Propulsion - Orbital Mechanics (page 6 of 6)
The position of the planets over the duration of the mission is shown below. The sun is not a major factor in terms of thermal noise as the satellite dish will never be pointed anywhere near the sun.
Figure 8: Swept
Out
Line-of-Sight between Venus and Earth
The total acceleration required of the space craft thrusters is formulated below:
Where a = F/m. M is the
mass of the space craft and F is the constant force applied by the
thrusters. We
neglect the fact that the mass of the spacecraft is lessened after
jettisoning.
This gives us the fuel we need for station keeping. The sum of the
velocity
changes is equal to:
Based on previous missions, the fuel is estimated
to be 1500kg (3)