News Article | May 25, 2017
Researchers from Universidad Politécnica de Madrid (UPM), Universidad Rey Juan Carlos (URJC) and Massachusetts Institute of Technology (MIT) have developed a model to optimize the decision making of airlines against their competitors. A team of researchers from two Spanish universities, UPM and URJC, in collaboration with MIT researchers has developed a mathematical model that assesses the competition between airlines, both legacy and low-cost airlines, and high-speed trains. This new approach is able to estimate the modal distribution of passenger demand, optimize fleet assignment and generate flight schedule. This math tool provides valuable and useful information that will help airlines to efficiently face the competition of high-speed trains. Airlines and high-speed trains are increasingly competing for passengers, especially in Europe and Asia. High-speed trains usually compete by providing similar or even greater service frequency and better connectivity to city centers. Besides, HST is often perceived as the safer and more comfortable mode, this situation generates a redistribution of passengers between aerial and railway alternatives. Thus, a group of researchers, including the Professor Ángel Martín from School of Aeronautics and Space Engineering, gathered to study the impact of the uncertainty on regular aerial transport. In this way, researchers have developed a competition model −considering the multimodal competition between aerial transport and high-speed trains and the aerial competition between legacy companies and low-cost companies− that uses a nested logit model that captures the impacts of the decisions taken by aerial companies on passenger demand. At the core of this modeling approach is an integrated schedule optimization model that includes frequency planning, approximate timetable development, fleet assignment, and passenger demand choice. The computational results were carried out on realistic problem instances of the Spanish airline IBERIA and show that the actual airline schedules are found to be reasonably close to the schedules generated by our approach. Researchers also used this optimization modeling approach under multimodal competition to evaluate multiple scenarios involving entry of high speed rail into new markets, taking into account the possibility of demand stimulation as a result of the new services. This model was validated by using data from markets that had an entry by high speed rail in the past. The validation results show a close match between the predicted and the observed solutions. In addition this model can predict the impacts of future entry by high speed rail on new markets. Consequently, the proposed modeling framework is attractive from the perspective of the airline operators. It allows them to plan better for the impending HST entry by fine-tuning schedules, fleets, and fares. According to Ángel Martín, a researcher involved in this study, "The framework can facilitate careful evaluation of various scenarios (such as competitor actions, fleet changes, fare changes, etc.) allowing the airline to be better prepared to adapt to the changing competitive environment." This research was carried out within the framework of the project "Robustness, efficiency and recovery of public transport systems," TRA2014-52530-C3-1-P research project of Ministry of Economy and Competitiveness.
News Article | May 26, 2017
The first Australian satellite in 15 years, UNSW-EC0, was successfully deployed from the International Space Station, but the UNSW engineers who built it were unable to establish contact when it made its first pass above Sydney. However, engineers say there could be many reasons for the silence and they are not overly concerned. UNSW-EC0 was ejected from the station at 3:25pm AEST, and made its first pass over Sydney at 4:21pm AEST. Engineers at UNSW's Australian Centre for Space Engineering Research (ACSER) were unable to pick up the signal it is meant to send to confirm the cubesat is operating as designed. "We're not overly concerned yet," said Elias Aboutanios, project leader of the UNSW-EC0 cubesat and deputy director of ACSER. "We're troubleshooting a number of scenarios for why we didn't detect it, from checking our ground equipment to exploring the possibility that the batteries might have discharged. But at the moment, we just don't know." "If it is the batteries, the satellite has solar panels and will be able to recharge," said Joon Wayn Cheong, a research associate at UNSW's School of Electrical Engineering and Telecommunications and technical lead of the UNSW-EC0 cubesat. "But because it was deployed in the Earth's shadow, we have to wait for it to make a few orbits before it has recharged, especially if it's tumbling. So it could be 24 to 48 hours." The International Space Station, or ISS, will make four more passes over Sydney on Friday 25 May, and the UNSW team of 15 researchers and students will again try to establish contact, and run a series of tests for scenarios to explain the lack of a signal. UNSW-EC0 is one of three Australian research satellites – two of them built at the UNSW – that blasted off just after on April 19 from Cape Canaveral Air Force Station in Florida. Its mission is to explore the little-understood region above Earth known as the thermosphere, study its atomic composition as well as test new robust computer chips and GPS devices developed at UNSW. In addition, its chassis is made entirely from 3-D-printed thermoplastic, itself an experiment to test the reliability of using 3-D-printing to manufacture satellites, making them cheaper and much more customisable. The cubesat is part of an international QB50 mission, a swarm of 36 small satellites – known as 'cubesats' and weighing about 1.3 kg each – that will carry out the most extensive measurements ever undertaken of the thermosphere, a region between 200 and 380 km above Earth. This poorly-studied and usually inaccessible zone of the atmosphere helps shield Earth from cosmic rays and solar radiation, and is vital for communications and weather formation. "These are the first Australian satellites to go into space in 15 years," said Andrew Dempster, director of ACSER at UNSW, and a member of the advisory council of the Space Industry Association of Australia. "There have only been two before: Fedsat in 2002 and WRESAT in 1967. So we've got more hardware in space today than Australia's had in its history." UNSW-EC0 was deployed from the ISS from a Nanoracks launcher, a 'cannon' that eject cubesats at a height of 380 km (the same as the ISS), allowing them to drift down to a lower orbit where they can begin their measurements. "This zone of the atmosphere is poorly understood and really hard to measure," said Aboutanios. "It's where much of the ultraviolet and X-ray radiation from the Sun collides with Earth, influencing our weather, generating auroras and creating hazards that can affect power grids and communications. "So it's really important we learn a lot more about it. The QB50 cubesats will probably tell us more than we've ever known about the thermosphere," he added. QB50 is a collaboration of more than 50 universities and research institutes in 23 countries, headed by the von Karman Institute (VKI) in Belgium. "This is the very first international real-time coordinated study of the thermosphere phenomena," said VKI's Davide Masutti. "The data generated by the constellation will be unique in many ways and they will be used for many years by scientists around the world." Explore further: Swarm of satellites to explore Earth's shield from International Space Station
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.
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.
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.