News Article | February 1, 2017
NASA has unveiled a new tool to gather information on solar storms that trigger magnetically structured clouds called coronal mass ejections. Named as EEGGL – the Eruptive Event Generator (Gibson and Low) – is a new space weather model that can simulate solar storms and deliver information on the path of coronal mass ejections before they hit Earth. Pronounced "eagle," EEGGL can trace the trajectory of CMEs and has been designed as part of a larger model of the sun's outer atmosphere called corona by a team led by Tamas Gombosi at the Michigan University's Department of Climate Space Engineering. Among sun's explosions, solar flares and coronal mass ejections are very prominent. Generally, in less than 10 minutes, the energy and x-rays of solar flare take to Earth as they travel at the speed of light. However, coronal mass ejections take more time to hit Earth as they are giant clouds of solar material and an average 70 hours will be required to reach Earth. The CMEs are dreaded for the disturbance it creates for satellites and communication networks. The clouds are massive and carry magnetically and electrically charged particles named plasma, triggering space weather effects. For NASA, EEGGL helps to study the path navigated by a CME through space toward Earth and the magnetic configuration it carries. "Incorporating the magnetic properties at CME initiation may give scientists a better idea of a CME's magnetic structure and ultimately, how this structure influences the CME's path through space and interaction with Earth's magnetic fields — an important piece to the puzzle of the sun's dynamic behavior," NASA noted. In guiding a CME's traction through space, EEGL would depend on the latter's plasma properties and magnetic free energy or electromagnetic forces to interpret the path. What makes EEGL more advanced is the focus on the magnetic structure of the CME right from its start at the sun as a new step in CME modeling. Though many models have initiated CMEs, their base was kinematic properties taken from spacecraft observations regarding mass and initial velocity. By focusing more on the magnetic properties of CME initiation, scientists are at an advantage in understanding CMEs' magnetic structure which governs the path through space and its interaction with the magnetic fields of the Earth. EEGGL provides a composite picture, beginning with spacecraft observations of a CME including the eruption's initial speed and location of the sun with updates on how the CME could travel under the laws of electromagnetics. Synthetic images already delivered by EEGGL are closely similar to actual observations made by NASA and ESA's SOHO. A recent study has said solar storms would wreak havoc in the United States in terms of blackouts across the country and the resulting financial losses will be an average $40 billion a day. The loss from disruption of power will be about 49 percent of the total potential macroeconomic cost, according to the paper published in Space Weather. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.
Tronc J.,Airbus |
Angeletti P.,European Space Agency |
Song N.,TU Ilmenau |
Haardt M.,TU Ilmenau |
And 2 more authors.
International Journal of Satellite Communications and Networking | Year: 2014
The objective of this paper is to review state-of-the-art techniques of beamforming in mobile satellite systems and evaluate the potential benefits/drawbacks of on-ground beamforming compared with on-board beamforming approach. The paper also provides a short analysis of beamforming error sources in on-ground beamforming such as propagation effects at feeder link level, on-board degradations at payload level, differential atmospheric perturbations, and Doppler shift effect. An investigation of signal processing techniques is also performed to provide a preliminary assessment of the interest for employing adaptive beamforming and precoding techniques in multi-spots mobile satellite systems. Copyright © 2013 John Wiley & Sons, Ltd. The objective of this paper is to review state-of-the-art techniques of beam forming in mobile satellite systems and evaluate the potential benefits/drawbacks of on-ground beam forming (OGB) compared with on-board beam forming approach. The paper also provides a short analysis of beam forming error sources in OGB and an investigation of signal processing techniques to evaluate the interest for employing adaptive beam forming and pre-coding techniques in multi-spots mobile satellite systems. Copyright © 2013 John Wiley & Sons, Ltd.
News Article | June 28, 2016
On June 25, China successfully launched its new Long March 7 rocket as well as a prototype, new-generation crew capsule. The event is the first liftoff that took place in the new Wenchang Satellite Launch Center. According to Chinese officials, the Long March 7 rocket lifted off at 8 p.m. on Saturday. China's new rocket was developed as part of its plan to have a crewed space station — the world's second operational space station in orbit, which the country aims to put in operation by early 2020s. The event tested both the Long March 7 rocket and the Wenchang Satellite Launch Center, China's new launch pad located on Hainan Island. Apart from the tests, the unmanned liftoff carried with it a scaled-down prototype of the next-generation crew capsule. After spending 20 hours in orbit on June 26, the prototype crew capsule completed a parachute-aided touchdown in the Badain Jaran Desert located in Inner Mongolian grasslands. According to the Chinese Manned Space Engineering (CMSE), the Long March 7 has a height of 174 feet and weighs 658 tons. "It is capable of sending 13.5 tons of payloads to low Earth orbit. Using new equipment such as the LOX/Kerosene engine, Long March 7 is a pollution-free launch vehicle and will boost China's space capabilities," said the CMSE. Officials said that the rocket will play a vital part in the building of the second space station, which aims to be in operation by 2022. CMSE added that the Long March 7's first mission completed the set goals and "opened a new chapter in China's space lab project." Chinese astronauts go into orbit using the Shenzhou capsules, which is a duplicate of Russian Soyuz. China is currently developing a new type of space capsule that is capable of accommodating larger crews and traveling further into space. "It was designed to collect aerodynamic and heat data for a re-entry capsule, to verify key technologies such as detachable thermal protection structure and lightweight metal materials manufacturing, and to carry out blackout telecommunication tests," said the CMSE. The scaled-down prototype was about half the size of the actual one, measuring approximately 7.5 feet in height and 8.5 feet in diameter. It had a total mass of 2.9 tons. Its successful launch and recovery delivered a "solid foundation" for the space capsule's design and development. © 2016 Tech Times, All rights reserved. Do not reproduce without permission.
