PDA

View Full Version : Liftoff!



ToSeek
2001-Nov-15, 02:27 PM
Liftoff! (http://antwrp.gsfc.nasa.gov/apod/ap011115.html)

Of course, this is obviously a fake photograph since the shuttle engine exhaust is practically invisible. /phpBB/images/smiles/icon_wink.gif

GrapesOfWrath
2001-Nov-15, 02:48 PM
More problems. I don't remember the shuttle being brown or even golden.

JayUtah
2001-Nov-15, 03:02 PM
And notice the "hot spot" on the clouds above the spacecraft. That could only have been produced by a studio light.

ToSeek
2001-Nov-15, 03:19 PM
And how did the photographer manage to take this photo at all? He would have been toasted!

Donnie B.
2001-Nov-15, 07:41 PM
On 2001-11-15 10:02, JayUtah wrote:
And notice the "hot spot" on the clouds above the spacecraft. That could only have been produced by a studio light.



Oh, you deluded fool. Can't you see there's a UFO hiding in there?

Mr. X
2001-Nov-15, 11:26 PM
Intriguing, I had never paid any attention to the shuttle-external tank attachment mechanism. Does anyone have a closer view and or plans?

Also why are the shuttle reactors and the back end of the shuttle angled upwards like that? I understand that the shuttle reactors are kept in place by "gimballs" I believe they're called which allow them to move, but why during liftoff angled like that? Why not parallel to the SRBs? Is it because of the different places different forces are applicated, and the SRBs "push" a lot more than the shuttle engines? If that were the case we'd keep them angled the other way around, and directing engine exhaust at a tank isn't exactly brilliant. So is it because, as I remember the shuttle becomes parallel to the tangent to the earth surface only upside down (meaning if everything didn't detach, we'd have the tank on top and shuttle towards the earth). So we apply that force on the back part of it to give it some sort of angular velocity so it ends up in the correct top down position? Is the position of the reactors adjusted with the gimballs during liftoff as the weight of the tank varies, so we don't end up with ridiculous angular velocity?

Do the SRBs have gimballs or are they static "cones" (referring to the parabola (I think) shaped thingies at the lower end of the SRB, I don't know the real english name)?

Is any fuel exchanged between the external tank and the shuttle? Maybe through that huge "thing" just underneath the lower part?

Are the engines used during reentry for anything else than maneuvering? Are the three main engines used?

How many engines does the shuttle itself have overall, I can see 5 on the back, how many elsewhere? Does it have any elsewhere, I sure hope it does otherwise it would be a nightmare to manoeuver in "high atmosphere"/space! Come to think of it, it must, but where are they, and how many are there? What kind of engines are they? Do they receive fuel through "pipes" within the shuttle? Do those have gimballs or do they just provide thrust in a predefined direction?

Are rudders or other air "flaps" used during ascent or is it all engines? (Certainly not the "flaps" I mean elevator "trim" or something along those lines)

I sure hope someone here knows a lot about aerospace engineering and has worked on the space shuttle! Please help me seek the truth!

<font size=-1>[ This Message was edited by: Mr. X on 2001-11-15 18:54 ]</font>

Donnie B.
2001-Nov-16, 02:15 AM
On 2001-11-15 18:26, Mr. X wrote:
Intriguing, I had never paid any attention to the shuttle-external tank attachment mechanism. Does anyone have a closer view and or plans?

Also why are the shuttle reactors and the back end of the shuttle angled upwards like that? I understand that the shuttle reactors are kept in place by "gimballs" I believe they're called which allow them to move, but why during liftoff angled like that? Why not parallel to the SRBs? Is it because of the different places different forces are applicated, and the SRBs "push" a lot more than the shuttle engines? If that were the case we'd keep them angled the other way around, and directing engine exhaust at a tank isn't exactly brilliant. So is it because, as I remember the shuttle becomes parallel to the tangent to the earth surface only upside down (meaning if everything didn't detach, we'd have the tank on top and shuttle towards the earth). So we apply that force on the back part of it to give it some sort of angular velocity so it ends up in the correct top down position? Is the position of the reactors adjusted with the gimballs during liftoff as the weight of the tank varies, so we don't end up with ridiculous angular velocity?

Do the SRBs have gimballs or are they static "cones" (referring to the parabola (I think) shaped thingies at the lower end of the SRB, I don't know the real english name)?

Is any fuel exchanged between the external tank and the shuttle? Maybe through that huge "thing" just underneath the lower part?

Are the engines used during reentry for anything else than maneuvering? Are the three main engines used?

How many engines does the shuttle itself have overall, I can see 5 on the back, how many elsewhere? Does it have any elsewhere, I sure hope it does otherwise it would be a nightmare to manoeuver in "high atmosphere"/space! Come to think of it, it must, but where are they, and how many are there? What kind of engines are they? Do they receive fuel through "pipes" within the shuttle? Do those have gimballs or do they just provide thrust in a predefined direction?

Are rudders or other air "flaps" used during ascent or is it all engines? (Certainly not the "flaps" I mean elevator "trim" or something along those lines)

I sure hope someone here knows a lot about aerospace engineering and has worked on the space shuttle! Please help me seek the truth!

<font size=-1>[ This Message was edited by: Mr. X on 2001-11-15 18:54 ]</font>


Wow, what a lot of questions! I'll try to answer the ones I know the answers to.

