Shuttle Questions Q & A (Part 4)

• #660 by Jim on 21 Feb, 2008 14:50
• good food or quiet with no trouble looking for seating?  they are mutually exclusive
• #661 by ntschke on 21 Feb, 2008 15:31

• Quote

  Jim - 21/2/2008 10:50 AM good food or quiet with no trouble looking for seating? they are mutually exclusive

  I think it would depend on how many are interested and on what day or time.  If 20 people say they are interested it will matter, if it's just 5 or 10 may not be a big issue. If the gambling cruise ships goes out, we'll get on a free ride just to catch a glimpse of the pads from the ocean. When do shipping/boating restrictions go into effect before a launch?  I'm pretty sure its hours and not days before right?

  As for a gathering, should all go well and the launch is sucessful this could be a tuesday afternoon/evening happy hour type thing.  Any locals that have a place it mind, let us tourists know.  

  (I added a new thread to the STS-123 section this morning so those that want to go can throw out their ideas)

• #662 by iamlucky13 on 21 Feb, 2008 21:42
• Quote

  mkirk - 20/2/2008  6:40 PM
  
  You can find diagrams out the wazooo at this public link: http://www.shuttlepresskit.com/STS-105/scom.htm
  
  4. Alpha (angle of attack) does not work that way. I thought you asked specifically for angle of attack and not pitch.  Angle of attack - defined as the angle between the wing chord line and the relative wind - is what I was trying to provide.
  
  As for the glideslope, that is weight dependent in the Space Shuttle world.  For heavy weight orbiters (222,000 pounds and above) the glideslope is 20 degrees - in the HUD video you would see two red and two white PAPI lights, lightweight orbiters (less than 222,000) use 18 degrees which equates to three red lights and one white light.  Of course you can also use the pitch ladder symbols on the HUD to determine orbiter pitch.
  
  As I said the Alpha on final is relatively small for the shuttle.  You can watch the HUD videos from today and guesstimate the approximate angle of attack by taking the cross hair symbol (plus sign) which represents the vehicle's X (longitudinal) body axis and the velocity vector (the circle with two small horizontal lines and one vertical line on the top).  I have no idea how close the X body axis actually is to the shuttle's wing chord line but this will give you a rough idea of what would be happening to Angle of Attck as the orbiter is stabalized on the glideslope.

  Thanks for all the information and to the others who helped answer my questions. I will look back through the video/screenshots from the landing for the velocity vector in the HUD.
  
  Yes, angle of attack is what I was looking for, as the pitch is more or less evident from the pictures. I guess my confusion is because I was assuming when you said 1.5 deg on final is that this meant during the flare. It should have been obvious to me this wasn't the case since you already said alpha was 8-14 degrees at touchdown and I think you distinguished between HAC and final.
• #663 by mjp25 on 22 Feb, 2008 03:06
• Ok, I understand that for the ALT, Enterprise needed simulated OMS pods because there were no flight articles at the time. I also understand that the tail cone was then constructed to match that. But afterwards, why didn't they make coverings for the OMS attachment points that were more aerodynamic for ferry flights? Is there a need for that volume? Or was it simply that there was no need to spend the money on new "covers", a new tail cone and the aerodynamic testing that would need to be done to confirm the new configuration? Was any thought given to this?
• #664 by mkirk on 22 Feb, 2008 03:28
• Quote

  iamlucky13 - 21/2/2008  4:42 PM
  
  Yes, angle of attack is what I was looking for, as the pitch is more or less evident from the pictures. I guess my confusion is because I was assuming when you said 1.5 deg on final is that this meant during the flare. It should have been obvious to me this wasn't the case since you already said alpha was 8-14 degrees at touchdown and I think you distinguished between HAC and final.

  
  
  I never said 1.5 degrees on final.  
  
  I did say that MAX L/D for the shuttle orbiter at subsonic speeds is 10.5 degrees.  
  
