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Space Shuttle Answered

this is a forum for people to discuss the space shittle oops i mean space shuttle the reason i say this is because i (and many others) believe that this was one of the least thought out project i think nasa has forgone for instance no bailout system, srb burnouts/the fact that their solid fuel to begin with, heat tiles either A) the same large surface area tiles apolo used or B titanium plates so on and so forth i don't mean to sound like i'm evil or anything im just trying to get my point accross.

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chase!! (author)2007-01-07

First, I'm no fan of the shuttle, but your raging against it is a little misguided.

The shuttle was never used as intended, NASA never got the funding it needed to do what the shuttles objectives were (which was to do many launches a year).

This brings up the first thing, the heat tiles are the shuttle were a fantastic idea given what the engineers in the 70s knew. They are theoretically reusable, but since NASA has been so conservative lately they just end up being replaced every launch. They deal with the unbelievable heat of reentry very well. Understand that without the tiles NASA would have needed to use an ablative [meaning the surface burns and produces a gas that pushes the shockwave off the body] system (like that on Apollo) which absolutely needs to be replaced every launch. Remember that the temperatures on reentry are on the order of a few thousand degrees Kelvin (no, I'm not kidding).

This brings me to my next point, the shuttle is designed the way it is to lower g-loading on reentry as much as possible to make space flight more accessible. Apollo capsules experience peak g-loading of ~8.5-9 more than once on reentry, the shuttle only experiences on the order of 3 g's. The trade off of the semi lifting body vs. a capsule is the heat fluxes are much, much, much higher. (Has to do with the bow shock formed in the hypersonic regimes, along with the ablative surface).

So in regards to the tiles and design of the shuttle it does basically what it was designed to do, it was not a failure.

In regards to the SRBs, they *are* the best choice in that application. Solid rockets are super simple, and they basically never fail even when stored for long periods of time. And you don't have to deal with a bunch of turbo machinery. Granted you can't stop them, or throttle them, but you can tailor the burn by the geometry of the propellant.

Oh, and to people complaining about the multisectioned SRBs, just remember that this has been a blessing because they're coming back for the CEV (but with an extra section)

I feel like i had more to deal with in this post, but I can't remember. I also never thought I'd be defending the space shuttle so much.

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trebuchet03 (author)chase!!2007-01-07

I also never thought I'd be defending the space shuttle so much.

Haha - I should have said the same thing :P To be fair (especially to the OP) -- here is my short list on what bugs me about the shuttle.

1. No air breathing engines (Hey, the Russians did it with their Buran spacecraft)
2. Engine layout -- want to avoid all of the foam technical difficulties? Put your vehicle above the danger zone :P
3. Reasons for abandoning Hubble <-- the last NASA administrator abandoned the Hubble telescope because it was too risky to go so far away from ISS (the ISS is used to survey the shuttle heat shield and as a lifeboat)
4. Must require a human to land -- really, why did they not connect the landing gear to the flight computer. That's one addition would allow autonomous landing possible (with programming of course :P)

If I had to pick the shuttle's best feature.... Software -- in the past three revisions of the shuttle's software -- there was 1 error in each (almost a half a million lines of code). In the 11 software revisions, a total of 17 errors. Amazing.

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chase!! (author)trebuchet032007-01-07

Re: 2) Before the first tile disaster the engineers didn't know about all the stuff flying near the foam because there weren't any cameras there. When I heard a NASA engineer talk about it, the collective reaction to the videos was "Holy shit!"

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trebuchet03 (author)chase!!2007-01-07

Good point and fair enough :D

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chase!! (author)chase!!2007-01-07

I forgot that brackets add a link, so ignore that link, it doesn't go anywhere.

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buildingteen (author)2007-01-07

so i would have to get ammonium percolate through like flin. and if not all bike tubes are rubber what can i use?

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buildingteen (author)2007-01-06

ive been doingsome research and from what i can find the srb fuel makeup is 69.83% ammonium perchlorate, 16% aluminum, 12% rubber, 2% curing agent, and more or less 0.17% iron oxide catalyst. would you get similar results with 69G of amonium percholate (isnt that weed killer) 16G aluminium (dust) 12G rubber (like a bike tube) and like 2G thermite melting the rubber and pouring in the other ingrediants?

