The payload fairing is the equipment used to protect the spacecraft and the third stage during the early portion of the boost phase when the aerodynamic forces from the atmosphere could affect the rocket. It is almost always in form of the nose cone at the top of the rocket that protects the spacecraft payload against the impact of dynamic pressure and aerodynamic heating during launch through an atmosphere. An additional function on some flights is to maintain the clean room environment for precision instruments. Once outside the atmosphere the fairing is jettisoned, exposing the payload to outer space.
Falcon 9 Fairings
SpaceX’s Falcon 9 payload fairings are 43 feet (13 meters) tall and just over 17 feet (5 m) wide. When assembled, they form a shell around satellite payloads to protect them during the first few minutes of a launch. Made of a carbon composite material, the fairing protects satellites on their way to orbit. The fairing is jettisoned approximately 3 minutes into flight, and SpaceX continues to recover fairings for reuse on future missions. Note that, SpaceX’s Dragon spacecraft, which carry cargo and crew to space, aren’t covered by a fairing.
Falcon 9 fairings recovery
Fairings might appear very simple and inexpensive (as compared to the rocket), but it is not too cheap to let it burn in the atmosphere. In Falcon 9, these fairings cost 6 million USD each. SpaceX has recovered and reused the fairings multiple times. SpaceX has added steering thrusters and parachutes to some fairing halves in order to reuse the fairings on multiple flights.
To catch them in the ocean, SpaceX has added giant nets to two retrieval ships, called Ms. Tree and Ms. Chief, to recover the fairings at sea. The recovery method involves using drogue parachutes for slowing them down and then intercepting them use of big nets carried by those ships. Recently, SpaceX has moved to simply recovering fairings from the water after splashdown.