Week in Space Data, every Friday.
Every change of more than a minute to this launch's date, as we observed it. Only a move between two dates known to the day counts as a slip; a placeholder such as “NET 2026” rolling to “2027” is shown but not counted. How we classify moves · on-time record by provider
The webcast for Atlas V N22 · Starliner-4 appears here once the provider posts it.
The broad sequence of an orbital launch. Details and times differ by rocket and mission; this is a guide, not live tracking.
In the last part of the count the rocket is fuelled, systems switch to internal power and the launch team is polled for a go.
The first-stage engines ignite and the rocket leaves the pad.
The moment of maximum aerodynamic pressure on the rocket during ascent.
The spent first stage separates and the upper stage takes over. Some rockets also drop side boosters earlier in the climb.
The upper stage burns to reach the planned orbit, sometimes in more than one burn with a coast in between.
The payload separates from the upper stage. On a crewed flight the capsule separates and flies on under its own power.
Chat opens two hours before liftoff once the launch time is set.
Telemetry and trajectory data shown is simulated for demonstration purposes. Real telemetry data would require integration with launch provider APIs.
Every entry is a change we recorded, not a forecast. Our sync checks Launch Library 2 every 15 minutes, so a time is when we saw the change and can trail the real moment. The liftoff time is the one the launch record states.
Target moved: placeholder roll
2028 to Dec 31, 2029 (decade precision)
recorded by the launch ledger
Atlas V (United Launch Alliance)
Atlas V flies a first stage powered by one Russian-built RD-180 engine and a Centaur upper stage with RL10 hydrogen engines, with up to five solid boosters depending on the version. ULA is flying out its remaining Atlas V rockets.
Source: ULA: Atlas V, checked 2026-09-27The provider's page for this flight
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