## 2 Literature Review
### LCA in Space Missions and Research Gap  
Table 2 shows the key literature exploring LCA across the various components of a complete space mission, including the launch segment, space segment, and ground segment. However, as the focus of this case study is on the space segment, we focused on 14 relevant papers from [41]. Of these, ten papers address the complete space mission, which include [42; 43; 44; 45; 46; 47; 48; 49; 50; 51], while four specifically focus on only space segment [52; 53; 54; 55]. Papers on complete space mission LCAs were also examined, as they encompass the space segment as part of the broader mission analysis. Based on Table 2, research from [42; 46; 47; 48; 49; 52; 54; 55] presents the LCA results based on their own manufacturing capabilities. Hence, they have the access to the primary data, which is essential for conducting space-specific LCAs. As they are also the manufacturers, performing the LCA is straightforward due to the availability of primary mass budget data. Refs. [43; 45] explored the relationship between orbital debris and LCA, although they did not provide any detailed calculations. Ref. [53] explored the LCA for three alternative space elevator design from another paper. Ref. [44] explored LCA for two alternative propellants for Sentinel 3 satellite. Ref. [51] performed an LCA using data from a NASA mission design, while [50] investigated the use of an open-source platform for conducting space mission LCA. Hence, it can be inferred that there is a clear gap in the availability of a generic method for predicting the mass budget of commercial satellites. This limitation hinders the ability \begin{table}
\begin{tabular}{l l l} \hline \hline
**LCA Category** & **Description** & **Sources** \\ \hline \multirow{3}{*}{Complete space mission} & Deloitte and Thales conducted an LCA on the & \\  & Sentinel-3 satellite, utilizing primary data & \\  & provided by Thales, the manufacturer of the & \\  & Sentinel-3 satellite & \\ \hline \multirow{3}{*}{Complete space mission} & Research focused on orbital debris; no calculation & \\  & done & [43] \\ \hline \multirow{3}{*}{Complete space mission} & LCA for two alterantive propellants & [44] \\ \cline{2-3}  & Research focused on orbital debris; no calculation & \\  & done & [45] \\ \hline \multirow{3}{*}{Complete space mission} & EPFL Cubesat primary data & [46] \\ \cline{2-3}  & Primary data from Stathyclyde mission design & [47] \\ \cline{2-3}  & team for MIOS mission & \\ \hline \multirow{3}{*}{Complete space mission} & Thales presenting Sentinel 3 result, as they are the manufacturer & [48] \\ \cline{2-3}  & Qinetiq is the manufacturer; LCA in this paper is & \\ \cline{2-3}  & also performed by Qinetiq with their primary data & [49] \\ \hline \multirow{3}{*}{Complete space mission} & Research focused on developing opern-source & \\  & LCA platform; no calculation done & \\ \hline \multirow{3}{*}{Complete space mission} & LCA for space-based solar power with data from & \\  & NASA mission & \\ \hline \multirow{3}{*}{Space segment} & LCA performed by Thales Aliena Space with & \\  & primary data from their missions & [52] \\ \hline \multirow{3}{*}{Space segment} & LCA performed for three space elevator designs & \\  & with mass data from another paper & [53] \\ \hline \multirow{3}{*}{Space segment} & LCA performed by OHB for CO2M mission with & \\  & primary data from OHB, as they are the prime & [54] \\ \cline{1-1}  & contractor & \\ \hline \multirow{3}{*}{Space segment} & LCA performed by TUDelft for their own Cubesat & \\ \cline{1-1}  & Delfi-n3 Xt & [55] \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Key literature of LCA in space missions. of users, other than those with direct access to primary mass budget data, to perform life cycle assessments (LCA) on satellite missions. Consequently, the current approach to LCA remains largely restricted to manufacturers or entities with privileged data access. As discussed in Section 2.1, a research gap exists in the field of \"sustainability for space\".