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#1600
by
Lee Jay
on 30 Jan, 2009 03:09
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The ET is structurually stable without pressurization. The pressurization inflight is for engine inlet conditions..
There's an unrelated presentation on L2 right now (Helium poppet valve failure) that disputes this. One comment in that presentation basically states that loss of O2 pressurization during ascent would result in ET structural failure. I'm wondering if its the same for the LH2 tank as well (guessing it is).
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#1601
by
usn_skwerl
on 31 Jan, 2009 00:39
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Thanks for the clarification, Jim. Clearly my source(s) were only partial truths, and inaccurate.
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#1602
by
shuttlefan
on 01 Feb, 2009 13:16
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Can anyone, who was at KSC for, or watched on TV, the 51I launch in Aug.'85, provide any stories about the launch that day? It seems like it was the worst weather ever for a shuttle launch. Did the vehicle fly through rain at all and were they taking a big gamble launching that day, even though no weather rules were broken, obviously, because they DID launch? Thank-you.
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#1603
by
christra1
on 07 Feb, 2009 13:09
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Does somebody know what kind of re-entry trajectory they used (or will use) for the Hubble missions?
If they use a steeper one they could do the deorbit burn around the same point in orbit like the ISS missions but they need to lower the perigee (longer burn). That would mean the Entry Interface is closer to the landing site.
On the other hand they could do the burn a little earlier and come in quite "normal".
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#1604
by
4dartist
on 10 Feb, 2009 16:14
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I'm trying to plot the altitudes in Y (up) and Z(east) for the first 30 seconds after take off for the orbiter. I just need a few key points to use i think, looking for rough numbers.
For example
T=0 Altitude=0 Distance=0
T=10 Altutude=? Distance=?
T=20
T=30
Anyone know where i can find that info? I'm not super good with math, but if the acceleration is a constant number i can probably figure out the rest, but i have a feeling as the weight of the SRB's and fuels drop the acceleration will increase, i don't know how to handle the math with that involved.
Thanks in advance if anyone can offer help.
Ben
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#1605
by
mkirk
on 10 Feb, 2009 16:21
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I'm trying to plot the altitudes in Y (up) and Z(east) for the first 30 seconds after take off for the orbiter. I just need a few key points to use i think, looking for rough numbers.
For example
T=0 Altitude=0 Distance=0
T=10 Altutude=? Distance=?
T=20
T=30
Anyone know where i can find that info? I'm not super good with math, but if the acceleration is a constant number i can probably figure out the rest, but i have a feeling as the weight of the SRB's and fuels drop the acceleration will increase, i don't know how to handle the math with that involved.
Thanks in advance if anyone can offer help.
Ben
The exact numbers change for each mission but you can find some good examples here at Bill Harwood's site. He usually posts the trajectory data package info for each mission.
http://www.cbsnews.com/htdocs/space_place/framesource_current.htmlIf you search the site, you can compare the differences for each mission.
Mark Kirkman
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#1606
by
4dartist
on 10 Feb, 2009 17:26
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Thanks very much!!
tva, can you tell what unit the range is in? Is that miles? looks like s** can't make it out.
this is exactly what i was looking for.
Ben
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#1607
by
tva
on 10 Feb, 2009 17:39
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what unit the range is in? Is that miles?
I guess it means statute mile since it is the US
this is exactly what i was looking for
I'm glad to hear it
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#1608
by
mkirk
on 10 Feb, 2009 17:49
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what unit the range is in? Is that miles?
I guess it means statute mile since it is the US
this is exactly what i was looking for
I'm glad to hear it
Yes range is given in statute miles.
FYI: for the link I posted above on the right hand side of the page click on STS-119 Ascent Date and you will find the predicted data for STS-119
Mark Kirkman
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#1609
by
tva
on 11 Feb, 2009 07:48
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The exact numbers change for each mission but you can find some good examples here at Bill Harwood's site.
Mark Kirkman
Hi Mark,
Where can I find generic descent trajectory data for an typical ISS-mission ?
Data with 1-5 minute pacing from deorbit burn to the HAC would be sufficient.
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#1610
by
ChrisC
on 12 Feb, 2009 03:17
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In the most recent NSF article, our esteemed Managing Editor mentions the three different planning documents used in the space shuttle program for long term flight planning:
- FAWG (Flight Assignment Working Group)
- STS and ISS launch schedule
- USA’s ISS/STS and Eastern Range schedule
Can someone with experience with these give me a little bit on the tradeoffs between these three documents? Which shows the most information? I've seen only the FAWG chart up close, and I'm amazed at how much data they pack in there.
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#1611
by
Jorge
on 12 Feb, 2009 03:24
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In the most recent NSF article, our esteemed Managing Editor mentions the three different planning documents used in the space shuttle program for long term flight planning:
- FAWG (Flight Assignment Working Group)
- STS and ISS launch schedule
- USA’s ISS/STS and Eastern Range schedule
Can someone with experience with these give me a little bit on the tradeoffs between these three documents? Which shows the most information? I've seen only the FAWG chart up close, and I'm amazed at how much data they pack in there.
