Question 4 10 points Save Answer If you have a spacecraft that is in orbit around the Sun at Mars' distance from the Sun. This would be the case for a forthcoming "sample return mission", now ready to return to Earth from Mars. What is the best way to do that, expending the least possible energy? Speed it up just enough so that it reaches Earth's orbit at the moment the spacecraft is as close to the Sun as it can be in its new elliptical orbit, before starting to back out. It should be the same moment that Earth reaches that point in its orbit. Slow down just enough so that it reaches Earth's orbit at the moment the spacecraft is as close to the Sun as it can be in its new elliptical orbit, before starting to back out. It should be the same moment that Earth reaches that point in its orbit. Shoot straight for Earth at the highest speed you can manage, "leading" the target a little as needed depending on where Earth and Mars are the moment the return home stars. Head directly at the Sun, then brake hard when you get to Earth's orbit and wait for Earth to catch up