Starlink Group 10-39

Starlink Group 10-39 lifted off on August 21, 2026 — 5 days ago on a Falcon 9 Block 5 from Space Launch Complex 40, Cape Canaveral SFS, FL, USA, adding 29 Starlink satellites to SpaceX's broadband constellation.

The mission name follows SpaceX's own convention: the group number identifies which slice of the constellation the batch was destined for, and the second number counts the flights to that group. Each group corresponds to a defined orbital shell with its own altitude and inclination, which is why missions to the same group fly the same trajectory from the same coast.

Why it flew from the east coast

Launching from Florida's Space Coast, the rocket flew out over the Atlantic — the trajectory SpaceX uses for Starlink's mid-inclination shells, which blanket the world's most heavily populated latitudes.

Eastward launches also collect a bonus. The Earth's surface is already moving east at roughly 1,600 km/h at these latitudes, and a rocket heading that way starts with that speed for free. It is a meaningful saving on the velocity needed to reach orbit, which is why most orbital launches worldwide head east where geography allows.

What happened after liftoff

The satellites rode up stacked flat inside the Falcon 9 Block 5 fairing and were released about 15 minutes after liftoff into a low parking orbit, a few hundred kilometres up — well below the roughly 550 km operational band. They separate gently, which is why a fresh batch stays bunched in a line for the first few days.

Each satellite then climbs to its assigned shell under its own power, using a low-thrust ion engine that moves it a few kilometres per day. The ascent takes weeks. Starting low is a deliberate safeguard: at that altitude atmospheric drag removes anything that fails checkout within months, so only satellites that prove they work reach an operational orbit.

The train may still be visible

This batch flew 5 days ago, which puts it squarely inside the window where the "Starlink train" is worth chasing. The satellites are still clustered along the same orbital path and still at low altitude, so they appear as a chain of steady lights crossing the sky in single file.

Look during twilight — roughly one to two hours after sunset, or the same window before sunrise. Face a broad, unobstructed stretch of sky and wait; once the first light appears the rest follow along the identical path, which is the moment it stops looking ambiguous.

The effect degrades quickly. The tight line lasts about three to five days, a looser chain for a week or two, and after roughly a month the satellites have spread around their orbital plane and there is no train left to see.