It used to be more clear cut than it is now. Used to be, the FAWG went out further but had much less detail, the launch schedule showed more detail about each launch, and the range schedule showed all the other launches at KSC/CCAFS.
Over time, the FAWG has become more detailed, including things like the payload bay drawings. And with the end of the shuttle program approaching, the FAWG doesn't go out much further in time than the other two schedules.
(The FAWG used to fill both sides of an 8.5x11" sheet and went out a good 6-7 years in the future. It fits on one side now.)
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#1612
by
Jim
on 12 Feb, 2009 11:45
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In the most recent NSF article, our esteemed Managing Editor mentions the three different planning documents used in the space shuttle program for long term flight planning:
- FAWG (Flight Assignment Working Group)
- STS and ISS launch schedule
- USA’s ISS/STS and Eastern Range schedule
Can someone with experience with these give me a little bit on the tradeoffs between these three documents? Which shows the most information? I've seen only the FAWG chart up close, and I'm amazed at how much data they pack in there.
The FAWG is the official shuttle manifest. And it is produced by the shuttle program. It used to have more than just ISS flights but.....
The STS and ISS launch schedule is produced by the ISS program to track all of its launches and it uses the FAWG manifest
USA’s ISS/STS and Eastern Range schedule is not an "official" document. It just consolidates information from many sources. It is a USA Florida product and not a range document
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#1613
by
ChrisC
on 12 Feb, 2009 16:50
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Outstanding, thanks Jorge and Jim! As an outsider, it's humbling and thrilling to be able ask questions like this here and get answers from the likes of you two
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#1614
by
christra1
on 12 Feb, 2009 17:26
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Does somebody know what kind of re-entry trajectory they used (or will use) for the Hubble missions?
If they use a steeper one they could do the deorbit burn around the same point in orbit like the ISS missions but they need to lower the perigee (longer burn). That would mean the Entry Interface is closer to the landing site.
On the other hand they could do the burn a little earlier and come in quite "normal".
Nobody here who has some answers to these high orbit re-entry trajectories?
Thanks for looking again.
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#1615
by
Jorge
on 12 Feb, 2009 19:59
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Does somebody know what kind of re-entry trajectory they used (or will use) for the Hubble missions?
If they use a steeper one they could do the deorbit burn around the same point in orbit like the ISS missions but they need to lower the perigee (longer burn). That would mean the Entry Interface is closer to the landing site.
On the other hand they could do the burn a little earlier and come in quite "normal".
Nobody here who has some answers to these high orbit re-entry trajectories?
Thanks for looking again.
Well, it *is* rather specialized knowledge... and I caution that I'm not an entry specialist.
I don't know about downrange or perigee, since deorbit doesn't target those parameters explicitly, but HST deorbits are typically done from HST altitude (i.e. no orbit adjust prior to deorbit unless required to bring in more landing opportunities), so the velocity and flight path angle at EI for HST missions are just a little faster and steeper than they are for other entries. Typically around 26100 fps and -1.6 degrees. There's some flight history data here:
http://spaceflight.nasa.gov/shuttle/reference/green/entare.pdf125 may do an orbit adjust on FD9 or 10 to reduce orbital debris risk (and before the conspiracy theorists get cranked up, that was in work long before the current Iridium kerfluffle...), but that would only reduce the deorbit delta V; conditions at EI should be pretty much the same.
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#1616
by
christra1
on 13 Feb, 2009 07:04
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Thanks Jorge!
I have attached a Deorbit Mnvr Exec display after loading the parameters for deorbit (no HST mission). Surrounded in red is the data of interest for me. If they deorbit from HST altitude they have two choices in my eyes:
1. do the burn early with still high downrange to landing site
2. do the burn with higher duration and come in steeper
What you say is that they come in steeper which would make the target perigee (TGT HP) more negative and the burn duration (TGO) would be longer.
Thanks again. More comments appreciated.
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#1617
by
Zoe
on 19 Feb, 2009 18:58
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Shuttle OPS modes
1: Ascent
2: Orbit
3: Deorbit
6: Abort
8: In flight checkout
9: Ground
Do modes 4,5 and 7 exist and if they don't is there any reason why not?
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#1618
by
Jorge
on 19 Feb, 2009 20:19
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Thanks Jorge!
I have attached a Deorbit Mnvr Exec display after loading the parameters for deorbit (no HST mission). Surrounded in red is the data of interest for me. If they deorbit from HST altitude they have two choices in my eyes:
1. do the burn early with still high downrange to landing site
2. do the burn with higher duration and come in steeper
What you say is that they come in steeper which would make the target perigee (TGT HP) more negative and the burn duration (TGO) would be longer.
Umm... no. They are steeper because HA is higher, not because HP is lower.
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#1619
by
Ronsmytheiii
on 21 Feb, 2009 16:23
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THis is a 3D image of part of an SSME, anyone know what it is?
To see the 3D effect, cross your eyes until the images converge.
