ENAE 483/788D
Principles of Space Systems Design
Fall, 2002

Question 2:

For both ENAE 483 and ENAE 788D:

a) NORAD radars have just discovered a Borg ship in low earth orbit, evidently monitoring us prior to assimilation. (Resistance is futile!) The ship is a cube, 1 km on a side. How many 1-mm sized impacts should the ship receive each year from micrometeoroids and orbital debris? (Use the MMOD chart from the lecture notes.)

b) The shielding on the ship can protect against any impacts smaller than 5 cm. How long can they expect to stay in orbit before they receive a damaging impact?

c) Following a particularly bad impact, the Borg ship goes out of control and begins to enter the atmosphere. It is oriented such that the side faces are parallel to the velocity vector, and the leading edge is 30deg off the velocity vector (see diagram). What are the lift and drag coefficients in this orientation?

For ENAE 788D only:

d) Following the impact, the Borg cube pops out a spherical command module with a 100m diameter. What are the lift and drag coefficients of the spherical module in Newtonian flow?