Blue Origin and Virgin Galactic showcase remarkable engineering in space tourism, yet they prompt vital questions about environmental effects amid pressing climate challenges. For Blue Origin's New Shepard launch, what is its true planetary pollution footprint?
The inaugural commercial flight of Jeff Bezos' New Shepard rocket was set for Tuesday, July 20, 2021, at 3 p.m. French time—just nine days after Richard Branson's crew flew aboard Virgin Galactic's VSS Unity.
Recent weeks have spotlighted concerns over the carbon emissions from these suborbital jaunts and the nascent space tourism sector. With limited historical data, assessments must be flight-specific for now.
So, how much pollution did Bezos and his crew produce during this suborbital ascent?
Blue Origin's New Shepard stands out as one of the cleanest launchers available. Its BE-3 engine burns liquid hydrogen with liquid oxygen (LOX), producing thrust primarily through water vapor and trace combustion byproducts, with virtually no CO2, explains Darin Toohey, an atmospheric scientist at the University of Colorado Boulder, in a LiveScience interview.
Water in the exhaust may thicken atmospheric clouds, including iridescent 'pearl' clouds visible at sunset post-launch, Toohey notes.
That said, water vapor is a potent greenhouse gas, and prolonged presence in the mesosphere or ionosphere could contribute to warming. Fortunately, New Shepard's engine cuts off early in flight, limiting this risk. With rocket launches still rare, these factors don't factor significantly into climate models.
Launch cadence is expected to rise as competitors chase the lucrative space tourism market, warranting deeper studies on cumulative effects.
Overall, spaceflight CO2 remains negligible: rockets accounted for roughly 0.0000059% of global emissions in 2018 (per Everyday Astronaut), versus about 2.4% from aviation.
Experts flag tiny particles like soot and aluminum oxides as bigger worries. Even minute quantities can profoundly affect the atmosphere, Toohey cautions. New Shepard produces few such particles, but future vehicles might not.
A 2010 study modeled 1,000 annual private suborbital flights, projecting polar temperature rises of 1°C and polar sea ice reductions of 5% to 15% from soot injection.