  I have attached a copy of the ENTRY ALPHA CUE CARD from the STS-122 Entry Checklist to give you an idea of what happens to ANGLE OF ATTACK all the way thru entry.  This card shows a reference entry trajectory with MACH NUMBER on the left column and ANGLE OF ATTACK in the second column, followed by RANGE in nautical miles, ALTITUDE in thousands of feet, SINK RATE in feet per second, and REFERENCE BANK ANGLES.
  
  The card is placed on the forward instrument panels next to the Commander and Pilot ADI (attitude direction indicators).  Although the card is de-orbit specific it does provide useful approximations to the crew for any of the de-orbit opportunities they might fly.  The card is particularly useful in No Comm situations and TAL Aborts.
  
  I don’t know if you are familiar with the concept of Power Curves but as you can see at MACH 1 – when MAX L/D becomes 10.5 – that the orbiter does not nominally fly MAX L/D.  In fact at MACH numbers above 3.5 the space shuttle orbiter flies on the back side of the curve and below 3.5 it is on the front side.
  
  The MAX L/D would be useful for the crew to fly in off nominal situations when they are low on energy and need to increase range (i.e. glide distance) as much as possible in an effort to make it all the way to the runway.
  
  Mark Kirkman

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• #665 by Lawntonlookirs on 22 Feb, 2008 18:30
• I just tried to search for this answer and wasn’t able to find anything that looked like the answer.  How does, and did, NASA come up with the mission numbers for the shuttle?  The started with STS-1 in 1981 and continued thru STS-9 in 1983.  Then they started STS- 41B in 1984 and continued thru STS 41G in the same year.  They then had several STS-51 in 1985 and then went to STS-61A, B and C.  Then they went back to STS-51L.  After that they has STS-26 and have been continuing the numbers through STS-130.  I did find out that the special missions set up for a rescue are STS-300's such as STS-323 which was the rescue for the recent Atlantis flight.  It appears that after the Challenger accident NASA decided to change the numbers.
• #666 by Bret on 22 Feb, 2008 18:47
• Quote

  Lawntonlookirs - 22/2/2008  1:30 PM
  
  I just tried to search for this answer and wasn’t able to find anything that looked like the answer.  How does, and did, NASA come up with the mission numbers for the shuttle?

  
  This has been answered here before, but here is a link to a pretty clear explanation:
  
  http://enterfiringroom.ksc.nasa.gov/funFactsSTSNumbers.htm
• #667 by Lawntonlookirs on 22 Feb, 2008 19:23
• Thanks Bret:  Very simnple once you understand it.  I still can't seem to get the search engine working on the forum.
• #668 by ChrisGebhardt on 23 Feb, 2008 02:59
• How does NASA determine the official mission duration for a space shuttle mission? I know it starts with SRB ignition, but does it end with main gear touchdown, nose gear touchdown, or wheel stop? It would appear, based on the shuttle page on the NASA website, that for STS-122 it was from SRB ignition to nose gear touchdown. But this doesn't always work out this way for other flights.
  
  NOTE: The search function on my computer doesn't work so if this has been answered before, please point me in the right direction.  
  
  Thanks.
• #669 by The-Hammer on 23 Feb, 2008 05:25
• The FDRD for STS-124 mentions, as part of the "Ascent Performance Analysis" on page 8, a "Multi-Stage De-Orbit" that results in +422lbp.
  
  How exactly does a "Multi-Stage De-Orbit" differ from the nominal EOM de-orbit?
• #670 by SpikeSpiegel on 23 Feb, 2008 15:05
• The search function is broke for me, so if this has been answered, just point me to the right place, But how does SRB ignition occur? Does it start in the upper section of the SRB, near the tail, or at points all along the internal channel. Thanks.
• #671 by Lawntonlookirs on 23 Feb, 2008 15:27
• I just found out from Chris that I was searching through to much information.  Narrow your search down to a SUBJECT or MESSAGE and then your time down to 6 months.  Then try to select a specific forum.  I will try to give you the screenshot that Chris gave me.