By "reactors", I take it that you mean the main engine nozzles. The shuttle main engines are indeed mounted on gimbals for steering. If you ever see a close-up film of the shuttle just before it lifts off, you will see the engines swiveling delicately into the correct positions as their thrust rises from zero to the predetermined liftoff power.

The main engines are angled out because they must direct their thrust through the center of mass of the whole assembly (shuttle, tank, and SRBs; that center of mass starts out somewhere in or near the external tank because of the weight of the fuel and oxydizer. As the fuel is burned, the center of mass moves, and the engines swivel to keep the overall thrust pointed the right way. They also adjust to correct for various perturbations due to wind, variations in SRB engine thrust, and so on, and to steer the assembly along the launch trajectory. They also vary in thrust (throttle up and down) over the course of the launch trajectory.

I believe (could be wrong) that the SRBs are unsteered, fixed nozzles (no gimbals). They give a lot of push but the main engines do the steering. And there's a lot of steering to be done; almost as soon as it clears the tower, the assembly rolls and begins to pitch over onto its back. The typical launch path is both up and eastward.

ALL the fuel in the exterior tank goes through the shuttle engines. The SRBs are solid fueled; they contain all the fuel they will ever burn.

The three main engines are not used during reentry; once in orbit, all maneuvering (including the deorbit burn) is done with the two smaller OMS (orbital maneuvering system) engines you noticed.

Other than those, there are no engines per se, but there are lots and lots of thrusters for attitude control. You can see them in pictures of the shuttle; they're black-colored round or oval openings near the nose, tail, and elsewhere. They are fueled with different fuels than the main engines (hydrazine rocket fuel), but I don't know the details of their "plumbing". They are fixed in position, so there are a lot of them to control the orbiter in all three axes.

I'm not sure whether the airfoil surfaces are used during launch. I don't think so.

Hope that covers most of your questions!

Mr. X
2001-Nov-16, 03:39 AM
On 2001-11-15 21:15, Donnie B. wrote:
Wow, what a lot of questions! I'll try to answer the ones I know the answers to.

Thanks!



By "reactors", I take it that you mean the main engine nozzles.

Yes, that's what I meant, didn't know the exact word.



The shuttle main engines are indeed mounted on gimbals for steering. If you ever see a close-up film of the shuttle just before it lifts off, you will see the engines swiveling delicately into the correct positions as their thrust rises from zero to the predetermined liftoff power.

I was intrigued by that, so I looked up the gimaball schematics but could only come up with older Apollo gimballs. I wasn't sure they were called gimballs at all, but I guess I was lucky!



The main engines are angled out because they must direct their thrust through the center of mass of the whole assembly (shuttle, tank, and SRBs; that center of mass starts out somewhere in or near the external tank because of the weight of the fuel and oxydizer. As the fuel is burned, the center of mass moves, and the engines swivel to keep the overall thrust pointed the right way. They also adjust to correct for various perturbations due to wind, variations in SRB engine thrust, and so on, and to steer the assembly along the launch trajectory. They also vary in thrust (throttle up and down) over the course of the launch trajectory.

Okay, I knew gimballs served the purpose of center of mass application of the forces, I wanted to know if it is overamplified to just apply it on the center of mass or center of mass + angular velocity to get it in that bottom down position?



I believe (could be wrong) that the SRBs are unsteered, fixed nozzles (no gimbals). They give a lot of push but the main engines do the steering. And there's a lot of steering to be done; almost as soon as it clears the tower, the assembly rolls and begins to pitch over onto its back. The typical launch path is both up and eastward.

Ah-ha! Right on, that's what I wanted to know, no gimballs on SRBs! It would make sense, the gimballs are only needed on the shuttle. Do you know how much of the mass (maybe in %) of the lot is the fuel in the tank, in the shuttle, the shuttle itself, the tank and how much are SRBs? At this point I don't know which one accounts for more of the mass.



ALL the fuel in the exterior tank goes through the shuttle engines. The SRBs are solid fueled; they contain all the fuel they will ever burn.

You're right, different kind of fuel for both, hence no exchange. Do the SRBs themselves contain fuel in the upper parts? How does the fuel flow from the tank to the boosters?



The three main engines are not used during reentry; once in orbit, all maneuvering (including the deorbit burn) is done with the two smaller OMS (orbital maneuvering system) engines you noticed.

Thanks, loud and clear!



Other than those, there are no engines per se, but there are lots and lots of thrusters for attitude control. You can see them in pictures of the shuttle; they're black-colored round or oval openings near the nose, tail, and elsewhere. They are fueled with different fuels than the main engines (hydrazine rocket fuel), but I don't know the details of their "plumbing". They are fixed in position, so there are a lot of them to control the orbiter in all three axes.

Exact figures for the number of those thrusters? Hydrazine, isn't that the standard shuttle part fuel? Could it be flowed from regular tanks?



I'm not sure whether the airfoil surfaces are used during launch. I don't think so.

Just had this thought that maybe the bottom down position is an effect more from the wings of the shuttle rather than the nozzle gimballs. Do the wings of the shuttle generate "lift" per se? Like an airplane? If they do and you didn't want it to go like it does (upside down) you would have to compensate with airfoil, right?



Hope that covers most of your questions!

Sure does, thanks mister!

