Chinese scientists have developed a new kind of “living cement” that could, in theory, be used to build structures on far-away planets like Mars. According to reports, it works using just a few ingredients, including “domestic” soil/regolith, gelatin, and genetically engineered yeast.

If able to scale, this technique could be used to build shelters and other structures for future long-term human missions to the planet. What’s more, the process is relatively cheap and could be combined with on-site 3D printers.

The researchers managed to engineer a special strain of Saccharomyces cerevisiae yeast that produces extremely adhesive proteins. One of these proteins is similar to those produced by mussels that enable them to stick to surfaces like rocks.

The idea is that these proteins could be used as a kind of cement to bind soil or regolith, effectively making a kind of biological cement. The yeast cells therefore behave a bit like millions of microscopic sticky particles inside the binder.

Building Martian structures using yeast

The gelatin component forms a hydrogel around everything, while the soil/regolith provides the bulk of the material. Initially gloopy in texture, this paste can be extruded through 3D-printer nozzles to form complex structures.

As for “curing” the mixture, the researchers believe it is best to work with the conditions on Mars rather than fight them. Mars has a very thin atmosphere (about 0.6 percent of that on Earth) and is much colder on average than Earth (about -63.4°F/−53°C).

Under these conditions, liquid water will freeze and sublimate, meaning it never really stays in liquid form for very long. That is essentially freeze-drying. What’s left behind is a lightweight porous network in which the gelatin, yeast-derived adhesive proteins, and mineral grains are locked together.

You can liken that to something akin to a mixture of freeze-dried sponge and concrete. What’s more, this new material is actually pretty strong, with 12 MPa compressive strength and 6 MPa flexural strength.

That’s about on par with low-strength and lightweight concrete here on Earth. Promising indeed, and if it can save shipping thousands of tons of material for construction, that would clearly be enormously beneficial.

Instead, in theory, you’d just need to send the biological starter material, some processing equipment, and a big robot printer. Interestingly, the material is also recyclable, meaning its constituent parts can be broken down and reused.

All well and good, but before this could be seriously considered for applications outside the lab, some important things need to be refined.

More work to do

The first is that the tested material used sand as a substitute for Martian regolith. Actual Martian regolith has different particle characteristics and contains things such as perchlorates. How the gelatin-yeast mix reacts to this is yet to be tested.

Another issue is that the gelatin is porcine, meaning that it would need to be “shipped in” to a building site. The team also tested a gelatin-free formulation, although its performance was lower, and the researchers say stronger fully biological binders will be needed.

Yet another major issue is enabling the material to build pressurized structures to protect people from Mars’s harsh environment. The team proposes a ready-made pressure-retaining membrane enveloped by a shell and shielding built using this new living concrete.

Overall, it is a promising proof-of-concept showing that Martian regolith might one day be turned into printable construction material using engineered biology, while exploiting Mars’s cold and near-vacuum conditions as part of the manufacturing process rather than treating them purely as obstacles.

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Spaceflight Now reports: "A SpaceX Falcon Heavy rocket launched from Florida Thursday night on a classified mission for the National Reconnaissance Office, America's spy satellite agency... The NRO has previously flown payloads on 22 Falcon 9 rockets but this is the first time it has used the heavy-lift Falcon Heavy, which consists of three Falcon 9 boosters and an upper stage, topped by a payload fairing. The powerful rocket, which lifts off under the power of 27 Merlin 1D engines, was introduced to great fanfare in 2018 and made its 14th flight Thursday night... NROL-97 was SpaceX's third Falcon launch of the day. In addition to the Crew 13 mission, the company launched 130 payloads on the Transporter 13 rideshare mission from its West Coast pad at Vandenberg Space Force Base in California. It was the first time the company has landed four boosters in a single day. CNN reports: As Starship flights ramp up, SpaceX has made clear that the company will phase out the use of two of its most iconic creations: the Dragon spacecraft, which ferries astronauts and cargo to and from the International Space Station, and the Falcon 9 rocket, which for a decade has dominated the global launch market. These vehicles not only revolutionized the space industry in their own way, they're also still very much essential to ongoing work in Earth orbit, without clear backup options in place. The prospect of this loss is already spurring panic among some satellite operators, said Caleb Henry, director of research at analytics firm Quilty Space... Henry said he expects that most of the remaining space on board Falcon 9 rockets has already been sold and — beyond early 2029 — such flights may be reserved solely for the US government. Even NASA, which currently counts the Dragon capsule as the only US-made spacecraft capable of getting its astronauts to and from the ISS, has also acknowledged the looming retirement of SpaceX's workhorse vehicles.... Despite the success of Falcon and Dragon, a peek at SpaceX's business book may hint at financial reasons for retiring the vehicles. In its first quarterly earnings report, SpaceX revealed its space segment — which includes Falcon, Dragon and Starship — lost $542 million. By comparison, its Starlink internet and connectivity business made nearly $1.7 billion. Starship is expected to continue to cost SpaceX untold millions as it moves out of the prototyping phase. But one reason SpaceX is willing to bet big on Starship is that it's simply "much better" for achieving the company's own long-term goals, said SpaceX president Gwynne Shotwell at a recent conference. So it makes sense to shift resources toward the megarocket's future.... This rocket supply crunch has been looming since 2022, when Russia invaded Ukraine — which immediately removed Russia's Soyuz and Proton rockets from the commercial market, Henry noted. On top of that, Amazon — which is deploying a space-based internet constellation to rival SpaceX's Starlink — stepped in to buy more than 100 launches from various rocket makers.... Though some satellite manufacturers are hopeful that space onboard future Starship launches will be offered to satellite operators, it's not clear when or if that will happen.... It is possible that a launch supply crunch could be averted, noted Micah Walter-Range, a space analyst and contributor to the VettaFi Space Index. But satellite operators may be wary because newer rockets that have for years promised to step up to compete with the Falcon 9 have not yet begun flying with any regularity. "The space industry hates uncertainty, particularly when it comes to planning of launches," Walter-Range said. The article notes that Rocket Lab, Firefly Aerospace, United Launch Alliance, and the Jeff Bezos-founded Blue Origin "have not yet reached the scale or launch cadence that the industry is demanding."

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