Ironflight

Ironflight

VAF Moderator / Line Boy
Mentor
I have had enough private emails that there must be some interest....

Launch attempt scrubbed today due to the fact that we don't like to launch through the anvils of thunderstorms- not a nice idea to launch an all-electric, fly-by-wire vehicle through high potential areas with a plume of aluminum exhaust connecting you to the ground. We write our Flight Rules for a reason, and we stick with them, even when they leave us disappointed.

Vehicle and crew were in good shape, and we'll try again tomorrow. Those of you in Florida understand the drill - its July, its afternoon, its Florida... there's no question you'll have thunderstorms - it's just a matter of exactly where...

Thanks to everyone that expressed interest, and keep watching!

Paul
 
Godspeed!

Paul, We're all looking forward to a successful mission! Break a leg!
 
That's what checklists are for! We're all pulling for a successful launch and flight when the right time comes. Good luck guys!!

We rushed home today to see a possible launch but we'll try again tomorrow!
 
Ah well....we'll take a day of, and see if we can light the really big bottle rockets on the Fourth! I've spent every major American holiday on console at least once - and some twice...maybe that increases our chances of a "Go" day.

Today was clearly not a good day to fly, and we quit trying early. But you'vegot to be ready to go if the weather gives you a break. Atl east I got som RV'ing in this morning!

Paul
 
mid afternoon thunderstorms

I know there is likely a million reasons why not, but why don't they wrap the foam in some kind of film to keep it from falling off if it cracks?

Two of my engineering Professors in college worked on the external tank, one in heat transfer and the other in structural vibration. Interesting stuff. Looks like tomorrow will be iffy.

Many lay people wrote into the TV stations and asked great questions. If you know mid afternoon is peak thunderstorm time, why not launch early in the morning or mid-night, when the convective activity is less. The answer is the rendezvous with the space station only allows one window to launch, mid afternoon. However I think they could re-position or re-time the space stations orbit to "fly-over" the Cape at 6am instead of 3:30pm or what ever the time is?
 
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gmcjetpilot said:
I know there is likely a million reasons why not, but why don't they wrap the foam in some kind of film to keep it from falling off if it cracks?

Two of my engineering Professors in college worked on the external tank, one in heat transfer and the other in structural vibration. Interesting stuff. Looks like tomorrow will be iffy.

Many lay people wrote into the TV stations and asked great questions. If you know mid afternoon is peak thunderstorm time, why not launch early in the morning or mid-night, when the convective activity is less. The answer is the rendezvous with the space station only allows one window to launch, mid afternoon. However I think they could re-position or re-time the space stations orbit to "fly-over" the Cape at 6am instead of 3:30pm or what ever the time is?
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Hello George - just got back after meetings today - we're going to go give it a try for a launch tomorrow. The weather looks better tomorrow than later in the week, and folks are comfortable with the foam issue, so it would be hard to pass up the opportunity.

Wrapping the foam in something? Interesting idea...we had a lot of folks that suggested chicken wire....You're right - there are probably a bunch of reasons why a wrap doesn't work, but I don't know what they are - the tank design guys have had some pretty bright folks working on the problem for the last couple of years, and they are a lot smarter than me!

In terms of launch windows, changing the planar phasing of a spacecraft's orbit is incredibly costly in terms of propellant. We all grew up with Star Trek and Star Wars where they just change orbits at will...but that ain't the reaility. What you asked is a reasonable question (we'd call it precessing the node), but it would take months to acomplish with more fuel required than the station has available. It's a VERY big mass! You're asking good questions though!

Time to get some sleep before the next attempt!

Paul
 
Ironflight said:
Wrapping the foam in something? Interesting idea...we had a lot of folks that suggested chicken wire....You're right - there are probably a bunch of reasons why a wrap doesn't work, but I don't know what they are - the tank design guys have had some pretty bright folks working on the problem for the last couple of years, and they are a lot smarter than me!
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My bright idea after last year's launch (we discussed it during almost an entire day at A&P school) was to use the white shrinkwrap that's used here in my neck of the woods for winterizing boats. The stuff's pretty thick, so unfortunately there'd probably be a significant weight penalty. Plus it'd be difficult to work the wrap around the various struts and external lines, which are the areas that I understand are the most fragile.

Another one I just thought of - how about a monofilament weave that's embedded in the foam during application? What I'm thinking is basically woven fishing line... It would (in my mind, anyway) do what rebar does in concrete - add strength, and hold chunks together if the concrete/foam were to begin cracking.


OK, that's enough off-track from me. I'll let you know where NASA can send the checks for using my idea(s)... :D :D :D
 
jarhead said:
how about a monofilament weave that's embedded in the foam during application? What I'm thinking is basically woven fishing line... It would (in my mind, anyway) do what rebar does in concrete - add strength, and hold chunks together if the concrete/foam were to begin cracking.