Simon
2001-Nov-16, 08:40 AM
Exact figures for the number of those thrusters? Hydrazine, isn't that the standard shuttle part fuel? Could it be flowed from regular tanks?

There's 44 of them, and they're technically called the RCS, reaction control system. Each thruster has seperate propellant tanks, I guess so a fault in one doesn't leave you completely out of fuel and unable to turn. They use hydrazine and nitrogen tetraoxide, which is the same stuff used in the Apollo LMs. If you mix it together it ignites by itself, so you don't need an ignition device.
Hey, here's a cool safety measure I discovered while looking up this info for you: The thrusters are designed so that if there's a fault in one, it'll burn through the wire that provides power to the valve, so it'll automatically shut off. That's pretty smart.
For more info about the RCS than you ever wanted to know, go to
http://spaceflight.nasa.gov/shuttle/reference/shutref/orbiter/rcs/



Just had this thought that maybe the bottom down position is an effect more from the wings of the shuttle rather than the nozzle gimballs. Do the wings of the shuttle generate "lift" per se? Like an airplane? If they do and you didn't want it to go like it does (upside down) you would have to compensate with airfoil, right?

I don't think the wings do much during launch. Any force they exert would be pretty insignificant compared to the force of the engines.

Donnie B.
2001-Nov-16, 12:44 PM
Mr. X:

The shuttle's main engines and OMS burn hydrogen and oxygen, not hydrazine. The orbiter has fuel tanks (a small fraction of the volume of the external tank, but big enough to carry fuel for the last part of the main engine burn and the OMS.

Hydrazine is extremely volatile and toxic, and would be virtually impossible to handle on the huge scale of the external fuel tank. Moreover, hydrogen produces more thrust per kilogram of fuel. Hydrazine isn't too bad in that regard, but it's used in the RCS for other reasons: self-ignition and no cryogenics required.

The SRBs are solid fueled. In fact, that's about all they are: big metal cylinders full of fuel, with an open central shaft. Think "Jell-O molds"; that's more or less how they're made. The fuel itself never goes anywhere; it burns from the center out and the hot exhaust gases flow down the cylinders to the nozzles.

I'm afraid I don't know the relative weight of orbiter/external tank/SRBs at launch; obviously the ratios would change as the fuel is used up in the latter two. My wild guess would be that the external tank would start out as the heaviest component, but would lose mass fastest.

Mr. X and Simon: the shuttle's wings produce little, if any, "lift" in the grade-school airfoil sense. The orbiter is, on the whole, more of a "lifting body", getting its aerodynamic characteristics more from its attack angle than from the wings' shape. Since the launch trajectory is essentially "straight through the air" rather than at a high attack angle, the wings provide little lift... and that's desirable, as otherwise you'd have to compensate for it with the engines to stay on course. That's both more complicated (since the lift would vary with speed and ambient air pressure) and less efficient (burning fuel to cancel out the force generated by the wings' lift).

(Edited to correct typos)

<font size=-1>[ This Message was edited by: Donnie B. on 2001-11-16 07:47 ]</font>

Donnie B.
2001-Nov-16, 01:09 PM
Extra! Extra!

It appears that the SRB engines can be steered, somewhat. I found a description that says they have "movable nozzles". No more details, though.

Clearly, due to the SRB design, the nozzles can't be truly "gimbal-mounted" like a liquid-fueled engine. But a movable nozzle means that the SRBs can contribute to the steering.

JayUtah
2001-Nov-16, 01:58 PM
The SRBs have steerable nozzles which achieve the same type of directed thrust as the gimbals on the SSMEs. (The SRBs are manufactured just a few miles north of where I live.)

The SRB steering is responsible primarily for roll control. When you see the shuttle roll from a tail-south orientation to a tail-east orientation a few seconds after liftoff, that's accomplished by the SRB nozzles.

The orbiter's aerodynamic control surfaces are not used during the ascent.

The OMS burns the same fuel as the RCS jets: monomethyl hydrazine and nitrogen tetroxide. Only the SSMEs burn liquid hydrogen and liquid oxygen. After MECO and ET separation the main engines and associated fuel lines are purged with helium so that no hydrogen residue remains in the orbiter.

The RCS jets are not steerable, although two strengths of jets are provided in each axis so that both coarse and fine adjustments can be made to attitude and position. The weak jets are important because the shuttle's strong ones would harm the delicate solar panels of the various space stations it has served.

Mr. X
2001-Nov-16, 02:24 PM
Woohoo, replies, yay!



On 2001-11-16 08:58, JayUtah wrote:
The SRBs have steerable nozzles which achieve the same type of directed thrust as the gimbals on the SSMEs. (The SRBs are manufactured just a few miles north of where I live.)

I see.



The SRB steering is responsible primarily for roll control. When you see the shuttle roll from a tail-south orientation to a tail-east orientation a few seconds after liftoff, that's accomplished by the SRB nozzles.

You mean when it lifts off and instead of having the back end of the shuttle perpendicular to the ground it slowly moves in a tangent position, bottom down, is that what you mean?



The orbiter's aerodynamic control surfaces are not used during the ascent.

