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#320
by
Ford Mustang
on 06 Jun, 2007 03:20
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Got the OBSS and the RMS mixed up.. Sorry bout that.
As to 1, I was told by another person that the KU, even stowed, could reach JSC for television coverage.
EDIT: Still, why can't they downlink the video, because they DO have a DV camera..
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#321
by
MKremer
on 06 Jun, 2007 03:28
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The best they could do is the 30 second/frame S-band video - the Ku antenna needs to search and lock on to the nearest TDRS (which means it tilts and yaws in the TDRS direction for the best signal lock position). Don't think that can safely happen in the stowed position.
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#322
by
Ford Mustang
on 06 Jun, 2007 03:38
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30 FPS isn't that bad, to be honest. I'd like to see a lot more PLB door openings. I find it fascinating. Loved the view on STS-1 (NTV special, TiVo baby!), and would love to see more.
That's just me.
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#323
by
MKremer
on 06 Jun, 2007 03:59
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Not 30fps, but each frame every 30 seconds, something we have always seen off and on during missions and EVAs when Ku is in blackout periods (S-band is much lower bandwidth).
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#324
by
Jim
on 06 Jun, 2007 05:23
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Ford Mustang - 5/6/2007 11:20 PM
Got the OBSS and the RMS mixed up.. Sorry bout that.
As to 1, I was told by another person that the KU, even stowed, could reach JSC for television coverage.
EDIT: Still, why can't they downlink the video, because they DO have a DV camera..
No TV, It can't transmit while stowed
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#325
by
psloss
on 06 Jun, 2007 10:48
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Payload bay opening has very occasionally been shown something close to live, but IIRC only on low-inclination flights -- perhaps it has something to do with the orbiter being in range of MILA. (And also the timeline was coincident with that pass.)
But that was also prior to the Columbia disaster. (Don't know if the attitudes they fly now are good for downlink to MILA.)
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#326
by
DaveS
on 06 Jun, 2007 10:59
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psloss - 6/6/2007 12:48 PM
Payload bay opening has very occasionally been shown something close to live, but IIRC only on low-inclination flights, since sometimes the timeline sync-ed up with the orbiter being in range of MILA...that was also prior to the Columbia disaster. (Don't know if the attitudes they fly now are good for downlink to MILA.)
They did show live payload bay door opening video on STS-112, when Atlantis flew over JSC. It's still pretty common that orbiter overflies JSC at about 90 minutes into the mission which is when door opening is usually scheduled for.
The most likely reason for not showing the payload bay doors opening is because that the post-launch press-conference happens at the same.
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#327
by
psloss
on 06 Jun, 2007 11:20
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DaveS - 6/6/2007 6:59 AM
They did show live payload bay door opening video on STS-112, when Atlantis flew over JSC. It's still pretty common that orbiter overflies JSC at about 90 minutes into the mission which is when door opening is usually scheduled for.
There you go, I stand corrected. Seems like in the past when they got downlink they've also replayed it, too, after the post-launch press conference (but that was still all prior to the Columbia disaster).
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#328
by
Danny Dot
on 06 Jun, 2007 15:49
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mkirk - 5/2/2007 2:59 PM
snip
As far as the wide HAC story goes I will have to double check, but that sounds to me like a major exaggeration of what was probably a “Low Energy” situation that was presumably recovered by the time the orbiter rolled out on final. However, I will research that one…
Mark Kirkman
It was STS-37. They landing 1,600 feet short of the runway at Edwards. Fortunately it was a dry lake bed runway, so landing short was OK. If this had been KSC, it would have been loss of orbiter and crew.
Danny Deger
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#329
by
brahmanknight
on 06 Jun, 2007 20:54
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Could anyone elaborate more on "High Energy" and "Low Energy" landings? Is it just a computer miscalculation that happens?
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#330
by
mkirk
on 07 Jun, 2007 00:12
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Danny Dot - 6/6/2007 10:49 AM
mkirk - 5/2/2007 2:59 PM
snip
As far as the wide HAC story goes I will have to double check, but that sounds to me like a major exaggeration of what was probably a “Low Energy” situation that was presumably recovered by the time the orbiter rolled out on final. However, I will research that one…
Mark Kirkman
It was STS-37. They landing 1,600 feet short of the runway at Edwards. Fortunately it was a dry lake bed runway, so landing short was OK. If this had been KSC, it would have been loss of orbiter and crew.
Danny Deger
Thanks Danny-
That was obviously long before my time. I will go look it up. I am surprised I never heard about it during my time in training - that is a big deal, I can only imagine the fallout from that within MOD/FCOD at the time.
Mark Kirkman
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#331
by
mkirk
on 07 Jun, 2007 00:52
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brahmanknight - 6/6/2007 3:54 PM
Could anyone elaborate more on "High Energy" and "Low Energy" landings? Is it just a computer miscalculation that happens?
Well, here is a quick and overly simplistic pass at this topic:
Energy – as it is used in this case – is a way of quantifying the orbiter’s ability to make it to the runway. For the most part energy is a function of the orbiter’s altitude and velocity. There are many variables that can affect the orbiter’s energy state. If you are very “LOW ENERGY” that means you are probably not gonna make it to the runway and you could fall on the “mouse’s house” over in Orlando (i.e. Disney World). If you are really “HIGH ENERGY” that means you are going to zip right on past the runway which at KSC means you are going for a swim.
Some of the many variables that can affect your energy state include, drag, atmospheric density, trim (i.e. flight control positions and gains), orbiter attitude, bad/degraded Guidance & NAV, flight control problems, late runway changes, winds, and many more…
The orbiter’s entry trajectory is optimized to allow for some margin both high and low. So for instance if the orbiter is low energy approaching the terminal area you can possibly down mode to a straight in approach rather than flying around the HAC – that results in an instant reduction in the distance the orbiter has to fly to get to the runway.
