Eco-design of future reusable launchers: insight into their life-cycle and atmospheric impact
Creators: name:  G.J. DOMINGUEZ CALABUIG 
name:   A.R. WILSON 
name:   L. MIRAUX 
name:   A. SARRITZU 
Publisher: name: Proceedings of  the 9th European Conference for Aerospace Sciences. Lille, France, 27 June - 1 July, 2022
Year: 2022
Subjects: SPACE
REUSABILITY
REUSABLE LAUNCH VEHICLE

description: Following the boom of the space arena, gathering a wide range of new stakeholders and space services, the number of launches per year is drastically increasing. The launcher sector is indeed significantly developing worldwide through public and private investments aimed at expanding each country own space capabilities. Private entities, such as SpaceX have originated this disruption of the market. This promotes a virtuous cycle of investments and technological developments which will bring the opportunity for more and more countries to get easier and cheaper space access. Indeed, while the market is quickly expanding, the latter is still a privilege limited to a small number of countries with Europe at the head. At the same time, humanity is becoming aware of its environmental limits, especially as climate change continues to unravel. While space access might contribute significantly in addressing these global issues, it raises an \"adaptation-mitigation dilemma\". Launch vehicles are the only anthropogenic object emitting directly in all atmospheric layers. With the raise of global launch rates, it may not be possible to neglect their environmental impact. The resulting public awareness may as a consequence steer policy and regulations in the sector. Launch vehicles have currently a small but wide environmental footprint, such as from stratospheric ozone depletion, climate forcing, eco-toxicity and materials depletion. The latter could be mitigated through reusability. Life Cycle Assessments (LCA) can assess these impacts over their full life cycle. Product Lifecycle Assessment is indeed a key topic identified by ESA for future developments towards introducing it as standard element for any mission and product design. Regarding launchers, these studies show that atmospheric impacts in terms of climate forcing are typically negligible compared to other phases when considering only direct forcing from CO2, H2O and other greenhouse gasses. However, they neglect the potentially significant radiative forcing from black carbon, aerosols, cloud formations and their interactions, which strongly drive aviation climate forcing. Indeed studies on the atmospheric impacts of launch vehicles by The Aerospace Corporation indicate that it might be larger than greenhouse gases by some orders of magnitude. In addition, with the introduction of reusability, it is expected that the impact from the launch and direct operation activities could increase compared to expendable vehicles. This can be a consequence of the introduction of recovery hardware leading to lower ascent performance and additional propellant consumption, especially if additional propulsive maneuvers are required. However, this can be mitigated through the amortization of development, manufacturing and end of life impacts over the number of reuses in an analogous way to vehicle launch costs. This study first reviews current state of knowledge on launchers environmental impact and eco-design before introducing a preliminary lifecycle and atmospheric impact assessment of the different technologies. The reusability question is addressed together with its system implications and possible eco-design approaches. The preliminary results of this early-stage study allow to quantify the possible benefits of reusability to mitigate certain environment impacts and identified the potential sustainability of hydrolox and methalox technologies.