I've been told by Donnie B. that the wings don't generate lift themselves, it's more the lower area of the shuttle that acts like this (I hope this generalization or interpretation of what he has said is okay!)Is the shuttle fixed in an exactly parallel position to the external tank? What is the purpose of the position? I mean how does the shuttle interact with the air at liftoff? Does it "inadvertantly" steer the whole thing in some direction? If it does is it compensated? If it would be compensated wouldn't it mean that aerodynamic surfaces are used at liftoff? By that I mean aerodynamic surfaces to neutralize if you will the effect of the shuttle on the external tank + SRBs? Or it could be compensated by the "gimballs", so that would be it.



The OMS burns the same fuel as the RCS jets: monomethyl hydrazine and nitrogen tetroxide. Only the SSMEs burn liquid hydrogen and liquid oxygen. After MECO and ET separation the main engines and associated fuel lines are purged with helium so that no hydrogen residue remains in the orbiter.

So they actually carry oxygen, hydrogen AND helium? And the other hydrazine fuel.



The RCS jets are not steerable, although two strengths of jets are provided in each axis so that both coarse and fine adjustments can be made to attitude and position. The weak jets are important because the shuttle's strong ones would harm the delicate solar panels of the various space stations it has served.

Are the two strenghts of jets in the same "hole" with some adjustment? Or different thrusters entirely?

Keep it going!

<font size=-1>[ This Message was edited by: Mr. X on 2001-11-16 09:50 ]</font>

ToSeek
2001-Nov-16, 03:14 PM
On 2001-11-16 07:44, Donnie B. wrote:

I'm afraid I don't know the relative weight of orbiter/external tank/SRBs at launch; obviously the ratios would change as the fuel is used up in the latter two. My wild guess would be that the external tank would start out as the heaviest component, but would lose mass fastest.

<pre>
Mass of shuttle components (lbs.):
Fueled Unfueled
Orbiter 230,000 230,000
External tank 1,655,600 66,000
SRB (each) 1,300,000 192,000
Total 4,500,000 680,000
</pre>


<font size=-1>[ This Message was edited by: ToSeek on 2001-11-16 10:19 ]</font>

Mr. X
2001-Nov-16, 03:18 PM
Yay!

Thanks ToSeek!

ToSeek
2001-Nov-16, 03:21 PM
On 2001-11-16 07:44, Donnie B. wrote:

I'm afraid I don't know the relative weight of orbiter/external tank/SRBs at launch; obviously the ratios would change as the fuel is used up in the latter two. My wild guess would be that the external tank would start out as the heaviest component, but would lose mass fastest.



If you look at the numbers and count the SRBs as one component, then they are both the heaviest and lose mass fastest, since they're gone within a couple of minutes while the tank lasts almost to orbit.

Donnie B.
2001-Nov-16, 03:32 PM
On 2001-11-16 08:58, JayUtah wrote:
The OMS burns the same fuel as the RCS jets: monomethyl hydrazine and nitrogen tetroxide. Only the SSMEs burn liquid hydrogen and liquid oxygen. After MECO and ET separation the main engines and associated fuel lines are purged with helium so that no hydrogen residue remains in the orbiter.


Oops, my bad. I picked up some misinformation somewhere, it seems. Thanks for the correction.

Donnie B.
2001-Nov-16, 03:47 PM
On 2001-11-16 09:24, Mr. X wrote:


The SRB steering is responsible primarily for roll control. When you see the shuttle roll from a tail-south orientation to a tail-east orientation a few seconds after liftoff, that's accomplished by the SRB nozzles.

You mean when it lifts off and instead of having the back end of the shuttle perpendicular to the ground it slowly moves in a tangent position, bottom down, is that what you mean?



No, he means the roll around the vertical axis. The pitch over "onto its back" comes later.





The orbiter's aerodynamic control surfaces are not used during the ascent.

I've been told by Donnie B. that the wings don't generate lift themselves, it's more the lower area of the shuttle that acts like this (I hope this generalization or interpretation of what he has said is okay!)



Not quite. The wings do generate lift during descent (if they didn't there would be no need for them at all). But they do so more by the angle of attack -- the shuttle flies nose-up with respect to the direction of travel. During launch, the nose is pointed straight into the wind, and the wings generate little lift. Whatever small effect they do have is corrected by steering the engines, as you suggested.




So they actually carry oxygen, hydrogen AND helium? And the other hydrazine fuel.



Helium is not a fuel. It's an inert gas that's used to "blow out" the remaining hydrogen from the plumbing after the external tank is discarded, for safety's sake. Only a relatively small amount is needed for that.

As JayUtah has informed us, the hydrogen/oxygen fuels are carried only in the external tank; onboard engines use hydrazine and nitrogen tetroxide.






The RCS jets are not steerable, although two strengths of jets are provided in each axis so that both coarse and fine adjustments can be made to attitude and position. The weak jets are important because the shuttle's strong ones would harm the delicate solar panels of the various space stations it has served.

Are the two strenghts of jets in the same "hole" with some adjustment? Or different thrusters entirely?


Different thrusters. They aren't throttleable; you control the amount of push by choice of small vs. large jet, and by length of burn.

Donnie B.
2001-Nov-16, 04:10 PM
On 2001-11-16 10:21, ToSeek wrote:

If you look at the numbers and count the SRBs as one component, then they are both the heaviest and lose mass fastest, since they're gone within a couple of minutes while the tank lasts almost to orbit.


