A milestone for parabolic flight

"Parabolic flights are an important part of our Research under Space Conditions programme. We bring researchers and their exciting experiments directly into microgravity conditions. Many experiments conducted on the International Space Station ISS were previously demonstrated during parabolic flight campaigns. So, our parabolic flights are also a gateway to space for scientific endeavours," says Walther Pelzer, DLR Executive Board Member and Director General of the German Space Agency at DLR, who will be on board the aircraft for the first time as part of the milestone campaign.

"With the 40th campaign, we look back on a long tradition of parabolic flights at DLR. Over 147 flight days, we have flown more than 4000 parabolas. During this time, we have issued a 'boarding pass' for microgravity to more than 600 experiments and just as many teams. For them, it is the only opportunity to carry out their own experiments under microgravity conditions," says Katrin Stang, Parabolic Flight Programme Manager at the German Space Agency at DLR, looking back on the past flights. This milestone campaign features three entirely new experiments: 'SCARLETT' investigates the slipping of a hill, mountain or crater wall on a simulated martian surface; the 'XIM' experiment tests a new 3D bio-printing technology under microgravity; 'MALCOM' explores machine learning methods for studying complex plasmas under microgravity. The eight other experiments have flown on previous campaigns. For these experiments, the upcoming flight will expand their gathered data with new test participants, addressing new questions or testing new materials. The experiments will be flown on three days from 23 to 25 May. The space YouTuber ‘Senkrechtstarter’ will also be on board for the first time.

SCARLETT – when Mars slopes begin to slip

Mars has an extremely thin atmosphere. While the atmospheric pressure on the surface of Earth is approximately 1000 hectopascals, it is on average just six hectopascals on the martian surface. This low pressure has consequences; gas can move from cold to warm spots in the porous soil in a process referred to as thermal creep. In the Solar System, this phenomenon is found only in the martian soil. The SCARLETT experiment is investigating whether and how this thermal creep can cause the slope of a hill, mountain or crater to slip above a certain angle of inclination. On Mars, above a certain angle, slopes in craters or on hills become unstable and slip. However, these slopes are much flatter than expected. Thermal creep is a possible cause of these reduced slope angles, as temperature differences occur naturally in the martian soil due to solar radiation. Shadows cast on slopes play a major role here, as they can generate very high local temperature differences. Researchers at the University of Duisburg-Essen are investigating under what conditions and at what angle the slopes begin to slip.

XIM – development of a volumetric 3D demonstrator

3D printing has the potential to support space missions as a cost-effective and versatile manufacturing method. For missions on the International Space Station ISS, readily available printing of spare parts and specific tools has already been tested. For long-term missions beyond Earth orbit, supply from Earth will be impossible. Therefore, for these missions to be successful, the necessary parts must be manufactured on board the spacecraft itself. But there is potential to go much further than the production of spare parts. 3D bioprinting may play a prominent role in long-term missions as part of a system of regenerative medicine to ensure the long-term health of the crew. During DLR’s 40th parabolic flight campaign, volumetric 3D printing using xolography will be tested for the first time under microgravity conditions. xolo GmbH will demonstrate that this process can be used regardless of the strength of gravity to precisely manufacture desired components. Thanks to the impressive speed of xolography compared to other methods, many experiments can be carried out in a very short time. Plastic materials will be studied and hydrogels will be printed, which serve as the starting substrate for biotechnological applications in regenerative medicine.

MALCOM – machine learning supports plasma research

Plasma is the term used to describe an electrically conductive gas, which is often also referred to as the fourth state of matter alongside solids, liquids and gases. In space, plasma is the default state of matter within stars and in interplanetary and interstellar space. On Earth, simple plasmas are used in fluorescent lamps and for integrated circuit production. But in complex plasmas – also referred to as dusty plasmas – gravity often becomes a major problem. As soon as one wants to create a larger dust cloud and introduce micrometre-sized particles into the plasma, gravity begins to pull the cloud down towards the base of the plasma. On parabolic flights, these experiments can be performed without this disturbing influence. This makes it possible to study and measure novel properties of the dust-plasma system. The behaviour of heavy particles in a complex plasma is of particular interest to researchers, as similar plasmas are also found in comet tails, the (dust) rings of planets and in the plasmas used in technological processes. The milestone parabolic flight campaign experiment will test the interaction of a special ‘Zyflex plasma chamber’ that was developed at the DLR Institute of Materials Physics in Space and is now operated by the University of Greifswald. The chamber has a stereoscopic camera setup for three-dimensional particle tracking at the University of Greifswald. Both are central components for the planned Complex Plasma Facility (COMPACT), an experiment which will be installed on the ISS. Machine learning methods are being developed to analyse the stereoscopic data, which will be applied to the data from this parabolic flight campaign.

DLR parabolic flights

Since 1999, the German Space Agency at DLR has regularly organised parabolic flights to enable biological, physiological, physical, technological and materials science experiments. The research aircraft, the A310 ZERO-G operated by the French company Novespace, is used once or twice a year for scientific campaigns by DLR, the European Space Agency (ESA) and the French space agency, CNES. A DLR parabolic flight campaign usually consists of three flight days with approximately four flight hours, during each of which up to 31 parabolas are flown. During each parabola, microgravity conditions are experienced for approximately 22 seconds. In total, a flight campaign provides approximately 35 minutes of microgravity conditions as the aircraft alternates between once and almost twice the gravitational acceleration experienced on Earth’s surface. Researchers uses these conditions for their experiments. Up to 40 researchers can take part in a flight, with between ten and 13 experiments on board.