In mid-January, a significant incident involving SpaceX's Starship megarocket occurred during its seventh test flight, resulting in potential contamination of Earth's upper atmosphere. Debris from the explosion fell into the Caribbean Sea, while metal and nitrogen oxides were released into the atmosphere, raising alarms about their impact on the ozone layer.
Astronomer Jonathan McDowell reported that the rocket's upper stage exploded at an altitude of approximately 146 kilometers and weighed around 85 tons without fuel. Atmospheric chemist Connor Barker from University College London estimated that the incident may have produced 45.5 tons of metal oxides and 40 tons of nitrogen oxides. These figures are preliminary and require further investigation.
While the exact extent of the pollution remains uncertain, Barker likened the emissions to one-third of the annual influx of meteoritic material burning up in the atmosphere. McDowell noted that a substantial portion of the debris likely fell into the ocean.
A positive aspect is that Starship is constructed from stainless steel, unlike many other rockets, including Falcon 9, which utilize aluminum. The combustion of aluminum at high temperatures creates alumina (aluminum oxide), detrimental to the ozone layer and atmospheric reflectivity.
The increasing number of satellites and rockets re-entering the atmosphere contributes to growing pollution. Alumina that reaches the mesosphere and upper stratosphere remains for extended periods, raising concerns among scientists. Currently, the level of this pollution is approaching that generated by cosmic debris containing minimal aluminum.
Additionally, the re-entry of satellites and debris produces nitrogen oxides due to heating and chemical reactions between nitrogen and oxygen at hypersonic speeds. As rocket launches increase, these emissions may escalate to levels threatening the ozone layer.
If the trend continues, the accumulation of pollutants could hinder the recovery of the ozone layer, already compromised by ozone-depleting substances used in industry. There is also a risk of altering the atmospheric thermal balance, potentially leading to unpredictable climate consequences.
Thus, the expansion of space activities necessitates careful monitoring of environmental impacts to minimize harm to the ecosystem.
Previously, reports indicated that local residents were alarmed by the intolerable noise from Starship.