**What is the equation for increasing Periapsis Height during Apoapsis Burn ???**

Hi, I am stuck at a problem I can't figure out at all, and it has to do with a space-craft conducting a burn once it is at APOAPSIS.

*figure 1*

With the equation above, where the angle to the spacecraft is Θ = 0° ; when I increase my current velocity from 1660 km/s to 2000 km/s ... my Apoasis increases and the formula checks out.

The equation is a problem because what if I am at Apoapsis and want to increase my Periapsis altitude using an equation, just like the image below:

*figure 2*

I have reviewed websites such as this link: http://www.braeunig.us/space/orbmech.htm#elements under

*motions of planets and satellites*but this is a problem when I program this using the equation above...

*Vp, Va, Rp, Ra and e are all dependent on each other ...*with the following

relationship:

[math]r_{p}v_{p}=r_{a}v_{a}[/math] where

**e = [imath]\frac{r_{p}v^{2}_{p}}{GM}-1[/imath]**

given 3D vectors [imath]\acute{v}[/imath] and [imath]\acute{r}[/imath] of a spacecraft, when I move these values such that it is at apopasis... the apopasis

continues to grow when increasing delta V to conduct

*hohmann's transfer*

PLEASE HELP...

PLEASE HELP...