ESA Space Engineering & Technology ESA Space Engineering & Technology
ESA opens oxygen plant – making air out of moondust
on January 17, 2020 at 12:30 pm
ESA’s technical heart has begun to produce oxygen out of simulated moondust.
High-gravity water waves
on January 15, 2020 at 7:37 am
Image: What might look like jelly being stirred is actually water subjected to 20 times normal Earth gravity within ESA’s Large Diameter Centrifuge – as part of an experiment giving new insight into the behaviour of wave turbulence.This research, led by Stéphane Dorbolo of University of Liège and Eric Falcon of CNRS and University of Paris, has been published in the prestigious Physical Review Letters.Wave turbulence occurs anywhere where a set of random waves interact with each other – from the ocean to the atmosphere, or in plasmas – but the exact mechanisms behind it are only dimly understood. For surface waves on a liquid, gravity dominates the behavior at low frequencies, while ‘capillary action’ based on surface tension becomes more important at high frequencies.To increase the range of frequencies where waves are dominated by gravity, the researchers conducted their experiment in the ESA’s Large Diameter Centrifuge (LDC) where they can create effective gravity levels up to 20 times that of Earth’s gravity.Within this extended range, the result was a surprise: the typical timescales of wave interactions and dissipation did not depend of the wave frequency, as predicted theoretically.Instead these timescales are set by the longest available wavelength within the system – namely the size of the container the waves occur within, an effect that current wave turbulence theories does not take into account.Prof. Falcon explains: “This result suggests that ‘container’ size needs to be considered in studies of water waves within an ocean—as well as atmospheric waves on Earth and magnetically confined plasma waves as in fusion experiments. “Notably, this experiment serves to complete the scientific picture of how gravity has an impact on surface wave turbulence, because tuning the gravity level to an opposing low value has already been performed in experiments in zero-G parabolic flights in 2009 and more recently aboard the International Space Station in 2019. This has allowed us to successfully observe pure capillary wave turbulence with no contribution from gravity.”Operating within a sci-fi style white dome, the LDC is an 8-m diameter four-arm centrifuge that gives researchers access to a range of hypergravity up to 20 times Earth gravity for weeks or months at a time. At its fastest, the centrifuge rotates at up to 67 revolutions per minute, with its six gondolas placed at different points along its arms weighing in at 130 kg, and each capable of accommodating 80 kg of payload.The LDC was made available for this experiment through the Continously Open Research Announcement of the SciSpace Programme, supported by ESA’s Directorate of Human and Robotic Exploration.
ESA and EDA joint research: advancing into the unknown
on January 9, 2020 at 9:14 am
ESA and the European Defence Agency (EDA) are embarking on new cooperative projects for exploring unknown or potentially hazardous environments: harnessing drones for the monitoring of disaster-stricken regions or toxic spill sites and making use of Artificial Intelligence (AI) to navigate across the surface of asteroids or other terra incognita.
