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Heidelberg Materials UK has set up a concrete batching plant at the Sizewell C nuclear site in Suffolk. A batching plant is a small factory that mixes concrete to order. This is the first one on site, and it makes nuclear-grade concrete.

Its first job is the cut-off wall, a watertight barrier around the edge of the site. Once it is in, about 4 million cubic metres of earth can be dug out for the two reactors. Heidelberg says it was the first UK company certified to make nuclear-grade concrete. It worked with the nuclear regulator on its quality and safety paperwork. It had more than 80 staff at Hinkley Point C at peak, and says Sizewell could reach 200.

On most British lines, drivers still read signals beside the track. ETCS (the European Train Control System) sends that information to a screen in the driver's cab instead.

This week, Grand Central's Class 180 trains became the first of their class approved to run with ETCS. Alstom fitted the kit to the fleet, which is owned by Angel Trains. Next come software updates, then a target of 50,000 miles (about 80,000 km) of fault-free running, starting in December. Digitally signalled trains between Welwyn and Hitchin, on the East Coast Main Line, are planned for spring 2027.

On 30 August, a fuel assembly tipped over inside the reactor at the Palisades nuclear plant in Michigan. An assembly is a bundle of fuel rods moved as one unit. It leaned at about 30°. Its bottom stayed in place and its top rested against the core shroud, the wall around the reactor core. Getting it out needed a purpose-built tool.

The plant's owner, Holtec, designed a custom lifting device and a special transfer canister. Crews lifted the assembly into the canister, sealed the lid in the reactor cavity, then moved it to the spent fuel pool. Holtec says the tool took about two weeks to design, make and deliver. The US regulator approved the method through a licence change. The plant still has to load fuel and pass tests before it can restart.

Most hydrogen today is made from natural gas, and the process gives off CO₂. Catching that CO₂ is hard when it is mixed with other gases.

Chemical engineers at the University of Manchester modelled another route, called chemical looping reforming. Solid particles carry oxygen to the natural gas, so the CO₂ comes out concentrated and easier to capture. In their models, the process reached up to 75% thermal efficiency and captured 90% to 99% of the CO₂, depending on the design. They modelled a 2 MW plant and a 600 MW one, and compared them with other low-carbon routes, including electrolysis. No plant has been built, no costs were given, and it still starts from fossil gas.

Last Thursday night (15 October), at SpaceX's rocket test site in McGregor, Texas, Tesla showed a prototype of its long-delayed Roadster. It drove up a curved ramp until it was upside down, launched off the end, flipped in mid-air and landed on its wheels. Then it hopped over a row of parked Teslas. Nobody was inside: Musk said automated controls did the driving.

Two tricks do the work. Electric fans under the car suck air out from beneath it, pressing it onto the surface (Tesla says up to 2 g, enough to hold it on an upside-down ramp). And cold-gas thrusters, borrowed from SpaceX, blow highly compressed gas through nozzles and burn no fuel. The top "Rocket" version has 10 nozzles and about 600 litres of tanks, and takes six to seven hours to refill. Tesla claims 0 to 60 mph in 0.81 seconds on a thruster-assisted run: about 3.4 g on average. None of this has been independently tested, the Rocket version isn't road-legal, and Musk now targets production in 2028. The car was first promised for 2020.

Big offshore wind farms far out at sea often send their power ashore as high-voltage direct current (HVDC), which loses less energy over long distances. The cables are specialist kit.

On 19 October, Japan's Sumitomo Electric opened what is said to be the UK's first factory for HVDC subsea cables. It is at the Port of Nigg in the Scottish Highlands. The £350m site covers 15 hectares. It will make 525 kV cables with XLPE insulation (cross-linked polyethylene, a tough plastic), plus the cables that link turbines to each other. The company expects more than 200 jobs on site. Some staff train in Japan, then train others.

Every conductor gives off faint electrical noise, because heat makes its electrons jiggle. Engineers usually try to filter this thermal noise out. A team at Stanford University used it to send data.

Their transmitter switches its antenna between two states. In one, it absorbs the noise around it. In the other, it reflects it. The receiver sees slightly "hotter" or "colder" noise and reads that as 1s and 0s. The transmitter sends no signal of its own. The team says a normal radio transmitter can use up to 1,000 times more energy. So far it only works inside an insulated lab chamber, and no data rate or range was given. The paper is in PNAS.

Acrylic glass, sold as Plexiglas or Perspex, is usually recycled by heating it above 400 °C until it breaks down. What comes out contains up to 3% impurities.