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Perchlorate hasn't been used in agriculture in decades and is considered a dangerous contaminate by certain environmental groups. You're most likely thinking of ammonium nitrate which is used as a fertilizer. Also, don't try melting rubber inside ;-)

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trebuchet03 (author)buildingteen2007-01-07

The rubber acts as a binding agent... it also acts as a non-essential fuel source. I'm no rocket materials scientist - but I'm pretty sure the processing is just as important as the materials themselves ;) Also, not all bike tubes are made from rubber ;)

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buildingteen (author)2007-01-06

sorry i left out a part of the titanium post the current heat tiles with titanium plates covering it so it would have 2 layers of protection in the unlikely event of titanium puncture the tiles would still stand a decent chance but the plating would be thin in the area of an eighth of an inch. and yes there is a low level bailout system but it is not possible during srb burn as it would kill them as they left the shuttle but it is possible under 100,000 feet on reentry but look at the columbia there is a very slim chance they are going to be able to set it to auto pilot (this is the position the switches were found in so thats all they were able to do) furthermore they then need to jetsen the door un buckle run to the door release the bars and hook on then jump thats like trying to put on a parachute before your plane crashes and what is your avatar anyways is it an estes spaceship one? oh yeah treb do you think u could E-mail me a diagram of some conical clutches or anything else that would be small enough to fit on a bike fairly simple and will work with a 3 horse power engine.

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trebuchet03 (author)buildingteen2007-01-06

My avatar is a fairing for a HPV ;) From scale tunnel testing -- I believe it was 30mph = 5lbs of aero drag force. Our top speed was 35mph on level ground through a 100m speed trap. During research, we found out that those holes provide a strong platform with minimal visibility loss. Not to mention how photogenic it becomes :P


During the supersonic portion shuttle re-entry -- the controls are handled by the shuttle's on board computers (I believe there's 4 -- 3 of them using different methods of calculations and 1 to mediate through a possibly 3 different answer). Only the final approach is is controlled by a warm meat pilot :P


Yes... srb burns are basically a light 'em and pray kind of thing. But again, to date there has been one failure and without the srb's nearly 2mil lbs of thrust, missions would be extremely expensive (remember, we're talking concepts developed using tech. from the 60's).

Now, not every problem requires bail out -- Colombia was not in a situation where bail out was an option for any vehicle. Diving out at over mach20 into a sheet of plasma isn't really something we (as humans) are capable of :P But remember, if your plane is crashing - the odds of escape are slim. No matter what plane you're in. Bail out is for an aborted mission that has already gone under way. In just about every aircraft, bail out requires a stable subsonic glide where unbuckling (which can be done faster than you can undo your car seatbelt) and sliding off the egress poll is viable and possible.

That being said, there was such a mission that required a post ignition abort - I can't recall the mission (I think it involved skylab2) by it successfully did an "Abort to Orbit." <-- something that was developed after challenger :/ That mission almost turned into a return to site (or trans Atlantic) or possibly a bail out.


Just in case anyone asks.... Ejection seats are not viable for the shuttle because much of the crew rides in the midship cabin. Surrounded by quite a bit of structure etc.

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buildingteen (author)2007-01-06

has the dyna soar ever flown cuz it looks bitchin

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buildingteen (author)2007-01-06

oh and yeah the first shuttle missions had ejectors because only 2 crew were in it in the later missions these were forgone whereas in the apollo capsules vs the shuttle like in the shuttle: oh crap! and then you have to do all of the things i stated before Apollo: oh crap! eject and your good

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buildingteen (author)2007-01-06

uh duh you need my E-mail skiking@ecentral.com

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buildingteen (author)2007-01-06

i do agree i was a little harsh and the srb's are multible pieces because of transportation issues with size they were sealed with two o rings but post challenger they have 3 o rings and heat resistant putty and dont get me wrong i still think the shuttle is an amazing machine but i think they should use either boiler plates as u called them or titanium plates as the titanium plates would stand up to the heat and be reusable
**cough-cheaper-cough** but there is no bailout system for in launch as the apollo capsules did and also the emergency landing sites are in africa europe and the us the site in florida is near impossible to pull off one second of error will cost them the momentum they need to make it there the ones in africa and europe they need to be at the altitude of 400000 or TAL but under that altitude they have to attempt the florida site or do the contingency abort (or as i call it suicide) ditchng the shuttle is like jumping off a bridge at 17.300 mph oh yeah and the other thing is this bull shit about at 50 miles altitude your concidered an astronaut because on the challenger mission Mike Smith was killed at 10 miles altitude and so he didn't die an astronaut im sorry when the hold down bolts blow your an astronaut and no their not analog but i still think maybe a little more brain power nasa discovery had a close call with th o rings as well yes i do know thats the makeup of the srb's but how is it mixed (im doing a science fair project on thrust of different propellants) oh and i agree with the cev but only becase its designed solely for the purpose for moon missions i think we need a vehicle like the shuttle for reusable transport but i agreee with updating the previous technology cuz we already know it works. and for the virgin thing i would be the test pilot as long as i could get up there (i want to be an astronaut) the only thing though with spaceship 2 is your not actually in space i think only 30 miles i mean dont get me wrong if i found 100k thats what id spend it on or if i won a trip but if i (and i use this term lightly) "only" had like 20 mil id gladly spend it on a week on the iss

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trebuchet03 (author)buildingteen2007-01-06

The shuttle's heat shield is reusable. Tiles are replaced as they fail safety criteria.

