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1 minute ago, sevenperforce said:

She referenced a "tensioner" release on the webcast -- I really wonder what the mechanism is like.

Dunno, but it's brilliantly simple. Any constellation not doing this going forward can't possibly catch up. A bunch of "normal looking" sats can't get remotely as many even into a NG fairing.

Regarding the fairings:

Dunno how/if they get these.

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13 minutes ago, tater said:

Dunno, but it's brilliantly simple. Any constellation not doing this going forward can't possibly catch up. A bunch of "normal looking" sats can't get remotely as many even into a NG fairing.

Per this screenshot there is apparently a tension rod of some kind involved. I wonder if it runs up the center and each of the sats somehow latches/grabs onto it?

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21 minutes ago, sevenperforce said:

Per this screenshot there is apparently a tension rod of some kind involved. I wonder if it runs up the center and each of the sats somehow latches/grabs onto it?

There are usually 4 pieces of debris associated with Starlink (from watching people who track that on twitter). I think 2 tension rods, and maybe 2 caps?

I think the sats are not "attached" to the rod at all, it merely constrains them by pressing them together (maybe passed through a hole in sat, but sats not "grabbing" it). Probably has a spring, and just shoots out, leaving the sats free to tumble around.

 

Edited by tater
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16 minutes ago, tater said:

There are usually 4 pieces of debris associated with Starlink (from watching people who track that on twitter). I think 2 tension rods, and maybe 2 caps?

I think the sats are not "attached" to the rod at all, it merely constrains them by pressing them together (maybe passed through a hole in sat, but sats not "grabbing" it). Probably has a spring, and just shoots out, leaving the sats free to tumble around.

I asked over at NSF, and it was explained that each sat has three cylindrical mounting points that nest into the next one down, preventing any tilting or planar motion during flight. There are four tension rods which keep the two stacks in compression; when the tension rods are dropped (evidently without much of a spring because we saw a tension rod drifting away quite slowly) the sats release each other and drift apart.

The three mounting points are shown here:

Spoiler

satellite__ANTENNA.jpg

 I wonder if the tension rods fit over the topmost mounts? They certainly can't pass all the way through the rings or the sats would end up stuck on the rod.

I wonder how they unload the reaction wheels. Maybe they can use the solar array in tidal tension?

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24 minutes ago, tater said:

There are usually 4 pieces of debris associated with Starlink (from watching people who track that on twitter). I think 2 tension rods, and maybe 2 caps?

I think the sats are not "attached" to the rod at all, it merely constrains them by pressing them together (maybe passed through a hole in sat, but sats not "grabbing" it). Probably has a spring, and just shoots out, leaving the sats free to tumble around.

Could be that sats are pushed in against a spring. Then the "tension rod is" slid in to hold them all there. When the rod is released, they all get pushed out by their springs.

Edited by mikegarrison
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Just now, mikegarrison said:

Could be that sats are pushed in against a spring. Then the "tension rod is slid in to hold them all there. When the rod is released, they all get pushed out by their springs.

The tension rod cannot slide through the rings, though. 

Looks like I will get a view of the new constellation in my neck of the woods right at around 6 PM local time. 3.6 mag might be too low to be visible from the city though.

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7 minutes ago, sevenperforce said:

The tension rod cannot slide through the rings, though. 

No, but it doesn't have to.

I picture this as something like a mousetrap but with much weaker springs. The sats are compressed against something slightly springy, and the "tension rod" is on the outside holding them there. When the rod is released, the sats are pushed out.

Or something like that.

Ausl%C3%B6sen_einer_Mausefalle.gif

Edited by mikegarrison
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2 hours ago, cubinator said:

Here's a placeholder prediction of the current batch's position based on estimates from before today's launch:

https://www.heavens-above.com/starlink.aspx

No idea if it's accurate.

Yup, looks like the next pass will be right overhead. 
 

Aaaaaaaaaand it’s cloudy. :mad:

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F9 B5 has now had 19 successes from 19 missions. The success rate based on Bayesian statistics is:

P{S} = (n{S}+1)/(n+2)

Where:

P{S}= Probability of mission success

n{S}= Number of successes

n = Number of attempts

P{S}= 95.2%

For falcon 9 as a whole, it's 76 successes from 78, or 96.3%

That has to be close to an industry leader surely.

 

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1 hour ago, RCgothic said:

F9 B5 has now had 19 successes from 19 missions. The success rate based on Bayesian statistics is:

P{S} = (n{S}+1)/(n+2)

Where:

P{S}= Probability of mission success

n{S}= Number of successes

n = Number of attempts

P{S}= 95.2%

For falcon 9 as a whole, it's 76 successes from 78, or 96.3%

That has to be close to an industry leader surely.

 

That's just 1% less than Soyuz

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