How's Atlantis' processing going?

• #100 by Chris Bergin on 02 Dec, 2005 22:17
• NASA'S SPACE SHUTTLE PROCESSING STATUS REPORT: S05-034
  
  Mission: STS-115 - 19th ISS Flight (12A) - P3/P4 Solar Arrays
  Vehicle: Atlantis (OV-104)
  Location: Orbiter Processing Facility Bay 1
  Launch Date: TBD
  Launch Pad: 39B
  Crew: Jett, Ferguson, Tanner, Burbank, MacLean and Stefanyshyn-Piper
  Inclination/Orbit Altitude: 51.6 degrees/122 nautical miles
  
  Atlantis processing continues on schedule. Thermal protection system
  gap-filler pull tests are complete. Work will begin soon to replace
  selected gap fillers identified during pull tests and analysis. This
  work is being performed due to two gap fillers that protruded from
  the underside of Discovery during STS-114. New installation
  procedures are being developed to ensure the gap fillers stay in
  place and do not pose a hazard during re-entry.
  
  Preparations to install the forward reaction control system continue.
  The cavity closeout photos were completed Thursday, and the
  installation of the system is scheduled for early next week. This
  control system provides the thrust for attitude maneuvers, pitch, yaw
  and roll, and for small velocity changes along the orbiter axis.
  
• #101 by Davros on 02 Dec, 2005 23:02
• Ok, so Atlantis has had her pull test and ready for replacements. It really is all down to the ETs.
• #102 by Do Shuttles Dream on 05 Dec, 2005 05:06
• Any chance a delay to later in the year would see Atlantis go first on STS-121, like Discovery got STS-114 off Atlantis? STS-121 was Atlantis' mission orignally wasn't it?
• #103 by nethegauner on 05 Dec, 2005 14:03
• Quote

  Do Shuttles Dream - 5/12/2005  7:06 AM
  
  Any chance a delay to later in the year would see Atlantis go first on STS-121, like Discovery got STS-114 off Atlantis? STS-121 was Atlantis' mission orignally wasn't it?

  Look at the May 13 schedule:
  
  STS-114
  OV-103
  July 23, 2005
  ISS-UF1
  
  STS-121
  OV-104
  September 9, 2005
  ISS-ULF1.1
  
  STS-115
  OV-104
  February 16, 2005
  ISS-12A
  
  NASA needs Atlantis to fly the STS-115 heavy lift mission. So instead of having a gap of five months between STS-121 and STS-115, it was decided to switch orbiters so that OV-103 can fly the ULF-1.1 mission.
  
  That's the reason behind the orbiter shuffle. Don't expect another switch. It would be unwise to let Atlantis do the ULF-1.1 job ...
• #104 by Launch Fan on 06 Dec, 2005 00:16
• Interesting, could you explain why it would be unwise for Atlantis to do the ULF-1.1 mission? I may have missed your point, but it sounds like there is a difference in capability between Atlantis and Discovery? I thought they were built very closely, and that makes me wonder what difference there would be?
• #105 by DaveS on 06 Dec, 2005 00:26
• Each subsequent orbiter is lighter than the previous one. So OV-099 was lighter than OV-102. OV-103 is lighter than OV-099. OV-104 is lighter than OV-103. And OV-105 is lighter than OV-104.
  
  And having OV-104 doing the ULF 1.1 flight prior to the 12A flight would put alot pressure on getting OV-104 turned around in time for the 12A launch. By switching ULF 1.1 to OV-103, some of that pressure is removed.
  
  Explantions:
  
  OV-099: Challenger
  OV-102: Columbia
  OV-103: Discovery
  OV-104: Atlantis
  OV-105: Endeavour
  ULF 1.1: STS-121
  12A: STS-115
• #106 by nethegauner on 07 Dec, 2005 12:44
• Quote

  Launch Fan - 6/12/2005  2:16 AM
  
  Interesting, could you explain why it would be unwise for Atlantis to do the ULF-1.1 mission? I may have missed your point, but it sounds like there is a difference in capability between Atlantis and Discovery? I thought they were built very closely, and that makes me wonder what difference there would be?

  There is indeed a difference in capabilities. Orbiter vehicles are constantly modified and improved, so none is exactly like the other. This also results in different vehicle masses. So if You have a heavy payload You might want to assign a lighter vehicle. OV-104 is capable of launching payloads heavier than the ULF-1.1 package.
• #107 by DaveS on 07 Dec, 2005 23:31
• In NASA Kennedy Space Center’s Orbiter Processing Facility Bay 1, installation of the forward reaction control system on Atlantis is complete.
  
  

  ---

  
• #108 by psloss on 08 Dec, 2005 12:55
• Quote

  nethegauner - 7/12/2005  8:44 AM
  There is indeed a difference in capabilities. Orbiter vehicles are constantly modified and improved, so none is exactly like the other. This also results in different vehicle masses. So if You have a heavy payload You might want to assign a lighter vehicle. OV-104 is capable of launching payloads heavier than the ULF-1.1 package.

  With all the changes made to the orbiters during the Mir and now ISS era, the performance differences are probably not quite as magnified as when Endeavour was delivered to KSC; however, Discovery is a little heavier than the other two remaining orbiters and the performance margins for the trusses with the alpha joints (P3/P4 and S3/S4) are tight, so either Atlantis or Endeavour will have to fly them.  This has been noted on sci.space.* a few times over the last couple of years (usually by Jorge Frank); this post notes that (at the time) the docking altitude would need to be lower than other flights:
  http://groups.google.com/group/sci.space.station/msg/2793fd935e7e7fa7?hl=en&
  
  Here's a more recent reference (the thread has other posts, too):
  http://groups.google.com/group/sci.space.shuttle/msg/7324652b42cd3184?hl=en&
  
  NASAWatch.com also posted a FAWG document pack in the Oct. 2004 timeframe that has some notations on performance margins...that was with the 28-flight manifest, but I think the performance numbers were only noted for flights within the U.S. Core Complete phase.
  