I'm not so sure how well a system made from titanium would work. Titanium is heavier, oxidizes, and will go through less favorable crystal transformation with every use. I think you might be confusing a materials ability to resist heat and a materials ability to conduct heat. The silica tile system resists heat AND does not conduct heat. Titanium resists heat AND conducts heat - I wouldn't touch the inside with a blow torch on the outside :P And as far as abundance (for cost) - silica sand vs. titanium :P I say that because any system is is going to need to meet a specs.

An alternative? http://www.flightglobal.com/Articles/2006/01/10/Navigation/200/203959/Water+to+cool+reusable+heat+shield.html
Water cooled ;)


One thing NASA specializes in is.... near impossible ;) That's what years of repetitive training is for. Yes, certain egress criteria must be met - but low altitude escape is possible -- here is the linkified link Animal posted ;) http://www.batnet.com/mfwright/shuttlejump.html


50 miles? I believe it's 65. And that's not a NASA thing ;) Also, Rattan's target altitude with spaceshiptwo is 76 miles ;) Searching on their site http://www.scaled.com/ -- that's why they registered the craft N400K <-- 400,000 feet :P

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Tool Using Animal (author)2007-01-06

Here's a link to the bailout system (http://www.batnet.com/mfwright/shuttlejump.html (sorry the stupid add link button isn't working))

My father worked on the predecessor to the shuttle, the DynaSoar http://www.astronautix.com/craft/dynasoar.htm, He never had anything nice to say about the shuttle.

BTW I'm happy that nasa is going backwards, simple robust technology. Yes it will cost more, this is the Gov't after all, they spend other peoples money.

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trebuchet03 (author)2007-01-06

There is a bailout system... It's not fun... Two MMU's + enough life support spheres for the remaining crew (I can't recall their proper names though). It may have changed, but the launch pad has (or had) a zip line for quick egress pre-launch -- why else have detonation charges in the door :P. As for the SRB's -- yes, once you fire -- you're somewhat committed and failure is catastrophic (which is why mission control has the capability of destroying it as they did for the rogue SRB after the challenger explosion). But, there's a protocol to abort launch after ignition -- this is why the space coast landing site must also be clear.


Next... You can't compare shuttle tiles to a ablative heat shield systems (boiler plates) used in the Apollo missions. Do some reading on the material that the shuttle heat shield is made of -- it's phenomenal stuff. I participated in a demo at the space coast -- you'd put your hand on one side of the tile and then a blow torch would be applied for a few minutes (could go much much longer - but people get bored). Are they sensitive? Yes, relatively speaking -- lets see a concrete wall from your house withstand the same impact.


Understand that the shuttle is the product of the 70's. It has gone many upgrades and retrofits (you think the instrumentation is 100% analog like in the movies?). If you want to talk about least thought out projects... look at the projects during the "Cheaper - Faster - More Frequent" campaign.


Solid Fuel... To date, there has been 1 critical failure due to the srb's. There have also been several close calls due to putty erosion. IMO, the design would be much more robust if they were made from a single piece - rather than several large pieces (I think 5). Why is it made of 5 pieces held together with a special putty and an O-ring? You could go back as far as a certain senator that wanted to make sure a certain state of his got the contract to manufacture **cough** Morton Thiokol - Utah **cough** BEFORE the specs were even drafted <-- why do I know this randomness? Our engineering dept. had us do an ethics analysis on the Challenger "anomaly" but I digress.

Solid fuel is what makes the shuttle "cheap." Amazingly, did you know that the SRB's fuel is Aluminum and Rust? Yep -- it's a catalyzed thermite reaction + oxidizer. <-- that's why stopping them is damn near impossible.


Now, am I saying that it's 100% awesome? Yes. Even cooler when you've seen it in the VAB for service. The shuttle is a testament to a great engineering era ;)

Am I saying that it should stay in service? No. I agree with the phase out. But wait for the next vehicle they have planned.... oh god I see the 60's returning. I don't know for sure, but I'll bet it will be more expensive to operate than the shuttle ;)

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trebuchet03 (author)trebuchet032007-01-06

Oh yeah... if someone wants to pay for my ticket (I think $100K), I'll gladly take the first ride on Virgin Galactic's Spaceship Two ;) <-- look at my avatar for a certain likeness to Spaceship one ;) I like the idea of assisted launches -- it's just not as practical for really big spacecraft :P

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