Rockets Don’t Run On Gasoline

The optics may not be good, but the facts tell a different story. The first thing to understand is that rockets do not use the same fuels that power cars, trucks and commercial aircraft. Starship’s tanks hold about 1,500 metric tons of propellant, consisting mainly of liquid oxygen and liquid methane cooled to cryogenic temperatures. A single launch does therefore not affect oil prices or domestic gasoline supplies. In other words, this rocket launch will not worsen the fuel crisis.

Why Methane Is Different

Many rockets use kerosene, a fossil fuel directly affected by the fuel crisis. By relying on methane, Starship is at the vanguard of a major transition in the launch business away from kerosene. That’s partly because it’s theoretically possible to produce methane on Mars using atmospheric carbon dioxide and water.

Methane, as used in Starship, is a fossil fuel, but its methane-burning Raptor engines are considered cleaner than older rocket systems that relied on kerosene-like fuels. Methane combustion produces mainly carbon dioxide and water vapor rather than thick soot and toxic chemicals.

Yet “cleaner” does not mean “clean.” Environmental researchers estimate that a single Starship launch can still produce tens of thousands of tons of carbon dioxide equivalent emissions.

The Climate Problem Above Our Heads

The bigger environmental concern is not methane-fueled Starship launches but the growing number of kerosene-burning rockets already operating at industrial scale. That includes SpaceX’s Falcon 9, which launched 167 times in 2025, compared with just five Starship launches.

Unlike aircraft, rockets inject exhaust directly into the upper atmosphere, where scientists are still trying to understand the long-term consequences. In a landmark paper published in 2022, scientists modeled the climate effects of rocket black carbon emissions — produced by kerosene-burning rocket engines, discarded rocket bodies and dead satellites falling back to Earth — and found they could warm the stratosphere and affect the ozone layer because pollutants can linger far longer at those altitudes than they do closer to Earth’s surface. The authors wrote that rocket soot increases stratospheric temperatures, alters atmospheric circulation and depletes the ozone layer.

Satellite Megaconstellations

Research published last week focused on satellite megaconstellations — such as SpaceX’s Starlink — of which there are now nearly 12,000 in orbit, with plans to increase that to 40,000. Other plans, such as Amazon’s Project Kuiper, Eutelsat OneWeb and China Satellite Network Group (SatNet), could push that to 65,000 or more. Most rockets currently launching megaconstellations still use kerosene-based fuels.

The researchers found that soot from such rockets absorbs sunlight, warming the upper layers of the atmosphere and decreasing the amount of sunlight reaching Earth's lower atmosphere, causing it to cool. “Rockets launching megaconstellations and other missions are like small-scale stratospheric aerosol injection experiments without forethought for potential unintended consequences,” reads the paper.

The analysis showed that in 2020, these megaconstellations accounted for about 35% of the total climate impact from the space sector and will reach 42% by 2029.

The Billionaire Space Race

Rockets are not driving the world’s fuel shortages, and Starship is cleaner than most traditional launch systems. But as the space industry enters a hyper-growth era, scientists are increasingly asking whether humanity is beginning to industrialize the upper atmosphere during a climate emergency.

Wishing you clear skies and wide eyes.