Scientists are concerned that an increase in rocket launches and the advent of space tourism would harm the environment and lead to climate change. Much of the globe gasped in wonder when billionaires Jeff Bezos and Richard Branson flew into space aboard their firms’ suborbital tourism spacecraft.
For other scientists, though, these milestones marked more than just a technological achievement. The missions signaled the potential start of a long-awaited period in which rockets may fly into the so-far relatively atmosphere’s pristine upper layers significantly more frequently than they do today, despite substantial hurdles. These flights are propelled by the hybrid engine which burns rubber and creates a cloud of soot in the instance of the SpaceShipTwo, the vehicle controlled by Branson’s Virgin Galactic.”Hybrid engines can run on a variety of fuels, but they always produce a lot of soot,” stated Filippo Maggi, Politecnico di Milano’s associate professor of the aerospace engineering in Italy who studies rocket propulsion and was part of a team that published an extensive assessment of the hybrid rocket engine emissions several years ago. “These engines act like a candle, and how they burn generates ideal conditions for soot formation.”
A single suborbital space tourism flight by Virgin Galactic, lasting roughly an hour and a half, can cause as many harmful emissions as a ten-hour trans-Atlantic flight, as per Dallas Kasaboski, lead analyst at the Northern Sky Research. Several experts find this alarming given Virgin Galactic’s plans to transport paying tourists to the space’s edge many times a day.
“Even if suborbital tourist business is starting at a fraction of the rate of the remainder of the [tourism] industry,” Kasaboski told Space.com, “each of their trips has a significantly bigger contribution, and that might be an issue.” Of course, Virgin Galactic’s rockets aren’t the only ones to blame. According to Maggi, all rocket motors that utilize hydrocarbon fuels produce soot. Like those used in the boosters of NASA’s space shuttle in the past, solid rocket engines burn metallic compounds and release aluminum oxide particles along with hydrochloric acid. Both are harmful to the environment.
On the other hand, the New Shepard suborbital vehicle of Blue Origin uses a BE-3 engine that generates thrust by combining liquid hydrogen and liquid oxygen. According to specialists, the BE-3 is a low-polluter compared to many other rocket engines, mainly producing water and a few minor combustion products. The biggest problem, according to Karen Rosenlof, a senior scientist at the US National Oceanic and Atmospheric Administration’s (NOAA) Chemical Sciences Laboratory, is that spacecraft pollute the upper layers of the atmosphere — stratosphere, which begins at about 6.2 miles (10 kilometers) and the mesosphere, which starts at 31 miles (48 kilometers) (50 km).