Lagrange points are positions where a small body can orbit in sync with two larger masses. Why L1, L2, and L3 are unstable but useful, why L4 and L5 are stable and ancient, and what JWST's halo orbit at L2 costs to maintain.
How do spacecraft generate power? From silicon solar cells degraded by particle radiation to plutonium-fuelled RTGs running for decades — the engineering of spacecraft power systems and the constraints that determine which technology fits which mission.
How does spacecraft thermal control work? From MLI blankets and heat pipes to phase change materials — a clear guide to keeping satellites at 20°C across a 270°C temperature swing.