NASA TV live

[grega 0]

If anyone is interested. Nasa is broadcasting space walk on ISS live at http://spaceflight.nasa.gov/realdata/nasatv/lowspeed.html

they're doing some work on S1 truss.

"George just lucky i guess!"

[Hooknswoop 19]

I just caught one of them taking pictures w/ the lens cap on.

Hook

[grega 0]

yup, showing the intelligence of nasas astrnoauts

Man i wish i could be up there right now.

"George just lucky i guess!"

[wmw999 2,132]

They were just doing it so that George Bush wouldn't feel so silly, after all the pictures posted.

Actually, NASA TV is really cool; as an official "rocket scientist"(tm), I get to watch rafterloads of it sometimes. There's so much rehearsal and contingency planning that goes on ahead of time; that's why you really see so few mistakes that don't end up just being learning opportunities.

Wendy W.

There is nothing more dangerous than breaking a basic safety rule and getting away with it. It removes fear of the consequences and builds false confidence. (tbrown)

[grega 0]

you're a rocket scientist
good for you

"George just lucky i guess!"

[Hooknswoop 19]

I worked w/ those guys for a year at the NBL. They are SHARP. They get 8-10 hours of NBL training time for each hour of actual spacewalk time.

Edited to add a pic of mein the NBL inside the mock-up of the S0 truss.

Hook

[wmw999 2,132]

Sort of; I'm a programmer for the space shuttle's main on-orbit computer system. Very old, very reliable, code.

But I have the T-shirt
Wendy W.

There is nothing more dangerous than breaking a basic safety rule and getting away with it. It removes fear of the consequences and builds false confidence. (tbrown)

[grega 0]

Cool so you'll know to answer one of my questions.
with one skydiving buddy of mine we are having this argue. he's saying that space shuttles are all made of verrryyy old electronics. no transistors or similar.
made only of (i don't know how to call this element in english...) "bulbs"
so is it true. or are there transistors and modern electronic systems in the heart of space shuttle.

"George just lucky i guess!"

[n2skdvn 0]

Quote

I'm a programmer for the space shuttle's main on-orbit computer

and you spend you time on dz.com"huston we have a problem the computer keeps saying Boobies..."

if my calculations are correct SLINKY + ESCULATOR = EVERLASTING FUN
my site

[billvon 2,411]

>he's saying that space shuttles are all made of verrryyy old
> electronics. no transistors or similar.
>made only of (i don't know how to call this element in
> english...) "bulbs"

Uh, no, the computers on the space shuttles do not use vacuum tubes in their processing elements. They do (or at least did) use some rather old technology, like core memory, but there are other reasons for that. Core memory is relatively immune to alpha errors, radiation-induced errors that plauge some kinds of modern semiconductors.

Last thing I heard was that they were planning to upgrade the CPU's to 486 equivalents. I don't know if that ever got done.

[wmw999 2,132]

Consider it community education

Actually, the space shuttle is a combination of old and new. The general purpose computers (which I'm most familiar with, obviously), are based on ones originally in the SR-71; definitely late 60's/early 70's technology. We have about 1Mb of memory, and no hard drive. The operating system and data for each phase of the flight is loaded from a solid state memory unit, and everything runs in memory for that phase of the flight.

The reason it's that antiquated is because it's generally better to have a system that does a little less, perfectly, than a lot more, with errors. Consider getting the blue screen of death during ascent

However, the display system is newer; currently the displays are multifunction glass boxes, and the processing needed to run them (and upgrade them very significantly) is being offloaded to another system, running VxWorks.

There are transistors on the shuttle; if nothing else, there are a lot of PCs there, and they can be hooked up to the GPC (which does all critical operations) to transmit payload controls through to the payloads.

There's a whole lot of wire on the shuttle. Miles and miles and miles. But when you consider how much verification and testing is invested into the system, hardware and software, and how much of it would have to be duplicated (20+ years' worth), it makes sense not to upgrade too often.

TMI, probably...

Wendy W.

There is nothing more dangerous than breaking a basic safety rule and getting away with it. It removes fear of the consequences and builds false confidence. (tbrown)

[VivaHeadDown 0]

Not TMI! Very interesting. I have a degree in rocket science, just not the job title, yet. Anything related to the space program is fascinating to me. It's what got me into skydiving, actually. I was in Tittusville, working at Space Camp during part of college to help pay the bills, and learned that since Challenger they've create an egress scenario during ascent (though highly questionable as to the likelyhood of actually working) that involves bailing out the side door dowm an extendable boom. So, me and a bunch of buddies went to the local DZ, did a tandem, and 4 years later I'm still jumping. Although things have shifted a bit towards the skydiving end of the spectrum since graduating and still not being employed as an aerospace engineer, but someday that'll turn around and I'll find the balance again.

[Hooknswoop 19]

I built the harness for Bail-Out training. The training was more "play time" for the divers and astronauts. The possibility of actually exiting the shuttle in an emergency wasn't considered realistic by the astronauts.