  Philip Sloss
  
• #109 by Chris Bergin on 08 Dec, 2005 15:08
• Hey Philip, welcome to the site.
• #110 by psloss on 08 Dec, 2005 18:06
• Quote

  Chris Bergin - 8/12/2005  11:08 AM
  
  Hey Philip, welcome to the site.

  Thanks.  Some interesting threads around here.
  
  Philip Sloss
  
• #111 by James Lowe1 on 09 Dec, 2005 00:03
• All very interesting, thanks for the links too.
• #112 by psloss on 09 Dec, 2005 01:55
• Quote

  psloss - 8/12/2005  8:55 AM
  NASAWatch.com also posted a FAWG document pack in the Oct. 2004 timeframe that has some notations on performance margins...that was with the 28-flight manifest, but I think the performance numbers were only noted for flights within the U.S. Core Complete phase.

  
  Here's the link to the document I was referring to (there's a link to a PDF version on the page):
  http://www.spaceref.com/news/viewsr.html?pid=14129
  
  115/12A doesn't have the numbers there, but the Ascent Performance Margin (APM) for the similar 117/13A flight was listed as -688 lbs. at the time, which seems indicative of being "tight" on performance.  (Though it was manifested to Endeavour in that document.)
  
  For what it's worth,
  
  Philip Sloss
• #113 by Mark Max Q on 09 Dec, 2005 02:20
• While I knew Columbia and Challenger were heavier, I didn't know about these slight differences between Discovery and Atlantis given how close in the timeline they were 'born'.
  
  I'm wondering how much of an handicap the OMSS has on the margin of error for Atlantis? I've no idea how much that wieghs, but we aren't entering Endeavour only terrortory with some ISS elements are we? Sorry if this is a dumb question
• #114 by psloss on 09 Dec, 2005 11:40
• Quote

  Mark Max Q - 8/12/2005  10:20 PM
  
  While I knew Columbia and Challenger were heavier, I didn't know about these slight differences between Discovery and Atlantis given how close in the timeline they were 'born'.
  
  I'm wondering how much of an handicap the OMSS has on the margin of error for Atlantis? I've no idea how much that wieghs, but we aren't entering Endeavour only terrortory with some ISS elements are we? Sorry if this is a dumb question

  I believe that the twin "3/4" trusses are the heaviest ISS launch elements, due to the solar alpha rotary joints on each.  The P6 and S6 trusses (the other ones with solar arrays on them) are fixed; (the P6 being on-orbit already).  The joints will allow all four array sets to track the sun more favorably (the wings themselves can also be pivoted.)
  
  From "reading between the lines" in a couple of Jorge's posts on Usenet, Discovery and Atlantis are fairly similar and differences are in the hundreds of pounds, which isn't much for a 100-ton vehicle, but the margins for these two truss launches (12A/115 and 13A/117) sound like they are in that ballpark.  
  
  OV-103 and OV-104 were originally almost twins in that they were manufactured very similarly.  But a lot has happened to the orbiter design and "implementation" in the 20 years or so since 103 and 104 were delivered, particularly with retrofits during the OMDPs.
  
  Dennis Jenkins' book remains a fantastic reference (and read) on most/all shuttle history:
  http://www.amazon.com/gp/product/0963397451/103-4778354-0009458?v=glance&n=283155
  
  Andy Foster's Launch Zone web site is also revealing in terms of ascent performance, particularly with respect to squeezing out a few pounds of performance here and there for ISS:
  http://www.theandyzone.com/launchzone/pe.html
  
  (Obviously things like the super-lightweight ET were a couple of order of magnitude more, but the items lower on the list are probably within the same general weight differences between the orbiters.)
  
  Philip Sloss
  
• #115 by Mark Max Q on 09 Dec, 2005 18:05
• Thank you very much! Learning all the time.
• #116 by Chris Bergin on 09 Dec, 2005 21:15
• STATUS REPORT: S05-035
  
  NASA'S SPACE SHUTTLE PROCESSING STATUS REPORT: S05-035
  
  Mission: STS-115 - 19th ISS Flight (12A) - P3/P4 Solar Arrays
  Vehicle: Atlantis (OV-104)
  Location: Orbiter Processing Facility Bay 1
  Launch Date: TBD
  Launch Pad: 39B
  Crew: Jett, Ferguson, Tanner, Burbank, MacLean and Stefanyshyn-Piper
  Inclination/Orbit Altitude: 51.6 degrees/122 nautical miles
  
  Technicians continue processing this mission to the International
  Space Station. Preparations are under way to drain Freon coolant loop
  No. 1 in support of a cold plate removal and replacement. The forward
  reaction control system was installed on Tuesday. This control system
  sits behind the nose cap and provides the thrust for rotational
  maneuvers and small velocity changes along the orbiter axis.
  
• #117 by tommy on 11 Dec, 2005 12:20
• I don't know much yet, but it's all very interesting. What is the order in which he shuttles were built?
• #118 by DaveS on 11 Dec, 2005 14:23
• This is the order of which the orbiters were built:
  
  OV-101(Enterprise)
  OV-102(Columbia)
  OV-099(Challenger)
  OV-103(Discovery)
  OV-104(Atlantis)
  OV-105(Endeavour)
• #119 by tommy on 11 Dec, 2005 14:53
• Thanks! Google was rubbish and started to do my head in when trying to find out, so I'm greatful, thank you.