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#1120
by
iskyfly
on 30 Apr, 2010 15:34
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I would have to know the context and who said it, can you point me to the particular video you heard this on?
Mark Kirkman
Sure! Here;
Around 42 second mark just after crew calls roll program.
Also, could you please comment on;
1:02
"1000 low"
1:23
"1500 low"
What caused this and how did the crew know?
Thank you!
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#1121
by
Jorge
on 30 Apr, 2010 16:22
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You could look at seat yourself at
http://www.panoscan.com/CubicDemos/Shuttle.html
Quicktime VR allows you to look all around
Ok, so we have an idea of where the orbiters may end up going, but what will end up happening to the sims?
Not all have been dispositioned yet. The Shuttle Mission Simulator Motion Base is going to Texas A&M University's Aerospace Engineering department, but that's all I know so far.
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#1122
by
mkirk
on 30 Apr, 2010 16:24
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I would have to know the context and who said it, can you point me to the particular video you heard this on?
Mark Kirkman
Sure! Here;
Around 42 second mark just after crew calls roll program.
Also, could you please comment on;
1:02
"1000 low"
1:23
"1500 low"
What caused this and how did the crew know?
Thank you!
Yeah the “small numbers” call sounds like a reference to the BFS ADI Digitals. During the roll maneuver the crew will cross check the values for R (roll), P (pitch), & Y (yaw) on the BFS version of the Ascent Trajectory Display against what they are seeing on the ADI (attitude director Indicator). The PASS (primary) computers are controlling the maneuver and that is where the info on the ADI is coming from but by verifying that the error values on the BFS Traj Display are small the crew knows that the BFS computer closely agrees with where the PASS computers are taking the vehicle. If the values were large then that would be a clue that the BFS does not agree with the PASS computers.
My best guess for the second set of numbers you asked about during throttle down is that the crew is cross checking the values on the Ascent ADI cue card which is attached with Velcro to the forward panels next to the two ADIs (a copy of the cue card is always in the Ascent checklist). The card provides a rough estimate of values for pitch, altitude (in thousands of feet), altitude rate (climb rate in feet per second) at a given time (in first stage) or a given velocity (in second stage). These are the pre-flight predictions of what the trajectory should be and can be affected by the real time conditions on launch day such as ambient temperature (which affects solid rocket booster performance) or winds, etc…
While there are some so called formal or standard intercom callouts made within the cockpit, each crew develops their own pattern/rhythm and you will notice these differences if you watch different ascent videos from other missions or sims.
Mark Kirkman
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#1123
by
psloss
on 30 Apr, 2010 17:13
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FWIW, this is STS-113.
I would have to know the context and who said it, can you point me to the particular video you heard this on?
Mark Kirkman
Sure! Here;
Around 42 second mark just after crew calls roll program.
Also, could you please comment on;
1:02
"1000 low"
1:23
"1500 low"
What caused this and how did the crew know?
Thank you!
Yeah the “small numbers” call sounds like a reference to the BFS ADI Digitals. During the roll maneuver the crew will cross check the values for R (roll), P (pitch), & Y (yaw) on the BFS version of the Ascent Trajectory Display against what they are seeing on the ADI (attitude director Indicator). The PASS (primary) computers are controlling the maneuver and that is where the info on the ADI is coming from but by verifying that the error values on the BFS Traj Display are small the crew knows that the BFS computer closely agrees with where the PASS computers are taking the vehicle. If the values were large then that would be a clue that the BFS does not agree with the PASS computers.
My best guess for the second set of numbers you asked about during throttle down is that the crew is cross checking the values on the Ascent ADI cue card which is attached with Velcro to the forward panels next to the two ADIs (a copy of the cue card is always in the Ascent checklist). The card provides a rough estimate of values for pitch, altitude (in thousands of feet), altitude rate (climb rate in feet per second) at a given time (in first stage) or a given velocity (in second stage). These are the pre-flight predictions of what the trajectory should be and can be affected by the real time conditions on launch day such as ambient temperature (which affects solid rocket booster performance) or winds, etc…
While there are some so called formal or standard intercom callouts made within the cockpit, each crew develops their own pattern/rhythm and you will notice these differences if you watch different ascent videos from other missions or sims.
Mark Kirkman
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#1124
by
10W29
on 30 Apr, 2010 19:55
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Bottom line is all the remaining orbiters have flown 5 tank sets for >15 years. I was just correcting an error in which it was stated that 103 & 104 didn't have the 5th tank set.
<15 years, AXAF launched in 1999
Chandra flew on 102 which is why I stated "remaining orbiters"
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#1125
by
brahmanknight
on 02 May, 2010 03:38
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Why was the clean launch pad approached, which was used for Saturn V, not used for the Space Shuttle? Was it due to the weight of the SRBs?
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#1126
by
Jim
on 02 May, 2010 12:49
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Why was the clean launch pad approached, which was used for Saturn V, not used for the Space Shuttle? Was it due to the weight of the SRBs?
The need to install payloads at the pad drove the RSS and there was no place to stick an FSS on the MLP.
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#1127
by
Sesquipedalian
on 03 May, 2010 01:47
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The need to install payloads at the pad drove the RSS
Why was there such a need? Why couldn't the payloads be installed in the VAB?
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#1128
by
iskyfly
on 03 May, 2010 13:17
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Many thanks Mark re: "small numbers" and other ascent call outs.
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#1129
by
Jim
on 03 May, 2010 13:39
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The need to install payloads at the pad drove the RSS
Why was there such a need? Why couldn't the payloads be installed in the VAB?
