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Everything posted by European Space Agency
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Video: 00:02:42 After a remarkable life in orbit, Aeolus is out of fuel and out of time – it’s returning to Earth this week. Planned and built before any regulations were put in place on ‘end-of-life’ disposal, the Earth Explorer was designed to naturally return through our atmosphere. After months of detailed planning and analysis, ESA together with industrial partners has designed a complex and never-before-performed set of manoeuvres to control, as much as possible, Aeolus’ fall. The assisted reentry attempt is built on four main phases, now begun at ESA’s mission control: Phase I: once Aeolus has fallen naturally to 280 km, the first manoeuvre is performed – the largest in the mission’s five years in orbit. The main objectives are to lower the satellite down to 250 km and to check how the satellite behaves when executing a large manoeuvre at such low altitudes – more than three times the size of any performed during routine operations. Phase II: after three to five days, a series of four manoeuvres will lower Aeolus’s ‘perigee altitude’ – the point in orbit closest to Earth – down to an altitude of about 150 km. Phase III: a final manoeuvre will lower [LJ1] Aeolus to a perigee altitude of 120 km. Phase IV: in the final, shortest phase, Aeolus the spacecraft becomes space debris, completing its final descent in just a few Earth revolutions. In this animation, round regions temporarily lit up in bright green show the moments that Aeolus is in contact with antennas on Earth. It is in these periods that mission control is in touch with the satellite and can send up commands and get its data down. Aeolus is repeatedly turned, or ‘slewed’ by 180° in order to switch from the routine orientation (or ‘attitude’), in which the satellite’s ‘X-band’ antenna points toward Earth and the GPS can function to track the mission – crucial to maintaining knowledge of its position – and the ‘retrograde’ attitude. This second, ‘upside down’ position is necessary for the thrusters to fire in the opposite direction to Aeolus’s flight direction, causing it to lose energy and lower in orbit. While the ultimate goal is for the spacecraft to burn up as it reenters through the atmosphere, teams need to keep it functioning long enough that they can continue to send up commands and control it on its path. After the final commands are sent, Aeolus will be ‘passivated’. Passivation is when any energy onboard a spacecraft is removed, for example, its propellant or batteries. Doing this prevents explosions and fragmentation events, that could cause the release of lots of pieces of unwanted space debris. For Aeolus, already out of fuel, it will simply be turned off. After this point, teams at mission control will continue to monitor the situation until Aeolus’s ultimate reentry location is confirmed. For rolling updates on Aeolus's reentry, follow ‘Aeolus reentry: live’ on the Rocket Science blog. Music: Yesterday’s Hero by Steve Rothery, published by Tunecore. Used with permission of Steve Rothery. View the full article
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On 10 July 2023, a volcano some 30 km from Iceland’s capital, Reykjavik, erupted following heightened seismic activity in the area. Satellites orbiting above us have captured the molten lava and smoke plume puffing from the Litli-Hrútur volcano. View the full article
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Globally, more than 70% of the freshwater withdrawn from Earth’s surface or from underground is used to irrigate crops. The need to produce more food for a growing population against the backdrop of climate change is challenging enough, but satellites reveal that extracting water doesn’t just affect the local environment – there are knock-on consequences for many aspects of the Earth system. View the full article
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New measurements by the NASA/ESA/CSA James Webb Space Telescope’s Mid-InfraRed Instrument (MIRI) has detected water vapour in the inner disc of the system PDS 70, located 370 light-years away. This is the first detection of water in the terrestrial region of a disc already known to host two or more protoplanets. View the full article
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Image: New Galileo station goes on duty View the full article
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Week in images: 17-21 July 2023 Discover our week through the lens View the full article
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Video: 00:05:00 ESA’s wind mission Aeolus is coming home. After five years of improving weather forecasts, the satellite will return in a first-of-its-kind assisted reentry. At ESA’s Space Operations Centre in Germany, mission control will use the satellite’s remaining fuel to steer Aeolus during its return to Earth. Find out more about the mission, its successes and how Aeolus is paving the way for safe reentries. View the full article
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Image: This Copernicus Sentinel-2 image highlights the colours of autumn over the southern part of New York state in the US. View the full article
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Astronomers using the NASA/ESA/ Hubble Space Telescope’s extraordinary sensitivity have discovered a swarm of boulders that were possibly shaken off the asteroid Dimorphos when NASA deliberately slammed the half-tonne DART impactor spacecraft into Dimorphos at approximately 22 500 kilometres per hour. DART intentionally impacted Dimorphos on 26 September 2022, slightly changing the trajectory of its orbit around the larger asteroid Didymos. View the full article
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Image: 3D-printed bend-based mechanism View the full article
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The Italian region of Emilia-Romagna was devastated by severe floods in May 2023, claiming lives and displacing thousands of people, resulting in an estimated €8.8 billion in damages. With the region still grappling with the aftermath, satellites have been instrumental in assessing the damages of the affected areas. View the full article
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Image: Dividing Earth and Moon View the full article
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For the first time, the NASA/ESA/CSA James Webb Space Telescope has observed the chemical signature of carbon-rich dust grains at redshift ~ 7 [1], which is roughly equivalent to one billion years after the birth of the Universe [2]. Similar observational signatures have been observed in the much more recent Universe, attributed to complex, carbon-based molecules known as polycyclic aromatic hydrocarbons (PAHs). It is not thought likely, however, that PAHs would have developed within the first billion years of cosmic time. View the full article
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Video: 00:45:00 After completing its mission in orbit, ESA’s wind mission Aeolus will soon reenter Earth's atmosphere. Currently orbiting 320 km above, Aeolus is being kept in orbit with its remaining fuel. This fuel is running out, and the satellite will soon succumb to Earth’s atmosphere and gravity. Going above and beyond what the satellite was technically designed to do, ESA is attempting a first-of-its-kind assisted reentry to reduce the (already very small) risk of damage from any fragments that survive the journey and reach the ground. ESA held an online media briefing on 19 July 2023 to explain more about this assisted approach and answer questions. View the full article
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ESA's Mars Express has revisited an old favourite: the distinctive and fascinating Mawrth Vallis, one of the most promising locations on Mars in our search for signs of life. View the full article
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Fuelled largely by climate change, our planet is being subjected to environmental changes that are having an unprecedented global impact on humans, animals and plants. Shockingly, in certain locations these changes are occurring at a rate never before witnessed. To keep pace with the challenges we face, ESA is embarking on a new Earth observation science strategy – and has reached out to the scientific community at this early stage in the process to help guide the Agency’s scientific agenda for the coming years. View the full article
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Week in images: 10-14 July 2023 Discover our week through the lens View the full article