This weekend the International Space Station will turn itself to face the Sun, enabling ESA’s SOLAR instrument to capture an entire rotation of the solar surface. This is the first time the Station has changed attitude for scientific reasons alone.
This instrument has been on the ISS since 2008, and for the first time will record a full rotation of the Sun. It began this effort on November 19, 2012, and on December 1, the Station will spend two hours turning about 7 degrees so that observations can continue. It will hold this angle for ten days before returning to its original attitude.
“We want to record a complete rotation of the Sun and that takes around 25 days,” said Nadia This, operations engineer at the Belgian User Support and Operations Centre that controls SOLAR.
SOLAR needs to be in direct view of the Sun to take measurements but the Space Station’s normal orbit obscures the view for two weeks every month.
All the international partners had to agree on changing the ISS’s orientation.
However, moving a 450-ton orbital outpost the size of a city block isn’t a simple undertaking. Aside from calculating the correct orbit to keep SOLAR in view of the Sun, other factors need to be taken into account such as ensuring the solar panels that power the Station also face the Sun. Additionally, communication antennas need to be reoriented to stay in contact with Earth and other scientific experiments must be adjusted.
The SOLAR instrument located on the exterior of the Columbus module on the ISS. Credit: ESA
The SOLAR instrument was originally designed to last about 18 months, but has been going strong for 5 years. It is installed on the outside of the ESA’s Columbus module.
The SOLAR payload consists of three instruments to the solar spectral irradiance throughout virtually the whole electromagnetic spectrum.
The three complementary solar science instruments are:
SOVIM (SOlar Variable and Irradiance Monitor), which covers near-UV, visible and thermal regions of the spectrum.
SOLSPEC (SOLar SPECctral Irradiance measurements) covers the 180 nm – 3 000 nm range.
SOL-ACES (SOLar Auto-Calibrating Extreme UV/UV Spectrophotometers) measures the EUV/UV spectral regime.
Scientists say SOLAR’s observations are improving our understanding of the Sun and allowing scientists to create accurate computer models and predict its behavior.
After NASA was forced to back out of the joint ExoMars mission with the European Space Agency due to budget constraints, it looked like the exciting rover-orbiter mission might not happen. However, ESA went elsewhere looking for help, and has now announced a tentative cooperative arrangement with Russia’s space agency where Roscosmos will provide the two launch vehicles for multi-vehicle European-Russian ExoMars missions in 2016 and 2018.
Plans are for the mission to have an orbiter for launch in 2016, plus an ESA-built rover mission in 2018. Roscosmos will provide Proton rockets for the launches of the two missions, as well as providing an instrument for both the orbiter and the rover as well as overseeing the landing of the rover. The orbiter would study Mars’ atmosphere and surface and the six-wheeled vehicle would look for signs of past or present life.
The orbiter would also provide telecommunications for the rover.
Frederic Nordland, ESA’s director of international relations, said the agreement would be finalized before the end of the year and that its principal characteristics are already known and accepted by both sides. The announcement was made at a meeting in Naples, Italy this week of ESA’s space leaders from the 10 different nations that comprise the organization. The leaders are discussing future objectives and priorities for Europe in space, with the aim of shaping the development of Europe’s space capability.
During the meeting, Poland officially joined ESA, becoming the 20th member of the European space organization. It joins the other member states of Austria, Belgium, Britain, the Czech Republic, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, The Netherlands, Norway, Portugal, Romania, Spain, Sweden and Switzerland.
ExoMars is now expected to cost ESA about 1.2 billion euros. So far, 850 million euros has been committed by the participating members, but officials remain confident the remaining funds can be raised.
ESA officials also said Russia’s Proton rocket might be used to launch Europe’s Juice mission to Jupiter in 2022, saving ESA’s science program some 170 million euros.
Caption: GOCE over ice. Credits: ESA – AOES Medialab
Since March 2009, the European Space Agency (ESA) mission, Gravity field and steady-state Ocean Circulation Explorer (GOCE) has been orbiting Earth. It carries highly sensitive instrumentation able to detect tiny variations in the pull of gravity across the surface of the planet, allowing it to map our planet’s gravity with unrivaled precision, producing the most accurate gravity map of Earth. With the planned mission completed, the fuel consumption has been much lower than anticipated, enabling ESA to extend GOCE’s life and put it into an even lower orbit, improving the quality of the gravity model.
