Falcon 9 to Launch SDA Tranche 1 Transport Layer A [Scrubbed]

SpaceX is targeting Monday, 5 October 2026, for a Falcon 9 launch of the United States Space Force’s Space Development Agency’s fourth Tranche 1 Transport Layer mission from Space Launch Complex 4 East at Vandenberg Space Force Base. Liftoff is targeted for 4:16 a.m. ET (1:16 a.m. PT), with a backup opportunity on Tuesday, 6 October, at 4:08 a.m. ET (1:08 a.m. PT).

Space Launch Schedule marked the attempt “Go For Launch” on 30 September at 12:02 p.m. ET, after previously listing the mission as no earlier than 5 October and pending confirmation on 25 September. This payload will be focused on carrying a military data network plane, as part of the contract with the Space Development Agency.

Twenty-One Satellites, One Plane

On the SDA-T1A mission page, SpaceX says Falcon 9 will deploy 21 data-transport satellites, forming the fourth orbital plane in the SDA’s Proliferated Warfighter Space Architecture.

This is the fourth of nine Tranche 1 missions Falcon 9 will launch on behalf of the SDA.

SpaceX describes the architecture as a mesh of optically connected spacecraft in low-Earth orbit. The optical links are laser connections between satellites, allowing data to move through the constellation without returning to a ground station at every step. The network is designed for global military tactical communications as well as missile warning, indication, and tracking. These 21 satellites will add another plane to the architecture toward completing Tranche 1.

Sixth Flight Back to the Pad

The first-stage booster, B1103, on this mission will make its sixth flight. SpaceX says it previously launched NROL-179, SDA-T1TL-E, and three Starlink missions. After stage separation, the booster is planned to land at Landing Zone 4 at Vandenberg, making this a return to the launch site rather than a droneship recovery. SpaceX’s approximate mission timeline places touchdown at about seven minutes and 19 seconds into the flight, with fairing separation at about three minutes and four seconds.

The webcast is scheduled to begin about 10 minutes before liftoff on the mission page and on X @SpaceX.

Residents of Santa Barbara, San Luis Obispo, and Ventura counties may hear one or more sonic booms as the booster returns. How noticeable they are will depend on weather and other conditions that morning. Next Spaceflight lists the liftoff at 4:16 a.m. ET and shows the window closing at 4:28 a.m. ET.