{'fraction_non_alphanumeric': 0.02289077828646174, 'fraction_numerical': 0.004578155657292348, 'mean_word_length': 5.6521739130434785, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Flight Demonstration of Autonomous Noncooperative Rendezvous in Low Earth Orbit

This paper presents ultimate design, implementation, and in-flight performance of the spaceborne guidance navigation and control system which enabled the Autonomous Vision Approach Navigation and Target Identification (AVANTI) experiment; a flight demonstration developed by the German Space Operations Center (GSOC) of the German Aerospace Center (DLR) and carried out in November 2016. Designed to prove the viability to perform far- to mid-range proximity operations with respect to a noncooperative flying object using only optical angle measurements, AVANTI realized the first autonomous vision-based rendezvous to a passive target spacecraft in low Earth orbit. Within this experiment, the DLR Earth-observation BIROS satellite approached down to less than 50 m of inter-satellite distance the BEESAT-4 CubeSat, previously released in orbit by BIROS itself. To this end, a dedicated spaceborne formation- 
flying system carried out relative navigation and maneuver planning tasks. Moreover, it took over BIROS orientation and maneuvering capabilities to steer the spacecraft along a passively safe rendezvous trajectory. During AVANTI, the images taken by BIROS constituted the only source of relative navigation information. In the absence of external, independent, and precise navigation data of the target satellite, AVANTI performances have been assessed against the ground-based post-facto reprocessing of the images collected in flight.