What happens before the rocket leaves the launch pad? This article provides a quick overview of launch operations processes.
Launch operations includes the procedures necessary for launching payloads to orbit. It does not include the management of payload or crew (for crewed vehicles) on orbit, which are generally considered mission operations. Launch operations can be divided into the following overlapping steps;
Processing and integration of vehicle: includes the assembly and testing of the launch vehicle, as well as the integration of electrical, mechanical, and fluid systems. For reusable, or partially reusable vehicles, this step also includes testing of refurbished components to assure that their characteristics remain within design specifications.
Processing and integration of payloads: comprises the assembly, testing, and mechanical and electrical integration of payloads with the launch vehicle. Payloads must also be tested with the vehicle's mechanical and electrical systems to assure they will not interfere with proper operation of the launch vehicle.
Launch management and control: includes the preparation and testing of the launch pad, the control center, and all of the other facilities critical for launch, as well as the actual launch countdown. During countdown, each critical subsystem must be continually monitored.
Post launch responsibilities: includes the retrieval, return, and refurbishment of all reusable vehicle components, and the cleanup and post-launch refurbishment of the launch pad. The launch of reusable, or partially reusable, vehicles introduces an extra layer of complexity to the launch process and involves additional facilities and personnel.
Logistics: encompasses the provision of spares, and replacement parts, as well as the scheduling of tasks, personnel, and equipment, which must be coordinated across the entire launch process.
For an overview regarding what happens after a rocket leaves the launch pad see this article After Artemis Has Successfully Launched… What Happens Next?