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The absence of piezoelectricity in silicon makes direct electromechanical applications of this mainstream semiconductor impossible. Integrated electrical control of the silicon mechanics, however, would open up new perspectives for on-chip actuorics. Here, we combine wafer-scale nanoporosity in single-crystalline silicon with polymerization of an artificial muscle material inside pore space to synthesize a composite that shows macroscopic electrostrain in aqueous electrolyte. The voltage-strain coupling is three orders of magnitude larger than the best-performing ceramics in terms of piezoelectric actuation. We trace this huge electroactuation to the concerted action of 100 billions of nanopores per square centimeter cross section and to potential-dependent pressures of up to 150 atmospheres at the single-pore scale. The exceptionally small operation voltages (0.4 to 0.9 volts), along with the sustainable and biocompatible base materials, make this hybrid promising for bioactuator applications.

An electrochemical change in the oxidation state of polypyrrole (PPy) can increase or decrease the number of delocalized charges in its polymer backbone (1). Immersed in an electrolyte, this is also accompanied by a reversible counter-ion uptake or expulsion and thus with a marcroscopic contraction or swelling under electrical potential control, making PPy one of the most used artificial muscle materials (1–5).

Here, we combine this actuator polymer with the three-dimensional (3D) scaffold structure of nanoporous silicon (6–8) to design, similarly as found in many multiscale biological composites in nature (9), a material with embedded electrochemical actuation that consists of a few light and abundant elemental constituents (i.e., H, C, N, O, Si, and Cl).

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The crusts of the Moon, Mercury, and many meteorite parent bodies are magnetized. Although the magnetizing field is commonly attributed to that of an ancient core dynamo, a longstanding hypothesized alternative is amplification of the interplanetary magnetic field and induced crustal field by plasmas generated by meteoroid impacts. Here, we use magnetohydrodynamic and impact simulations and analytic relationships to demonstrate that although impact plasmas can transiently enhance the field inside the Moon, the resulting fields are at least three orders of magnitude too weak to explain lunar crustal magnetic anomalies. This leaves a core dynamo as the only plausible source of most magnetization on the Moon.

The Moon presently lacks a core dynamo magnetic field. However, it has been known since the Apollo era that the lunar crust contains remanent magnetization, with localized surface fields reaching up to hundreds of nanoteslas or higher and spanning up to hundreds of kilometers (1). Magnetic studies of Apollo samples and the lunar crust indicate that the magnetizing field likely reached tens of microteslas before 3.56 billion years (Ga) ago (1, 2). The origin of the strongest lunar crustal anomalies and the source of the field that magnetized them have been longstanding mysteries.

Although magnetic fields in rocky bodies are commonly explained by convective dynamos in their metallic cores, a convective dynamo on the Moon may not have had sufficient energy to produce the strongest implied surface paleofields (3, 4). This may imply that a fundamentally different nonconvective dynamo mechanism operated in the Moon or that a process other than a core dynamo produced such magnetization.

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SpaceX is developing a new satellite bus for the Space Development Agency based on the Starlink design.

WASHINGTON — The Space Development Agency awarded SpaceX a $149 million contract and L3Harris a $193.5 million contract to each build four satellites to detect and track ballistic and hypersonic missiles.

The contracts announced Oct. 5 are for the first eight satellites of a potentially much larger Space Development Agency constellation of sensor satellites known as Tracking Layer Tranche 0. This is SpaceX’s first military contract to produce satellites.

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The U.S. #military, like many others around the world, is investing significant time and resources into expanding its electronic #warfare capabilities across the board, for offensive and defensive purposes, in the air, at sea, on land, and even in space. Now, advances in #machinelearning and #artificialintelligence mean that electronic warfare systems, no matter what their specific function, may all benefit from a new underlying concept known as advanced “Cognitive Electronic Warfare,” or #Cognitive EW. The main goal is to be able to increasingly automate and otherwise speed up critical processes, from analyzing electronic intelligence to developing new electronic warfare measures and countermeasures, potentially in real-time and across large swathes of networked platforms.

The holy grail of this concept is electronic warfare systems that can spot new or otherwise unexpected threats and immediately begin adapting to them.

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SkyWatch Space Applications, the Canadian startup whose EarthCache platform helps software developers embed geospatial data and imagery in applications, announced a partnership Oct. 5 with Picterra, a Swiss startup with a self-service platform to help customers autonomously extract information from aerial and satellite imagery.

“One of the things that has been very difficult to achieve is this ability to easily and affordably access satellite data in a way that is fast but also in a way in which you can derive the insights you need for your particular business,” James Slifierz, SkyWatch CEO told SpaceNews. “What if you can merge both the accessibility of this data with an ease of developing and applying intelligence to the data so that any company in the world could have the tools to derive insights?”

SkyWatch’s EarthCache platform is designed to ease access to aerial and satellite imagery. However, SkyWatch doesn’t provide data analysis.

Picterra is not a data provider. Instead, the company helps customers build their own machine-learning algorithms to detect things like building footprints in imagery customers either upload or find in Picterra’s library of open-source imagery.

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