Dalakas V.,Harokopio University |
Takis Mathiopoulos P.,Institute for Space Applications and Remote Sensing |
Di Cecca F.,Space Engineering |
Gallinaro G.,Space Engineering
IEEE Transactions on Broadcasting | Year: 2012
This paper presents a detailed comparative study of two single-carrier frequency-division multiple access (SC-FDMA) schemes, namely localized FDMA scheme (LFDMA) and interleaved FDMA scheme (IFDMA), versus orthogonal FDMA scheme (OFDMA), for a satellite uplink. The air-interface of the latter is based on the digital video broadcasting (DVB) family of standards. Considering two state-of-the-art high power amplifiers (HPAs), operating in the K-and S-bands, the performance of synchronous and asynchronous LFDMA, IFDMA and OFDMA is evaluated in a multi-user environment. Systematic comparison results show that although for synchronous reception IFDMA outperforms the other two schemes, for asynchronous reception it is the most sensitive to degradation caused by inter-block interference (IBI). Furthermore, due to its relatively large envelope fluctuations, OFDMA is the most sensitive scheme to non-linear distortion. Although for synchronous reception LFDMA shows only slightly inferior performance as compared to IFDMA, it outperforms the other two schemes for the asynchronous reception considered, especially for increased IBI distortion. © 2012 IEEE.
Doumanis E.,Queen's University of Belfast |
Goussetis G.,Queen's University of Belfast |
Kosmopoulos S.A.,Space Engineering
IEEE Microwave and Wireless Components Letters | Year: 2011
A new inline coupling topology for narrowband helical resonator filters is proposed that allows to introduce selectively located transmission zeros (TZs) in the stopband. We show that a pair of helical resonators arranged in an interdigital configuration can realize a large range of in-band coupling coefficient values and also selectively position a TZ in the stopband. The proposed technique dispenses the need for auxiliary elements, so that the size, complexity, power handling and insertion loss of the filter are not compromised. A second order prototype filter with dimensions of the order of 0.05λ, power handling capability up to 90 W, measured insertion loss of 0.18 dB and improved selectivity is presented. © 2011 IEEE.
News Article | January 18, 2016
A mining operation in space could bear some resemblance to what people have seen in movie theatres considering the venture has backing from Avatar director James Cameron, but thankfully WA's resource industry has more to learn than fear from a space mining push. The frontrunner of the space mining corporate scene, which also counts Google bosses Larry Page and Eric Schmidt among its key investors, has lauded the US Congress's approval of the Spurring Private Aerospace Competitiveness and Entrepreneurship (SPACE) Act in late 2015. This controversially allows private companies to claim ownership of any non-living resources they obtain in space plus extends existing indemnities related to any possible catastrophic commercial aerospace launch failures up to 2025. There are various problems with the SPACE Act, according to Australian Centre for Space Engineering Research director Professor Andrew Dempster, but he says it is a good start. "Mining in space is real and we need to start thinking about how to regulate it, at an international level," he says. Asteroid hunters also have a new tool at their disposal with scientists recently developing a gamma-ray spectroscope capable of detecting metals in these orbiting rocks. But the asteroid scoping technology is also expected to help the conventional mining industry. "With companies in this business for a few years now, it is not surprising that new sensors for space prospecting are emerging," Prof Dempster says. "This is not a threat to terrestrial mining—quite the opposite in fact—the new sensors are also likely to be useful on Earth. Prof Dempster estimates that a full off-earth mining operation is a decade or two away. "It's not happening tomorrow, but it is within the time-frames with which big mining companies operate," he says. However, Planetary Resources is mainly hunting for significant oxygen and hydrogen-hosting asteroids to produce rocket fuel for space shuttles. This strategy avoids the headaches of making any asteroid product survive the re-entry into Earth's atmosphere at a profit. Curtin University astrogeologist Dr Martin Towner says WA could learn and contribute a lot to future off-Earth mining. "The sort of technologies of autonomous and remote robotics used in space are very similar to the remote systems that are now arriving in the resource industry, so technology could flow both ways," he says. Explore further: Space mining startup set for launch in US This article first appeared on ScienceNetwork Western Australia a science news website based at Scitech.