No clean room. Also, the payloads don't want to be in the orbiter for more than 4 weeks
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#1130
by
DaveS
on 08 May, 2010 00:23
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#1131
by
Ronsmytheiii
on 09 May, 2010 21:34
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#1132
by
padrat
on 11 May, 2010 12:25
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No clean room. Also, the payloads don't want to be in the orbiter for more than 4 weeks
I think also that the Air Force wanted the ability to install and change payloads at the pad.
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#1133
by
Ronsmytheiii
on 12 May, 2010 02:51
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No clean room. Also, the payloads don't want to be in the orbiter for more than 4 weeks
I think also that the Air Force wanted the ability to install and change payloads at the pad.
Wouldn't that depend on payload latches, which as far as I know can only be changed in the OPF?
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#1134
by
TJL
on 12 May, 2010 22:15
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For anyone that's been involved with the shuttle program pre-Challenger...
I was watching a video the other day that showed a crew in the white room preparing to enter the orbiter.
As was normal in those days, they wore the blue flight suits.
What surprised me was that they put their helmets on in the white room.
Was there a reason for not putting them on while in the orbiter, as is done presently?
Thank you.
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#1135
by
wally
on 13 May, 2010 09:38
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I would like to better understand how the shuttle rendezvous with the ISS. I've practice a bit in Orbiter, but I'm not sure it's a very accurate approach the one I do there.
So, after MECO, the shuttle it's on a stable, closed orbit. What parameters does this first orbit generally have (periapsis, apoapsis, inclination)? At what point on orbit are the first corrections made, and how? When is the inclination correction made, and how does the real shuttle does that? I guess that the rendezvous maneuverer follows the inclination correction. How does a shuttle get close to ISS? What comes to mind is a shuttle orbit something like 350x180 km (first being approximatively the altitude of ISS, second being high enough to avoid significant atmospheric drag) and then wait to catch ISS, usually takes 2-4 days in Orbiter, if launched accordingly (real date and time for a specific mission). Is this a realistic, fuel efficient, approach?
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#1136
by
Jorge
on 13 May, 2010 14:14
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I would like to better understand how the shuttle rendezvous with the ISS. I've practice a bit in Orbiter, but I'm not sure it's a very accurate approach the one I do there.
So, after MECO, the shuttle it's on a stable, closed orbit. What parameters does this first orbit generally have (periapsis, apoapsis, inclination)?
For ISS missions, HA=122 nmi, HP=32 nmi, and i=51.6 deg.
At what point on orbit are the first corrections made, and how?
OMS-2 burn, near the apogee of the post-MECO trajectory (~40 min after launch). Posigrade burn, raises the other side of the orbit to at least 85 nmi, but exact magnitude depends on the phase angle between the orbiter and ISS (in other words, OMS-2 isn't just a circularization burn, it's also the first rendezvous phasing burn, though the name doesn't reflect that).
When is the inclination correction made, and how does the real shuttle does that?
The shuttle launches in-plane with ISS, so no "inclination correction" maneuver is necessary. There is a placeholder for a planar correction burn (NPC) on flight day 2, but it is normally only needed to take out dispersions.
I guess that the rendezvous maneuverer follows the inclination correction. How does a shuttle get close to ISS? What comes to mind is a shuttle orbit something like 350x180 km (first being approximatively the altitude of ISS, second being high enough to avoid significant atmospheric drag) and then wait to catch ISS, usually takes 2-4 days in Orbiter, if launched accordingly (real date and time for a specific mission). Is this a realistic, fuel efficient, approach?
There are typically phasing maneuvers at the beginning and end of each flight day prior to rendezvous day to adjust the phasing rate. So NC-1 at the end of flight day 1, NC-2 at the beginning of flight day 2, and NC-3 at the end of flight day 2. There is also the aforementioned NPC burn placeholder during flight day 2. NPC may be combined with either NC-2 or NC-3 if the common node between the planes happens to coincide with either burn.
On flight day 3, the crew enters the rendezvous timeline. There is an optional NH burn to adjust the height (specifically to place apogee near ISS altitude). This burn may not be required for short phasing cases since previous burns may have already raised apogee (in the extreme short phasing case, OMS-2 itself would raise apogee to ISS and the remaining NC burns just gradually raise perigee). At the post-NH apogee, the orbiter performs the final NC burn (NC-4). This should occur at a point 40 nmi behind ISS and adjusts the phasing rate to put the orbiter 8 nmi behind ISS one orbit later. From NC-4 on, the trajectory and procedures are standard and can be found in the publicly available flight data file.
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#1137
by
wally
on 13 May, 2010 15:19
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Great, thank you very much!
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#1138
by
mmeijeri
on 14 May, 2010 08:13
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From
The Space Shuttle Decision:
Though recent research had increased confidence that they indeed would serve, what made tiles more attractive yet was that NASA could count with reasonable assurance on using ablative heat shields as a backup. Ongoing work with ablatives had cut their cost dramatically while reducing their weight to 15 pounds per square foot, matching the weight of the tiles.
This was the first time I'd ever heard of ablative TPS on the Shuttle. Given that the tiles turned out to be so much more expensive than expected, would they still be less expensive than an ablative shield? How does an ablative shield compare when it comes to ruggedness? Could it withstand foam strikes or even MMOD strikes better than the tiles? Was an ablative TPS ever considered again after the loss of Columbia?
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#1139
by
iskyfly
on 14 May, 2010 13:27
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I am interested to know more about the KU band failure on the previous mission- what was the cause, how was it diagnosed, how was it fixed, what checks / fixes if any were done on Atlantis. I do not have L2 access.
Thanks!
