Gamma-ray binaries are a system of massive, high-energy stars and compact stars. They appear bright bluish-white stars when observing with visible light. When observing X-rays and gamma-rays, their properties differ drastically from those of other binaries. Once the gamma-ray binaries were established as a new astrophysical class, it was quickly recognized that an extremely efficient acceleration mechanism should operate in them. Some gamma-ray binaries are known to emit strong gamma-rays with energies of several megaelectron volts (MeV). Such gamma rays are quite challenging to observe as they were detected from only around 30 celestial bodies in the whole sky. But, what’s mysterious is that such binaries emit strong radiation even in this energy band. This means a beneficial particle acceleration process must be going on within them. The past few studies made it clear that a gamma-ray binary is generally made of a massive primary star that weighs 20-30 times the Sun’s mass and a companion star that must be compact. But, it remains unclear whether the close star is a black hole or a neutron star. Scientists at the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) have studied previously collected data to infer the nature of a magnetar orbiting within LS 5039, the brightest gamma-ray binary system in the Galaxy. Scientists focused on LS 5039 because of its position as the brightest gamma-ray binary in the X-rays and gamma-ray range.
Earlier, it was thought that the LS 5039 must have a neutron star because of its stable X-ray and TeV gamma-ray radiation. However, until now, attempts to detect such pulses had been conducted with radio waves and soft X-rays—and because radio waves and soft X-rays are affected by the primary star’s stellar winds, detection of such periodical pulses had not been successful.
Now, for the first time, scientists focused on the hard X-ray band (>10 keV) and observation data from LS 5039 gathered by the hard X-ray detector (HXD). The data was collected from the space-based telescopes Suzaku (between September 9 and 15, 2007) and NuSTAR (between September 1 and 5, 2016).
Both observations provided evidence on the presence of a neutron star within the core of LS 5039:the periodic signal from Suzaku with a period of about 9 seconds. The probability that this signal arises from statistical fluctuations is only 0.1 percent. NuSTAR also showed a very similar pulse signal. Combining these results also inferred that the spin period is increasing by 0.001 s every year.
Based on the derived spin period and the rate of its increase, the group precluded the rotation powered and accretion- powered scenarios. They found that the neutron star’s magnetic energy is the sole energy source that can power LS 5039.
The required magnetic field reaches 1011 T, three orders of magnitude higher than those of typical neutron stars. This value is found among so-called magnetars, a subclass of neutron stars with such a powerful magnetic field.
The pulse period of 9 seconds is typical of magnetars. This strong magnetic field prevents the primary star’s stellar wind from being captured by a neutron star, explaining why LS 5039 does not exhibit properties similar to X-ray pulsars.
Strangely, the 30 magnetars that have been found so far have all been seen as isolated stars, so their existence in gamma-ray binaries was not viewed as a standard idea. Other than this new theory, the group recommends a source that powers the non-thermal emission inside LS 5039—they suggest that the emission is caused by a collaboration between the magnetar’s magnetic fields and dense stellar winds. Indeed, their figurings recommend that gamma-rays with energies of several megaelectronvolts, which has been unclear, can be unequivocally emitted if they are produced in a region of a powerful magnetic field, close to a magnetar.
These results potentially settle the mystery of the compact object’s nature within LS 5039 and the underlying mechanism powering the binary system. However, further observations and refining of their research are needed to shed new light on their findings.
