# poliastro.twobody.thrust¶

## Package Contents¶

### Functions¶

 change_a_inc change_argp Argument of perigee change, with formulas developed by Pollard. change_ecc_quasioptimal Quasi optimal eccentricity-only change, with formulas developed by Pollard. change_inc_ecc Simultaneous eccentricity and inclination changes.
poliastro.twobody.thrust.change_a_inc(k, a_0, a_f, inc_0, inc_f, f)
Guidance law from the Edelbaum/Kéchichian theory, optimal transfer between circular inclined orbits

(a_0, i_0) –> (a_f, i_f), ecc = 0.

Parameters
• k (float) – Gravitational parameter.

• a_0 (float) – Initial semimajor axis.

• a_f (float) – Final semimajor axis.

• inc_0 (float) – Initial inclination.

• inc_f (float) – Final inclination.

• f (float) – Magnitude of constant acceleration

Notes

Edelbaum theory, reformulated by Kéchichian.

References

• Edelbaum, T. N. “Propulsion Requirements for Controllable Satellites”, 1961.

• Kéchichian, J. A. “Reformulation of Edelbaum’s Low-Thrust Transfer Problem Using Optimal Control Theory”, 1997.

poliastro.twobody.thrust.change_argp(k, a, ecc, argp_0, argp_f, f)

Guidance law from the model. Thrust is aligned with an inertially fixed direction perpendicular to the semimajor axis of the orbit.

Parameters

f (float) – Magnitude of constant acceleration

poliastro.twobody.thrust.change_ecc_quasioptimal(ss_0, ecc_f, f)

Guidance law from the model. Thrust is aligned with an inertially fixed direction perpendicular to the semimajor axis of the orbit.

Parameters
• ss_0 () – Initial orbit, containing all the information.

• ecc_f (float) – Final eccentricity.

• f (float) – Magnitude of constant acceleration

poliastro.twobody.thrust.change_inc_ecc(ss_0, ecc_f, inc_f, f)

Guidance law from the model. Thrust is aligned with an inertially fixed direction perpendicular to the semimajor axis of the orbit.

Parameters
• ss_0 () – Initial orbit, containing all the information.

• ecc_f (float) – Final eccentricity.

• inc_f (float) – Final inclination.

• f (float) – Magnitude of constant acceleration.