2. What is the difference between prograde and retrograde orbits? What are some examples of these? 3. What does conservation of momentum mean? If two asteroids collided with each other, what is the total momentum before and after the collision? What about if there are hundreds of small fragments created by the collision? 4. Use the forces involved in spaceflight to explain how a rocket achieves vertical motion in the upwards direction during a launch 5. Does lift play a role during a rocket launch? How does it affect the launch? 6. How does a rocket's fuel consumption change as the rocket ascends? 7. Why do rocket scientists use different stages? What's the difference between parallel and serial staging? What are the pros/cons of each