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ULA launch and discussion thread

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what do the zeros mean?

and Zulu? what?

00590?

OOOOH 4:59

 

Edited by StupidAndy

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Zulu is the code name for Greenwich mean time.

Edited by Leszek
typo
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All the primary time zones have a letter associated to them. GMT+1 is Alpha.  Though most of the time you only hear about Zulu.  There is not an India or an Oscar.

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8 hours ago, StupidAndy said:

what do the zeros mean?

and Zulu? what?

00590?

OOOOH 4:59

 

00:59:00 Z means 12:59 AM UTC, which is 4:59 PM PST.

Best,
-Slashy

20 minutes until the next disappointment :D

8 hours ago, Leszek said:

Zulu is the code name for Greenwich meantime.

Minor pedantic correction: UTC is GMT without the DST correction. "Zulu" is UTC, not GMT. Only reason I know this is because I have one of those pilot's watches with the circular slide- rules. Every time DST hits, it gives me fits. <-- Incorrect minor pedantic correction was corrected by another minor pedantic correction :D
 

 Also, scrubbed.

Best,
-Slashy

Edited by GoSlash27
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Scrubbed :(

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 I'm glad they scrubbed it. Minor glitches can snowball into catastrophes, especially when safety interlocks malfunction. Better to take the scrub and get the problem fixed, because a spy sat doesn't really care when it gets launched.

Best,
-Slashy

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1 hour ago, GoSlash27 said:

 I'm glad they scrubbed it. Minor glitches can snowball into catastrophes, especially when safety interlocks malfunction. Better to take the scrub and get the problem fixed, because a spy sat doesn't really care when it gets launched.

Best,
-Slashy

I was not impressed by their QC, yes it averted risks, but I have not seen a choke like that since the 80's.

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4 hours ago, GoSlash27 said:

Minor pedantic correction: UTC is GMT without the DST correction. "Zulu" is UTC, not GMT. Only reason I know this is because I have one of those pilot's watches with the circular slide- rules. Every time DST hits, it gives me fits.

Pedantic correction to your pedantic correction: DST is never applied to GMT. When DST is applied in Britain, their timezone changes to BST (British Summer Time). This is analogous North America where, for example, EST (Eastern Standard Time) becomes EDT (Eastern Daylight Time) during the summer months. GMT is the colloquial term for UTC - the mean solar time at the Greenwich meridian - and it is based on the Earth's rotation, not some weird backy-forthy dance that we perform every spring and fall to allow ourselves to take advantage of longer evenings in the summer and brighter mornings in the winter.

Edited by PakledHostage
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PakledHostage,
 Yeah, you're right. I confused "GMT" with "London".

Best,
-Slashy

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Greenwich Mean Time is essentially Mariners time UT1 before standardized clocks. "GMT was formerly used as the international civil time standard, now superseded in that function by Coordinated Universal Time (UTC). Today GMT is considered equivalent to UTC for UK civil purposes (but this is not formalised) and for navigation is considered equivalent to UT1 (the modern form of mean solar time at 0° longitude); "
Zulu = UT1

This is valid in all ground and Sea operations and on ISS but should be substituted for operations in deep space with corrected time.

Greenwich Observatory, interestingly is a time observatory, it marks the passing of the sun at noon.

Quote

The basis of longitude, the meridian that passes through the Airy transit circle, first used in 1851, was adopted as the world's Prime Meridian at the International Meridian Conference on 22 October 1884 (voting took place on 13 October).[9] Subsequently, nations across the world used it as their standard for mapping and timekeeping. The Prime Meridian was marked by a brass (later replaced by stainless steel) strip in the Observatory's courtyard once the buildings became a museum in 1960, and, since 16 December 1999, has been marked by a powerful green laser shining north across the London night sky. -wikipedia

Quote

The Prime Meridian of these modern reference systems is 102.5 metres east of the Greenwich astronomical meridian represented by the stainless steel strip, which is now 5.31 arcseconds West. The modern location of the Airy Transit is 51°28′40.1″N 0°0′5.3″W[12]

International time from the end of the 19th century until UT1 was based on Simon Newcomb's equations, giving a mean sun about 0.18 seconds behind UT1 (the equivalent of 2.7 arcseconds) as of 2013; it coincided in 2013 with a meridian halfway between Airy's circle and the IERS origin: 51°28′40.1247″N 0°0′2.61″W.[13]

And to point out that if you use WGS84 or the 2000 time standard that these 'space' times will be off from UTC1. The reason I brought this up is I once recently tried to add a 'spatial' time element to one of my programs and its turns out that time gets very hairy when you try to universalize it. For example if at the vernal equinox (a point on the surface of the earths equator that passes directly under the sun at noon during march). The moment this is done using our sec, minute, day . in fact any sec . . the time starts to drift. . . and so what ever time you have you have to specify your reference and go through an elaborate correction. The other problem is that the Earth is not a sphere, its not even an oblate sphere although UTC forces this, and if one is say monitoring the x, y, z coordinate (which references some vernal equinox) of a space craft with respect to time one is going to find significant deviation of position using UTC, ergo UT1.

Edited by PB666

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Stream is live for today's attempt.

Having a problem with the ground helium system. No T-0 announced yet.

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3 minutes ago, GoSlash27 said:

Stream is live for today's attempt.

Link for this thread page:

 

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Helium valve problem is resolved.

 

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I think they just said "T- 1:05:00"...

2211z

 

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T-5 minutes!

EDIT: 15 minutes, forgot about the hold.

Edited by Ultimate Steve

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4 minute count starts now  Disregard.forgot to carry the one :D

Edited by GoSlash27

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I heard 8 minutes in there somewhere

guess its only T-4:00

Edited by StupidAndy

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3 minutes ago, GoSlash27 said:

4 minute count starts now  Disregard.forgot to carry the one :D

1

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Here we go with the final checks.

All go. starting the clock at 22:07

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