Spacecraft
launch opportunities are planned far in advance
using geometry, spherical
trigonometry and orbital mechanics. If a launch
window is not practical for a particular orbit,
then the spacecraft may launch into a parking orbit
and transfer to final orbit later.
Launch
Windows
Time
of launch depends on the relationship between the
launch site and desired orbit. Given Earth's rotation,
the spacecraft launches when the site comes under
the intended orbital track.
Location
latitude must be less than or equal to the inclination
of the nominal orbit.
Velocity
is dependent upon launch site latitude and resultant
eastward rotational velocity along with the velocity
required to overcome gravity and put the vehicle
into its desired orbit.