Australian rocket company, Gilmour Space Technologies, has signed a Memorandum of Understanding (MOU) with global aerospace giant Northrop Grumman Corporation to work on developing sovereign space capabilities in Australia. "Northrop Grumman aims to lead industry support in developing Australian sovereign space capabilities to help meet the needs of defence and realise the Australian Space Agency vision," said Chris Deeble, chief executive, Northrop Grumman Australia. "Our approach is consistent with the Australian government's recently announced Modern Manufacturing Strategy, to make space hardware in Australia while securing sovereign capabilities in priority areas that includes defence and space." As an initial task under the MOU, Northrop Grumman will join Gilmour Space as an industry partner on a previously announced Cooperative Research Centre Project (CRC-P) to develop composite rocket tanks for low-cost space transport. The CRC-P, which includes Griffith University and Etamax Engineering, will manufacture composite tanks up to two metres in diameter and trial them in rocket flights, in an effort to reduce weight and increase reliability. Gilmour Space CEO Adam Gilmour said the company is excited to work with Northrop Grumman on this opportunity. "It is great to gain the support of Northrop Grumman who, through this investment, have further demonstrated their commitment to grow Australian space capability."
The next five years will be a critical time for Australia to develop a world-class sovereign space industry.
"With the right support, we will see innovative, well capitalised, and highly capable Australian space companies like Gilmour Space emerge as future Australian space primes. We look forward to working with Northrop Grumman as we work to launch our first commercial payloads to orbit in 2022."
A joint U.S.-European satellite built to monitor global sea levels lifted off on a SpaceX Falcon 9 rocket from Space Launch Complex 4E at Vandenberg Air Force Base in California Saturday at 9:17 a.m. PST (12:17 p.m. EST). About the size of a small pickup truck, Sentinel-6 Michael Freilich will extend a nearly 30-year continuous dataset on sea level collected by an ongoing collaboration of U.S. and European satellites while enhancing weather forecasts and providing detailed information on large-scale ocean currents to support ship navigation near coastlines. "The Earth is changing, and this satellite will help deepen our understanding of how," said Karen St. Germain, director of NASA's Earth Science Division. "The changing Earth processes are affecting sea level globally, but the impact on local communities varies widely. International collaboration is critical to both understanding these changes and informing coastal communities around the world." After arriving in orbit, the spacecraft separated from the rocket's second stage and unfolded its twin sets of solar arrays. Ground controllers successfully acquired the satellite's signal, and initial telemetry reports showed the spacecraft in good health. Sentinel-6 Michael Freilich will now undergo a series of exhaustive checks and calibrations before it starts collecting science data in a few months' time.
Continuing the Legacy The spacecraft is named in honor of Michael Freilich, the former director of NASA's Earth Science Division, who was a leading figure in advancing ocean observations from space. Freilich passed away Aug. 5, 2020. His close family and friends attended the launch of the satellite that now carries his name.
"Michael was a tireless force in Earth sciences. Climate change and sea level rise know no national borders, and he championed international collaboration to confront the challenge," said ESA (European Space Agency) Director of Earth Observation Programmes Josef Aschbacher. "It's fitting that a satellite in his name will continue the 'gold standard' of sea level measurements for the next half-decade. This European-U.S. cooperation is exemplary and will pave the way for more cooperation opportunities in Earth observation."
"Mike helped ensure NASA was a steadfast partner with scientists and space agencies worldwide, and his love of oceanography and Earth science helped us improve understanding of our beautiful planet," added Thomas Zurbuchen, NASA associate administrator for science at the agency's headquarters. "This satellite so graciously named for him by our European partners will carry out the critical work Mike so believed in - adding to a legacy of crucial data about our oceans and paying it forward for the benefit of future generations."
Sentinel-6 Michael Freilich will continue the sea level record that began in 1992 with the TOPEX/Poseidon satellite and continued with Jason-1 (2001), OSTM/Jason-2 (2008), and eventually Jason-3, which has been observing the oceans since 2016. Together, these satellites have provided a nearly 30-year record ofprecise measurements of sea level height while tracking the rate at which our oceans are rising in response to our warming climate. Sentinel-6 Michael Freilich will pass the baton to its twin, Sentinel-6B, in 2025, extending the current climate record at least another 10 years between the two satellites.
Global Science Impact This latest mission marks the first international involvement in Copernicus, the European Union's Earth Observation Programme. Along with measuring sea levels for almost the entire globe, Sentinel-6 Michael Freilich's suite of scientific instruments will also make atmospheric measurements that can be used to complement climate models and help meteorologists make better weather forecasts.
