The German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) is participating in the SpaceTech Expo from 16 to 18 November 2021 in Bremen. At its 70 square metre stand (J28) in Hall 5, DLR will showcase exhibits relating to spaceflight and highlight technology transfer, with themes that have emerged from research and found their way into practical applications. The focal points of the trade fair presence are the use of robotics, laser technology and radar technology in space, as well as European participation in future crewed lunar missions.
"Globally deployable space technologies have become indispensable in a world of accelerating change with ever more closely intertwined economic systems. Global challenges such as climate change, interdisciplinary traffic and goods transport management, and the world's digital divide need answers that combine with the technological capabilities of space," says Anke Kaysser-Pyzalla, Chair of the DLR Executive Board. "The Space Tech Expo is gaining in importance against this backdrop. DLR has been present at this growing space technology hub since 2015, and a wide range of business relationships have already been established and deepened at European and international levels."
On the first day of the fair, Anke Kaysser-Pyzalla gave a keynote speech at the accompanying conference.
"At DLR, we focus our space research on societal and economic needs and deliver new technological solutions in this context. The combination of fundamental and applied research allows us to align our goals with demand. By systematically designing and considering complex scenarios, DLR is able to carry out large-scale and long-term projects. We see Space Tech Expo Bremen as the ideal platform for bringing our developments and innovations closer to government and manufacturers in civilian commercial spaceflight," adds Anke Pagels-Kerp, DLR's Divisional Board Member for Space.
DLR is presenting the following topics at this year's Space Tech Expo:
The number of satellites in Earth orbit has risen rapidly over recent years. Satellite manufacturers have a keen interest in technologies capable of servicing satellites and repairing them immediately in the event of a failure. In the past, astronauts were used for such missions, despite the higher risks and costs involved. Robotic systems represent a cost-effective alternative. The DLR Institute of Robotics and Mechatronics has developed the CAESAR (Compliant Assistance and Exploration SpAce Robot) system for that very purpose. It combines innovative electronics and mechanics with new control methods. The robot has seven degrees of freedom, making it similar in effect to a human arm, with greater flexibility than a standard robotic arm. A SpaceHand installed on the robot will also allow it to grip onto and stabilise tumbling or non-cooperative satellites.
Satellite laser ranging – high precision distance measurement
Satellite Laser Ranging (SLR) allows the distance between a satellite and a specific point on Earth to be determined with a high level of precision. This laser-based method of measurement, presented by the DLR Institute of Technical Physics, is used in Earth observation, satellite operations and the detection of space debris. With SLR, the distance between and ground station and a satellite can be measured using special laser systems with an accuracy of just a few millimetres at a distance of up to 25,000 kilometres. The ground station emits a laser beam, which illuminates the satellite; this is reflected back and recorded by the ground station using a telescope and detector. The time taken for the laser light to travel this distance can be used to calculate the distance between the satellite and ground station with a high level of precision.
Laser-based satellite communications
Lasers can be used not only to measure distances, but also to exchange data between satellites. This laser transmission technology includes a communication terminal equipped with reflectors on the satellite. These reflectors must be precisely aligned in order to pass on information accurately. A number of tests have shown fibre-reinforced ceramics from the DLR Institute of Structures and Design to be especially suitable as housing structures or as support structures for mirrors and optical instruments. These fibre-reinforced ceramics have the advantage of not expanding even at very different temperatures. They can be used to produce particularly stiff yet lightweight sandwich panels that retain a remarkable level of dimensional stability even in space. Having telescope tubes impervious to expansion made laser data transmission between the TerraSAR-X and NFIRE satellites possible for the very first time.
Radar technology for safety in space
German Experimental Surveillance and Tracking Radar (GESTRA) is a radar system for observing and tracking objects in space, including satellites, spacecraft and space debris. It opens up the possibility of alerting space systems or the International Space Station (ISS) of a potential collision with debris in good time. According to estimates, 128 million small particles of debris are currently orbiting the Earth. With an average speed of 28,000 kilometres per hour, they pose a threat to active space technology.
The GESTRA system, which can detect the larger of these objects, works in the microwave range and explores low-Earth orbit at an altitude of 300 to 3000 kilometres – the range in which most satellites and the ISS are located. The system is expected to be put into operation in 2022 at its site in Koblenz.
Service module for the Orion spacecraft
The German Space Agency at DLR is presenting the European Service Module (ESM) developed for the new NASA crew spacecraft, Orion. The ESM is at the heart of the Orion spacecraft and sits beneath the crew capsule. It contains the main engine and supplies power via four solar arrays. It also regulates the climate and temperature within the spacecraft and stores the crew's fuel, oxygen and water supplies. The Orion spacecraft and thus the ESM are considered to be a key milestone in future human spaceflight missions to the Moon, Mars and beyond.
The European consortium building the ESM is led by Airbus Defence and Space in Bremen. Overall, companies from 10 ESA member states are involved, in addition to the USA. Orion's first uncrewed flight with the ESM is scheduled for 2022. The first ESM is called EMS-1 'Bremen' because much of it was built in that German city. Astronauts will fly to the Moon with Orion/ESM for the first time in 2023.