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Archive for the ‘satellites’ category: Page 67

Dec 6, 2021

Quantum processor swapped in for a neural network

Posted by in categories: climatology, quantum physics, robotics/AI, satellites

To handle this, people have trained neural networks on regions where we have more complete weather data. Once trained, the system could be fed partial data and infer what the rest was likely to be. For example, the trained system can create a likely weather radar map using things like satellite cloud images and data on lightning strikes.

This is exactly the sort of thing that neural networks do well with: recognizing patterns and inferring correlations.

What drew the Rigetti team’s attention is the fact that neural networks also map well onto quantum processors. In a typical neural network, a layer of “neurons” performs operations before forwarding its results to the next layer. The network “learns” by altering the strength of the connections among units in different layers. On a quantum processor, each qubit can perform the equivalent of an operation. The qubits also share connections among themselves, and the strength of the connection can be adjusted. So, it’s possible to implement and train a neural network on a quantum processor.

Dec 3, 2021

Gaia EDR3 proper motions of Milky Way dwarfs. II: Velocities, Total Energy and Angular Momentum

Posted by in categories: energy, satellites

Abstract: Here we show that precise Gaia EDR3 proper motions have provided robust estimates of 3D velocities, angular momentum and total energy for 40 Milky Way dwarfs. The results are statistically robust and are independent of the Milky Way mass profile. Dwarfs do not behave like long-lived satellites of the Milky Way because of their excessively large velocities, angular momenta, and total energies. Comparing them to other MW halo population, we find that many are at first passage, $\le$2 Gyr ago, i.e., more recently than the passage of Sagittarius, $\sim$4–5 Gyr ago. We suggest that this is in agreement with the stellar populations of all dwarfs, for which we find that a small fraction of young stars cannot be excluded. We also find that dwarf radial velocities contribute too little to their kinetic energy when compared to satellite systems with motions only regulated by gravity, and some other mechanism must be at work such as ram pressure. The latter may have preferentially reduced radial velocities when dwarf progenitors entered the halo until they lost their gas. It could also explain why most dwarfs lie near their pericenter. We also discover a novel large scale structure perpendicular to the Milky Way disk, which is made by 20% of dwarfs orbiting or counter orbiting with the Sagittarius dwarf.

From: Francois Hammer [view email].

Dec 3, 2021

NASA’S TESS Spots Planet On Incredibly Short 7.7-Hour Stellar Orbit

Posted by in categories: satellites, sustainability

An international team of astronomers using NASA’s Transiting Exoplanet Survey Satellite (TESS) has detected a rocky planet, about half the mass of Earth, in an extraordinarily short 7.7-hour orbit around its parent star.

It’s a reminder that the science of extrasolar planet hunting seems to enter bizarro land with each new discovery. Planetary scientists still haven’t figured out how our own tiny Mercury — which orbits our Sun once every 88 days — actually formed and evolved. So, this iron-rich ultrashort-period (USP) planet, dubbed GJ 367b should really boggle their minds.

It’s completely rocky, unlike most previously detected gaseous hot Jupiters on extremely short stellar orbits. As a result, the tiny planet is estimated to have a surface with temperatures of 1,500 degrees Celsius, hot enough to melt iron; hardly an Earth 2.0.

Dec 2, 2021

SpaceX Is Planning on Bringing Space-Based Internet Service to Aircraft

Posted by in categories: internet, satellites

They plan to offer internet to airlines ‘as soon as possible.’

A SpaceX representative said on Tuesday that the company is testing its ability to provide inflight broadband access to aircraft, according to a report by Bloomberg. VP Jonathan Hofeller told a crowd at the Airline Passenger Experience Association Expo in Long Beach, California, that it will begin offering its services to airlines “as soon as possible.”

A sky-high opportunity SpaceX will join a crowded field of companies competing to service the in-flight wifi market, which is worth about $3.3 billion per year, according to one estimate. Commercial aircraft have conventionally connected to the internet either through cell towers on the ground or through large satellites in geosynchronous orbit. For example, industry leader ViaSat Inc. operates one satellite over the U.S. and a second satellite that covers most of Canada, the North Atlantic, and parts of Europe. Surprisingly, the company has contracted SpaceX to launch a third satellite next year.

Nov 30, 2021

New discovery opens the way for brain-like computers

Posted by in categories: drones, mobile phones, particle physics, robotics/AI, satellites

Research has long strived to develop computers to work as energy efficiently as our brains. A study, led by researchers at the University of Gothenburg, has succeeded for the first time in combining a memory function with a calculation function in the same component. The discovery opens the way for more efficient technologies, everything from mobile phones to self-driving cars.

In recent years, computers have been able to tackle advanced cognitive tasks, like language and image recognition or displaying superhuman chess skills, thanks in large part to artificial intelligence (AI). At the same time, the is still unmatched in its ability to perform tasks effectively and energy efficiently.