"NASA is but one of several partners involved in Sentinel-6 Michael Freilich, but this satellite speaks to the very core of our mission," said NASA Administrator Jim Bridenstine. "Whether 800 miles above Earth with this remarkable spacecraft or traveling to Mars to look for signs of life, whether providing farmers with agricultural data or aiding first responders with our Disasters program, we are tirelessly committed not just to learning and exploring, but to having an impact where it's needed."
The initial orbit of Sentinel-6 Michael Freilich is about 12.5 miles (20.1 kilometers) lower than its ultimate operational orbit of 830 miles (1,336 kilometers). In less than a month, the satellite will receive commands to raise its orbit, trailing Jason-3 by about 30 seconds. Mission scientists and engineers will then spend about a year cross-calibrating data collected by the two satellites to ensure the continuity of sea level measurements from one satellite to the next. Sentinel-6 Michael Freilich will then take over as the primary sea level satellite and Jason-3 will provide a supporting role until the end of its mission.
"This mission is the very essence of partnership, precision, and incredible long-term focus," said Michael Watkins, director of NASA's Jet Propulsion Laboratory in Southern California, which manages the mission. "Sentinel-6 Michael Freilich not only provides a critical measurement,it is essential for continuing this historic multi-decadal sea level record."
Sentinel-6 Michael Freilich and Sentinel-6B compose the Sentinel-6/Jason-CS (Continuity of Service) mission developed in partnership with ESA. ESA is developing the new Sentinel family of missions to support the operational needs of the Copernicus program, managed by the European Commission. Other partners include the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), and National Oceanic and Atmospheric Administration, with funding support from the European Commission and technical support from France's National Centre for Space Studies.
"The data from this satellite, which is so critical for climate monitoring and weather forecasting, will be of unprecedented accuracy," said EUMETSAT Director-General Alain Ratier. "These data, which can only be obtained by measurements from space, will bring a wide range of benefits to people around the globe, from safer ocean travel to more precise prediction of hurricane paths, from greater understanding of sea level rise to more accurate seasonal weather forecasts, and so much more."
The OSAM-1 mission, formerly known as Restore-L, will demonstrate robotic servicing technologies in orbit, including satellite refueling, assembly and in-space manufacturing. The SPIDER payload's lightweight 16-foot (5-metre) robotic arm will assemble multiple antenna reflector elements to form a single, functional 9-foot (3-metre) communications Ka-band antenna. MDA has announced that it has signed multiple contracts with Maxar Technologies to provide advanced space robotics technologies for the Space Infrastructure Dexterous Robot (SPIDER), a technology demonstration on NASA's On-orbit Servicing, Assembly, and Manufacturing 1 (OSAM-1) mission. MDA will deliver an enabling technology suite of advanced robot control software and interfaces to help achieve assembly and servicing tasks never done to date. These include:
+ A dexterous end effector; + Robotic arm control software; + Motor control software; + Robotic console command and control software and computers; + Grapple fixtures and targets for on-orbit assembly interfaces, and + Compact cameras and controllers for situational awareness and robotic arm operation.
MDA will also deliver the Motor Control Electronics and Arm Control Electronics on the SPIDER robotic arm. These essential components drive and control each of the motors and joints of the arm as well as providing the data routing and interfacing between joints and cameras.
The work on these three contracts will be performed at MDA facilities in Brampton and Ste-Anne-de-Bellevue. These products will be delivered in mid-to-late 2021 and incorporated into Maxar's robotic system. They will not only support the goal of making on-orbit assembly commercially viable, but could also support other on-orbit services like debris removal, anomaly resolution, life extension, and salvage of stranded spacecraft.
There is a clear need to service the world's space infrastructure, both commercial and government, and MDA is well positioned to address this burgeoning market.