Right you are. My instincts were wrong; those SRBs must be very dense indeed when fully fueled.

Point of interest: the orbiter itself makes up only 5% of the weight of the fully-fueled assembly. The fuel is 85%, the other 10% comprises the tank and the shells of the SRBs.

ToSeek
2001-Nov-16, 04:34 PM
On 2001-11-16 08:09, Donnie B. wrote:
Extra! Extra!

It appears that the SRB engines can be steered, somewhat. I found a description that says they have "movable nozzles". No more details, though.



Some details on the SRB engine gimbals:


The nozzle expansion ratio of each booster beginning with the STS-8 mission is 7-to-79. The nozzle is gimbaled for thrust vector (direction) control. Each SRB has
its own redundant auxiliary power units and hydraulic pumps. The all-axis gimbaling capability is 8 degrees. Each nozzle has a carbon cloth liner that erodes and
chars during firing. The nozzle is a convergent- divergent, movable design in which an aft pivot- point flexible bearing is the gimbal mechanism.


from http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/srb.html#srb

This surprised me, too - I didn't think the SRB motors could be aimed, though I knew the shuttle main engines could.

Mr. X
2001-Nov-16, 10:05 PM
On 2001-11-16 10:47, Donnie B. wrote:


On 2001-11-16 09:24, Mr. X wrote:


The SRB steering is responsible primarily for roll control. When you see the shuttle roll from a tail-south orientation to a tail-east orientation a few seconds after liftoff, that's accomplished by the SRB nozzles.

You mean when it lifts off and instead of having the back end of the shuttle perpendicular to the ground it slowly moves in a tangent position, bottom down, is that what you mean?

No, he means the roll around the vertical axis. The pitch over "onto its back" comes later.


Huh? You mean when it "spins" around a mathematical Z-axis? I think I know what you mean, but to make sure do you mean that seen from above the top of the rudder would describe a circle, is that what you mean?







The orbiter's aerodynamic control surfaces are not used during the ascent.

I've been told by Donnie B. that the wings don't generate lift themselves, it's more the lower area of the shuttle that acts like this (I hope this generalization or interpretation of what he has said is okay!)

Not quite. The wings do generate lift during descent (if they didn't there would be no need for them at all). But they do so more by the angle of attack -- the shuttle flies nose-up with respect to the direction of travel. During launch, the nose is pointed straight into the wind, and the wings generate little lift. Whatever small effect they do have is corrected by steering the engines, as you suggested.

That's what I meant to say, sorry if it was very very hazy. I mean that lift isn't just the product of the wings, but the lower part, the "black" belly part also helps by offering a lot of resistance.





So they actually carry oxygen, hydrogen AND helium? And the other hydrazine fuel.

Helium is not a fuel. It's an inert gas that's used to "blow out" the remaining hydrogen from the plumbing after the external tank is discarded, for safety's sake. Only a relatively small amount is needed for that.

**Sighs**. I knew that! I know I shouldn't have done some sentence like that mixing them all as if they were the same things. Sorry for the confusion, I'll try to be clearer next time. I sometimes make ambiguous sentences or sentences that make me look ridiculously mentally challenged. I just have problems with scientific english, since it isn't my language. And maybe english syntax at times. I do my best, sorry if there's a huge blunder like that at times.



As JayUtah has informed us, the hydrogen/oxygen fuels are carried only in the external tank; onboard engines use hydrazine and nitrogen tetroxide.

Whoa, I just realized I had majorly misunderstood what you had said previously. I'd like more precision, because I think you said no fuel is exchanged between the shuttle and the external tank. Did you mean the SRBs and the external tank? Well, very simply put, what is in the external tank? Solid or hydrogen/oxygen?







The RCS jets are not steerable, although two strengths of jets are provided in each axis so that both coarse and fine adjustments can be made to attitude and position. The weak jets are important because the shuttle's strong ones would harm the delicate solar panels of the various space stations it has served.

Are the two strenghts of jets in the same "hole" with some adjustment? Or different thrusters entirely?

Different thrusters. They aren't throttleable; you control the amount of push by choice of small vs. large jet, and by length of burn.

Ah thanks! Very clear! Is it done by the astronauts through calculations or intuitively? I mean "hmm, to roll this way like this I will need a burn of x seconds with thruster number something, then another one from thruster to cancel motion on that direction..." or do they just fiddle with the controls?

I have a question non-related to the design of the shuttle, how do the astronauts get in before liftoff? Through the hatch, on the side, I know that, but I've stepped in a replica of the shuttle, and since it is in a vertical position, how do they get to their seats? My first asessment from stepping in is that you could get seriously hurt if you didn't land on your seat? How do they reach the seats without falling to the bottom of the cabin?

<font size=-1>[ This Message was edited by: Mr. X on 2001-11-16 17:06 ]</font>

ToSeek
2001-Nov-17, 06:17 PM
On 2001-11-16 17:05, Mr. X wrote:

Whoa, I just realized I had majorly misunderstood what you had said previously. I'd like more precision, because I think you said no fuel is exchanged between the shuttle and the external tank. Did you mean the SRBs and the external tank? Well, very simply put, what is in the external tank? Solid or hydrogen/oxygen?


hydrogen/oxygen. It's fed to the space shuttle main engines, which are on the orbiter.