The GOCE spacecraft was designed to fly low and has spent most of its mission roughly 500km below most other Earth-observing missions, at an altitude of 255km. ESA’s Earth Scientific Advisory Committee recommended lowering the orbit by 20km at a rate of about 300m per day, starting in August. After coming down by 8.6 km, the satellite’s performance and orbit were assessed. Now, GOCE is again being lowered while continuing its gravity mapping. It is expected to reach 235 km by February.
Decreasing the altitude increases the spatial resolution and the precision of the data. The expected increase in data quality is so high (possibly 35%) that scientists are calling it GOCE’s ‘second mission. Volker Liebig, ESA’s Director of Earth Observation Programmes has said “What the team of ESA engineers is now doing has not been done before and it poses a challenge. But it will also trigger new research in the field of gravity based on the high-resolution data we are expecting.”
Caption: The image on the left shows GOCE’s gravity measurements over northern Europe, acquired from its previous altitude. The image on the right depicts the expected measurements over the same area after the satellite has been lowered. Credits: ESA / GOCE+ Theme 2
The first ‘geoid’ based on GOCE’s gravity measurements was unveiled in June 2010. It is a crucial reference for conducting precise measurements of ocean circulation, sea-level change and ice dynamics. The mission has also been studying air density and wind in space, and its data was recently used to produce the first global high-resolution map of the boundary between Earth’s crust and mantle, called the Mohorovicic, or “Moho” discontinuity.
As the orbit drops, atmospheric drag increasingly pulls the satellite towards Earth, so GOCE has to use the tiny thrust of its ion engine to continuously compensate for any drag to stay aloft and maintain the stability it needs to measure Earth’s gravity. GOCE has enough xenon fuel for another 50 weeks of operations. When the fuel runs out the satellite will be pulled into the deep atmosphere where it will burn up
Caption: Bedrest volunteer in bed during a study conducted in 2005. Credit: ESA
As you get older, do feel you could do with more rest? Our bodies lose bone density and muscle strength as we age. Astronauts in space suffer similar changes but at a much faster rate. Finding ways to understand and combat this process is important to space agencies, hospital patients and all of us as we grow older. A new study is about to commence at the French Institute for Space Medicine and Physiology, in the clinical research facility in Toulouse, France, that hopes to understand and address changes in astronauts’ bodies in space as well as in bedridden people on Earth. 12 volunteers will spend 21 days in bed. Sound relaxing? Think again.
The volunteers taking part in the study, will lie for 24 hours a day with their heads tilted 6° below the horizontal. They will not be allowed to get up, for any reason. Not for a breath of fresh air, a change of scenery, a shower or to use the toilet, until the 21 days are over. This will cause their bodies to react in similar ways to being weightless, without the expense or risks involved in sending them into space.
In microgravity, bone loss occurs at a rate of 1 to 1.5% a month. This bone demineralization increases the risks of kidney stones and bone fractures as well as altering the ability of bones to heal after fractures. Loss of muscle mass, strength and endurance, increases risk of fatigue and injury. The heart may experience diminished cardiac function and possible disturbances in heart rhythm.
Microgravity also causes body fluids to be redistributed away from the extremities, which results in puffiness in the face during flight. The body’s neurovestibular system that controls balance, stabilizes vision and body orientation in terms of location and direction may also become impaired, leading to disorientation and lack of coordination. The body can also suffer loss of blood volume, low red blood cell levels and immunodeficiency
Although many of the effects are reversible upon return to Earth, astronauts may have problems standing up, stabilizing their gaze, walking and turning, immediately after landing. Some astronauts find their blood pressure drops abnormally low when they move from lying down to a sitting or standing position.
The participants in this latest study will be scientifically scrutinised to see how they adapt to staying in bed for long periods, but they will also be divided into three groups to test a set of measures designed to counteract muscle and bone loss. The control group will be given no countermeasures, while a second group will use resistive and vibrating exercise machines. The last group will use the exercise machines and eat nutritional supplements of whey protein – a common supplement used by bodybuilders to train their muscles.
