Rocket man, burning out his fuse up here alone
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.
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.