Problem on spacecraft
Assuming that ground stations are equally distributed on the Earth, how many ground stations are required to maintain constant contact with a spacecraft at 750 km altitude, and 72 degrees inclination?
Expert
Given:
θ (theta) = 72°, Perpendicular distance of spacecraft=750 km.
We know that, 1° = π/180 radian, Radius of earth=6400 km. So, 72°= (72*π)/180 radian, = 2*π/5Since,θ = Arc/Radius,
Therefore, Arc = θ*Radius, =2*π*750/5, = 300π
Circumference of earth = 2*π*Radius = 2*π*6400
No. of space station = Circumference of earth/2*Arc = (2*π*6400)/(2*300*π) = 21 space station (approx.)
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