I apologize if my question is badly formulated I know it's really specific but here what I would like to know :

I managed to compute the turning angle of the velocity for a body along a hyperbola trajectory thanks to the following equation :

$\delta = 2 \arcsin(1/e)$

This equation give me the turning angle at the end of the flyby. What I would like to know is the original angle, at start, of that spacecraft with respect to the planet velocity vector.

I thought using the HORIZONS Web-Interface and put the settings as following :

  • Ephemeris Type : VECTORS
  • Target Body : The spacecraft (e.g. Voyager 1)
  • Coordinate origin : The planet (e.g. Jupiter)
  • Time Span : Start of fly-by (e.g. 1979-Mar-4 / 1979-Mar-5 )

But then I'm completely lost in the generated tables ! Am I at the right place to find what I'm looking for ?

Thanks for your help

  • $\begingroup$ If the transfer orbit is coplanar with the planet's orbit and the planet orbit is circular, it'd be the flight path angle: en.wikipedia.org/wiki/Elliptic_orbit#Flight_path_angle . Another option might be to get the space craft vector and planet vector in a sun centered coordinate system. $\endgroup$ – HopDavid Apr 11 '17 at 12:28

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.