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This estimated $8 billion procurement, known as Evolved Strategic Satcom (ESS), will supplement and eventually replace the existing Advanced Extremely High Frequency (AEHF) satellite constellation. The new system will provide critical jam-resistant communication channels for the National Command Authorities and deployed forces worldwide, even in the North Polar region – a capability lacking in the current system.

Join our newsletter to get the latest military space news every Tuesday by veteran defense journalist Sandra Erwin.

Under the agreement, Agile Space — based in Durango, Colorado — will supply the main engines, attitude control thrusters, propellant tanks, and other critical propulsion components for True Anomaly’s spacecraft.

Gravitics, which develops modules for commercial space stations, will work on tactically responsive space applications for the U.S. Space Force.

Solar Cycle 25 is about to hit its peak, making this an important time to increase space weather monitoring.

WASHINGTON — Russia, as expected, vetoed April 24 a United Nations Security Council resolution crafted in response to reports that the country was developing a nuclear anti-satellite weapon.

Russia cast the only vote against the draft resolution that reaffirmed provisions in the Outer Space Treaty prohibiting the placement of nuclear weapons or other weapons of mass destruction in space. Thirteen other members of the Security Council voted in favor of the resolution while China abstained. As a permanent member of the Security Council, though, Russia’s vote acted as a veto preventing adoption of the resolution.

Japan and the United States drafted the Security Council resolution, which they billed as the first devoted to outer space issues. The resolution directed members to uphold Article 4 of the Outer Space Treaty, which forbids countries from placing nuclear weapons in orbit or on celestial bodies. It also called on countries not to develop nuclear weapons or other weapons of mass destruction specifically designed to be placed in orbit.

In this study, we leverage wavelet-based bispectral analysis of magnetic fluctuation data to identify likely candidates for nonlinear three-wave coupling, which are subsequently investigated with bandpass filtering. The participating waves, two TAEs and a low-frequency magnetohydrodynamic (MHD) mode, are seen to satisfy coupling conditions in both frequency and toroidal wavenumber, consistent with nonlinear generation. We conclude that the detection of quadratic nonlinearities on sub-millisecond time scales is possible with this technique.

The paper is organized as follows: Sec. II provides an overview of the relevant theory of TAE, while Sec. III contextualizes the experiment and describes its data. Section IV provides a primer on bicoherence analysis, in addition to simple examples of its implementation. Section V applies time-resolved bispectral analysis to the experimental data, focusing on the detection of quadratic nonlinearities. Section VI summarizes our work and considers the next steps of the analysis.

With the continual miniaturization of electronic devices, there is an urgent need to understand the electron emission and the mechanism of electrical breakdown at nanoscale. For a nanogap, the complete process of the electrical breakdown includes the nano-protrusion growth, electron emission and thermal runaway of the nano-protrusion, and plasma formation. This review summarizes recent theories, experiments, and advanced atomistic simulation related to this breakdown process. First, the electron emission mechanisms in nanogaps and their transitions between different mechanisms are emphatically discussed, such as the effects of image potential (of different electrode’s configurations), anode screening, electron space-charge potential, and electron exchange-correlation potential. The corresponding experimental results on electron emission and electrical breakdown are discussed for fixed nanogaps on substrate and adjustable nanogaps, including space-charge effects, electrode deformation, and electrical breakdown characteristics. Advanced atomistic simulations about the nano-protrusion growth and the nanoelectrode or nano-protrusion thermal runaway under high electric field are discussed. Finally, we conclude and outline the key challenges for and perspectives on future theoretical, experimental, and atomistic simulation studies of nanoscale electrical breakdown processes.

The double-cone ignition scheme is a novel approach with the potential to achieve a high gain fusion with a relatively smaller drive laser energy. To optimize the colliding process of the plasma jets formed by the CHCl/CD shells embedded in the gold cones, an x-ray streak camera was used to capture the spontaneous x-ray emission from the CHCl and CD plasma jets. High-density plasma jets with a velocity of 220 ± 25 km/s are observed to collide and stagnate, forming an isochoric plasma with sharp ends. During the head-on colliding process, the self-emission intensity nonlinearly increases because of the rapid increase in the density and temperature of the plasma jets. The CD colliding plasma exhibited stronger self-emission due to its faster implosion process. These experimental findings effectively agree with the two-dimensional fluid simulations.

This article is part of a series of pieces on advances in sustainable battery technologies that Physics Magazine is publishing to celebrate Earth Week 2024. See also: Q&A: Electrochemists Wanted for Vocational Degrees; Research News: Lithium-Ion “Traffic Jam” Behind Reduced Battery Performance; Q&A: The Path to Making Batteries Green; News Feature: Sodium Batteries as a Greener Lithium Substitute.

Since the first prototype made its debut in 2000, rechargeable magnesium batteries have continued to be both technologically attractive and commercially out of reach. The attraction arises from magnesium’s advantages over lithium: it is 1,000 times more abundant in Earth’s crust and is chemically less hazardous. The unrealized commercialization is largely down to the difficulty in identifying a material to serve as an effective and robust cathode. Tomoya Kawaguchi of Tohoku University in Japan and his collaborators may now have solved that problem through their demonstration of a material that satisfies one of the most important requirements of a good cathode: it can reversibly accept and release ions over repeated charging cycles [1].

The discharge of an electrochemical battery releases electrons that flow through the connected circuit. It also releases ions from the battery’s anode that flow through the battery’s electrolyte, in the opposite direction to the electrons, and then lodge in the cathode. The flows reverse directions during recharging. In a lithium-ion battery, the cathode is made from a lithium oxide and takes the form of either a layered material or a crystalline solid known as a spinel.