Each group of volunteers will participate in all the regimes, one after the other, over the course of the entire experiment of more than a year. They will be given four months between each bedrest session to recuperate. After the first 21-day session, they will return to the at the MEDES Space Clinic in Toulouse, for another session and once more in 2013 for a final session. After all that I bet they will need a rest.
Read more about this study here
And read diaries from participants in a similar study that ran for 60 days in 2005 here
The European Space Agency (ESA) was founded by 10 European states back in 1975 with the idea that “We can do more, together.” Today Europe’s gateway to space is a cooperative, intergovernmental organisation, with 20 European member nations representing 500 million citizens, coming together in their national interest and common good. On 20-21 November ESA’s space ministers are meeting in Naples to decide the Agency’s future course. Continue reading “Space for the Cost of a Movie Ticket”
Caption: ESA’s giant Malargüe tracking station Credits: ESA/S. Marti
To keep in contact with an ever growing armada of spacecraft ESA has developed a tracking station network called ESTRACK. This is a worldwide system of ground stations providing links between satellites in orbit and ESA’s Operations Control Centre (ESOC) located in Darmstadt, Germany. The core ESTRACK network comprises 10 stations in seven countries. Major construction has now been completed on the final piece of this cosmic jigsaw, one of the world’s most sophisticated satellite tracking stations at Malargüe, Argentina, 1000 km west of Buenos Aires.
ESA’s Core Network comprises 10 ESTRACK stations: Kourou (French Guiana), Maspalomas, Villafranca (Spain), Redu (Belgium), Santa Maria (Portugal), Kiruna (Sweden), Perth (Australia) which host 5.5-, 13-, 13.5- or 15-metre antennas. The new tracking station (DSA3) at Malargüe in Argentina, joins two other 35-metre deep-space antennas at New Norcia (DSA1) in Australia (completed in 2002) and Cebreros (DSA2) in Spain, (completed in 2005) to form the European Deep Space Network.
The essential task of ESTRACK stations is to communicate with missions, up-linking commands and down-linking scientific data and spacecraft status information. The tracking stations also gather radiometric data to tell mission controllers the location, trajectory and velocity of their spacecraft, to search for and acquire newly launched spacecraft, in addition to auto-tracking, frequency and timing control using atomic clocks and gathering atmospheric and weather data.
Deep-space missions can be over 2 million kilometres away from the Earth. Communicating at such distances requires highly accurate mechanical pointing and calibration systems. The 35m stations provide the improved range, radio technology and data rates required to send commands, receive data and perform radiometric measurements for current and next-generation exploratory missions such as Mars Express, Venus Express, Rosetta, Herschel, Planck, Gaia, BepiColombo, ExoMars, Solar Orbiter and Juice.
DSA3 is located at 1500m altitude in the clear Argentinian desert air, this and ultra-low-temperature amplifiers installed at the station, have meant that performance has exceeded expectations. The first test signals were received in June 2012 from Mars Express, over a distance of about 193 million km, proving that the station’s technology is ready for duty.
“Initial in-service testing with the Malargüe station shows excellent results.” “Our initial in-service testing with the Malargüe station shows excellent results,” says Roberto Maddè, ESA’s project manager for DSA 3 construction. “We have been able to quickly and accurately acquire signals from ESA and NASA spacecraft, and our station is performing better than specified.”
All three tracking stations are also equipped for radio science, which studies how matter, such as planetary atmospheres, affects the radio waves as they pass through. This can provide important information on the atmospheric composition of Mars, Venus or the Sun.
The tracking capability of all three ESA deep space stations also work in cooperation with partner agencies such as NASA and Japan’s JAXA, helping to boost science data return for all. The three Deep Space Antenna can be linked to the 7 stations comprising the Core Network as well as five other stations making up the larger Augmented Network and eleven additional stations that make up a global Cooperative Network with other space agencies from around the world.
Now that major construction is complete, teams are preparing DSA 3 for hand-over to operations, formal inauguration late this year and entry in routine service early in 2013.
Find out more about Malargüe and the Deep Space Antenna here and the other ESTRACK tracking stations here
Its massive gravitational field warping space, the huge elliptical galaxy A2261-BCG, seems to have a diffuse halo of stars instead of a bright central galactic core. Image credit: NASA/ESA Hubble
Bloated far beyond the size of normal galaxies, one or more black holes may have puffed up an elliptical galaxy to a whopping size, according to astronomers. To their surprise, however, the black holes are missing.
