# Electrical power system of a spacecraft mission to a comet

• Andy314
In summary, to calculate the solar array power capacity required at the start of the mission, we need to determine the power requirement at the end of the mission, which is 510 W. We also need to calculate the total power output from the Sun, which is 3.8x10^26 W, and take into account the solar array degradation of 30% over the 10-year mission and the Sun angle off normal of 45°. Using the equation P(t) = [P][/o][e][/(-0.693t/[τ][/(1/2)]), where P(t) is power at any given time, P_o is initial power, t is duration of mission and τ_1/2 is

## Homework Statement

Calculate the solar array power capacity required at the start of the mission
• Mission duration is 10 years
• Distance from the Sun at end of mission is 4.8x[10][/8] km
• The power requirement for the spacecraft at the end of life is 510 W
• Solar array degradation over mission life = 30%
• Sun angle off normal = 45°
• Silicon solar cell efficiency at the spacecraft operating temperature = 12.5%
• Total power output from the Sun = 3.8x[10][/26] W
• The mass per unit area of a solar array is 2 kg [m][/-2]

## Homework Equations

Could only think of P(t) = [P][/o][e][/(-0.693t/[τ][/(1/2)])]
where P(t) is power at any given time, P_o is initial power, t is duration of mission and τ_1/2 is the time required for half of the power to be used up.

## The Attempt at a Solution

No real progress :(