The Minimum Energy Orbits to travel to Jupiter and Neptune are shown in the diagram below.
Energy and Velocity Changes for Orbit Transitions
|Energy Change |
|Earth orbit to Jupiter Transfer Orbit||8.7||297|
|Jupiter Transfer orbit to Jupiter orbit||5.6||57.8|
|Earth orbit to Neptune Transfer Orbit||11.5||409|
|Transfer orbit to Neptune orbit||4.1||13.8|
|Earth Orbit to Jupiter Orbit||-||355|
|Earth orbit to Neptune Orbit||-||423|
|Transition||Velocity Change (km/s)||Energy MJ/kg|
|Earth Orbit to Orbit #1||9.2||316.5|
|Orbit #2 to Neptune Orbit||2.30||9.9|
So the use of Jupiter's Gravitational Assist saves (423 - 326) = 97 MJ/kg. Another benefit is a reduction of the velocity change needed at Neptunes orbit with there is less fuel available.
Created by L.Bogan - June 07, 2005