Normally, scientists measure a concentrated peak of light surrounding the central black hole surrounded by a fuzzy halo of stars. Instead, astronomers, using NASA’s Hubble Space Telescope, find that the galaxy, known as A2261-BCG, is just a diffuse, bloated foggy patch of light. The intensity of starlight remains even across the entire galaxy. Past Hubble observations show supermassive black holes, each weighing billions of times more than our Sun, reside at the cores of nearly all galaxies.
“Expecting to find a black hole in every galaxy is sort of like expecting to find a pit inside a peach,” explained astronomer and co-author Tod Lauer in a press release. Lauer is with the National Optical Astronomy Observatory in Tucson, Ariz. “With this Hubble observation, we cut into the biggest peach and we can’t find the pit. We don’t know for sure that the black hole is not there, but Hubble shows that there’s no concentration of stars in the core.”
So where are the black holes?
Astronomers, in a paper that appeared in the September 10 issue of The Astrophysical Journal, have two ideas, both involving galactic billiards, for the galaxy’s puffy appearance. In one scenario, a pair of merging black holes gravitationally stir up then scatter the galaxy’s stars. In another, the merging black holes are ejected leaving the swarm of stars with no gravitational anchor allowing them to wander outward.
Galaxy cores tend to be sized proportionally to the wheeling expanse of the host galaxy. In the case of A2261-BCG, which spans about a million light-years (10 times that of our Milky Way Galaxy), the central region is three times larger than other very luminous galaxies, according to the paper. The monster galaxy is the most massive and brightest galaxy in the Abell 2261 galaxy cluster.
Team leader Marc Postman of the Space Telescope Science Institute in Baltimore, Md., said in the press release that the galaxy stood out in the Hubble image. “When I first saw the image of this galaxy, I knew right away it was unusual,” Postman explained. “The core was very diffuse and very large. The challenge was then to make sense of all the data, given what we knew from previous Hubble observations, and come up with a plausible explanation for the intriguing nature of this particular galaxy.”
The team admits the ejected black-hole ideas sound far-fetched, “but that’s what makes observing the universe so intriguing — sometimes you find the unexpected,” said Postman.
As a follow-up, the team is searching for the sound of material falling into the black hole using the Very Large Array (VLA) radio telescope in New Mexico. Comparing the VLA data with Hubble images will allow the researchers to confirm the existence of a black hole and map its location.
Caption: Artist impression of Cheops. Credit: University of Bern
Big isn’t always better. This is certainly true at ESA’s new Science Programme. They are looking to low cost, small scale missions that can be rapidly developed, in order to offer greater flexibility in response to new ideas from the scientific community, to complement the broader Medium- and Large-class missions. Back in March ESA called for ideas for dedicated, quick-turnaround missions focusing on key issues in space science. From 26 proposals submitted, ESA has now approved a new mission to be launched in 2017. Though small in scale this mission is big on ambition: to search for nearby habitable planets.
Cheops stands for CHaracterising ExOPlanets Satellite. It has a planned mission lifetime of 3.5 years during which it will operate in a Sun-synchronous low-Earth orbit at an altitude of 800 km, free from distortion by Earth’s atmosphere. It will target nearby, bright stars already known to have planets orbiting around them.
By high-precision monitoring of the star’s brightness, Cheops will search for signs of a ‘transit’ as a planet passes across the star’s face, it will also be able to look for smaller planets, impossible to see using ground based telescopes, around those stars.
While NASA’s Kepler mission has confirmed 77 planets so far, with another 2,321 candidate planets, not one is close enough to Earth to be analysed in detail. Cheops on the other hand, will be able to take accurate measurements of the radius of the planet. For those planets with a known mass, this will reveal the planet’s density and provide an indication of the internal structure. It will help scientists understand the formation of planets from ‘super-Earths’, a few times the mass of the Earth, up to Neptune-sized worlds. It will also identify planets with significant atmospheres which can then be analysed for signs of life by ground-based telescopes, and the next generation of space telescopes now being built, such as the ground-based European Extremely Large Telescope and the NASA/ESA/CSA James Webb Space Telescope.