ToSeek
2001-Nov-17, 06:26 PM
On 2001-11-16 17:05, Mr. X wrote:
I have a question non-related to the design of the shuttle, how do the astronauts get in before liftoff? Through the hatch, on the side, I know that, but I've stepped in a replica of the shuttle, and since it is in a vertical position, how do they get to their seats? My first asessment from stepping in is that you could get seriously hurt if you didn't land on your seat? How do they reach the seats without falling to the bottom of the cabin?

<font size=-1>[ This Message was edited by: Mr. X on 2001-11-16 17:06 ]</font>


Here's a cool diagram that at least partially addresses the issue:

http://www.hq.nasa.gov/office/pao/History/diagrams/shuttle/e3-25.htm

And a whole page full:

http://www.hq.nasa.gov/office/pao/History/diagrams/shuttle/shuttle.htm

Still looks kind of tricky getting in, but on the other hand there doesn't seem to be too far to fall.

ToSeek
2001-Nov-17, 06:35 PM
On 2001-11-16 17:05, Mr. X wrote:

Ah thanks! Very clear! Is it done by the astronauts through calculations or intuitively? I mean "hmm, to roll this way like this I will need a burn of x seconds with thruster number something, then another one from thruster to cancel motion on that direction..." or do they just fiddle with the controls?


Most of this is done automatically. (Even the stick controls go through the flight computers.) According to the website given, the only thing that has to be done manually is docking.

http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts-gnnc.html

Mr. X
2001-Nov-17, 07:30 PM
On 2001-11-17 13:17, ToSeek wrote:


On 2001-11-16 17:05, Mr. X wrote:

Whoa, I just realized I had majorly misunderstood what you had said previously. I'd like more precision, because I think you said no fuel is exchanged between the shuttle and the external tank. Did you mean the SRBs and the external tank? Well, very simply put, what is in the external tank? Solid or hydrogen/oxygen?


hydrogen/oxygen. It's fed to the space shuttle main engines, which are on the orbiter.


Thanks! Well I knew the part about where the engines were! How is it fed, though? Can we see where it's attached to the orbiter?

Thanks also for the getting in thing, but it still looks tough, and that you could get some pretty bad injuries if you fell head down!

Speaking of which, how is the shuttle:
1-attached to the external tank? (while it is horizontal or vertical? How do they do it!)
2-flipped over in the vertical position?

Thanks!

ToSeek
2001-Nov-17, 08:05 PM
On 2001-11-17 14:30, Mr. X wrote:

Speaking of which, how is the shuttle:
1-attached to the external tank? (while it is horizontal or vertical? How do they do it!)
2-flipped over in the vertical position?

Thanks!


The top image here shows a diagram from the ET perspective as to how they're connected:

http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/et.html#et

The orbiter is the last thing to be added to the launch vehicle, so it's done last (and vertically) Here's a writeup on the integration process:

http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/stsover-prep.html#stsover-intg

Here's a cool set of photos showing the orbiter being raised from horizontal to vertical and being attached:

http://www.spaceflightnow.com/shuttle/sts101/000423galleries/

ToSeek
2001-Nov-17, 08:12 PM
Here's the home page of a guy who actually works on the shuttles, with more cool photos (including another set showing the orbiter being picked up and attached to the launch vehicle):

Kim Keller's Home Page (http://www.geocities.com/kimekeller/)

ToSeek
2001-Nov-17, 08:24 PM
At last! Here's a video of a shuttle commander clambering (and I use that word with precision!) into his seat - you're right, it's not easy!:

http://www.spaceflightnow.com/shuttle/sts092/001011video/ingress_qt.html

Mr. X
2001-Nov-17, 08:36 PM
Hehe, it doesn't seem very easy to climb in that seat!

I had this idea that maybe they had some highly clever way of getting it attached or upwards. Guess it isn't all that ingenious and it's pretty straighforward. Maybe they're just lazy! /phpBB/images/smiles/icon_smile.gif

David Hall
2001-Nov-18, 09:51 AM
Here's an interesting article I just dug up about shuttle upgrades. It's a couple of years old now, but some of it was new to me.

It's on The New York Times website, so it requires free registration to view (Well worth it in my opinion. The NYT has some good stuff).

http://www.nytimes.com/library/national/science/050499sci-shuttle-upgrade.html

Mr. X
2001-Nov-19, 12:00 AM
Thanks David!

Other question for you shuttle knowers:

When the "assembly" is ready for launch, what is it standing on? Not on the nozzles of the SRBs I hope! So what's it standing on? It certainly isn't levitating and I can't see any sort of restraints aside from those external tank "appendages".

Thanks!

ToSeek
2001-Nov-19, 02:29 PM
On 2001-11-18 19:00, Mr. X wrote:
When the "assembly" is ready for launch, what is it standing on? Not on the nozzles of the SRBs I hope! So what's it standing on? It certainly isn't levitating and I can't see any sort of restraints aside from those external tank "appendages".


It's supported by the mobile launch platform, attached by bolts to the SRBs.

Description:
http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/centers.html#sts-ksc-mlp

Kim Keller has some photos of the hold-down bolts and of the base of the launch vehicle on the pad:

http://www.geocities.com/kimekeller/SRBdetail1.html
http://www.geocities.com/kimekeller/Padb.html

I was trying to find a good diagram, but I haven't yet.

