ESA kosmose uudised
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.
To kickstart the 30th anniversary year of the NASA/ESA Hubble Space Telescope, Hubble has imaged a majestic spiral galaxy. Galaxy UGC 2885 may be the largest known in the local universe. It is 2.5 times wider than our Milky Way and contains 10 times as many stars.
The year 2020 will see new and exciting European space missions, from journeys to the Sun and back to Mars, and from innovative telecommunications satellites to the continuing operation of Copernicus Earth observation satellites. The second ExoMars mission will see a European rover on the 'Red Planet' and the ESA/NASA Solar Orbiter mission will be launched around the Sun. This year marks probably the last time an ESA astronaut flies on a Russian Soyuz spacecraft - future European astronaut flights are likely to be on the new US spacecraft, in particular the NASA Orion vehicles, which feature European-built Service Modules, now being prepared for flights to the Moon and beyond. The year also sees the first flight of ESA’s new Vega-C launcher from Europe’s Spaceport in French Guiana, where Ariane 6 operations are also taking shape for its first flight.
ESA Impact 2019 - Quarter 4
As the year comes to a close, it is once again time to look back and reflect on some of the achievements and highlights of European spaceflight. The new Gaia star catalogue and the launch of Cheops are keeping ESA at the forefront of space science, as will Solar Orbiter, being prepared for launch next year. The Copernicus programme continues to be the largest Earth observation programme in the world, with ESA preparing even more missions. On the Space Station, Luca Parmitano became the third European to command an ISS expedition. During his second mission, he made some of the space programme's most complex and demanding spacewalks. At the end of 2019, the ESA Space19+ ministerial conference agreed to give ESA its largest budget ever and expressed continued support for Europe’s independent access to space with Ariane 6 and Vega-C.
On 6 February, ESA’s #SolarOrbiter will be launched from the Kennedy Space Center in the USA on a mission to study the Sun up-close.
Enjoy a recap of 2019 with our year in images.
The European Space Agency is currently looking for a new Director of Telecommunications to join its executive board and support the Director General, with responsibility for relevant ESA programmes and overall objectives.
ESA astronaut Luca Parmitano shares a message with everyone back on Earth as he and his crew prepare to celebrate Christmas on board the International Space Station.
Though Beyond is Luca’s second mission to the Space Station, 2019 will be the first time he spends Christmas in orbit. In this message Luca reflects on the things he will miss, including his family and all the lights, colours, food and smells that go along with the holiday season.
As Luca reflects on Christmas on Earth, he also reflects on the next step in space exploration and the importance of preserving our home planet for future generations.
Luca is the third European and first Italian commander of the International Space Station. He was launched for his second mission from the Baikonur Cosmodrome in Kazakhstan on 20 July 2019 and will return to Earth in February 2020.
While in orbit, Luca is supporting more than 50 European experiments across a broad range of disciplines. This vital research in microgravity helps us progress medicine and technology on Earth while preparing us to explore even farther in space.
ESA Highlights 2019: a closer look at ESA's achievements in the past year
The Galileo satellite navigation system has been providing Initial Services for three years now. Meanwhile Europe’s other satnav system has marked its tenth anniversary: EGNOS has been delivering enhanced positioning to users across our continent, including safety-critical services such as aircraft landings for a growing number of European airports.
With Christmas almost here, the red and white of this Copernicus Sentinel-2 image bring a festive feel to this week’s image featuring Tromsø – the largest city in northern Norway.
This false-colour image was processed in a way that included the near-infrared channel, which makes vegetation appear bright red. The snow over the surrounding mountains is visible in white, adding to the Christmassy feel of the image.
Most of Tromsø, lies on the island of Tromsøya, visible at the top of the image. Owing to its northerly location, the city is a popular area to experience the majestic phenomenon of the aurora borealis, or northern lights.
Tromsø is over 300 km north of the Arctic Circle. During the winter, it’s shrouded in darkness – the Sun sets in late-November and doesn’t rise again until January. The image was captured on 15 October 2019, which means it is one of the last images that Sentinel-2 could acquire before darkness descended.
During the long winter months, the Copernicus Sentinel-1 mission is used to monitor this region instead of Sentinel-2. As an advanced radar mission, Copernicus Sentinel-1 can image the surface of Earth through cloud and rain and regardless of whether it is day or night.
In September 2019, the German research icebreaker Polarstern left from Tromsø for a mammoth Arctic expedition. The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition involves the icebreaker spending a year drifting in the Arctic sea ice.
Spearheaded by the Alfred Wegener Institute (AWI), MOSAiC is the biggest shipborne polar expedition of all time. The data gathered during the expedition will be used by scientists around the world to study the Arctic as the epicentre of global warming and gain fundamental insights that are key to better understand global climate change.
This image is also featured on the Earth from Space video programme.
Season's greetings from the European Space Agency
A series of ground-based tests designed to check the extraction of the ExoMars 2020 mission’s parachutes from their bags have started successfully with promising results to keep the mission on track for next year’s launch.
A series of clips from different angles and at different speeds showing parachute extraction tests using a NASA/JPL test rig powered by compressed air. The lid of the parachute assembly is pulled along a suspended cable at high speed while the end of the assembly is fixed to a wall. When the release mechanism is activated, the parachute bag is pulled away from the parachute at the target speed, mimicking the extraction as it will be on Mars. At the highest speeds, the tests enable the extraction to take place at more than 200 km/h.
Press Release N° 26–2019
ESA invites media to a start of year press conference laying out plans for the new budget committed to by Member States at Space19+ and looking ahead at 2020. ESA Director General Jan Wörner and ESA Directors will meet the media at the ESA headquarters in Paris on the morning of Wednesday, 15 January 2020.
The Space Station has grown to the size of a football field and space agencies are looking to extend its lifetime until 2030. European-built computers have quietly been keeping this orbital outpost on track and in the right position, running in the background since 2000.
ESA and partners celebrate 40 years of Ariane – a launch vehicle operating in the international space arena, and a symbol of cooperation and innovation that ensures independent access to space for Europe.
ESA’s Cheops mission lifted off on a Soyuz-Fregat launcher from Europe’s Spaceport in Kourou, French Guiana, at 09:54:20 CET on 18 December on its exciting mission to characterise planets orbiting stars other than the Sun.