A sustainable aviation alternative that enables intrepid luxury travel, OceanSky Cruises’s airship is a 100-metre-long hybrid aircraft, combining buoyancy from helium with aerodynamic lift created by the shape of its hull. Driven forward by four propellors, the vehicle can fly continuously for days. Can it run on SAF?
In the skies above Britain and across the Asia-Pacific, a green revolution is accelerating—not in the fields, but in the jet streams. Two major international moves this month signal that Sustainable Aviation Fuel (SAF) is no longer a niche technology but a critical pillar of the future of flight. And as Earth-bound aircraft start to go green, a tantalizing question arises: can space travel do the same?
The United Kingdom has taken a decisive step in accelerating SAF adoption by raising its co-processing blend limit from 5% to 30%. Endorsed by the UK Ministry of Defence and enshrined in Defence Standard 91-091, this regulatory leap allows waste oils and renewable feedstocks to be refined alongside fossil fuels—without requiring massive infrastructure overhauls.
Industry players like BP and the International Air Transport Association (IATA) have applauded the move, highlighting that SAF produced under these standards meets rigorous global aviation fuel benchmarks such as ASTM D1655. This isn’t a backdoor greenwashing scheme. It’s vetted, safe, and compatible with existing jet engines.
The UK’s action sends a powerful signal to the global market: SAF isn’t tomorrow’s promise—it’s today’s policy.
GenZero
Meanwhile, Singapore’s GenZero, in partnership with the World Economic Forum, has launched the Green Fuel Forward Initiative, aiming to scale SAF across the Asia-Pacific region. This initiative unites airlines, aerospace manufacturers, and financiers to create a self-sustaining SAF market—one that can meet the demand of one of the world’s fastest-growing aviation hubs.
Where the UK is setting standards, GenZero is building ecosystems. Together, these initiatives create a transcontinental roadmap for clean flight.
Despite the momentum, experts caution against declaring SAF a silver bullet. While SAF can reduce lifecycle emissions by up to 80% compared to conventional jet fuel, this is contingent on the sustainability of feedstocks, regional production capabilities, and carbon accounting accuracy. Feedstock availability, economic viability, and infrastructure bottlenecks all remain significant hurdles.
In short: cleaner skies are coming—but we’re not off the hook yet.
Companies like Virgin Galactic, Blue Origin, and SpaceX are pushing commercial spaceflight into the mainstream. But their environmental footprint is enormous. One rocket launch can emit hundreds of tons of CO₂ and black carbon, which lingers in the stratosphere, disrupting climate systems more than emissions at lower altitudes.
Some progress is being made. Blue Origin uses liquid hydrogen and liquid oxygen—fuels that, when combusted, emit only water vapor. But hydrogen’s production is often energy-intensive, and other space companies still rely on kerosene-based propellants.
Startups and research labs are quietly experimenting with green rocket fuels made from bioethanol, renewable methane, or even algae-based feedstocks. But these remain in early stages, with limited commercial uptake.
Could SAF tech inspire the next leap? Perhaps. SAF producers like Gevo, Neste, and Velocys are already investing in Fischer-Tropsch and gasification technologies that could be adapted for high-energy rocket fuel equivalents.
For investors with one eye on Earth and the other on the stars, SAF is emerging as one of the most promising clean tech sectors. Here are a few companies at the forefront:
Neste (Finland): The world’s largest SAF producer, partnering with airports and airlines globally.
Gevo (NASDAQ: GEVO): A US-based innovator turning agricultural waste into renewable jet fuel.
Velocys (UK): Converts municipal and forest waste into aviation-grade hydrocarbons.
XCF Global (NASDAQ: XCF): Set to become the only pure-play SAF producer on the US public market after acquiring New Rise Renewables.
SkyNRG (Netherlands): A pioneer in SAF deployment, collaborating with airports and corporate clients.
Shell and World Energy: Though fossil giants, both are investing heavily in SAF R&D and infrastructure.
Flying sustainably is no longer science fiction. But guilt-free air travel—let alone guilt-free space tourism—isn’t as simple as swapping fuels. It requires layered transformation: regulatory reform, feedstock innovation, public-private collaboration, and bold investment.