MDA has unparalleled and proven space servicing capabilities developed through various government programs over the last 40 years, including the Canadian government's Canadarm program for the US Space Shuttle and International Space Station programs as well as other on-orbit servicing demonstrations such as the successful DARPA Orbital Express mission and NASA's Robotic Refueling Missions on the space station.
NASA's Curiosity Mars rover has a new selfie. This latest is from a location named "Mary Anning," after a 19th-century English paleontologist whose discovery of marine-reptile fossils were ignored for generations because of her gender and class. The rover has been at the site since this past July, taking and analyzing drill samples. Made up of 59 pictures stitched together by imaging specialists, the selfie was taken on Oct. 25, 2020 – the 2,922nd Martian day, or sol, of Curiosity's mission. Scientists on the Curiosity team thought it fitting to name the sampling site after Anning because of the area's potential to reveal details about the ancient environment. Curiosity used the rock drill on the end of its robotic arm to take samples from three drill holes called "Mary Anning," "Mary Anning 3," and "Groken," this last one named after cliffs in Scotland's Shetland Islands. The robotic scientist has conducted a set of advanced experiments with those samples to extend the search for organic (or carbon-based) molecules in the ancient rocks. Since touching down in Gale Crater in 2012, Curiosity has been ascending Mount Sharp to search for conditions that might once have supported life. This past year, the rover has explored a region of Mount Sharp called Glen Torridon, which likely held lakes and streams billions of years ago. Scientists suspect this is why a high concentration of clay minerals and organic molecules was discovered there.
This close-up shot shows the three drill holes created by NASA's Curiosity Mars rover at the "Mary Anning" location.
Credit: NASA/JPL-Caltech/MSSS.
It will take months for the team to interpret the chemistry and minerals in the samples from the Mary Anning site. In the meantime, the scientists and engineers who have been commanding the rover from their homes as a safety precaution during the coronavirus pandemic have directed Curiosity to continue its climb of Mount Sharp. The rover's next target of exploration is a layer of sulfate-laden rock that lies higher up the mountain. The team hopes to reach it in early 2021.
NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, leads the Curiosity mission. Curiosity took the selfie using a camera called the Mars Hand Lens Imager (MAHLI), located on the end of its robotic arm. (Videos explaining how Curiosity's selfies are taken can be found here.) MAHLI was built by Malin Space Science Systems in San Diego.
For galaxies, as for people, living in a crowd is different from living alone. Recently, astronomers used the National Science Foundation's Karl G. Jansky Very Large Array (VLA) to learn how a crowded environment affects galaxies in the Perseus Cluster, a collection of thousands of galaxies some 240 million light-years from Earth. Left: The giant galaxy NGC 1275, at the core of the cluster, is seen in new detail, including a newly revealed wealth of complex, filamentary structure in its radio lobes. Center: The galaxy NGC 1265 shows the effects of its motion through the tenuous material between the galaxies. Its radio jets are bent backward by that interaction, then merge into a single, broad "tail." The tail then is further bent, possibly by motions within the intergalactic material. Right: The jets of the galaxy IC 310 are bent backward, similarly to NGC 1265, but appear closer because of the viewing angle from Earth. That angle also allows astronomers to directly observe energetic gamma rays generated near the supermassive black hole at the galaxy's core. Such images can help astronomers better understand the complex environment of galaxy clusters, which are the largest gravitationally= bound structures in the universe, and which harbor a variety of still poorly understood phenomena.
Galaxies in the Perseus Cluster, left to right: NGC 1275, NGC 1265, IC 310.
"These images show us previously unseen structures and details and that helps our effort to determine the nature of these objects," said Marie-Lou Gendron-Marsolais, an ESO/ALMA Fellow in Santiago, Chile. She and a number of international collaborators are announcing their results in the Monthly Notices of the Royal Astronomical Society.
