cooling of such structures and ensuring the possibility of thrust changes over time are particularly important. These are the main (though not the only) challenges that are faced by engineers of the consortium working on the aerospike nozzles.
During the works, known conceptual solutions, both existing ones and those that will be created during the project, will be reviewed and assessed. Not only the technological solutions themselves will be assessed, but their implementation costs will also be estimated.
The program will result in the design of a demonstrator unit that will be most consistent with the requirements for lander engines. The demonstrator unit will be powered by liquid oxygen and liquid methane, and the expected thrust of such an engine lies in the range of 5-6 kN. This structure will be tested in the dynamometer of the German Space Agency (Deutsches Zentrum für Luft- und Raumfahrt), where the fulfillment of the project assumptions will be verified in a practical way.
Consortium means teamwork
The project of developing and testing a demonstrator unit of a rocket engine with an aerospike nozzle is a complex undertaking, participated by several specialized entities. The entire project was commissioned by the European Space Agency, and all work will be performed by an international consortium, led by Technische Universität Dresden. Teams from two Fraunhofer institutes will cooperate with scientists from the Łukasiewicz – Institute of Aviation: Fraunhofer-Institut für Werkzeugmaschinen und Umformtechnik IWU (Fraunhofer Institute for Machine Tools and Forming Technology) and Fraunhofer-Institut für Lasertechnik ILT (Fraunhofer Institute for Laser Technology), and the whole will be completed by tests conducted in the dynamometer of the German Space Agency.
We would like to wholeheartedly congratulate the team of Łukasiewicz Institute of Aviation on their participation in another important project in an excellent, international company.