Falcon 9 Launches Missile Detection Satellites

     USSF-124, a classified payload for the US Missile Defense Agency, was launched aboard a SpaceX Falcon 9 rocket on February 14, 2024. The rare daylight mission left Cape Canaveral Space Force Station’s LC-40 at 5:30 pm EST. Aboard were six satellites designed to detect and track faint-signal hypersonic missiles. Two Hypersonic and Ballistic Tracking Space Sensor (HBTSS), built by Northrup Grumman, were the primary payload. Originally set for last year, unspecified technical issues delayed the mission. Four SDA Tranche-0 warning satellites, constructed by L3 Harris, shared the ride – these were not ready for a previous Tranche mission launched in 2023.

Photo credit Dennis Hlavsa

      At 38 minutes before launch, RP-1 flowed into both stages, a super-chilled version of kerosene which allows more fuel to fit inside the Falcon 9. Liquid oxygen, needed for combustion, began to fill simultaneously. Sixteen minutes before t-zero, LOX flowed in the second stage, which is
always a brand-new vehicle. Actions controlled by computers ensured significant milestones were executed on time, including engine chill-down and tank pressurization. Nine Merlin engines commenced ignition, lofting the Falcon 9 skyward. Separation occurred 2:29 seconds later. As the second stage ignited its lone engine moments later, the first, B1078, performed a flip maneuver then a boost-back burn. Grid fins and cold gas thrusters aligned the descending stage. Six minutes after launch, three engines ignited for the entry burn. This began to slow down the rocket as it lowered to CCSFS. The landing burn allowed B1078 to gently touch down on the concrete pad at LZ-2. Moments later, a double sonic boom spread across the local area. The stage made its 7 th flight; previous deliveries include Crew-6, SES mPower, and four Starlink missions.
Due to the classified nature of USSF-124, little post-separation information was made public.