I'm trying to figure out the answer to this question. It seems to easy, so I have my doubts.

Question:
Calculate the minimum change in velocity (delta V or ∆V) required for the Orion MPCV to decrease its altitude to 60 miles if it’s orbiting with an apogee of 260 miles and a perigee of 220 miles above the surface of Earth

Use the rule of thumb that below an altitude of 500 miles, for every 2 feet per second (fps) change in the orbiting space craft’s velocity its altitude will change by 1 mile

I have the answer of -320/fps. by subtracting apogee (260) and perigee(220)
getting 160. Then multiplying -2X160 get my answer of -320/fps

Im not asking anyone to do the problem for me but guidance or example of a similar problem. thank you

160 milesalt decrease* 2fts/*milealt=your answer.

I'm not sure I understand your example. can you elaborate?

I repeated what you did...and you don't understand it?

To calculate the minimum change in velocity (delta V or ∆V) required for the Orion MPCV to decrease its altitude to 60 miles, you'll need to apply the rule of thumb provided.

Let's break it down step by step:

1. Calculate the current altitude of the Orion MPCV: Since the apogee (highest point) is given as 260 miles and the perigee (lowest point) is given as 220 miles, you can find the average altitude by adding these two values and dividing by 2: (260 + 220) / 2 = 240 miles.

2. Calculate the difference in altitude: Subtract the final altitude of 60 miles from the initial average altitude of 240 miles: 240 - 60 = 180 miles.

3. Apply the rule of thumb: According to the rule, for every 2 feet per second (fps) change in velocity, the altitude changes by 1 mile. Since we want to decrease the altitude, the change in velocity will be negative. Therefore, for a change in altitude of 180 miles, the change in velocity will be -180 * 2 = -360 fps.

So, the minimum change in velocity (delta V or ∆V) required for the Orion MPCV to decrease its altitude is -360 fps.

It seems that your answer of -320 fps is incorrect. You mentioned subtracting the apogee (260) and perigee (220) to get 160, then multiplying by -2. However, this calculation does not match the problem's requirements and the rule of thumb provided. Make sure to follow the steps outlined above to correctly solve similar problems.