“By concentrating on specific known exoplanet host stars, Cheops will enable scientists to conduct comparative studies of planets down to the mass of Earth with a precision that simply cannot be achieved from the ground,” said Professor Alvaro Giménez-Cañete, ESA Director of Science and Robotic Exploration.
The plan is for Cheops to be the first of a series of similar small missions, that can be rapidly developed at low cost to investigate new scientific ideas quickly. Cheops will be developed as a partnership between ESA and Switzerland, with a number of other ESA Member States delivering substantial contributions.
Caption: Artist’s impression of ESA’s orbiting gamma-ray observatory Integral. Image credit: ESA
Integral, ESA’s International Gamma-Ray Astrophysics Laboratory launched ten years ago this week. This is a good time to look back at some of the highlights of the mission’s first decade and forward to its future, to study at the details of the most sensitive, accurate, and advanced gamma-ray observatory ever launched. But the mission has also had some recent exciting research of a supernova remnant.
Integral is a truly international mission with the participation of all member states of ESA and United States, Russia, the Czech Republic, and Poland. It launched from Baikonur, Kazakhstan on October 17th 2002. It was the first space observatory to simultaneously observe objects in gamma rays, X-rays, and visible light. Gamma rays from space can only be detected above Earth’s atmosphere so Integral circles the Earth in a highly elliptical orbit once every three days, spending most of its time at an altitude over 60 000 kilometres – well outside the Earth’s radiation belts, to avoid interference from background radiation effects. It can detect radiation from events far away and from the processes that shape the Universe. Its principal targets are gamma-ray bursts, supernova explosions, and regions in the Universe thought to contain black holes.
5 metres high and more than 4 tonnes in weight Integral has two main parts. The service module is the lower part of the satellite which contains all spacecraft subsystems, required to support the mission: the satellite systems, including solar power generation, power conditioning and control, data handling, telecommunications and thermal, attitude and orbit control. The payload module is mounted on the service module and carries the scientific instruments. It weighs 2 tonnes, making it the heaviest ever placed in orbit by ESA, due to detectors’ large area needed to capture sparse and penetrating gamma rays and to shield the detectors from background radiation in order to make them sensitive. There are two main instruments detecting gamma rays. An imager producing some of the sharpest gamma-ray images and a spectrometer that gauges gamma-ray energies very precisely. Two other instruments, an X-ray monitor and an optical camera, help to identify the gamma-ray sources.
During its extended ten year mission Integral has has charted in extensive detail the central region of our Milky Way, the Galactic Bulge, rich in variable high-energy X-ray and gamma-ray sources. The spacecraft has mapped, for the first time, the entire sky at the specific energy produced by the annihilation of electrons with their positron anti-particles. According to the gamma-ray emission seen by Integral, some 15 million trillion trillion trillion pairs of electrons and positrons are being annihilated every second near the Galactic Centre, that is over six thousand times the luminosity of our Sun.
A black-hole binary, Cygnus X-1, is currently in the process of ripping a companion star to pieces and gorging on its gas. Studying this extremely hot matter just a millisecond before it plunges into the jaws of the black hole, Integral has discovered that some of it might be escaping along structured magnetic field lines. By studying the alignment of the waves of high-energy radiation originating from the Crab Nebula, Integral found that the radiation is strongly aligned with the rotation axis of the pulsar. This implies that a significant fraction of the particles generating the intense radiation must originate from an extremely organised structure very close to the pulsar, perhaps even directly from the powerful jets beaming out from the spinning stellar core.
Just today ESA reported that Integral has made the first direct detection of radioactive titanium associated with supernova remnant 1987A. Supernova 1987A, located in the Large Magellanic Cloud, was close enough to be seen by the naked eye in February 1987, when its light first reached Earth. Supernovae can shine as brightly as entire galaxies for a brief time due to the enormous amount of energy released in the explosion, but after the initial flash has faded, the total luminosity comes from the natural decay of radioactive elements produced in the explosion. The radioactive decay might have been powering the glowing remnant around Supernova 1987A for the last 20 years.