In our infinite universe, stars can go bump in the night. When this happens between a pair of burned-out, crushed stars called neutron stars, the resulting fireworks show, called a kilonova, is beyond comprehension. The energy unleashed by the collision briefly glows 100 million times brighter than our Sun. What’s left from the smashup? Typically an even more crushed object called a black hole. But in this case Hubble found forensic clues to something even stranger happening after the head-on collision. The intense flood of gamma-rays signaling astronomers to this event has been seen before in other stellar smashups. But something unexpected popped up in Hubble’s near-infrared vision. Though a gusher of radiation from the aftermath of the explosion—stretching from X-rays to radio waves—seemed typical, the outpouring of infrared radiation was not. It was 10 times brighter than predicted for kilonovae. Without Hubble, the gamma-ray burst would have appeared like many others, and scientists would not have known about the bizarre infrared component. The most plausible explanation is that the colliding neutron stars merged to form a more massive neutron star. It’s like smashing two Volkswagen Beetles together and getting a limousine. This new beast sprouted a powerful magnetic field, making it a unique class of object called a magnetar. The magnetar deposited energy into the ejected material, causing it to glow even more brightly in infrared light than predicted.
Magnetar-Powered Kilonova Blast. Credit: NASA, ESA, and D. Player (STScI)
(If a magnetar flew within 100,000 miles of Earth, its intense magnetic field would erase the data on every credit card on our planet!)
This image shows the glow from a kilonova caused by the merger of two neutron stars. The kilonova, whose peak brightness reaches up to 10,000 times that of a classical nova, appears as a bright spot (indicated by the arrow) to the upper left of the host galaxy. The merger of the neutron stars is believed to have produced a magnetar, which has an extremely powerful magnetic field. The energy from that magnetar brightened the material ejected from the explosion. Credit: NASA, ESA, W. Fong (Northwestern University), and T. Laskar (University of Bath, UK)
Long ago and far across the universe, an enormous burst of gamma rays unleashed more energy in a half-second than the Sun will produce over its entire 10-billion-year lifetime. In May of 2020, light from the flash finally reached Earth and was first detected by NASA’s Neil Gehrels Swift Observatory. Scientists quickly enlisted other telescopes — including NASA’s Hubble Space Telescope, the Very Large Array radio observatory, the W. M. Keck Observatory, and the Las Cumbres Observatory Global Telescope network — to study the explosion’s aftermath and the host galaxy. It was Hubble that provided the surprise.
Based on X-ray and radio observations from the other observatories, astronomers were baffled by what they saw with Hubble: the near-infrared emission was 10 times brighter than predicted. These results challenge conventional theories of what happens in the aftermath of a short gamma-ray burst. One possibility is that the observations might point to the birth of a massive, highly magnetized neutron star called a magnetar.
“These observations do not fit traditional explanations for short gamma-ray bursts,” said study leader Wen-fai Fong of Northwestern University in Evanston, Illinois. “Given what we know about the radio and X-rays from this blast, it just doesn’t match up. The near-infrared emission that we’re finding with Hubble is way too bright. In terms of trying to fit the puzzle pieces of this gamma-ray burst together, one puzzle piece is not fitting correctly.”
Without Hubble, the gamma-ray burst would have appeared like many others, and Fong and her team would not have known about the bizarre infrared behavior. “It’s amazing to me that after 10 years of studying the same type of phenomenon, we can discover unprecedented behavior like this,” said Fong. “It just reveals the diversity of explosions that the universe is capable of producing, which is very exciting.”
Light Fantastic
The intense flashes of gamma rays from these bursts appear to come from jets of material that are moving extremely close to the speed of light. The jets do not contain a lot of mass — maybe a millionth of the mass of the Sun — but because they’re moving so fast, they release a tremendous amount of energy across all wavelengths of light. This particular gamma-ray burst was one of the rare instances in which scientists were able to detect light across the entire electromagnetic spectrum.
