Lifeboat Foundation

The James Webb Space Telescope was fuelled inside the payload preparation facility at Europe’s Spaceport in French Guiana ahead of its launch on Ariane 5.

Webb’s thrusters will use this propellant to make critical course-corrections after separation from Ariane 5, to maintain its prescribed orbit about one and a half million kilometers from Earth, and to repoint the observatory and manage its momentum during operations.

Fuelling any satellite is a particularly delicate operation requiring setup of the equipment and connections, fuelling, and then pressurization.

If someone told you that the world’s biggest laser was in California that has something to do with space and national defence, you might imagine it was a super-weapon designed to blast enemy satellites out of the sky. But the reality is quite different. The new laser is a unique research tool for scientists, capable of creating the extreme conditions that exist inside stars and nuclear explosions.

The giant laser is located at the Lawrence Livermore National Laboratory (LLNL) in Livermore, California, and it goes by the rather cryptic name of the National Ignition Facility (NIF). That’s because, in the context of nuclear science, “ignition” has a very specific meaning according to the Lawrence Livermore National Laboratory. It refers to the point at which a fusion reaction becomes self-sustaining – a condition that is found inside the sun and other stars, but is extremely difficult to achieve in an earthbound laboratory. Triggering nuclear fusion requires enormously high temperatures and pressures, and that’s where NIF’s giant laser comes in.

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.

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].

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.

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.

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 human brain 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.

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.

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.