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#300
by
psloss
on 02 Jun, 2007 21:38
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#301
by
gordo
on 02 Jun, 2007 22:35
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cheers jim, I guess the MLP has a hoist type system to lift it up to work height
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#302
by
Jim
on 02 Jun, 2007 22:36
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Yes, it has built in hoists for the SSME platform as well the SRB platforms.
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#303
by
Danny Dot
on 03 Jun, 2007 17:28
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madmardy - 2/6/2007 4:23 PM
I'm not sure whether this has been covered before
but whats the difference between the roles of booster and main engines in MCC?
as in the STS-93 video they seem to be doing very similar things
Main Engines works for Booster. Booster is in the main flight control room and Main Engines is in a back room. Most if not all people in the flight control room have about 4 people in the backrooms that talk to them.
Danny Deger
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#304
by
Mark Dave
on 03 Jun, 2007 18:32
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Does the stack sway a lot before launch? I saw a clip of the new simulator ride on NASA TV and it showed the stack sway a bit. What causes this to happen?
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#305
by
DaveS
on 03 Jun, 2007 18:40
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MarkD - 3/6/2007 8:32 PM
Does the stack sway a lot before launch? I saw a clip of the new simulator ride on NASA TV and it showed the stack sway a bit. What causes this to happen?
You never heard of the "Twang"? The "Twang" is caused by the SSMEs being offset from the cg of the stack. When the SSMEs fire they cause the stack to bend as much as 6 ft and then the stack "twangs" back and when the stack is pure vertical again, the SRBs are ignited.
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#306
by
ShuttleDiscovery
on 03 Jun, 2007 19:55
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DaveS - 3/6/2007 7:40 PM
MarkD - 3/6/2007 8:32 PM
Does the stack sway a lot before launch? I saw a clip of the new simulator ride on NASA TV and it showed the stack sway a bit. What causes this to happen?
You never heard of the "Twang"? The "Twang" is caused by the SSMEs being offset from the cg of the stack. When the SSMEs fire they cause the stack to bend as much as 6 ft and then the stack "twangs" back and when the stack is pure vertical again, the SRBs are ignited.
That's why the SSMEs ignite at T-6.6 seconds, as it gives enough time for the twang to occur so that at T-0, the stack is pure vertical.
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#307
by
Jim
on 03 Jun, 2007 20:06
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actually, it isn't where it is vertical but where the moment at the base of the SRB's is at a minimum
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#308
by
Mark Dave
on 03 Jun, 2007 21:25
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No, no. I know of the twang. I meant before launch happens. Such as the clip I saw, while the stack is on the pad it moves a little. Even in the documentary "Blast Off" that was on TLC astronauts even said the stack does move a little while sitting there. There was even a bit of video from the White Room showing the shuttle move.
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#309
by
Jim
on 04 Jun, 2007 02:06
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Wind makes it move
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#310
by
spaceshuttle
on 04 Jun, 2007 03:40
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Must be some strong winds, huh?!
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#311
by
rdale
on 04 Jun, 2007 03:53
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Winds aren't normally that excessive, what leads you to believe they regularly get hammered by strong gusts?
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#312
by
spaceshuttle
on 04 Jun, 2007 03:57
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rdale - 3/6/2007 10:53 PM
Winds aren't normally that excessive, what leads you to believe they regularly get hammered by strong gusts?
Somebody said that wind nudges the stack while on the launch pad, but considering how heavy the thing is, I was 'caught off guard'. I didn't think that the stack would move that easily.
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#313
by
Mark Dave
on 04 Jun, 2007 13:18
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Well, considering the two TSMs that support the orbiter, and the arms to hold the orbiter are designed to move during the "twang". I've read it feels like you're sitting ontop of a tree on a windy day and you feel yourself swaying.
Wouldn't the swaying affect the LOX vent arm? I was just wondering given how winds can affect the stack.
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#314
by
Jim
on 04 Jun, 2007 19:28
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MarkD - 4/6/2007 9:18 AM
Well, considering the two TSMs that support the orbiter, and the arms to hold the orbiter are designed to move during the "twang". I've read it feels like you're sitting ontop of a tree on a windy day and you feel yourself swaying.
TSM's do not physically support the orbiter. They only house the umbilicals to the orbiter. The orbiter weight is totally supported by the ET.
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#315
by
brahmanknight
on 05 Jun, 2007 21:25
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What kind of metal is the MLP made of? Steel?
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#316
by
Jim
on 05 Jun, 2007 21:34
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yes
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#317
by
brahmanknight
on 05 Jun, 2007 21:47
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Haha. Ask a simple question, get a simple answer. Thanks, Jim!
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#318
by
Ford Mustang
on 06 Jun, 2007 01:58
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1: Why don't they show the PLB Doors opening? The KU band is within reach (all over the Earth).. Just askin', simply because it's cool to see.
2: Things in space are in micro gravity. Couldn't astronauts just push the truss/whatever they're adding around themselves? I know it's safer using the OBSS.. Just a question.
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#319
by
Jim
on 06 Jun, 2007 02:24
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Ford Mustang - 5/6/2007 9:58 PM
1: Why don't they show the PLB Doors opening? The KU band is within reach (all over the Earth).. Just askin', simply because it's cool to see.
2: Things in space are in micro gravity. Couldn't astronauts just push the truss/whatever they're adding around themselves? I know it's safer using the OBSS.. Just a question.
1. The Ku-band antenna is in the payload bay and it is stowed
2. OBSS is only used for surveying the orbiter TPS, not for handling payloads, that is the RMS's job.
Even though the truss has no weight, it still has mass and inertia. The crew can't handle that large of a structure by hand and still maintain adequate control