  ---

  
• #672 by ChrisGebhardt on 23 Feb, 2008 18:47
• Quote

  Lawntonlookirs - 23/2/2008  11:27 AM
  
  I just found out from Chris that I was searching through to much information.  Narrow your search down to a SUBJECT or MESSAGE and then your time down to 6 months.  Then try to select a specific forum.  I will try to give you the screenshot that Chris gave me.

  
  
  And that would be wonderful, but the search function doesn't work on our computers. I'm in the same position as SpikeSpiegel... we can't search through the forums. So if you can, can you post a link to the forum(s) were our questions are answered?
• #673 by ChrisGebhardt on 23 Feb, 2008 18:50
• Quote

  The-Hammer - 23/2/2008  1:25 AM
  
  The FDRD for STS-124 mentions, as part of the "Ascent Performance Analysis" on page 8, a "Multi-Stage De-Orbit" that results in +422lbp.
  
  How exactly does a "Multi-Stage De-Orbit" differ from the nominal EOM de-orbit?

  
  
  And someone who knows better can correct me on this, but didn't STS-120 perform a multi-stage de-orbit? If so, then I believe this is when they do more NC burns to get the vehicle into a better position for a short deorbit burn at EOM.
• #674 by Jim on 23 Feb, 2008 18:54
• Quote

  SpikeSpiegel - 23/2/2008  11:05 AM
  
  The search function is broke for me, so if this has been answered, just point me to the right place, But how does SRB ignition occur? Does it start in the upper section of the SRB, near the tail, or at points all along the internal channel. Thanks.

  
  http://spaceflight1.nasa.gov/shuttle/reference/shutref/srb/ignition.html
  
  The fire 2 commands cause the redundant NSDs to fire through a thin barrier seal down a flame tunnel. This ignites a pyro booster charge, which is retained in the safe and arm device behind a perforated plate. The booster charge ignites the propellant in the igniter initiator; and combustion products of this propellant ignite the solid rocket motor initiator, which fires down the length of the solid rocket motor igniting the solid rocket motor propellant.
• #675 by SpikeSpiegel on 23 Feb, 2008 19:04
• Quote

  Jim - 23/2/2008  2:54 PM
  
  
  http://spaceflight1.nasa.gov/shuttle/reference/shutref/srb/ignition.html
  
  SNIP

  
  Once again Jim, you prove you are the man. ^_^
• #676 by Jim on 23 Feb, 2008 19:21
• Quote

  Trekkie07 - 23/2/2008  2:47 PM
  
  

  Quote

  Lawntonlookirs - 23/2/2008  11:27 AM
  
  I just found out from Chris that I was searching through to much information.  Narrow your search down to a SUBJECT or MESSAGE and then your time down to 6 months.  Then try to select a specific forum.  I will try to give you the screenshot that Chris gave me.

  
  
  And that would be wonderful, but the search function doesn't work on our computers. I'm in the same position as SpikeSpiegel... we can't search through the forums. So if you can, can you post a link to the forum(s) were our questions are answered?

  
  They are answered in the previous posts in the shuttle Q&A thread.  There are 4 threads and first post in each has links to the previous ones
  
  open each shuttle Q&A thread and click on "printer friendly version"   Then use the browser search function on the "large" page
• #677 by madmardy on 23 Feb, 2008 23:44
• After landing the flight director polls the various stations asking "do they have any deltas?"
  And i have heard capcom transmissions to the crew stating "no deltas"
  
  What are these deltas?
• #678 by rdale on 24 Feb, 2008 00:03
• Delta is the word for "change"
• #679 by John2375 on 24 Feb, 2008 21:40
• I know the SRBs are sent back to Utah and then returned to KSC for another launch; what is the 'turnaround time' on them?  Is there a way to figure out what flights used the same SRBs?
  For example the ones used on STS-85, is there a way to figure out when each one flew again?
  just curious is all.. I'm sure the ones used now won't be used again.