During the peak of the explosion elements from oxygen to calcium were detected, which represent the outer layers of the ejecta. Soon after, signatures of the material from the inner layers could be seen in the radioactive decay of nickel-56 to cobalt-56, and its subsequent decay to iron-56. Now, after more than 1000 hours of observation by Integral, high-energy X-rays from radioactive titanium-44 in supernova remnant 1987A have been detected for the first time. It is estimated that the total mass of titanium-44 produced just after the core collapse of SN1987A’s progenitor star amounted to 0.03% of the mass of our own Sun. This is close to the upper limit of theoretical predictions and nearly twice the amount seen in supernova remnant Cas A, the only other remnant where titanium-44 has been detected. It is thought both Cas A and SN1987A may be exceptional cases
Christoph Winkler, ESA’s Integral Project Scientist says “Future science with Integral might include the characterisation of high-energy radiation from a supernova explosion within our Milky Way, an event that is long overdue.”
Find out more about Integral here
and about Integral’s study of Supernova 1987A here
The reddish object in this infrared image is ULASJ1234+0907, located about 11 billion light-years from Earth. The red color comes from vast amounts of dust, which absorbs bluer light, and obscures the supermassive black hole from view in visible wavelengths. Credit: image created using data from UKIDSS and the Wide-field Infrared Survey Explorer (WISE) observatory.
As if staring toward the edge of the Universe weren’t fascinating enough, scientists at the University of Cambridge say they see enormous, rapidly growing supermassive black holes barely detectable near the edge of time.
Thick dust shrouds the monster black holes but they emit vast amounts of radiation through violent interactions and collisions with their host galaxies making them visible in the infrared part of the electromagnetic spectrum. The team published their results in the journal Monthly Notices of the Royal Astronomical Society.
The most remote object in the study lies at a whopping 11 billion light-years from Earth. Ancient light from the supermassive black hole, named ULASJ1234+0907 and located toward the constellation of Virgo, the Maiden, has traveled (at almost 10 trillion kilometers, or 6 million million miles, per year) across the cosmos for nearly the estimated age of the Universe. The monster black hole is more than 10 billion times the mass of our Sun and 10,000 times more massive than the black hole embedded in the Milky Way Galaxy; making it one of the most massive black holes ever seen. And it’s not alone. Researchers say that there may be as many as 400 giants black holes in the tiny sliver of the Universe that we can observe.
“These results could have a significant impact on studies of supermassive black holes” said Dr Manda Banerji, lead author of the paper, in a press release. “Most black holes of this kind are seen through the matter they drag in. As the neighbouring material spirals in towards the black holes, it heats up. Astronomers are able to see this radiation and observe these systems.”
The team from Cambridge used infrared surveys being carried out on the UK Infrared Telescope (UKIRT) to peer through the dust and locate the giant black holes for the first time.
“These results are particularly exciting because they show that our new infrared surveys are finding super massive black holes that are invisible in optical surveys,” says Richard McMahon, co-author of the study. “These new quasars are important because we may be catching them as they are being fed through collisions with other galaxies. Observations with the new Atacama Large Millimeter Array (ALMA) telescope in Chile will allow us to directly test this picture by detecting the microwave frequency radiation emitted by the vast amounts of gas in the colliding galaxies.”
Huge black holes are known to reside at the centers of all galaxies. Astronomers predict the most massive of these cosmic phenomena grow through violent collisions with other galaxies. Galactic interactions trigger star formation which provides more fuel for black holes to devour. And it’s during this process that thick layers of dust hide the munching black holes.
“Although these black holes have been studied for some time,” says Banergi, “the new results indicate that some of the most massive ones may have so far been hidden from our view. The newly discovered black holes, devouring the equivalent of several hundred Suns every year, will shed light on the physical processes governing the growth of all supermassive black holes.”
Astronomers compare the extreme case of ULASJ1234+0907 with the relatively nearby and well-studied Markarian 231. Markarian 231, found just 600 million light-years away, appears to have recently undergone a violent collision with another galaxy producing an example of a dusty, growing black hole in the local Universe. By contrast, the more extreme example of ULASJ1234+0907, shows scientists that conditions in the early Universe were more turbulent and inhospitable than today.
Image Credit: Markarian 231, an example of a galaxy with a dusty rapidly growing supermassive black hole located 600 million light years from Earth. The bright source at the center of the galaxy marks the black hole while rings of gas and dust can be seen around it as well as “tidal tails” left over from a recent impact with another galaxy. Courtesy of NASA/ESA Hubble Space Telescope.
