// ORBITAL LOGISTICS AND PROPULSION TERM
Scrub
To cancel or postpone a launch or other planned operation, usually due to technical issues, weather, or other unforeseen problems. A scrub means the event will not happen as scheduled.
TECHNICAL DEFINITION
To Scrub means to cancel or postpone a planned launch attempt or critical operation, typically due to technical malfunctions, adverse weather conditions, range safety violations, or other factors that would jeopardize mission success or safety.
BACKGROUND
The Space Launch System (SLS) is an American two-stage super heavy-lift expendable launch vehicle used by NASA. The primary launch vehicle for the Artemis program, SLS is designed to launch the four-person Orion spacecraft for missions to the Moon, on a trans-lunar injection trajectory. The rocket first launched in November 2022, carrying the uncrewed Artemis I mission. Its first crewed launch was for the Artemis II lunar flyby in April 2026, becoming the second launch vehicle to carry humans beyond low Earth orbit (LEO), after NASA's Saturn V of the Apollo program.
READ MORE ON WIKIPEDIASYNONYMS & ALIASES
- Postpone
- Cancel
- Delay
- Abort
USAGE NOTE
The launch was scrubbed due to high winds at the launch site.
DEVELOPERS
Organizations developing technology related to Scrub.
The National Aeronautics and Space Administration operates Launch Control Centers, such as the one at Kennedy Space Center, which use sophisticated software and hardware to monitor every aspect of a launch vehicle's health, ground systems, and weather, forming the basis for 'go/no-go' and scrub decisions.
As a vertically integrated launch provider, SpaceX develops its own automated launch countdown sequencers, vehicle health monitoring systems, and ground support equipment. This technology is designed to automatically detect anomalies that would trigger a hold or scrub, improving launch reliability and safety.
ULA is known for its high-reliability launch services. The company develops and operates advanced pre-launch checkout and validation systems for its Atlas and Vulcan rockets, designed to meticulously verify all systems are nominal to prevent last-minute technical issues that often lead to scrubs.
L3Harris provides critical range and launch support technology, including telemetry, tracking, and flight termination systems. Their instrumentation provides the real-time data on vehicle performance and weather conditions that launch controllers use to monitor the countdown and make scrub decisions.
Operating as a federally funded research and development center (FFRDC), The Aerospace Corporation provides mission assurance and technical analysis for national security space launches. They develop analytical tools and methodologies to assess launch readiness and identify risks that could lead to a scrub or mission failure.
Vaisala specializes in environmental and weather measurement technology. They provide critical systems for launch sites, including lightning detection networks and weather radar, which deliver the precise, localized atmospheric data needed to make weather-related scrub decisions, a primary cause of launch postponements.
Rocket Lab develops technology for high-cadence, responsive launch with its Electron vehicle. This includes highly automated ground systems and vehicle check-out procedures designed to minimize human intervention and quickly identify any issues, thereby reducing the likelihood of scrubs that would disrupt a tight launch schedule.
The European launch service provider operates the Guiana Space Centre and develops the complex command and control systems for its Ariane and Vega family of rockets. These integrated systems manage the entire launch chronology, from fueling to final checks, and are essential for detecting issues that necessitate a scrub.