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Near the end of the hold at T-10 the announcer noted that, in determining a new T0, the launch team had to consider "various cutouts in the launch window, varying from 1 seconds up to a minute".

LIVE stream queued at t=2:59:40

In this launch window, which we're currently 26 minutes into, and it's 2 hours long, it runs until 3:04am Eastern Time, we have what's called 40 cut-outs, and in those cut-outs, they range from about a second to about a minute, these are times where can't launch. These cut-outs must be accounted for when determining a new T0.

I'm familiar with cutouts in the launch window due to unfavourable alignment of the Sun, Earth and Moon eclipsing the space craft too long, as explained in e.g. this NASASpaceFlight.com article:

Within the 10- to 15-day periods that have a daily opportunity to launch, there may be a day or two “cut out” by the 90-minute maximum eclipse time constraint for Orion. “Occasionally [you] have this odd seasonal constraint that comes along where the Sun is behind the Earth during the outbound transit to the Moon or during the return transit that [eclipse time] exceeds 90 minutes. And just the angle of the solar eclipse from the spacecraft’s standpoint causes an odd day to be cut out every now and then"

But those are multi-day cutouts.

What causes the very short cutouts in the 120 minute launch window?

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    $\begingroup$ I’m making this as a comment because I haven’t got a reference to point you to: but the short cutouts tend to be because of orbital conflicts with satellites or tracked debris that are orbiting up there. $\endgroup$ Nov 16, 2022 at 12:03
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    $\begingroup$ @MartinKochanski reference here confirming your comment: twitter.com/thesheetztweetz/status/1565690660484796416 Quoted person is Jeremy Parsons, Exploration Ground Systems deputy director $\endgroup$ Nov 16, 2022 at 17:13

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These are COLA (Collision On Launch Assessment / Avoidance) cutouts. In other words: they are to avoid hitting stuff.

Since LEO debris and/or satellites are extremely fast compared to the ground, those windows are typically only seconds long. However, there may be high-value satellites (for example, with humans on them) or clusters / trains of multiple satellites which result in longer cutouts.

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