Every few days, giant rockets blow up fiery trails through the atmosphere, allowing satellites to penetrate orbit, perform space missions, and perform other tasks. Since 2017, both the number of fires and the size of cargo loads have increased dramatically. Large numbers of satellites and other objects Every startup. In 2016, a total of 221 objects were launched into space. In 2023, the number was 2,644. Currently, there are around 10,000 satellites in low-Earth orbit, with thousands of people halting their work. Approximately 6,000 people belong to SpaceX Company alone, and its owner, Elon Musk, vowed to increase them to 40,000. In addition to that, there Over 130 million chunks Spawning large, broken ships floating around “space junks” of various sizes.
There’s a sale Local influenceincluding a huge cloud of temporary contamination from fuel burning, and a short ail of sheet metal, insulation and other debris from the collapsed rocket stage. And of course, what is rising must go down. Anything sent into orbit will eventually return to Earth, and as launches increase, the re-entering of failed or decommissioned spacecrafts will also increase. Most people get burned out when they hit the atmosphere, but they are not always perfect. last year, A lot of metal components have arrived, Harmless, but in rural North Carolina forests, near the roof of a Florida home, fields of farms in Saskatchewan, and small villages in Kenya.
Kostas Tsigaridis I’m an atmospheric scientist at Columbia Climate School. Climate System Research Center And its belonging NASA Goddard Space Research Institute. He is not worried about short-lived local pollution in the lower atmosphere or the still rambling of the still unharmed wreckage. However, he is concerned about byproducts from the burning of fuel as the rocket passes through the atmosphere above, and byproducts from the re-burning of the remains there. Both can alter upper atmosphere chemistry, temperature and circulation that can affect planetary climate.
He and his colleagues are trying to understand the potential for such an effect. The preliminary model was used to estimate that there could be a potential launch of 1,000 or 10,000 people per year by 2050. We spoke with Tsigaridis about this relatively new field of research.
Why are you investigating the possible impact of rockets?
Rocket launches and satellite reentry are increasing at unprecedented speeds. Given that there are no regulations of any kind on that number, we expect them to start becoming a prominent contaminant in the near future. Furthermore, they constitute a unique anthropogenic source of short-lived chemicals in the upper atmosphere. Given the rapidly expanding activity, we should not wait for something to happen before studying it. It’s better to try this as the best thing you can start from now on.
What do most rockets use for fuel, and what are their typical by-products?
It is the most popular kerosene, and solid fuels are rich in carbon, producing black carbon as a by-product, just like automobiles. Hydrogen used in its blue origin does not contain carbon and most of it has water as a by-product, but has a lower lifting capacity per fuel mass than carbon-based fuels. Liquefied natural gas (LNG), which is mostly methane, is expected to dominate space travel in the future. LNG is still carbon-based, but burns much more efficiently than kerosene and contains much less black carbon.
Black carbon is important because of the long lifespan of the upper atmosphere. Near the surface, rain will quickly fall depending on the amount of precipitation, but if the clouds and surfaces are not high, including the stratosphere, only gravity and atmospheric circulation can be ultimately removed. Both of these are very slow processes. Therefore, it accumulates and increases the impact on chemistry and climate. Cleaner LNG fuel reduces the amount of black carbon with each launch, but given the number of future projections launches, we’re still talking about the substantial amounts injected into the upper atmosphere.
Are there still perceptible effects? What could happen in the future?
First, let me explain why we care about the stratosphere. It starts at the altitude of the aircraft. This is where the ozone layer is located, protecting the life of this planet from harmful solar radiation. It is sandwiched between the troposphere, part of the atmosphere we live in, and above it, between the mid-sphere. The troposphere is very humid, with clouds, rain, humidity and more. The stratosphere is very cold and very dry. The coldest part between the troposphere and stratosphere is called the frugal sphere, which prevents water from entering the stratosphere. There are many features that make the stratosphere unique, but here water and ozone are important. And, like I’ve already said, the new component introduced by Rocketry is black carbon.
As the name suggests, black carbon is black, so absorbs solar radiation. It heats up the environment around it. This is a very well understood effect. What we recently discovered is new: stratospheric heating from black carbon heats up the convection and allows water to “leak” into the stratosphere. This changes chemistry and destroys stratospheric ozone. Ozone erosion does not appear to have a significant impact on a global scale, but ongoing analysis means that polar ozone depletion will occur. Additionally, normal atmospheric circulation lowers most of the black carbon near the polar regions, where it can land on snow and ice, and accelerates melting by reducing the reflectivity of those surfaces. This is an effect that has not been studied yet, but there are plans to dig deeper into it soon.
What about the debris that reenter the atmosphere? What does it produce and what will the outcome?
Space debris is a very different story. In mesospheres, black carbon is not involved and burn (more precisely called ablation) is higher. The ablation temperature is high enough to break down molecular nitrogen, the most abundant chemical in the atmosphere. This can form nitrogen oxides and affect mesospheric chemistry in the region. Additionally, satellites that send into orbit contain a large amount of aluminum in their structure. This oxidizes into alumina, which reflects sunlight and forms very small particles that affect chemistry. In principle, they are similar, but not exactly the same as the gases from major volcanic eruptions. These particles, like several other satellite origination metals, are detected in the stratosphere on their way from the Mesosphere to the Surface. Their roles have not yet been accurately quantified.
What is your next step?
While defining work on the role of black carbon in stratospheric water, we are preparing to study the reentry of debris in terms of both nitrogen oxides and alumina. We also investigate regional and not global as preliminary analyses show that polar atmospheres are disproportionately affected.
