What Stoke Space says: its first vehicle and the larger Nova Block 2 both use stainless steel skin-and-stringer construction, which it says needs almost no fixed tooling. The reusable upper stage re-enters behind an actively cooled metallic base heat shield with liquid hydrogen flowing through it, which Stoke's article contrasts with passive ceramic tiles. Block 2 is quoted at 15 t to low Earth orbit in a fully reusable configuration, and the page says Nova can deliver more than 4 t to GTO (it names no block and no reuse mode). Pathfinder flies seven Zenith engines; its first flight is planned for the first part of 2027 and Block 2's for 2029.
Why it matters for materials: a cooled metal shield replaces a ceramic insulator with plumbing, so the open question is how the metal and its cooling passages survive repeated re-entry heating, thermal stress and fatigue.
Our take: this is an architecture announcement from the company. No alloy grade, temperatures or reuse life are given, the heat-shield metal is not named, and the comparison with tiles is one-sided and unsourced. Almost no fixed tooling and all flight dates are company claims or targets. For context, our type 301 stainless page (Stoke names no stainless grade) lists a thermal conductivity of 16.3 W/m-K at 20 to 100 °C (annealed, ATI), while our CuCrZr page lists about 320 W/m-K for a copper alloy at 20 °C (Luvata). We are not saying which metal Stoke uses, because it does not say.
What we would watch: the named shield alloy, coolant flow and any flown data. What would worry you most in a cooled shield?
What TCT Magazine reports: Skyrora ran six hot-fire tests of its 3.5 kN low-Earth-orbit engine at its Midlothian site. The article describes a titanium-coated component and says Skyrora is said to have cut weight by about 44% by using titanium instead of a nickel-based alloy; it does not say who made the claim or what the weight refers to. It says the component was engineered with Skyrora's in-house Skyprint 2 hybrid directed-energy-deposition printer, under the EU-funded MADE-3D programme. No damage to the modified components was reported.
Why it matters for materials: swapping a nickel-based alloy for titanium usually trades high-temperature strength for much lower mass, so it tends to suit a part that sees moderate heat or is protected. That is our inference; the article says only that the part is designed for the engine's demanding thermal environment.
Our take: the saving is close to what the density gap alone would give. In our archive Ti-6Al-4V is 4.43 g/cm3 and Inconel 718 is 0.297 lb/in3, about 8.22 g/cm3, so titanium is roughly 46% lighter for the same volume, for those two grades. Which grades Skyrora used is not stated, and the page calls the part titanium-coated and also speaks of using titanium instead of a nickel-based alloy, so we cannot tell a surface layer from a bulk swap. The 44% has no baseline mass, and test durations, measured thrust, pressures and temperatures are not given. Six hot-fires with no reported damage do not show it is flight-qualified.
What we would watch: which part it is, how hot it runs, and whether it survives repeated firing. Would you trust titanium there?
What Xinhua reports: a fourth round of outside-the-station exposure experiments is under way, covering eight projects and 26 sample units, exposed for one to two years to vacuum, atomic oxygen, radiation, sharp temperature swings and micrometeoroids. A stainless magnesium alloy is described as the world's first in-orbit check of its space stability. Solid-liquid composite and gel lubricants reportedly reached near-zero wear, and simulated lunar-soil bricks stayed intact after a year of exposure. The quoted expert, Pang Zhihao, says the results may transfer to aviation, nuclear power and precision transmission parts.
Why it matters for materials: a rolling programme of one-to-two-year exposures is another source of low-Earth-orbit durability data, like MISSE, covering a magnesium alloy, space lubricants and lunar-construction bricks.
Our take: none of the claims comes with property values, test methods or a paper. World's first and near-zero wear are unquantified, the magnesium alloy's composition is not given, and the whole article rests on one expert interview. These are leads to chase, not numbers to cite. For context, our magnesium WE43 page lists a minimum 0.2 % proof stress of 172 MPa, a minimum tensile strength of 220 MPa and a 2 % minimum elongation (Luxfer's guaranteed minimums for a heat-treated WE43 casting). WE43 is a rare-earth casting alloy and Xinhua does not name its alloy, so this shows the type of figure to expect, not a like-for-like baseline.
What we would watch: whether a data release or paper follows, with the alloy named. What would you want reported before you trusted it?
A small satellite just 3D printed a beam in open space. Not inside the space station, where printing has been done before, but outside, in vacuum. The company is Orbital Matter and the satellite is called Replicator 2.
I find this one exciting. Today every solar panel and antenna has to be folded up tightly to fit inside a rocket, then unfolded in orbit. If a satellite can print its own structure once it is up there, that whole problem starts to go away. You launch a small box and it grows its own arms.
The way it works is simple. The printer pushes out a resin in a spiral and ultraviolet light hardens it on the spot. The company says the beam is 30 cm long and took about half an hour to print.
I would be a little careful with the headlines though. TechCrunch wrote that the beam is half a metre and that it already opened a solar array. The company's own page says 30 cm, and calls the solar array the next step. So the print looks real, but some of the bigger claims are ahead of what the company itself says.
The thing I keep wondering about is the plastic. Space is hard on plastics. Sunlight, oxygen atoms and the swing between hot and cold wear them down over time. Printing a beam is one thing. A beam that stays straight and strong for years is another, and nobody has shown numbers for that yet. I hope the company publishes them.
Still, for a satellite the size of a suitcase, this is a big step. The next mission is planned for 2028 with a much larger solar array.
What do you think: will satellites print their own parts in ten years, or will this stay a demo?
What CompositesWorld reports: DLR's SpaceMast, a carbon-fibre-reinforced composite mast with a thin-walled double-omega cross-section that flattens into a band and winds onto a spool, completed what DLR researcher Martin Zander calls its first major operational test in orbit, after about five months in space. According to SpaceNews, it launched on 30 March 2026 on SpaceX Transporter-16, carried by D-Orbit's ION Satellite Carrier. The test ran more than 8.5 hours: the mast extended to 1.7 m, then fully retracted and stowed. The mast carries a tip camera meant to image the host vehicle, according to a 2025 DLR conference paper; the article reports no images. More cycles are planned, with extensions up to 2.5 m. DLR says its patented Floating-Core-Interface nearly doubles bending strength.
Why it matters for materials: a thin composite shell is elastically flattened and coiled, then deployed again. That tests whether the fibre and resin system survives repeated stowage strain, which is a different question from how it ages in vacuum, thermal cycling or atomic oxygen. The article gives no data on those.
Our take: this is trade press relaying a DLR researcher's LinkedIn post (he is co-founding a spin-off) and DLR material. Fibre, resin, layup, mass and orbit are not given, and nearly doubles has no numbers behind it. For a sense of how directional a laminate is, our CFRP page lists a unidirectional IM7/HexPly 8552 laminate at 2724 MPa tensile strength along the fibres and 64 MPa across them (Hexcel data, 25 °C, dry), so layup matters a great deal for any thin composite shell; the article does not give SpaceMast's layup.
What we would watch: the cycle count at which stiffness changes, and any thermal data. What failure would you look for first?