News Article | March 14, 2016
Successful takeoff! The Trace Gas Orbiter (TGO) was launched into space this morning from the Baikonur Cosmodrome in Kazakhstan and is on its way to Mars. Scheduled to reach its destination in October, it's carrying a camera developed at the University of Bern. Researchers from EPFL's Space Engineering Center (eSpace) will participate in the data analysis from this instrument. They will discuss the project and present their particular contribution to it at a public talk that will be held at EPFL on Wednesday, 16 March. This launch is the first mission in the ExoMars program, a joint initiative of the European Space Agency (ESA) and Roscosmos, the Russian space agency. Its main purpose is to search for signs of present or past life on Mars. The second mission, which will land an exploration rover, is planned for 2018. When the TGO reaches Mars, it will go into orbit around the planet. That's when it gets down to work: it will seek trace concentrations of gases – less than 1% – in the Martian atmosphere. It will then attempt to identify their geographical source. This is of interest because, as previous analyses have shown, the accumulation of certain chemical substances, like methane, can vary by location and season. The TGO will help expand our knowledge of the planet's topography, which turns out to be more dynamic than once thought, in order to determine whether these fluctuations are biological or only geological in origin. The camera that the Swiss team developed – a high resolution imaging system called CASSIS (Colour and Stereo Surface Imaging System) – will play a key role in this task. It will work together with the other instruments on the probe, including the NOMAD spectrometer and the FREND neutron detector, in the effort to identify geological sites. Sites whose features – crevasses or traces of erosion, runoff or volcanism – indicate potential sources of gas will then be analyzed in greater detail by CASSIS. The camera will take color photos using stereoscopic imaging, a process of taking photos from two different angles, and at a high resolution: better than 5 m. The TGO will be in a non-sun-synchronous orbit – it won't fly over the same spot at the same time – which means that the probe will allow researchers to observe the surface of the planet at different times of day. They will be able to see various processes at work, like condensation and ice sublimation at the poles and the formation of dust devils. The data will also be used to identify landing sites for future probes. Researchers at EPFL's eSpace worked mainly on the calculations for calibrating the camera as well as on algorithms for processing information provided by the stereoscopic images. "The CASSIS camera is designed to enable easy generation of digital elevation models – 3D representations of the surface," said Anton Ivanov, the lead researcher on the project at eSpace. Together with PhD student Stepan Tulyakov, he also developed a program to precisely identify the position of photographed sites, which will supplement data obtained during previous missions.
Ruggerini G.,Space Engineering |
Toso G.,European Space Agency |
Angeletti P.,European Space Agency
Proceedings of the 5th European Conference on Antennas and Propagation, EUCAP 2011 | Year: 2011
Some advances on the design, manufacturing and testing of an aperiodic bootlace active lens generating a multiple spot contiguous beams coverage are presented in the paper. The antenna represents an interesting architecture based on a single aperture able to replace conventional antennas based on multi reflector dishes onboard geo or non-geo stationary satellites. The antenna has been optimized in terms of number of radiators, dimensions, weight, and power amplifiers efficiency. The first experimental results on a passive antenna system have demonstrated interesting features. The implementation of a real active solution is now on going. © 2011 EurAAP.
Angeletti P.,European Space Agency |
Toso G.,European Space Agency |
Ruggerini G.,Space Engineering
8th European Conference on Antennas and Propagation, EuCAP 2014 | Year: 2014
A deterministic algorithm based on simple analytical equations for designing planar circular sparse array antennas is presented. The positions and the dimensions of the radiating elements are jointly exploited and optimized using simple analytical equations. The algorithm permits solving one of the main limitations associated to sparse arrays, i.e. the poor aperture efficiency especially when patterns with low sidelobe levels are obtained using only the density of the elements avoiding any amplitude tapering. © 2014 European Association on Antennas and Propagation.
News Article | September 23, 2016
Chinese officials confirmed rumors, which began circulating in June, that the country’s first orbiting laboratory, the Tiangong-1, is expected to crash-land into Earth sometime in late 2017. Tiangong-1, or “Heavenly Place” was launched in 2011. Weighing more than 8 tons, it was capable of hosting three astronauts for up to 20 days. It was designed with an operational lifetime of two years, but remained functional for four-and-a-half. Its functional life ended in March of this year. A few months later, a theory that Chinese officials lost control of the lab began to spread. The Tiangong-1 was an initial step in progressing China’s overall space program, with the goal of building a long-term space station by the early 2020’s. Officials confirmed the news of Tiangong-1 before successfully launching the Tiangong-2 on Sept. 15. The Shenzhou 11 spacecraft is scheduled to carry two astronauts to the orbiting laboratory sometime in October, but the date and identity of the team has not yet been announced. During the announcement, officials eased any concerns over the potential danger of the crash-landing of Tiangong-1. “Based on our calculation and analysis, most parts of the space lab will burn up during falling,” said Wu Ping, deputy director of the Manned Space Engineering Office, according to the official New China News Agency. Officials will continue to monitor the situation, and provide a landing forecast if needed. NASA and other space agencies have reported that the odds of one specific individual being hit by a specific piece of space debris is about one in several trillion. Nick Johnson, chief scientist with NASA’s Orbital Debris noted in a 2011 interview that there have been zero reports of anyone in the world being struck by re-entering debris. Other examples of re-entering, uncontrolled debris include the UARS and ROSAT satellites in 2011 and GOCE in 2013.