*3.1. Payload Range Diagram and Design Point*

As hydrogen was chosen as the main energy carrier, the shape of the payload range diagram is significantly different from typical diagrams. The high gravimetric energy density of the fuel leads to a very shallow middle section, making it impossible to place the TLAR mission on this section without breaking the maximum payload requirement. Therefore, the chosen design point is the required maximum payload of 5800 kg for a 400 km mission as shown in Figure 4 with the blue line and dot. The TLAR mission can be achieved as shown by the red dot.

**Figure 4.** Payload-range diagram with design point (blue) and TLAR mission (red).