Water drop antenna lens
on January 8, 2020 at 8:03 am
Image: This novel ‘water drop’ antenna lens design for directing radio wave signals was developed by a pair of antenna engineers from ESA and Sweden’s Royal Institute of Technology, KTH.In the same way that optical lenses focus light, waveguide lenses serve to direct electromagnetic radio wave energy in a given direction – for instance to send out a radar or a communication signal – and minimise energy loss in the process.Traditional waveguide lenses have complex electrically-sensitive ‘dielectric’ material to restrict electromagnetic signals as desired, but this water drop waveguide lens – once its top plate has been added on – comes down purely to its curved shape directing signals through it.The inventors of this new lens design, which received an ESA Technical Improvement award in February 2017, like to call it the ‘water drop’ lens because its shape resembles the ripples produced by a water drop at the surface of a fluid.The lack of dielectrics in this shape-based design is an advantage, especially for space – where they would risk giving off unwanted fumes in orbital vacuum.“The lens’s extremely simple structure should make it easy and cheap to manufacture, opening up avenues to a wide variety of potential materials such as metallised plastics,” explains ESA antenna engineer Nelson Fonseca.“This prototype has been designed for the 30 GHz microwave range but the simplicity of its shape-based design also means it should be applicable to a broad frequency range – the higher the frequency, the smaller the structure, facilitating its integration”.The idea came out of a brainstorming session during a conference, explains KTH antenna engineer Oscar Quevedo-Teruel: “We took the ‘Rinehart-Luneburg lens’, also called the geodesic lens, as our starting point. This is a cylindrical waveguide lens developed in the late 1940s, mostly for radar applications.“We wanted the same performance, while reducing its size and height. So the idea we had was to retain the functional curvature of the original design by folding it in on itself, reducing its profile by a factor of four in the specific case of the manufactured prototype.”This first prototype of a water drop lens was tested at KTH facilities, Oscar adds, to measure its radiation patterns, efficiency and gain: “While a conventional Luneburg lens might suffer from elevated dielectric losses, especially when used at higher frequencies, this design shows marginal signal loss thanks to its fully metallic design.”Besides space applications, such as Earth observation and satellite communications on small satellites, this antenna has also attracted the attention of non-space companies. The Ericsson company is looking into using the compact design for the fifth generation mobile phone networks. The concept could also be used for guidance radars in the next generation of self-driving cars.
OPS-SAT in orbit: a stepping stone to smarter space operations
on December 20, 2019 at 1:15 pm
ESA’s shoebox-sized OPS-SAT is in orbit and sending healthy signals to mission controllers on Earth. The miniature satellite will work as a test lab in orbit, for experiments in new mission control software and techniques.
New NASA STI Today's Listing of New NASA STI in the NASA Technical Reports Server (NTRS).
The Potential for Health Monitoring in Expandable Space Modules: The Bigelow Expandable Activity Module on the ISS
on May 31, 2017 at 4:07 pm
Abstract: Expandable modules for use in space and on the Moon or Mars offer a great opportunity for volume and mass savings in future space exploration missions. This type of module can be compressed into a relatively small shape on the ground, allowing them to fit into space vehicles with a smaller cargo/fairing size than a traditional solid, metallic structure based module would allow. In April 2016, the Bigelow Expandable Activity Module (BEAM) was berthed to the International Space Station (ISS). B...
Spacecraft Charging Considerations and Design Efforts for the Orion Crew Module
on May 31, 2017 at 3:40 pm
Abstract: The Orion Crew Module (CM) is nearing completion for the next flight, designated as Exploration Mission 1 (EM-1). For the uncrewed mission, the flight path will take the CM through a Perigee Raise Maneuver (PRM) out to an altitude of approximately 1800 km, followed by a Trans-Lunar Injection burn, a pass through the Van Allen belts then out to the moon for a lunar flyby, a Distant Retrograde Insertion (DRI) burn, a Distant Retrograde Orbit (DRO), a Distant Retrograde Departure (DRD) burn, a s...
A Simulation Based Investigation of High Latency Space Systems Operations
on May 31, 2017 at 3:33 pm
Abstract: No abstract available
EVA Systems Technology Gaps and Priorities 2017
on May 31, 2017 at 2:56 pm
Abstract: Performance of Extra-Vehicular Activities (EVA) has been and will continue to be a critical capability for human space flight. Human exploration missions beyond LEO will require EVA capability for either contingency or nominal activities to support mission objectives and reduce mission risk. EVA systems encompass a wide array of products across pressure suits, life support systems, EVA tools and unique spacecraft interface hardware (i.e. EVA Translation Paths and EVA Worksites). In a fiscally...
NASA-STD-6001B Test 7: Impact of Test Methodology and Detection Advancements on the Obsolescence of Historical Offgas Data
on May 31, 2017 at 2:50 pm
Abstract: NASA-STD-6001B states "all nonmetals tested in accordance with NASA-STD-6001 should be retested every 10 years or as required by the responsible program/project." The retesting of materials helps ensure the most accurate data are used in material selection. Manufacturer formulas and processes can change over time, sometimes without an update to product number and material information. Material performance in certain NASA-STD-6001 tests can be particularly vulnerable to these changes, such as ...