On the Path to Success: SWFO-L1 Mission Rehearsals

NOAA’s Space Weather Follow On – Lagrange 1 (SWFO-L1) satellite has arrived at the Astrotech Space Operations Facility in Titusville, Florida and will undergo final testing and preparations in anticipation of its launch from NASA’s Kennedy Space Center. SWFO-L1 will share a ride to space with NASA’s Interstellar Mapping and Acceleration Probe (IMAP) and the Carruthers Geocorona Observatory, all bound for the Lagrange 1 (L1) point, which is roughly one million miles from Earth.

While the spacecraft awaits launch, the Mission Operations Support Team (MOST) is already hard at work. Beginning six months prior to launch, the team has been conducting a series of intensive mission rehearsals, or exercises to build proficiency in operating this unique satellite. During these exercises, satellite operators, engineers, the satellite and instrument providers, and operations management work together to ensure every system functions as intended.

In a controlled environment, the team simulates several key events. These include establishing initial telemetry and command connectivity, performing deployments of devices such as the High Gain Antenna, activating the instruments, and performing propulsive burns to adjust our trajectory in order to cruise toward L1. They also practice inserting the spacecraft into its final orbit, which involves a series of carefully planned burns. Throughout these rehearsals, system displays and commands are tested to confirm that all of the spacecraft components and instruments operate together seamlessly. Each team member follows a carefully planned sequence of procedures to test their roles, ensuring that when launch day arrives, everything runs smoothly.

Mission rehearsals aren’t just about running through checklists. They are also meant to help build teamwork, practice problem solving under pressure, and catch unexpected issues before they become real. Much like a sports team fine-tuning their strategy before a crucial championship game, the operations team uses these practice sessions to refine procedures, coordination, and their overall skills to ensure the mission’s success.

Mission rehearsals use a simulator to test different parts of launch and post-launch events, such as powering on the satellite’s instruments to confirm that the mission’s ground system is responding properly. NOAA’s ground systems are a global network of receiving stations that distribute satellite data and its derived products to NOAA’s end users. Mission rehearsals are especially useful for launch because they simulate both standard (“nominal”) operations and scenarios when a procedure does not go as planned (“contingencies”). This way, the team will be ready for anything.  

Just as important as testing the systems involved in a launch, these satellite simulators also help train the operations personnel. Prior to the launch of SWFO-L1 in September 2025, the team will have completed five Mission Rehearsals at the NOAA Satellite Operations Facility (NSOF) in Suitland, Maryland, as well as one Ground Mission Rehearsal, conducted primarily at Wallops Command and Data Acquisition Stations (WCDAS) in Wallops Island, Virginia, with support at NSOF. Four of these rehearsals start with a simulated liftoff and cover a range of critical activities, such as powering on components and orienting the satellite, firing thrusters to adjust its trajectory, deploying the high gain antenna and magnetometer boom, and more. Another rehearsal focuses on the ground system, including the new SWFO Antenna Network (SAN) that will be used to communicate with the satellite in space. A subsequent rehearsal centers on power up and calibration activities needed for each of the satellite’s suite of four instruments.

The SWFO-L1 ground lead, Toby Hutchings, describes a mission rehearsal as “an exercise that involves executing a series of procedures used as a training mechanism for personnel and a validation tool for equipment and products.” After all, a mission rehearsal’s goal is to instill confidence in the teams that will execute the first-time flight activities. He also calls the rehearsals “the lively part of operations.” Mission rehearsals are not about predicting every single contingency, but more about “training the ability to deal with unforeseen events or circumstances” and working under pressure, according to Toby Hutchings. During an actual launch and early orbit phase, if something goes wrong, the team may have only moments to react. These rehearsals help the operations team and everyone else involved practice gaining proficiency in controlling the spacecraft, protecting the mission, and performing orbital analysis. It’s rocket science in action!

Mission rehearsals also strengthen team coordination in more realistic operational environments. The overall goal is to ensure that all flight system elements and the operations team can meet mission objectives as one cohesive unit. The program also focuses on reducing the amount of risk in space-based operations that people, processes, procedures, or systems may cause. Last but not least, a mission rehearsal’s goal is to instill confidence in the teams that will execute the first-time flight activities. Mission rehearsals also bring together other agencies, such as NASA or private industry, and in this case, spacecraft vendor BAE Systems, the ground antenna vendor KBR, and L3 Harris, who built the command and control system.  

As we prepare for the upcoming SWFO-L1 launch, scheduled for no earlier than September 23, 2025, mission rehearsals ramp up, much like a sports team intensifying practice for a big championship game. The SWFO-L1 team is honing their skills the way professional athletes train to anticipate and respond to game-changing moments, ensuring they are ready for anything that game day (or launch day) might throw their way. With the help of mission rehearsals, the SWFO-L1 mission is gearing up for the final stretch, ready to score big and deliver a winning performance come launch day!