Speaker
Description
Rocket launch is a major human activity that deposits pollutants directly into the upper atmosphere. These pollutants can affect different atmospheric layers differently. Life Cycle Assessments (LCAs) quantify total emissions output but ignore how the output will have different impacts depending on the environment and the amount deposited in each layer. This proposed methodology simulates the space and time profile emissions from specific launch profiles to educate and influence launch design. The primary impacts of launch, such as black carbon or water output, are shown in a 3D space around and above launch sites. Secondary impacts, how these emissions affect the local and global environment, are also shown. Primary impacts in a two-dimensional space have previously been studied in the field, finding that the majority of propellant mass is consumed in the troposphere and stratosphere, and in 2022, the mesosphere was injected with almost 80% of all Carbon Monoxide (CO) and gaseous reactive nitrogen oxides (NOx) emissions from space launches. Secondary impacts are studied through LCA endpoint results covering damage to human health, ecosystems and resource availability. However, endpoint LCA is rarely done in industry due to the complex and time-consuming process. An example of a secondary impact would be the <0.5 pH acidic rain observed up to 22km from the launch site, resulting from Solid Rocket Motors (SRMs). Launches with this fuel were also found to reduce the pH of local water sources, killing large amounts of fish in the surrounding area. Being able to demonstrate possible primary and secondary impacts of launch will help understand how different communities, in addition to local flora and fauna, may be impacted by space activities. These emissions and impacts will then be compared to other emitters, such as the aviation or automotive industry, to illustrate the magnitude of the space industry's impact. The emissions and their impacts are separated into surface, tropospheric, stratospheric, mesospheric, thermophoretic, and exospheric impacts. This separation allows for more accurate atmospheric chemical reaction prediction and improved impact visualisation. For example, radical catalysts such as chlorine (Clx) will cause significant amounts of ozone destruction when emitted into the stratosphere but will have little impact if emitted at a higher altitude. The outputs for this methodology will be simulations of a single launch, an accumulation of a series of launches for a constellation, or simulations of specific time periods. Using historical and future scenario projections, a variety of time periods can be illustrated, including future periods of growth or decline in the space industry. Having near and far future primary and secondary impact projections can help influence decisions made in the space industry today. Decisions such as launch vehicle, fuel choice and launch location can be made with a deeper understanding of the impacts they will have on the local and global environment. The goal of this work is to enable space actors to make educated and informed decisions when designing future missions.