Is it really just a 1 minute launch window? That seems incredibly tight. If there's any hitch in the countdown, that would pretty much mean a scrubbed launch. Not being well versed in orbital mechanics, why would the window be so short?
Based on that, I guess the one upside would be that you have the window available every day as the L1/L2 positions never move relatively. Unlike a launch to Mars or other solar system body where you definitely want everything to be lined up efficiently.
[−]Polizeiposaune · 2026-08-29 Sat 22:42 UTC ·
link
Not unusual, and there are likely a number of contributing factors.
Falcon launches to the ISS typically have an instantaneous launch window (roughly, when the plane of the ISS's orbit sweeps over the launch site). If they miss it, they try again about a day later.
Falcon (both Heavy and its little sibling Falcon 9) uses subcooled densified propellants which limit how long it can sit waiting for launch while fueled before the LOX warms and expands too much.
A short window means they only have to compute and verify and program one trajectory.
[−]ButlerianJihad · 2026-08-30 Sun 01:23 UTC ·
link
It is important to point out, since you did not note the timezone with that quote, that the launch is actually scheduled for NET 07:26am EDT or 11:26:00 UTC.
You can get live countdowns and updates at https://www.spacex.com/launches which will link to first-party livestream coverage during the launch.
No need to go through third-party and advertising-laden dot-com sites.
The Falcon 9 and Falcon Heavy are intolerant to countdown holds late in the sequence. In particular, after propellant has been loaded, there must be no delay in launch. Any countdown holds will necessarily turn into a scrub for the day, as the propellant must be completely unloaded and the process restarted to prepare for launch. With the instantaneous window, it'll either be "go/no-go" at 07:26am EDT, or they'll go-around to another opportunity on Monday morning, around 07:22am.
The timezone has no bearing on the the one minute wide window. This was not posted as an advertisement of launch time. I provided the link the info was taken. If you click on it, it shows you the localized time. Not really sure why you feel like this was the important part of the question.
06:25 AM Window Open
06:26 AM Window Close
Is it really just a 1 minute launch window? That seems incredibly tight. If there's any hitch in the countdown, that would pretty much mean a scrubbed launch. Not being well versed in orbital mechanics, why would the window be so short?
Falcon launches to the ISS typically have an instantaneous launch window (roughly, when the plane of the ISS's orbit sweeps over the launch site). If they miss it, they try again about a day later.
Falcon (both Heavy and its little sibling Falcon 9) uses subcooled densified propellants which limit how long it can sit waiting for launch while fueled before the LOX warms and expands too much.
A short window means they only have to compute and verify and program one trajectory.
You can get live countdowns and updates at https://www.spacex.com/launches which will link to first-party livestream coverage during the launch.
No need to go through third-party and advertising-laden dot-com sites.
The Falcon 9 and Falcon Heavy are intolerant to countdown holds late in the sequence. In particular, after propellant has been loaded, there must be no delay in launch. Any countdown holds will necessarily turn into a scrub for the day, as the propellant must be completely unloaded and the process restarted to prepare for launch. With the instantaneous window, it'll either be "go/no-go" at 07:26am EDT, or they'll go-around to another opportunity on Monday morning, around 07:22am.