“Vom Wasserwerk zur Sternwarte (From the waterworks to the observatory)” – over the rooftops of Stuttgart, just a few hundred metres south of the main railway station, next to the waterworks which were erected in 1893, under the aegis of the ‘Schwäbische Sternwarte e.V.’ astronomy club, a small observatory was constructed in 1921 for amateur astronomers. Since then, the public tours conducted there have generated a great positive response and generate great interest.
Since 2013, the Institute of Technical Physics of the German Aerospace Center (DLR) has been represented by a research observatory to monitor space debris at the Uhlandshöhe observatory. Together, scientists, engineers and technicians test different instruments for the laser-based orbit determination of debris in space. The proximity to the DLR Stuttgart site enables researchers to perform measurement series quickly and flexible when observing conditions are good, as well as to make equipment modifications.
The heart of the 3.6-metre shell dome observatory is a 17-inch Dall-Kirkham mirror telescope, with which the DLR researchers track fast moving objects in orbit. The rapid movements make it challenging to implement the tracking of the telescope’s field of vision on the pieces of debris. High sensitivity camera technology enables the passive optical tracking of objects while they are illuminated by the sun at dusk and are already visible in the dark sky. The DLR researchers from Stuttgart have successfully detected objects as small as 10 centimetres in satellite orbits.
In a further expansion stage, DLR researchers will use active illumination by means of a pulsed laser to measure the distances of objects in space. From the transit time of pulses of the laser to a piece of debris and back again to a tracking telescope, the distance of the object can be determined to within a few metres.
The exact orbital position of a piece of debris can be calculated from a number of distance measurements and the corresponding position determinations in space and thus potential collision hazards with other objects or satellites can be predicted in a timely manner.