a spacecraft is in a circular orbit about an asteroid with a gravitational parameter of mu. assume that the asteroid is instanteously replaced with a different asteroid that has a mu value half that of the original asteroid. the position and velocity of the spacecraft remains unchanged at the instant that mu decreases. answer the questions that follow. a) what type of conic is the spacecraft on after the decrease in mu? b_ what are the values of eccentricity (e) and the semilatus rectum (p) of the orbit after the decrease