# Total amount of torques and forces in Lunar L2 Halo orbits

I want to design a spacecraft control systems around Earth-Moon L2 Halo orbits but at the first place, I want to have an estimation about the total torques and forces which the control devices should cancel.

This estimation can help me to estimate the control devices weight and need power. But I didn't find any database about this.

UPDATE-1: I have created a list of perturbations and wants to calculate them to have a very exact model for them but at first I just want a rough number to estimate the Attitude Control devices weight and power which help me to select devices and my spacecraft total weight.

• Your question is short but the topic is complex. There are two main forces; gravity from the Earth and gravity from the Moon. Depending on what frame you are using, you would treat gravity from the Sun and other bodies as perturbations. In terms of torques there are extremely weak tidal forces from the gravity gradients, and torques from radiation pressure depending on the shape of the craft, but these are pretty small too. I think you will get more response if you add to your question a description of what you know so far, what you've read, etc. – uhoh Jan 10 '19 at 5:29
• Stack Exchange is not usually a good "first stop" when learning something new because readers are looking for specific questions that have clear, concise answers. So try some basic reading first, and read other questions and answers here as well, and then see if you can add some more specificity to your question. Welcome to Space! – uhoh Jan 10 '19 at 5:30
• How realistic do you want your model to be? Is it a simple (but still non-trivial) model or you want it as realistic as possible? You know that the more realistic it gets, the complexity goes off the chart and the mathematical tools get really complex. So which one is it? Is it only the Earth and the Moon you want to take into account? Do you want to include the motion of Earth around the Sun? do you accept moon's orbit to be circular relative to Earth, do you accept it to be classical elliptical (Keplerian) or you want perturbation from the sun, inomogeneity of gravitational fields, etc? – Futurologist Jan 12 '19 at 3:19