OK, that's enough off-track from me. I'll let you know where NASA can send the checks for using my idea(s)... :D :D :D
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Ken: You and I think alike. I wonder why?

Jekyll
 
Remember when the shuttle fuel tanks were painted? Foam delamination never seemed to be an issue then. How about a coating on the Orbiter side of the tank only?
I'll be rooting for the USA and praying for a safe mission.
H
 
It's the heat.........

My bright idea after last year's launch (we discussed it during almost an entire day at A&P school) was to use the white shrinkwrap that's used here in my neck of the woods for winterizing boats. The stuff's pretty thick, so unfortunately there'd probably be a significant weight penalty. Plus it'd be difficult to work the wrap around the various struts and external lines, which are the areas that I understand are the most fragile.

It's the heat that's the problem. Remember how fast the wing melted during the disastrous reentry?
 
Howie said:
Remember when the shuttle fuel tanks were painted? Foam delamination never seemed to be an issue then. How about a coating on the Orbiter side of the tank only?
I'll be rooting for the USA and praying for a safe mission.
H
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Boy, you remember a long way back! Actually, we only flew twice with painted tanks (STS-1 and 2), and no one knows if foam came off then or not. We stopped painting to save several hundred pounds of weight (which, just like airplanes) translates into more useful load to orbit....folks looked at painting again during the downtime, and that thin paint wouldn't do the trick. The problem is not in keeping the overall "acreage" foam from coming off - it is the odd-shaped chunks that cover protuberances that are the trouble, and that is tougher than simple containment - you get huge loads on things that stick out at supersonic speeds, so considerable strength is required.

Weather is supposedly an 80% Go probability today according to the latest forecast...

Paul
 
Beautiful Launch

You NASA guys sure stepped up at a good time to give our countrymen something to be really proud of.

Thanks.

Bob Axsom
 
Paul, it is still truly unbelievable every time the shuttle goes up! Way to go. I'll be watching NASA TV!

Regarding the foam, there are many reports that the shedding foam problem was increased significantly when freon was eliminated as a blowing agent in favor of a more environmentally friendly agent. This supposedly occured in 1997. As with all things largely public, expensive and political, it is very difficult to ascertain what is really going on. There are many news stories outlining this and here is one example:

http://www.foxnews.com/story/0,2933,77832,00.html

It is clear that something in the process has changed. I hope that science and not politics can win this one.

BTW, for you geeks out there, I calculated that the kinetic and potential energy in the space shuttle while it is in orbit is equivalent to lifting an aircraft carrier straight up two miles. Think about that!
 
pierre smith said:
It's the heat that's the problem. Remember how fast the wing melted during the disastrous reentry?
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I think you misunderstood me - I was referring to shrinkwrapping the external tank, after the foam insulation is applied, to contain any foam debris. I think it would solve the shedding-foam issue, but it would pack on quite a few hundred pounds - possibly more than NASA gained by not painting the tanks, since I don't know the weight of the wrap. Moot point, anyway - I don't think there's enough flights left in the program to test my theory.
 
Alex hit the nail on the head. Why not just go back to the original formulation?! Last night after hearing the shuttle lauched successfully, my wife asked why NASA was having all the problems with the "foam". I told her, IMO, it was because NASA changed formulations to reduce CFC emisions. She said, "why? It not like they're building them (tanks) every day."

I believe the Columbia and it's crew perished in large part because of enviro-political correctness. Seems to me that applying mass-production, consumer level regulation (on CFC products) to the most technologically advanced and complex machine in existence was not a technically sound decision.

But since the space program administration seems ****-bent on using the less effective new formulation, how about using fiber reinforcement. Mix in long fibers with the foam resin. As I understand it, the foam is sprayed on anyway. The fiber reinforcement shouldn't add a lot of weight. maybe just use the fiber reinforrced formulation over the protuberences?

2 cents
 
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A lot of interesting ideas folks, and that is what good engineering is all about!

Ken made a key observation that points out how everything in a large project inevitably comes down to risk trades, and that semi-awful word "compromise". All designs are compromises in some way, and in this case, you have to weigh the risks of flying with the improvements we have made against further improvements to a system that will only fly a limited number of times in a couple of more years. We have been mandated to quit flying the Shuttle in 2010, and re-engineering (and recertifying) the ET insulation system would take years more than that. It isn't as easy as coming up with an idea for our RV, building a piece, installing it, and going to fly....

(Oh, and the extremists can have my good old-fashioned Halon fire extinguisher when they can pry it from my cold dead hands...!) ;)

Paul
 
How do you....

D.R. and others,
How do you insert another person's 'quote' into your reply? I see them appearing in a bluish box,
Thanks, :confused:
 
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