SpaceXLaunch SuccessfulGovernment/Top Secret

USSF‑366

Name: Falcon 9 Block 5 | USSF-366
Start: 2026-08-16T01:50:45Z
Location: Space Launch Complex 4E, Vandenberg SFB, CA, USA

Falcon 9 Block 5

Launched Sun, Aug 16 · 1:50:45 AM UTC2026-08-16 01:50:45 UTCSpace Launch Complex 4E, Vandenberg SFB, CA, USA

Reached orbit
Booster landed on Of Course I Still Love You

Follow SpaceX in the app Watch the replay

Success

Reached Low Earth Orbit

Landed

B1088 Landed

The first stage landed on Of Course I Still Love You, on its 18th flight.

Worldwide

193rd

orbital launch attempt in 2026

SpaceX

99th

launch this year

Space Launch Complex 4E

52nd

launch from this pad this year

Pad turnaround

3 d 21 h

since the pad's previous launch

Replay

Replay: SpaceX USSF-366

The Flight Plan

Planned times, from liftoff at 1:50 AM UTC. The result is at the top of the page.

Countdown9

T−38:001:12 AMLaunch director verifies go for propellant load
T−35:001:15 AMStart of propelland loading
T−35:001:15 AMStart of liquid oxygen loading in the first stage
T−16:001:34 AMStart of liquid oxygen loading in the second stage
T−7:001:43 AMStart of engine chilling
T−1:001:49 AMThe onboard computer takes control over the countdown and runs last checks
T−1:001:49 AMFuel tanks are pressurized to flight levels
T−0:451:50 AMLaunch director verifies go for launch
T−0:031:50 AMStart of the engine ignition sequence

Show the countdown (9 steps)

T−38:001:12 AMLaunch director verifies go for propellant load
T−35:001:15 AMStart of propelland loading
T−35:001:15 AMStart of liquid oxygen loading in the first stage
T−16:001:34 AMStart of liquid oxygen loading in the second stage
T−7:001:43 AMStart of engine chilling
T−1:001:49 AMThe onboard computer takes control over the countdown and runs last checks
T−1:001:49 AMFuel tanks are pressurized to flight levels
T−0:451:50 AMLaunch director verifies go for launch
T−0:031:50 AMStart of the engine ignition sequence

Ascent6

T+0:001:50 AMFirst upwards movement of the rocket
T+1:071:51 AMMaximum dynamic pressure
T+2:251:53 AMCut-off of the main engine
T+2:291:53 AMSeparation of the second stage from the first
T+2:361:53 AMFirst start of the second engine
T+2:581:53 AMSeparation of the payload fairing

Booster Return4

T+6:011:56 AMStart of the atmospheric entry burn
T+6:251:57 AMEnd of the atmospheric entry burn
T+7:581:58 AMStart of the first stage landing burn
T+8:201:59 AMLanding of the first stage

Mission

USSF-366 is a classified mission for the United States Space Force. It is possibly a batch of classified LEO satellites based on SpaceX’s Starshield satellite bus, based on locations of rocket stage drop zones being exact fits with previous Starlink Group 15 launches.

Launch Provider

SpaceX

Commercial · United States of America · Founded 2002 · CEO Elon Musk

Space Exploration Technologies Corp., known as SpaceX, is an American aerospace manufacturer and space transport services company headquartered in Hawthorne, California. It was founded in 2002 by entrepreneur Elon Musk with the goal of reducing space transportation costs and enabling the colonization of Mars. SpaceX operates from many pads, on the East Coast of the US they operate from SLC-40 at Cape Canaveral Space Force Station and historic LC-39A at Kennedy Space Center. They also operate from SLC-4E at Vandenberg Space Force Base, California, usually for polar launches. Another launch site is being developed at Boca Chica, Texas.

Launches

742

Successful

727

98%

Landings

687

of 715

Upcoming

136

scheduled

FliesFalcon Starship Dragon

All SpaceX launches Website Wikipedia

Updates

Aug 16 · 3:27 PM
Launch success.
Cosmic_Penguin
Aug 16 · 4:07 AM
Spacecraft separation.
Cosmic_Penguin
Aug 16 · 1:51 AM
Liftoff.
Cosmic_Penguin
Aug 16 · 1:38 AM
Unofficial Re-stream by SPACE AFFAIRS has started
Launch Library 2
Aug 15 · 6:58 PM
Now targeting Aug 16 at 01:50 UTC
Cosmic_Penguin

Show earlier updates

Aug 15 · 4:35 PM
Now targeting Aug 15 at 23:47 UTC
Cosmic_Penguin
Aug 15 · 4:58 AM
Now targeting Aug 15 at 21:54 UTC
hitura-nobad
Aug 10 · 8:39 PM
GO for launch.
Cosmic_Penguin
Aug 6 · 7:30 PM
Added launch per NOTAMs; Payload identities very uncertain.
Cosmic_Penguin

Falcon 9 Block 5

Vehicle history

Height

70m

Diameter

3.6m

To low Earth orbit

22,800kg

Liftoff thrust

7,607kN

Space Launch Now for iOS and Android

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SpaceXLaunch SuccessfulGovernment/Top Secret

USSF‑366

Falcon 9 Block 5

Launched Sun, Aug 16 · 1:50:45 AM UTC2026-08-16 01:50:45 UTCSpace Launch Complex 4E, Vandenberg SFB, CA, USA

Reached orbit
Booster landed on Of Course I Still Love You

Follow SpaceX in the app Watch the replay

Success

Reached Low Earth Orbit

Landed

B1088 Landed

The first stage landed on Of Course I Still Love You, on its 18th flight.