Hook

[Craig 0]

Quote

Not TMI! Very interesting. I have a degree in rocket science, just not the job title, yet. Anything related to the space program is fascinating to me. It's what got me into skydiving, actually. I was in Tittusville, working at Space Camp during part of college to help pay the bills, and learned that since Challenger they've create an egress scenario during ascent (though highly questionable as to the likelyhood of actually working) that involves bailing out the side door dowm an extendable boom. So, me and a bunch of buddies went to the local DZ, did a tandem, and 4 years later I'm still jumping. Although things have shifted a bit towards the skydiving end of the spectrum since graduating and still not being employed as an aerospace engineer, but someday that'll turn around and I'll find the balance again.

It can actually only be used during glide, either during re-entry or after seperating SRB's and leveling off for glide. To add: The pole extends out and curves down. The crew would clip on to the boom with a short tether which starts inside the orbiter and push themselves out the hatch opening. The pole is somewhere around 8 feet long and when the come to the end their attachment slides off the end and they end up traveling under the wing. I could see where it may be useful in some situations but during ascent with the "fires" buring I would say your SOL for more reasons than one...

[VivaHeadDown 0]

If they could level off, then there'd be no reason to bail out. It's a glider, one with a glide ratio resembling that of a rock, or level 7 AFF trying to track, but a glider none the less. The hatch and boom intent is to make space travel look safe to the public. The public, in the form of the Gov't, funds NASA, so every moron's opinion matters. It's easier to make the village idiot think it's safe, than to explain to him that it will always be inherently dangerous. Things like this, and the zip line down from the gantry then run over to the bunker and wait for the super tank to come save them all before the massive explosions, they're just ways of showing that something was done. As we all know, it's the decisions made by each individual involved that can make it safer, but how do you explain that to the guy who thinks kayaking at his local lake is extreme. You don't, you waste time and resources building unrealistic contraptions that he'll never understand, but for the life of me I'll never understand, he'll accept. Man, I hate the average guy.

[wmw999 2,132]

Well, now, the real advantage of the zip line is that you get to practice on it, and that looks like fun. I've thought about asking them if they need a zip line tester.

And before we laugh too much about that contingency, consider the famous student-in-tow contingency. Also low probability, also risky. But if you plan for the weird shit, then you have some thinking and plans in place when the even weirder shit that you never could have imagined happens.

Wendy W.

There is nothing more dangerous than breaking a basic safety rule and getting away with it. It removes fear of the consequences and builds false confidence. (tbrown)

[PhillyKev 0]

Saw a little blurb on the H channel a few nights ago. They said the computers that filled the huge room at NASA used for the first moon landing had the processing power of today's average pocket calculator. That's amazing.

[Craig 0]

Quote

If they could level off, then there'd be no reason to bail out. It's a glider, one with a glide ratio resembling that of a rock, or level 7 AFF trying to track, but a glider none the less....

Yeah, but this is providing they can make it to terra firma for somthing resembling a landing. Problem during inital stages of ascent over Atlantic where they could not make it to land if a problem came up. In any event yes, I think the escape system may be of comfort those who think that the crew would actually use it.

[billvon 2,411]

>I've thought about asking them if they need a zip line tester.

Taz made several test jumps on the emergency egress system (with full pressure suit and the actual parachute system) and from his description you really wouldn't want to do it. Some items:

-With the suit sealed you can't see or feel anything once the parachute opens; the helmet ring rides up around your head.

-You can't feel the ripcord with the gloves on (not a big deal since there's a sequencer.)

-The suit doesn't float.

He did it 3 or 4 times, and each time it took him several minutes from "go" to actually getting out the door. He doesn't think there's much chance of it being successfully used in an actual emergency.

[billvon 2,411]

>If they could level off, then there'd be no reason to bail out.

Anything other than a perfect landing isn't very survivable in an orbiter. If they have to abort to Siberia, it would be more survivable to be able to get out than to try to land on rough ground. That being said, the current system doesn't seem like a great way to do that.

[wmw999 2,132]

Noooo! I don't want to test it with full gear! You're right, that's no fun. I just want to slide down it and feel kinda like Tarzan.

Wendy W.

There is nothing more dangerous than breaking a basic safety rule and getting away with it. It removes fear of the consequences and builds false confidence. (tbrown)

[VivaHeadDown 0]

Oh yeah, perfect landing is a must, but under what circumstances would you be able to level off, and not be able to control it. If something went wrong, then it probably went TERRIBLY wrong and pieces are missing. At this point, there is no leveling off and yet they still need to get out. I guess there's the odd chance that the SRB's just happen to fall off at the same time early, or a seagull gets stuck in the SSME after liftoff, but then again, there's no way in hell that stuff is going to happen. Even if bailing out was easier, quicker, and possible, the idea that it is only a plan for something going a little wrong is just silly. There are no little problems. Either things go very bad and are followed up by the impossible solution actually working, or they just go bad and the inherent dangers are once again realized.

[MyUserID 0]

Holly crap !! I worked at the Titusville Space Camp for the past 3 summers. Damn shame it has closed down since.

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Remember kids, eagles may soar, but at least weasels dont get sucked into jet engines.