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I'd imagine there is also an inertial guidance unit in there somewhere at least for backup within LEO,  and possibly for development of the guidance system for Starship beyond LEO.

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34 minutes ago, Meecrob said:

I'd imagine there is also an inertial guidance unit in there somewhere at least for backup within LEO,  and possibly for development of the guidance system for Starship beyond LEO.

Pretty sure its an inertial guidance unit who kicks in if gps signals are spotty who can be an problem during reentry and definitely will be an problem on Starship.
Even google map on an phones uses that as it makes sense in tunnels unless its to long. Its also an reason gps jamming of bombs, missiles and shells has limited efficiency. 
You start adjusting your trajectory after the gps data early and if gps falls out you are already on an pretty good trajectory. I also assume it sanity checks the gps data so it you get something weird like you are 1000 km east its get dumped. 

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1 hour ago, magnemoe said:

Pretty sure its an inertial guidance unit who kicks in if gps signals are spotty who can be an problem during reentry and definitely will be an problem on Starship.
Even google map on an phones uses that as it makes sense in tunnels unless its to long. Its also an reason gps jamming of bombs, missiles and shells has limited efficiency. 
You start adjusting your trajectory after the gps data early and if gps falls out you are already on an pretty good trajectory. I also assume it sanity checks the gps data so it you get something weird like you are 1000 km east its get dumped. 

Also, GPS is a signal that can be lost or jammed. IGU is self contained.

 

I think I am missing something here...but it seems to me (obviously I'm NOT a rocket scientist) that GPS is a dead end for space. What do you do between the GPS of Earth and the GPS of the Moon or Mars or any other destination in the solar system that we hypothetically set up a GPS around? Have a "Milky-Way Positioning System" out by the Oort cloud?

Edited by Meecrob
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Not very technical interview below, but reiterates the tone Musk is trying to set for this upcoming attempt.  I'm thinking of it as Starship Early Access now, with no expectations of it being smoothly playable in the short, or medium, term.  ;)

https://twitter.com/esherifftv/status/1647754805413138438?t=e8n_o7mvZxcym542F5YW8g&s=19

The big upside, of course, is Ellie finally got that interview with Musk

Edited by darthgently
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2 minutes ago, RCgothic said:

NASA WB57 observation aircraft is now airborne and en-route to Starbase.

 

 

...showing off its got a bigger gas tank than my car if its launching this early.

 

Edit: seriously, is it landing there or orbiting the launch site?

Edited by Meecrob
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21 minutes ago, Meecrob said:

...showing off its got a bigger gas tank than my car if its launching this early.

 

Edit: seriously, is it landing there or orbiting the launch site?

It'll fly above Starbase and the gulf for a while to observe the launch and then return to the runway it took off from.

It appears that fuelling of Starship is yet to start, so T-0 looks like it's slipping later into the window.

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Thanks! But I mean its flight endurance...I know its got long legs and will be filming the test attempt, but taking off early to observe the starship flight is confusing me....Unless they launch to texas, then refuel, then launch for the photo flight.  But I'm just guessing.

Edited by Meecrob
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Go for prop load! T-0 has slipped 20m.

 

 

Fuelling has begun:

 

 

7 minutes ago, Meecrob said:

Thanks! But I mean its flight endurance...I know its got long legs and will be filming the test attempt, but taking off early to observe the starship flight is confusing me....Unless they launch to texas, then refuel, then launch for the photo flight.  But I'm just guessing.

WB57s have a flight endurance of about 6.5h. Minus an hour to and from, that's 4.5h availability over the launch site. And as you mention it can always land in South Texas if it needs to stay up a little bit longer.

Should easily cover the entire flight window.

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13 minutes ago, RCgothic said:

Go for prop load! T-0 has slipped 20m.

 

 

Fuelling has begun:

 

 

WB57s have a flight endurance of about 6.5h. Minus an hour to and from, that's 4.5h availability over the launch site. And as you mention it can always land in South Texas if it needs to stay up a little bit longer.

Should easily cover the entire flight window.

What about the re-entry observation over Hawaii? It can’t get that far west that fast. 

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:popcorn:

 

I might have missed it up thread, but I’m assuming the flight path is mainly over water until orbit planned reentry is established just in case it’s not?

 

edit: I misspoke, having been advised it’s not an orbital flight.    Question still stands though  

 

I fully expect a scrub, followed by a strong chance of RUD, and then a decent possibility of a successful mission.  

Edited by Gargamel
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