This category covers how spacecraft are designed and operated, and how space is used as a platform for science, observation, and experimentation. Coverage at Interesting Engineering spans space discoveries, launch vehicles, satellites, space stations, planetary missions, and space-based observatories. That includes communications and navigation satellites, Earth observation and climate monitoring, astrophysics missions, planetary science, heliophysics, and exploration beyond Earth orbit. Space systems face constraints that don't exist elsewhere: mass limits, radiation exposure, extreme temperatures, long delays, and the inability to repair hardware once it's deployed. On the science side, the category looks at how instruments are designed, calibrated, and validated, and how raw data becomes usable science.