Tanager-2 Launch 101

Whether you’re following the launch of Tanager-2, built by Planet Labs, in-person or virtually, there’s more to look for beyond liftoff! This primer includes some information and key launch milestones to follow on SpaceX’s livestream. 

Quick Facts

• Satellite: Like Tanager-1 launched in 2024, Tanager-2 is designed and optimized to detect methane and carbon dioxide emissions from space. 
• Launch mission: Tanager-2 is being launched into orbit on board SpaceX's Transporter-18 mission.
• Launch rocket: Transporter-18 will be launched by a Falcon 9, which is a reusable, two-stage rocket. 
• Launch location: Vandenberg Space Force Base in California 
• Launch date/time: October 1, 2026. The launch window will open at 11:18 a.m. PDT

Launch Milestones:

All times are approximate. Steps with an asterisk will be visible to those attending the launch in-person.

Pre-launch countdown
Starting approximately a full day prior to launch, SpaceX initiates their pre-launch countdown, which includes a series of steps to ready Falcon 9 for liftoff.

T - 00:00:45: Launch Director go for launch

*T - 00:00:07: Water deluge system activation
The water deluge system on a Falcon 9 rocket is activated seconds before liftoff to reduce the energy and sound produced by the rocket's Merlin engines. The system is also known as "Niagara".

T - 00:00:03: Engine start sequence
Seconds before launch, the nine engines of the first stage ignite. The rocket computer commands the launch mount to release the vehicle for flight.

*T + 0:00:00: Main engine ignition and liftoff
This starts the phase of the launch most visible from Vandenberg! Nine engines field with liquid oxygen and rocket-grade kerosene generate more than 1.7 million pounds of thrust. 

*T + 1:10: Max Q
The engines will throttle up after passing through maximum dynamic pressure.

*T + 00:02:30: Main engine cutoff and second stage separation and ignition 
The main engines are cut off as Falcon 9 nears the edge of Earth’s atmosphere. Launch attendees may notice that things will temporarily get quiet at this stage, but sharp-eyed observers may notice the rocket’s ascent. 

Once Falcon 9 has moved beyond Earth’s atmosphere, the second stage separates from the rocket’s first stage. The second stage then ignites to continue ascent.

T+ 00:02:40: Stage 1 boost-back burn
Engines ignite on the first stage, setting it on a path back to the rocket’s landing site. 

T + 00:03:00: Fairing separation
The fairing separates from the second stage, exposing the satellites that are being transported on the rocket and readying them for deployment from the vehicle into their orbits.

*T + 00:07:20 - 00:07:40: First stage landing burn 
The first stage returns to the launch site. Landing legs deploy so it can land safely on its platform, and engines light a final time. Viewers at Vandenberg may notice a big sonic boom seconds after landing! 

T+ 00:08:20: Second stage engine cut off 1
Following the landing of the first stage, the second stage cuts off its engine which essentially positions the vehicle in its “parking” orbit as an interim step before reaching the final orbit. This orbit is highly elliptical (where the apogee, or the point of orbit farthest from Earth is much higher than perigee, or the point of the orbit closest to Earth). 

T+ 00:50:00: Second stage 3 second burn  
After coasting halfway around the planet, the second stage will do another short (3 second) burn to raise the perigee thereby circularizing the orbit before deploying satellites. 

T + 00:53:00 - approximately 01:30:00: Deployment of most satellites including Tanager-2! 
Tanager-2 will be released into orbit. Following deployment, Tanager-2 will boot up its computer, activate core systems to stabilize pointing, and then initiate contact with the ground.

NOTE: The predicted time window for Tanager-2 deployment is approximately T+01:01:00 (or 12:19 PDT assuming 11:18 liftoff).

What’s next:

Releasing the Tanager-2 satellite into orbit is just the beginning. Much more needs to occur before the satellite starts collecting observations and sending data. The next step is to establish contact with the satellite. Once that happens, Planet Labs will work to complete spacecraft initialization and check how the satellite’s equipment and systems are operating.

Soon, you’ll hear more about first light, first emissions detections, and much more.

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