Closed loop simulations for in-air capturing - the FALCon project

Do you think it could be possible to catch a returning launcher stage with an airplane and a rope?

Watch our closed loop simulations for the FALCon project.

The project is focused on the study of advanced RLV-stage return mode using an “in-air-capturing” procedure. It marks a fundamental contribution to the progress of in-air capturing procedure as it already has delivered key data to help increasing the TRL of this specific procedure.

For conducting the closed-loop-simulations our software #ASTOS and #DCAP was used. As part of the final results, we are proud to present the video capture from #ASTOS’ astroviewer.

The videos demonstrate the maneuvers of a capturing device used for the ‘In-Air Capturing’ of a Reusable Launch Vehicle (RLV). The innovative concept involves recovery of winged launcher stages mid-air and towing it back to launch site by an aircraft. To capture the RLV mid-air, an Aerodynamically Controlled Capturing Device (ACCD) attached to a rope is released from the aircraft. This is done when the aircraft and RLV are in close vicinity. The device must then navigate its way to the RLV and establish connection.

From the first video we can see that this agile device is capable of performing multiple maneuvers within a short time span of 80s even in the presence of vibrations from the rope. In the second video a critical external disturbance coming from the wake of the aircraft is included. Within the wake the capturing device is flung around in circular patterns which is typical of wake turbulence. It is hence unable to perform the commanded maneuvers when exposed to the wake. This is one of the critical challenges of ‘In-Air Capturing’ and the FALCon team is working hard to bring this promising technology to life!

The full-scale multibody model (including the rope model), dynamic kinematic environment and closed-loop simulation setup was developed at Astos Solutions , using the ACCD controller developed by German Aerospace Center (DLR) - SART and the aerodynamic data and wake-field model is coming from our partner at von Karman Institute for Fluid Dynamics .

The #ASTOS software (Analysis, Simulation and Trajectory Optimization Software for Space Applications) represents one of the most elaborated software tools for launch vehicle design and analysis as well as for satellite design and mission performance analysis.?Launch vehicle developers and suppliers, launch sites and space agencies, also satellite developers and suppliers use this COTS software worldwide. It is free of charge for education and non-commercial research.

The #DCAP stand-alone software is a dedicated MBS tool for space applications. The graphical user interface and programming interface allows to model and to analyze specific user models, like ropes for capturing spacecraft. Recently it has been integrated in #ASTOS as the so called MBS feature.

This work was performed under the Horizon 2020 project ‘Formation flight for in-Air Launcher 1st stage Capturing demonstration’ (FALCon) for development and testing of the “In-Air Capturing” technology. FALCon, coordinated by German Aerospace Center (DLR) - SART, is supported by the EU in the Programme 5.iii. Leadership in Enabling and Industrial Technologies – Space with EC grant 821953.

Further information on FALCon can be found at https://www.FALCon-iac.eu

What do you think about this exiting approach to catch a returning stage?