Any future space debris removal or on-orbit servicing mission faces the problem of the initial relative orbit determination of the servicing satellite to the non-cooperative target. In this work, we analyse the relative navigation accuracy that can be achieved in low Earth orbit, by using ground-based orbit determination from radar tracking measurements for the target, and classical GPS-based orbit determination for the servicing satellite. The analysis is based on the radar tracking measurements obtained from a 10 × 10 × 34 cm small object at an altitude of 635 km. The results show that the relative orbit can be determined with accuracy down to 2 m (RMS) in the semi-major axis, and down to 20 m (RMS) in both the radial and normal separations. From the results, we derive requirements on radar-tracking campaigns.

No abstract

No abstract

No abstract

Compact and inexpensive Earth observation satellites in low Earth orbit are now routinely developed by universities, "New Space" businesses, and space agencies. They enable new opportunities for fast turnaround times of imaging data takes, which is e. g. particularly important for disaster response. For this kind of satellites and the missions enabled by them a ground system exhibiting the same characteristics, namely being compact and mobile, yet inexpensive and flexible, is desired.We present DLR's approach for the provisioning of a ground segment fit for the kind of missions outlined above. The objective of this project consists of the engineering, delivery, and demonstration of a compact and yet complete Mission Operations System, runnable on commodity mobile hardware, enabling fully automated workflow-driven operations of alike missions from anywhere in the world with access to a ground station or ground station network.Just as disasters strike suddenly, the ground segment needs to be set up and spun up in a timely manner. This leads to the requirement of being able to quickly roll out the system on new hardware, possibly even several of these systems in parallel. Our paper provides insight on how we perform the automatic deployment and provisioning.Because the system is supposed to be decentralized and used in the field, particular challenges need to be overcome resulting from the lack of all of the infrastructure typically present in conventional control centers, such as network connectivity. An embedded Flight Dynamics system is taking care of automated orbit determination and related event generation to support the mission needs and maneuver capabilities. Special effort is made to cope with auxiliary data that may not be updated on a regular basis in a closed mission environment.The feasibility of the concept is demonstrated by a first system deployment as drop-in replacement for the existing conventional Mission Operations System for DLR's BIROS satellite at the GSOC control center. A second demonstration campaign is performed from a remote location without access to control center infrastructure.