Our Task as Designers:
Given:
(1) Payload mass, WL = 10 kg
(2) Mission Delta Vee, V = 9100 m/sec
(3) Specific Impulse, Isp = 400 sec
Invent a 4th input parameter called GLOW (Gross Lift-Off Weight):
(4) GLOW = Wp+Wi+WL
Find:
Substituting for GLOW, the Rocket equation becomes 1 Equation in 1 unknown:
(1) Inert Wt., V = g*Isp* ln[ GLOW / (Wi + WL) ]
(2) Propellent Wt., V = g*Isp* ln[ GLOW / (GLOW - Wp) ]
Copyright (c) 2000 by Rainier Anacker
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