CosmicElightTool is your helper for quick space math and mission checks. It lets you find payload mass fraction, staging efficiency, and burn time with ease. You can see how fast a craft speeds up under thrust and solve the rocket equation without headaches. Check specific impulse (Isp) and fuel mass ratio to size engines and tanks the simple way. Estimate reentry heat load to plan safe returns. Use the G-Force Calculator to know what crews or payloads will feel. Plan smart flybys with the Gravity Assist tool to save fuel and gain speed. Built for students, hobby rocketeers, and makers who want fast, clear answers with plain words.