<font size=-1>[ This Message was edited by: ToSeek on 2001-11-19 09:30 ]</font>

Russ
2001-Nov-20, 08:07 PM
This is to Mr.X.

If you follow the link below you will have all of your questions answered (correctly) in detail. Under the picture there is a brief description with embedded links to more information. I clicked on some of the links. VERY INTERESTING! Well worth the time to read all of the information.

I can't remember all of your questions but can give you a synopsis of the ones I do.

The SRB's have gimbled nozzles actuated by a Hydrolic Power Unit (HPU) powered by a Hydrazine fueled combustion turbine.

During launch, all manuvering is done by vectoring thrust from the engines. Using wing/tail control surfaces would cause drag which would tend to slow the stack or require more thrust to compensate.

The reason the shuttle is rolled on it's back after launch is to protect it from high altitude, high velocity winds.

The wings of the shuttle do provide lift during landing but due to the stack configuration they are sheltered in the slip stream of the External Tank and, therefore, don't provide lift during launch.

Those are the only questions I can remember, and the answers I learned from reading the blurbs from the link below.

Liftoff! (http://antwrp.gsfc.nasa.gov/apod/ap011115.html)

Mr. X
2001-Nov-20, 08:19 PM
Are you sure it's the correct link? All I see is the Astronomy Picture of the Day page. What was that link you wanted to give, or where do you want me to me to click in there?

And thanks to ToSeek for those answers, that guy has certain obvious abilities with search engines!

Who dares now to say that it is easy to climb in your seat in the space shuttle in the vertical position! /phpBB/images/smiles/icon_smile.gif

Russ
2001-Nov-20, 09:59 PM
On 2001-11-20 15:19, Mr. X wrote:
Are you sure it's the correct link? All I see is the Astronomy Picture of the Day page.


Yes. I am sure that the Astronomy Picture of the Day Page is where I'm sending you. If you look under the picture, there is a caption that explains briefly what you are looking at. The blue underlined words in that caption are links to pages with more detail. For example "solid rocket boosters" takes you to http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/srb.html , a page that will answer all of you questions about the SRB's plus more questions that you didn't even think about.

That is just one example out of 12. Follow those links and have fun! /phpBB/images/smiles/icon_smile.gif

Mr. X
2001-Nov-21, 02:28 PM
Ah, yes, I've already seen it, but it takes time to go to exactly what I am looking for and since my english skills are passable, it's actually better to let someone else look it up in there for me.

Thank you!

And ToSeek's seeking abilities are just too good to pass up and they're free FREE FREE! /phpBB/images/smiles/icon_biggrin.gif

ToSeek
2001-Nov-21, 04:38 PM
On 2001-11-21 09:28, Mr. X wrote:

And ToSeek's seeking abilities are just too good to pass up and they're free FREE FREE! /phpBB/images/smiles/icon_biggrin.gif


Be careful or I'll start charging! Or maybe I'll just tell you to stop posting so often so I can try to catch up. /phpBB/images/smiles/icon_wink.gif

<font size=-1>[ This Message was edited by: ToSeek on 2001-11-21 11:39 ]</font>

Mr. X
2001-Nov-21, 06:11 PM
Remember your Hippopotamus oath! /phpBB/images/smiles/icon_biggrin.gif

"Thou shalt not charge!"

/phpBB/images/smiles/icon_lol.gif

ToSeek
2001-Nov-21, 06:41 PM
On 2001-11-21 13:11, Mr. X wrote:
Remember your Hippopotamus oath! /phpBB/images/smiles/icon_biggrin.gif

"Thou shalt not charge!"

/phpBB/images/smiles/icon_lol.gif


Sounds more like a rhinoceros oath to me. /phpBB/images/smiles/icon_wink.gif

Russ
2001-Nov-21, 11:25 PM
On 2001-11-21 09:28, Mr. X wrote:
Ah, yes, I've already seen it, but it takes time to go to exactly what I am looking for and since my english skills are passable, it's actually better to let someone else look it up in there for me.


Just out of curriosity, what is your native language? The reason I ask, NASA has its' sites in several languages and they may have yours. Just a thought. /phpBB/images/smiles/icon_smile.gif

Mr. X
2001-Nov-22, 09:19 PM
I'm afraid that's classified /phpBB/images/smiles/icon_biggrin.gif, however if you let me know where I can find those pages I'll tell you whether it's there or not. /phpBB/images/smiles/icon_razz.gif

SpacedOut
2001-Nov-29, 04:19 PM
Great photo and thread - I never would have guessed that the SRB's had moveable nozzle's - Getting REAL information is much more interesting than the HB dribble.

ToSeek
2001-Nov-29, 07:23 PM
On 2001-11-29 11:19, SpacedOut wrote:
Great photo and thread - I never would have guessed that the SRB's had moveable nozzle's - Getting REAL information is much more interesting than the HB dribble.


Yes, that surprised me, too. I thought the SSME gimbals were sufficient.

Mr. X
2001-Nov-29, 07:31 PM
Well, of course.

You can always thank me, and if you don't think you can thank me enough, you can offer me your mind, spirit, soul and life for all eternity. /phpBB/images/smiles/icon_biggrin.gif

That goes for all you too!

