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#20
by
Jim
on 19 May, 2010 19:41
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1. One thing that I didn't know about (caveat: I'm a launch newbie) before I read that document was the concept of PCS, second stage Probability of Command Shutdown >= 99.7% (page 12).
For the benefit of anybody else who might wonder what that means, to save them from having to dig, the Delta people's explanation is that "0% PCS means spacecraft orbit insertion at second-stage cutoff always occurs due to a propellant depletion shutdown (PDS) and is never commanded by guidance."
So, apparently, given the various things that fluctuate from nominal on launch day (like weather), and assuming successful launch vehicle operation, you have a 99.7% chance of not running out of "gas" before you've reached your target destination.
2. I'd be curious if anyone knows more about, on chart 5, which signals are sent to the re-radiating antennae outside the fairing, and which are just leaking through the 14" diameter RF window? I'm assuming the re-rad antennae are for S-band telemetry of the vehicle?
1. Which means the vehicle has reserves for 3 sigma dispersions (99.7%)
2. The re-rad is for the spacecraft telemetry
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#21
by
HIPAR
on 19 May, 2010 22:18
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Here's a picture of the GPS satellite being prepared for transport to the Cape.
--- CHAS
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#22
by
Chris Bergin
on 21 May, 2010 17:55
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Cape Canaveral AFS, Fla., (May 21, 2010) - A United Launch Alliance Delta IV rocket with the Air Force’s Global Positioning System GPS IIF SV-1 (GPS IIF SV-1) satellite sits poised on its Space Launch Complex-37 launch pad ready to launch tonight. The launch is set for 11:25 p.m. EDT with the launch window extending until 11:43 p.m. EDT. The weather forecast calls for a 90 percent chance of acceptable weather during the launch window. GPS IIF SV-1 is the first in a series of next generation GPS satellites. Following its nearly three hour, 33 minute flight, it will join a worldwide timing and navigation system utilizing 24 satellites approximately 11,000 miles above the Earth’s surface. Photo by Pat Corkery, United Launch Alliance
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#23
by
Chris Bergin
on 21 May, 2010 22:15
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Moved for live coverage.
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#24
by
jcm
on 21 May, 2010 23:13
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Mission booklet:
Thanks for that link, Chris! I found it informative.
I notice that this mission booklet doesn't give the parking orbit heights - usually the Delta mission books have a few more details than this.
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#25
by
HIPAR
on 22 May, 2010 00:22
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Mission booklet:
Thanks for that link, Chris! I found it informative.
I notice that this mission booklet doesn't give the parking orbit heights - usually the Delta mission books have a few more details than this.
This GPS satellite is going directly to its operational orbit.
--- CHAS
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#26
by
Chris Bergin
on 22 May, 2010 00:47
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All ok with three hours to go, according to ULA.
William's oveview article will be on in around an hour.
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#27
by
Ronsmytheiii
on 22 May, 2010 01:21
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#28
by
butters
on 22 May, 2010 01:23
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#29
by
Ronsmytheiii
on 22 May, 2010 01:25
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#30
by
Chris Bergin
on 22 May, 2010 01:25
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#31
by
DaveS
on 22 May, 2010 01:26
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So... I see that NASA PAO is doing some sort of Delta IV coverage here:
http://science.ksc.nasa.gov/shuttle/countdown/video/chan12large.jpg
But I can't find any video feed, and the NASA TV schedule website doesn't mention this launch. Am I missing something?
Yes, not a NASA launch. NASA neither own nor operates the GPS program. That's an engineering feed from ULA as the ULA logo in the lower right corner indicates.
The views on the web-cam page of science.ksc.nasa.gov, are engineering views, none are broadcast on NASA TV unless selected by the NASA TV operator.
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#32
by
Ronsmytheiii
on 22 May, 2010 02:13
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Ground path from Mission booklet:
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#33
by
tonthomas
on 22 May, 2010 02:40
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#34
by
Ronsmytheiii
on 22 May, 2010 02:48
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#35
by
Chris Bergin
on 22 May, 2010 02:55
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#36
by
Nick L.
on 22 May, 2010 02:58
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#37
by
Ronsmytheiii
on 22 May, 2010 03:00
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#38
by
Andrewwski
on 22 May, 2010 03:00
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#39
by
Nick L.
on 22 May, 2010 03:01
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