Mark Kirkman
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#332
by
MKremer
on 07 Jun, 2007 01:14
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mkirk's descriptions are excellent.
Just to add..."energy" means kinetic energy - the mass/velocity energy you have at any particular time.
As an example, say you're in an unpowered glider - if you dive, you're gaining energy; if you climb, you're losing energy.
Gravity has a large effect on kinetic energy, and managing that energy (via climb/dive/banks/turns) in an atmospheric craft (especially an unpowered one!) is very important.
It's even more important with the Shuttle orbiter, which has been (probably accurately) described as "a brick with wings".
Energy management (mass/velocity) when approaching the runway site - turning into the final alignment at the correct location and time, and the approach to the runway itself - all require managing energy correctly to finally touch down at the necessary point on the runway.
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#333
by
Danny Dot
on 07 Jun, 2007 02:11
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mkirk - 6/6/2007 7:12 PM
Danny Dot - 6/6/2007 10:49 AM
mkirk - 5/2/2007 2:59 PM
snip
As far as the wide HAC story goes I will have to double check, but that sounds to me like a major exaggeration of what was probably a “Low Energy” situation that was presumably recovered by the time the orbiter rolled out on final. However, I will research that one…
Mark Kirkman
It was STS-37. They landing 1,600 feet short of the runway at Edwards. Fortunately it was a dry lake bed runway, so landing short was OK. If this had been KSC, it would have been loss of orbiter and crew.
Danny Deger
Thanks Danny-
That was obviously long before my time. I will go look it up. I am surprised I never heard about it during my time in training - that is a big deal, I can only imagine the fallout from that within MOD/FCOD at the time.
Mark Kirkman
For a detailed write-up see:
http://groups.google.com/group/sci.space.shuttle/browse_thread/thread/209e4408b4786d02/5c6efd21ae4f32a1?lnk=st&q=&rnum=1#5c6efd21ae4f32a1Danny Deger
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#334
by
mkirk
on 07 Jun, 2007 02:47
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Danny Dot - 6/6/2007 9:11 PM
For a detailed write-up see:
http://groups.google.com/group/sci.space.shuttle/browse_thread/thread/209e4408b4786d02/5c6efd21ae4f32a1?lnk=st&q=&rnum=1#5c6efd21ae4f32a1
Danny Deger
Thanks for that write up, that told me a lot...and yes with the rules in place right now I could not imagine how this could have happend. I think that is why I didn't beleive the original post on this subject and just assumed they had heard the space program's version of an urban myth.
I still don't recall ever hearing about this specific flight during my training. Of course they may have discussed it and I just didn't pick it up - part of that whole drinking from a fire hose mentality.
After reading that all I can do is shake my head, I can't believe the program ever let itself get into that kind of corner.
Mark Kirkman
P.S.
I thought I recognized your name when you first started posting on this site but I couldn't figure out why. Now I think it is becuase I must have read some of your training stuff when I was an instructor.
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#335
by
Jorge
on 07 Jun, 2007 04:12
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MKremer - 6/6/2007 8:14 PM
mkirk's descriptions are excellent.
Just to add..."energy" means kinetic energy - the mass/velocity energy you have at any particular time.
That's actually oversimplifying a bit. "Energy" means total energy - the sum of kinetic and potential energy. Kinetic energy is proportional to velocity squared, potential energy to height.
As an example, say you're in an unpowered glider - if you dive, you're gaining energy; if you climb, you're losing energy.
In an unpowered glider, your total energy is always decreasing, due to drag. If you dive, you're trading potential energy for kinetic energy; if you climb, you're trading potential for kinetic. But the sum of potential and kinetic is always getting smaller.
Gravity has a large effect on kinetic energy, and managing that energy (via climb/dive/banks/turns) in an atmospheric craft (especially an unpowered one!) is very important.
It's even more important with the Shuttle orbiter, which has been (probably accurately) described as "a brick with wings".
Compared to other winged aircraft, yes. The orbiter has a subsonic L/D around 4, compared to around 20 for most subsonic aircraft. But that's still a lot better than any lifting body or capsule.
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#336
by
sketterer
on 07 Jun, 2007 04:56
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In one of the hi-res pictures on the NASA site, (for example, today's picture of Rick Sturckow and Lee Archambault standing by the traing jet), there are tags attached to the astronauts' shoes. Sturckow's tags were both red and imprinted with the letter 'A,' and Archambault's were yellow, imprited with the letter 'B.' Any idea of what they're used for? Is it a search-an-rescue thing or just a way to keep track of "stuff?"
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#337
by
MKremer
on 07 Jun, 2007 06:13
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Interesting observations. Now that you mentioned it, I'm curious also about those details.
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#338
by
mkirk
on 07 Jun, 2007 18:38
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The color coding of the tags allows for easy identification of the specific crew members by duty position.
Commander – Red (A)
Pilot –Yellow (B)
MS1 – Blue (C)
MS2 – Green (D)
MS3 – Orange (E)
MS4/PS1 – Brown (F)
MS5/PS2 – Purple (G)
MS6/PS3 – Beige (H)
MS7/PS4 – Black (I)
MS8/PS5 – Light Gray (J)
Mark Kirkman
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#339
by
elmarko
on 07 Jun, 2007 18:50
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Edit: Well that was odd, stand by.
Edit 2: OK, i clicked on the "last post" in the General Discussion thread, but the thread had changed between me loading the page and me clicking. Ignore/prune the post please