Chemists at ETH Zurich in Switzerland found a gentler route. They add one cheap chemical that is already on sale. It starts the long polymer chains "unzipping" back into monomer, the small building block they were made from. Once started, the reaction keeps going by itself, with no solvent, from just over 200 °C. Up to 98% comes back as monomer. Plastic made from it is as good as new, even when the waste was dyed or dirty. The paper is in Nature Chemistry, and ETH is looking for companies to take it further.

Sodium-ion batteries use sodium instead of lithium. Sodium is cheaper and easier to find. They need better cathodes, the positive electrode.

At the University of Surrey, two postgraduate researchers made 28 versions of a sodium manganese oxide cathode. In each, some of the manganese was swapped for iron, titanium or vanadium. Iron raised capacity. Vanadium helped the cells last more charge cycles. A little titanium helped at fast charging. Some titanium versions kept over 90% of their capacity after 100 cycles. The results trained a machine-learning model, though the authors say 28 recipes is too few for reliable predictions yet.

On Monday evening UK time, Japan's H3 rocket launched MMX (Martian Moons eXploration). The plan: land on Phobos, the larger of Mars's two moons, collect at least 10 g of its surface and return it to Earth in 2031.

The 4,480 kg spacecraft carries two different samplers. One is a corer on an arm that drills more than 2 cm down. The other, supplied by NASA, uses gas to push loose material into a container. It also carries IDEFIX, a 25 kg rover built by the French and German space agencies. Gravity on Phobos is so weak that the rover would weigh about as much as 15 g does on Earth. MMX should reach Mars in August 2027.

BETA Technologies' ALIA A250 is a battery-powered aircraft that takes off and lands vertically. This week it became the first eVTOL (electric vertical take-off and landing aircraft) to get a US Federal Aviation Administration certificate for market surveys. That lets BETA fly it with possible customers and operators.

On 20 October it flew 63 km (34 nautical miles) in 20 minutes, from Plattsburgh, New York, to Burlington, Vermont. It can carry up to five passengers or more than 540 kg (1,200 lb) of cargo. This is not full certification, so it can't yet run a passenger service.

Agility Robotics builds Digit, a two-legged robot for warehouses. In an essay for IEEE Spectrum, co-founder Jonathan Hurst explained why Digit 5 was redesigned from scratch: to work safely next to people.

Digit 5 weighs over 120 kg and lifts 23 kg bins onto shelves 1.75 m high, again and again. If a person comes close, it stops, puts the load down, sits on the floor and cuts power to its motors. Safety-rated sensors and separate safety computers keep watch. Batteries and cooling fill about 75% of its torso. It runs for about 90 minutes, then recharges in 9. The trade-off: it can no longer run or jump, and it is the heaviest and most expensive Digit yet.

Reinforcement learning trains a robot by trial and error, usually in a simulation. But it gives no promise the robot will stay stable when the real world differs from the model. A part that weighs 1 kg in the simulation might really weigh 1.2 kg.

Aerospace engineers at the University of Illinois Urbana-Champaign added that promise. Their method, called CARL, sets a mathematical limit on how far a robot can drift from its planned path. They tried it on a wheeled robot, a flapping drone and a six-legged robot. It followed paths up to 15% more closely than existing methods. The paper is in IEEE Transactions on Robotics, and the code is free online.

Muscles give off small electrical signals when they move. Many prosthetic arms pick these up with sensors on the skin. Some of those need recalibrating every day, says US company Phantom Neuro.

Phantom Neuro puts its sensor under the skin instead. It is a flexible silicone strip, 2 cm by 10 cm, with two rows of electrodes. It sends the signals out wirelessly and gets its power from a coil outside the body, like a cochlear implant. Surgeons in Melbourne have fitted it in two patients. The first operation was about five months before the 20 October announcement. The second operation took about 45 minutes. The arm can't yet combine moves, such as turning the wrist while moving the fingers, and outside experts told IEEE Spectrum they want more data.

Engineers at the National University of Singapore made a touchscreen out of fibres, then wove 54 of them into a sleeve.

Each fibre is about 1 mm thick and holds a row of 96 tiny LEDs, with a touch layer underneath. Together they make a 96 × 54-pixel screen, 168 mm by 105 mm, that plays video at 30 frames a second. It took more than 5,000 chips and 20,000 electrical connections. It worked almost as well after 50 washes with detergent and 1,000 tight bends. The resolution is low, and so far there is one prototype. The paper is in Nature.