“Finding new ways of performing calculations that resemble the brain’s energy-efficient processes has been a major goal of research for decades. Cognitive tasks, like image and voice recognition, require significant computer power, and mobile applications, in particular, like mobile phones, drones and satellites, require energy efficient solutions,” says Johan Åkerman, professor of applied spintronics at the University of Gothenburg.

Nov 30, 2021

‘A revolution’: China may be first with global laser satellite network

Posted by in category: satellites

China has conducted a pioneering high-speed communication experiment using lasers, rather than the usual radio signals, between satellites in its BeiDou navigation system and ground stations on Earth.


Technology could potentially transmit data a million times faster than by radio signal to almost any location.

Nov 30, 2021

NASA Postpones Astronauts’ Spacewalk Due To Risk From Debris

Posted by in categories: military, satellites

It feels a bit like a headline ripped from the plotline of the 2013 flick “Gravity” — NASA astronauts suddenly find themselves having to worry more about the threat of space debris whipping around Earth at over 17,000 miles per hour.

Just two weeks after the current crew of the International Space Station had to take emergency shelter in the Russian Soyuz and SpaceX Crew Dragon capsules that are docked to the ISS, NASA has now postponed a planned spacewalk because of the threat.

One source of the increased threat is Russia’s recent anti-satellite missile test that created hundreds, if not thousands, of new pieces of debris in low-earth orbit. On November 15 it was reported that Russia blasted one of its own defunct satellites to smithereens, a move that drew global condemnation.

Nov 29, 2021

SpaceX drone ship heads to sea for record-breaking Starlink launch

Posted by in categories: drones, internet, military, satellites

SpaceX’s newest drone ship is on its way out into the Atlantic Ocean for a Starlink mission that will break the company’s record for annual launch cadence.

Somewhat confusing known as Starlink Shell 4 Launch 3 or Starlink 4–3, the batch of 53 laser-linked V1.5 satellites is scheduled to fly before Starlink 4–2 for unknown reasons and at the same time as Starlink 2–3 is scheduled to fly before Starlink 2–2 on the West Coast. Regardless of the seemingly unstable launch order, perhaps related to the recent introduction of Starlink’s new V1.5 satellite design, drone ship A Shortfall of Gravitas’ (ASOG) November 27th Port Canaveral confirms that SpaceX is more or less on track to launch Starlink 4–3 no earlier than (NET) 6:20 pm EST (23:20 UTC) on Wednesday, December 1st.

In a bit of a return to stride after launching 20 times in the first six months but only three times in the entire third quarter of 2021, Starlink 4–3 is currently the first of four or even five SpaceX launches scheduled in the last month of the year. Nevertheless, if Starlink 4–3 is successful, it will also set SpaceX up to cross a milestone unprecedented in the history of satellite launches.

Nov 27, 2021

Trees found to reduce land surface area temperatures in cities up to 12°C

Posted by in categories: climatology, satellites

A team of researchers with the Institute for Atmospheric and Climate Science, ETH Zurich, has found evidence that indicates that stands of trees can reduce land surface area temperatures in cities up to 12°C. In their paper published in the journal Nature Communications, the group describes how they analyzed satellite imagery for hundreds of cities across Europe and what they learned.

Prior research has suggested that adding to cities can help reduce high air temperatures during the warm months—cities are typically hotter than surrounding areas due to the huge expanses of asphalt and cement that absorb heat. In this new effort, the researchers looked at possible impacts on land surface areas instead of air temperatures. Such temperatures are not felt as keenly as air temperatures by people in the vicinity because it is below their feet rather than surrounding them.

The work by the team involved analyzing data from satellites equipped with land surface temperature sensors. In all, the researchers poured over data from 293 cities across Europe, comparing land surface temperatures in parts of cities that were covered with trees with similar nearby urban areas that were not covered with trees. For comparison purposes, they did the same for rural settings covered in pastures and farmland.

Nov 27, 2021

ESA’s Solar Orbiter Spacecraft Is Skimming Earth for a Gravity Assist — And It’s One of the Riskiest Planetary Flybys Ever

Posted by in categories: energy, satellites

The chance that ESA’s Solar Orbiter spacecraft will encounter space debris during its upcoming Earth flyby is very, very low. However, the risk is not zero and is greater than any other flyby ESA has performed. That there is this risk at all highlights the mess we’ve made of space – and why we need to take action to clean up after ourselves.

On November 27, after a year and eight months flying through the inner Solar System, Solar Orbiter will swing by home to ‘drop off’ some extra energy. This will line the spacecraft up for its next six flybys of Venus.

Continue reading “ESA’s Solar Orbiter Spacecraft Is Skimming Earth for a Gravity Assist — And It’s One of the Riskiest Planetary Flybys Ever” »

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