Worldwide

193rd

orbital launch attempt in 2026

SpaceX

99th

launch this year

Space Launch Complex 4E

52nd

launch from this pad this year

Pad turnaround

3 d 21 h

since the pad's previous launch

Replay

Replay: SpaceX USSF-366

The Flight Plan

Planned times, from liftoff at 1:50 AM UTC. The result is at the top of the page.

Countdown9

T−38:001:12 AMLaunch director verifies go for propellant load
T−35:001:15 AMStart of propelland loading
T−35:001:15 AMStart of liquid oxygen loading in the first stage
T−16:001:34 AMStart of liquid oxygen loading in the second stage
T−7:001:43 AMStart of engine chilling
T−1:001:49 AMThe onboard computer takes control over the countdown and runs last checks
T−1:001:49 AMFuel tanks are pressurized to flight levels
T−0:451:50 AMLaunch director verifies go for launch
T−0:031:50 AMStart of the engine ignition sequence

Show the countdown (9 steps)

T−38:001:12 AMLaunch director verifies go for propellant load
T−35:001:15 AMStart of propelland loading
T−35:001:15 AMStart of liquid oxygen loading in the first stage
T−16:001:34 AMStart of liquid oxygen loading in the second stage
T−7:001:43 AMStart of engine chilling
T−1:001:49 AMThe onboard computer takes control over the countdown and runs last checks
T−1:001:49 AMFuel tanks are pressurized to flight levels
T−0:451:50 AMLaunch director verifies go for launch
T−0:031:50 AMStart of the engine ignition sequence

Ascent6

T+0:001:50 AMFirst upwards movement of the rocket
T+1:071:51 AMMaximum dynamic pressure
T+2:251:53 AMCut-off of the main engine
T+2:291:53 AMSeparation of the second stage from the first
T+2:361:53 AMFirst start of the second engine
T+2:581:53 AMSeparation of the payload fairing

Booster Return4

T+6:011:56 AMStart of the atmospheric entry burn
T+6:251:57 AMEnd of the atmospheric entry burn
T+7:581:58 AMStart of the first stage landing burn
T+8:201:59 AMLanding of the first stage

Mission

Launch Provider

SpaceX

Commercial · United States of America · Founded 2002 · CEO Elon Musk

Launches

742

Successful

727

98%

Landings

687

of 715

Upcoming

136

scheduled

FliesFalcon Starship Dragon

All SpaceX launches Website Wikipedia

Updates

Aug 16 · 3:27 PM
Launch success.
Cosmic_Penguin
Aug 16 · 4:07 AM
Spacecraft separation.
Cosmic_Penguin
Aug 16 · 1:51 AM
Liftoff.
Cosmic_Penguin
Aug 16 · 1:38 AM
Unofficial Re-stream by SPACE AFFAIRS has started
Launch Library 2
Aug 15 · 6:58 PM
Now targeting Aug 16 at 01:50 UTC
Cosmic_Penguin

Show earlier updates

Aug 15 · 4:35 PM
Now targeting Aug 15 at 23:47 UTC
Cosmic_Penguin
Aug 15 · 4:58 AM
Now targeting Aug 15 at 21:54 UTC
hitura-nobad
Aug 10 · 8:39 PM
GO for launch.
Cosmic_Penguin
Aug 6 · 7:30 PM
Added launch per NOTAMs; Payload identities very uncertain.
Cosmic_Penguin

Falcon 9 Block 5

Vehicle history

Height

70m

Diameter

3.6m

To low Earth orbit

22,800kg

Liftoff thrust

7,607kN

Next From Vandenberg SFB

Vandenberg SFB schedule

Oct30Fri

Starlink Group 15-18SpaceX · Falcon 9 Block 5 · Space Launch Complex 4E, Vandenberg SFB, CA, USALow Earth OrbitGo for launch4:02 AM UTC Nov2Mon

USSF-432SpaceX · Falcon 9 Block 5 · Space Launch Complex 4E, Vandenberg SFB, CA, USALow Earth OrbitGo for launch1:56 AM UTC

Space Launch Now for iOS and Android

Notifications before every launch you follow, live countdowns on your home screen and watch, and webcasts as they start.

See what's in the app

Scan to open on your phone

USSF‑366

Replay

More Videos

The Flight Plan

Countdown9

Ascent6

Booster Return4

Mission

SpaceX

Updates

Falcon 9 Block 5

USSF‑366

Replay

More Videos

The Flight Plan

Countdown9

Ascent6

Booster Return4

Mission

SpaceX

Updates

Falcon 9 Block 5

Next From Vandenberg SFB

Next From Vandenberg SFB

USSF‑366

Replay

More Videos

The Flight Plan

Countdown9

Ascent6

Booster Return4

Mission

SpaceX

Updates

Falcon 9 Block 5

Never Miss a Launch.

USSF‑366

Replay

More Videos

The Flight Plan

Countdown9

Ascent6

Booster Return4

Mission

SpaceX

Updates

Falcon 9 Block 5

Next From Vandenberg SFB

Never Miss a Launch.

Next From Vandenberg SFB