Table B.5.

Tsiolkovsky Rocket Equation Calculations for Phase C2

C2: RST (Return SpaceTug)	Step1	Step2
Vehicle	Tug1RST	RST
Init Mass (mt)	44.20	22.80
Final Mass (mt)	25.70	14.90
Prop (mt)	18.50	7.90
Isp (s)	450.50	450.50
ΔV (km/s)	2.40	1.88
Margin (mt)	0.15	12.15
Margin (boil-off days)	1.5	121.2

Table B5 comments.

To LEO: Tug1RST launched on F9, 2 weeks later RST launched on a F9.

Tug1RST Initial Mass = 21.40 mt after 14 days LOX/LH₂ boil-off.

RST Initial Mass = 22.80 mt (full propellant load of 20.05 mt).

To LLFPO.

Step1: Tug1RST pushes RST towards TLI and then separates and deorbits to Earth.

Step2: RST pushes itself to TLI, then to LLFPO and RPOD with Gateway (if present).