For Wednesday's event, NASA will drop an Orion test capsule from a C-17 military aircraft at an altitude of over six miles. It will be used to verify that the capsule's 11 parachutes, cannon-like mortars and pyrotechnic devices deploy in sequence during the landing procedure. Each element in the sequence has to work perfectly to be able to slow down the spacecraft for a safe landing.
Back in 2013, Orion engineer Stu Mcclung explained that putting the landing system through various scenarios is necessary, because parachute deployment "is inherently chaotic and not easily predictable." That's why these past years, NASA dropped test versions of Orion into the ocean, tested it in various weather conditions and had it go through several failure scenarios to see if the system works as intended. The Orion capsule was designed to take humanity beyond Low Earth Orbit, into the moon, Mars and farther into outer space. It's scheduled to launch on top of NASA's Space Launch System for the first time next year.