2001-Nov-30, 11:09 AM
0
On 2001-11-15 18:26, Mr. X wrote:
2 # Why are the "Clam Tides" 7 days from S:M
3 ? at what rate does the moons N/S max decay
4 when measuring lunar tides
5 who should i believe as to best link
6 are there any links to TIDE data
7 "for the moon? MoonLink? {darn}
8 yes? who has a lazer uplind data path
9 No I do not, I cat even get Quak data
10 oppsi link to or's gos here
1 ok Lun's outbound about 3mm/Moon nowAdays?
2 in 60e9 moon thats 180e9mm's
3 or 180e6 M's or 186e3 Km
4 Hoow come "these numbers chang anyway?
5 how far away from me was the moon on day 0?
6 in fact how far away will it be on Sunday
7 Now back to the "Clam Tide" Debait
8 and whatever thats call on the moon
9 "i'll call it" ggreen cheese breeze'$

2001-Nov-30, 11:13 AM
On 2001-11-17 13:35, ToSeek wrote:


On 2001-11-16 17:05, Mr. X wrote:

Ah thanks! Very clear! Is it done by the astronauts through calculations or intuitively? I mean "hmm, to roll this way like this I will need a burn of x seconds with thruster number something, then another one from thruster to cancel motion on that direction..." or do they just fiddle with the controls?


Most of this is done automatically. (Even the stick controls go through the flight computers.) According to the website given, the only thing that has to be done manually is docking.
1-11-30 4:46 A.M. there were 58 pages?
http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts-gnnc.html
so when does this thread > GENERAL ?

ToSeek
2001-Nov-30, 01:09 PM
On 2001-11-30 06:13, HUb' wrote:
so when does this thread > GENERAL ?


Maybe I should make some statement like "The Project Apollo computers couldn't have been sophisticated enough at the time to do the precise maneuvers required" in order to keep the thread in this board. /phpBB/images/smiles/icon_wink.gif

Mr. X
2001-Nov-30, 01:27 PM
Well is that thread really astronomy? /phpBB/images/smiles/icon_biggrin.gif

sts60
2001-Nov-30, 02:43 PM
Back on the "getting into the seats" part... I didn't check the web sites mentioned, but when doing tests, and later when loading the crew, engineers and techs stand on metal plates covering the aft wall of the flight deck, where the RMS controls are. The plates are removed right before buttoning up for launch.

Here's a picture of STS-80 commander Ken Cockrell and mission specialist Story Musgrave, perched on these plates during preflight tests aboard Columbia. The CDR and PLT seats are above them, not visible in the picture. It's pretty cramped in there!

<a href=http://www.bitward.com/images/s_crew.jpg>http://www.bitward.com/images/s_crew.jpg</a>

Excaliber
2002-Mar-29, 04:47 PM
I hope that you are kidding. But if you are not it is obvious that you have never seen a Shuttle launch live or on TV....As for having seen several Shuttle launches....The exhaust trail can be seen for hundreds of miles....The shuttle travels not only up but in a nothern direction...therefore you can see the trail as far away as the coast of Georgia.

quote]
On 2001-11-15 09:27, ToSeek wrote:
Liftoff! (http://antwrp.gsfc.nasa.gov/apod/ap011115.html)

Of course, this is obviously a fake photograph since the shuttle engine exhaust is practically invisible. /phpBB/images/smiles/icon_wink.gif
[/quote]

Excaliber
2002-Mar-29, 04:49 PM
"hot spot"....Have you ever heard of the sun...It appears in the photo that it is overcast....and what you are seeing is the sun through an opening in the clouds!

On 2001-11-15 10:02, JayUtah wrote:
And notice the "hot spot" on the clouds above the spacecraft. That could only have been produced by a studio light.

[/quote]

Excaliber
2002-Mar-29, 04:51 PM
Have you ever heard of refection?
On 2001-11-15 10:19, ToSeek wrote:
And how did the photographer manage to take this photo at all? He would have been toasted!
[/quote]

Excaliber
2002-Mar-29, 04:52 PM
Its called remote camera....
On 2001-11-15 10:19, ToSeek wrote:
And how did the photographer manage to take this photo at all? He would have been toasted!
[/quote]

ToSeek
2002-Mar-29, 05:04 PM
On 2002-03-29 11:47, Excaliber wrote:
The exhaust trail can be seen for hundreds of miles....


Yes, but that's not strictly the shuttle exhaust - the main engine exhaust (as evident in the photo) is practically invisible.

As for our other comments, we were mocking comments by those who think the Apollo moon landings were a hoax - they make statements like ours but actually seem to believe them.

Excaliber
2002-Mar-29, 05:06 PM
I think that its called reflection....
On 2001-11-15 09:48, GrapesOfWrath wrote:
More problems. I don't remember the shuttle being brown or even golden.
[/quote]

JayUtah
2002-Mar-30, 02:49 AM
[b]The exhaust trail can be seen for hundreds of miles[b]

The SRB exhaust, yes. The SSME exhaust, no. They test the SRBs just a few dozen miles from my house.

(BTW, we're being sarcastic in this thread.)

GrapesOfWrath
2002-Mar-30, 03:36 AM
On 2002-03-29 11:51, Excaliber wrote:
Have you ever heard of refection?

Not until you mentioned it, I think. It's a pretty good word, I'm going to add it to my vocabulary. Ame. Her. Dic.: refection, n., Refreshment with food and drink