This illustration shows the sequence for forming a magnetar-powered kilonova, whose peak brightness reaches up to 10,000 times that of a classical nova. 1) Two orbiting neutron stars spiral closer and closer together. 2) They collide and merge, triggering an explosion that unleashes more energy in a half-second than the Sun will produce over its entire 10-billion-year lifetime. 3) The merger forms an even more massive neutron star called a magnetar, which has an extraordinarily powerful magnetic field. 4) The magnetar deposits energy into the ejected material, causing it to glow unexpectedly bright at infrared wavelengths. Credit: NASA, ESA, and D. Player (STScI)
“As the data were coming in, we were forming a picture of the mechanism that was producing the light we were seeing,” said the study’s co-investigator, Tanmoy Laskar of the University of Bath in the United Kingdom. “As we got the Hubble observations, we had to completely change our thought process, because the information that Hubble added made us realize that we had to discard our conventional thinking, and that there was a new phenomenon going on. Then we had to figure out what that meant for the physics behind these extremely energetic explosions.”
Gamma-ray bursts — the most energetic, explosive events known — live fast and die hard. They are split into two classes based on the duration of their gamma rays.
If the gamma-ray emission is greater than two seconds, it’s called a long gamma-ray burst. This event is known to result directly from the core collapse of a massive star. Scientists expect a supernova to accompany this longer type of burst.
If the gamma-ray emission lasts less than two seconds, it’s considered a short burst. This is thought to be caused by the merger of two neutron stars, extremely dense objects about the mass of the Sun compressed into the volume of a city. A neutron star is so dense that on Earth, one teaspoonful would weigh a billion tons! A merger of two neutron stars is generally thought to produce a black hole.
These two images taken on May 26 and July 16, 2020, show the fading light of a kilonova located in a distant galaxy. The kilonova appears as a spot to the upper left of the host galaxy. The glow is prominent in the May 26 image but fades in the July 16 image. The kilonova’s peak brightness reaches up to 10,000 times that of a classical nova. A merger of two neutron stars—the source of the kilonova—is believed to have produced a magnetar, which has an extremely powerful magnetic field. The energy from that magnetar brightened the material ejected from the explosion, causing it to become unusually bright at infrared wavelengths of light. Credit: NASA, ESA, W. Fong (Northwestern University), T. Laskar (University of Bath, UK) and A. Pagan (STScI)
Neutron star mergers are very rare but are extremely important because scientists think that they are one of the main sources of heavy elements in the universe, such as gold and uranium.
Accompanying a short gamma-ray burst, scientists expect to see a “kilonova” whose peak brightness typically reaches 1,000 times that of a classical nova. Kilonovae are an optical and infrared glow from the radioactive decay of heavy elements and are unique to the merger of two neutron stars, or the merger of a neutron star with a small black hole.
Magnetic Monster?
Fong and her team have discussed several possibilities to explain the unusual brightness that Hubble saw. While most short gamma-ray bursts probably result in a black hole, the two neutron stars that merged in this case may have combined to form a magnetar, a supermassive neutron star with a very powerful magnetic field.
“You basically have these magnetic field lines that are anchored to the star that are whipping around at about a thousand times a second, and this produces a magnetized wind,” explained Laskar. “These spinning field lines extract the rotational energy of the neutron star formed in the merger, and deposit that energy into the ejecta from the blast, causing the material to glow even brighter.”
This animation shows the sequence for forming a magnetar-powered kilonova, whose peak brightness reaches up to 10,000 times that of a classical nova. In this sequence, two orbiting neutron stars spiral closer and closer together before colliding and merging. This triggers an explosion that unleashes more energy in a half-second than the Sun will produce over its entire 10-billion-year lifetime. The merger forms an even more massive neutron star called a magnetar, which has an extraordinarily powerful magnetic field. The magnetar deposits energy into the ejected material, causing it to glow unexpectedly bright at infrared wavelengths. Credit: NASA, ESA, and D. Player (STScI)
If the extra brightness came from a magnetar that deposited energy into the kilonova material, then within a few years, the team expects the ejecta from the burst to produce light that shows up at radio wavelengths. Follow-up radio observations may ultimately prove that this was a magnetar, and this may explain the origin of such objects.
