OpenRocket is a strangely addictive spacecraft simulator that lets you design your own rocket from nosecone to tail fins. Once you've finished, OpenRocket launches it into simulated space and shows you how it performs in the air.
Why you need it
It might be rocket science, but building your own spacecraft is straightforward and fun. Just select and add components (internal and external), then adjust options such as size and shape. There are helpful notes to explain any particularly esoteric terms.
Once you're confident that your creation is spaceworthy, OpenRocket will simulate its flight, giving you real-time details of its altitude, velocity and acceleration. The simulation is extremely detailed, and you can see the effect of each of your choices on its performance.
OpenRocket is brilliant fun, and completely free. Download it today and give it a try!
Download here: OpenRocket