$LastChangedDate: 27-Juil-2011 $

# CL_cw_twoImpulse

Two-impulse transfer

## Calling Sequence

       [delta_vi,delta_vf]=CL_cw_twoImpulse(pv_ini,pv_fin,alt,t_transfer[,er[,mu]])

## Description

- Computes the delta_v needed for a two impulse transfer.

  The transfer is performed with a maneuver at the starting point (delta_vi at A) and a maneuver at the end point (delta_vf at B).

  The local orbital reference frame tied to the target is LVLH.

## Parameters

pv_ini:

  Initial chaser position and velocity vector (A in the figure) in the target's LVLH frame [rx;ry;rz;vx;vy;vz]_ini [m] (6x1)

pv_fin:

  Final chaser position and velocity vector (B in the figure) in the target's LVLH frame [rx;ry;rz;vx;vy;vz]_fin [m] (6x1)

alt:

  Target's altitude [m]

t_transfer:

  Transfer time (time between the two maneuvers) [s]

er:

  (optional) Equatorial radius [m] (default is %CL_eqRad)

mu:

  (optional) Gravitational constant [m^3/s^2] (default value is %CL_mu)

delta_vi:

  Delta_v for the first maneuver [m/s] (3x1)

delta_vf:

  Delta_v for the second maneuver [m/s] (3x1)

## Authors

- CNES - DCT/SB

## See also

- CL_cw_Nmatrix

- CL_cw_Mmatrix

## Bibliography

- 1) Mecanique spatiale, CNES - Cepadues 1995, Tome II, 16.3

- 2) Orbital Mechanics for engineering students, H D Curtis, Chapter 7 (section 7.5)

## Examples

    pv_ini=[-30000,0,6000,10.18,0,0]'
    pv_fin=[-15860,0,0,0,0,0]'
    alt=450000;
    omega=CL_kp_params('mm',%CL_eqRad+alt);
    periode=2*%pi/omega;
    t_transfer=periode/2;
    [delta_vi,delta_vf]=CL_cw_twoImpulse(pv_ini,pv_fin,alt,t_transfer)