“With its amazing sensitivity at near-infrared wavelengths, Hubble really sealed the deal with this burst,” explained Fong. “Amazingly, Hubble was able to take an image only three days after the burst. Through a series of later images, Hubble showed that a source faded in the aftermath of the explosion. This is as opposed to being a static source that remains unchanged. With these observations, we knew we had not only nabbed the source, but we had also discovered something extremely bright and very unusual. Hubble’s angular resolution was also key in pinpointing the position of the burst and precisely measuring the light coming from the merger.”
NASA’s upcoming James Webb Space Telescope is particularly well-suited for this type of observation. “Webb will completely revolutionize the study of similar events,” said Edo Berger of Harvard University in Cambridge, Massachusetts, and principal investigator of the Hubble program. “With its incredible infrared sensitivity, it will not only detect such emission at even larger distances, but it will also provide detailed spectroscopic information that will resolve the nature of the infrared emission.”
The team’s findings appear in an upcoming issue of The Astrophysical Journal.
The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington, D.C.
The TAU-SAT1 nanosatellite, approximately the size of a shoebox, is currently undergoing pre-flight testing at the Japanese space agency JAXA prior to a planned launch by NASA in the first quarter of 2021. TAU-SAT1 was entirely devised, developed, assembled, and tested at Tel Aviv University's Nanosatellite Center, an interdisciplinary endeavor of the University's Iby and Aladar Fleischman Faculty of Engineering, Raymond and Beverly Sackler Faculty of Exact Sciences, and Porter School of Environmental Studies. "TAU-SAT1 is the first nanosatellite designed, built and tested in an Israeli university, and the entire process, from conception through design, software development and testing, was done at TAU," explains Dr. Ofer Amrani, head of TAU's minisatellite lab. While other universities in Israel, including The Technion, Ben-Gurion University, and Ariel University, are investing in similar space projects, the TAU satellite will be the first to enter the Earth's orbit. TAU-SAT1 is a research satellite and will conduct several experiments while in orbit, including the measurement of cosmic radiation in space. "We know that that there are high-energy particles moving through space that originate from cosmic radiation," says Dr. Meir Ariel, director of the University's Nanosatellite Center. "Our scientific task is to monitor this radiation, and to measure the flux of these particles and their products. To this end, we incorporated a number of experiments into the satellite, which were developed by the Space Environment Department at the Soreq Nuclear Research Center."
One challenge was to extract the data collected by the TAU-SAT1 satellite. The satellite will complete an orbit around the Earth every 90 minutes. "In order to collect data, we built a satellite station on the roof of the engineering building," says Dr. Amrani. "Our station, which also serves as an amateur radio station, includes a number of antennas and an automated control system. When TAU-SAT1 passes over Israel, the antennas will track the satellite's orbit and a process of data transmission will occur between the satellite and the station."
The satellite is expected to be active for several months. Because it has no engine, its trajectory will fade over time as the result of atmospheric drag. It will eventually burn up in the atmosphere and return to the Earth as dust.
The launch of the TAU-SAT1 nanosatellite is just TAU's first step on its way to joining the "new space" revolution, Dr. Amrani says.
"The idea behind the new space revolution is to open space up to civilians as well. In the not-too-distant past, satellites involved a very expensive development process that took many years and required the involvement of large and cumbersome governmental systems. We were able to complete the planning, building, and testing of our own satellite in less than two years.
"Moreover, we built the infrastructure on our own - from the cleanrooms, to the various testing facilities such as the thermal vacuum chamber, to the receiving and transmission station we placed on the roof. Now that the infrastructure is ready, we can begin to develop TAU-SAT2.
"The idea is that any researcher and any student, from any faculty at TAU or outside of it, will be able to plan and launch experiments into space in the future - even without being an expert in the field," Dr. Amrani concludes.
