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Thread moved from the technical forums, so no Homework Template is shown.

**Summary::**You have a spacecraft the size of a cube (2x2x2 m^3, m=3000 kg. It has 24 thrusters (2N each) and one main engine. For preparing your spacecraft for maneuvers, you want to rotate by 180 degrees. For the rotation, you'll use n=4 attitude thrusters per burn.

What am I doing wrong? Please read below.

I have this project assignment. I'll say the questions and explain what I did.

Q1) Minimum total maneuver to slew the spacecraft by 180 degrees=? (assume center of mass is in middle of cube).

Answer: I used this formula:

tb=sqrt(θm*Iz/n*F*L), where I already have θm=180 degrees or pi, Iz=(2*m*(b^2))/3=8000 kg*m^2, n=4, L=d/2=0.5 m, F=2N.

From all these I get tb=79.26 sec. So tm=4 (the thrusters)*tb=317.04 sec.

Q2) It is given a=0.95 and e=0.85. What is the temperature (in Celsius) when reaching Mars, when you know that only one of the faces is illuminated by the Sun and that the heat flow is distrubuted homogeneously?

Answer: I used this formula: T=(a/e)^(1/4) * ((S*An)/(σ*Atot))^(1/4).

Atot=24 m^2, right? So An=2 m^2. (A are surfaces). S=1.4 kW/m^2 and σ=5,67*10^(-8) W/m^2*K^4. These two are contstants.

With these numbers I found T=217.23 K, so T=-55.92 Celsius.

Q3) The power which is generated in the spacecraft can be considered as input power for the radiation balance. How much power (in Watt) should be dissipated inside the spacecraft , in order to achieve 0 Celsius?

Answer: 0 Celsius in Kelvin is 237.15, right? So I decided to use this formula: Pe=e*σ*T^4*Atot. I have everything, so I find Pe=3658.5 Watt.

I believe I'm doing something wrong with my calculations with the numbers, or I'm using wrong formulas. Whatever it is, the results above are not right.

What's you insight on this problem? Are the calculations wrong? Thanks in advance.