What supports the weight of a shuttle before launch

hairyslug

Its a quiet Friday, I'm googling random stuff. It all started when I looked at Kennedy space centre on Google maps.

Now please excuse my ignorance with this.

When a shuttle is sitting upright on the pad, what supports the weight of it all, surely it can't just be the 2 boosters to either side of it.

Beeker

hairyslug wrote: »

Its a quiet Friday, I'm googling random stuff. It all started when I looked at Kennedy space centre on Google maps.

Now please excuse my ignorance with this.

When a shuttle is sitting upright on the pad, what supports the weight of it all, surely it can't just be the 2 boosters to either side of it.

Yes it sure is. All the weight is held up by both boosters. The boosters are connected to the pad with eight bolts (Four on each one) these are explosively detonated at T-0 to release the Shuttle stack for liftoff.

hairyslug

Beeker wrote: »

Yes it sure is. All the weight is held up by both boosters. The boosters are connected to the pad with eight bolts (Four on each one) these are explosively detonated at T-0 to release the Shuttle stack for liftoff.

Cheers, and what keeps it stable, again, a stupid question but is it just balanced right so that it stays upright or are there "stabalisers" to keep it from tipping over

Beeker

hairyslug wrote: »

Cheers, and what keeps it stable, again, a stupid question but is it just balanced right so that it stays upright or are there "stabalisers" to keep it from tipping over

Its not balanced very well as it happens, just the bolts or more correctly "hold down posts" that keep it secured to the launch pad.

tricky D

Beeker wrote: »

Its not balanced very well as it happens, just the bolts or more correctly "hold down posts" that keep it secured to the launch pad.

You can see it rocking at launch in this video. I also thinks it doesn't quite go straight up with some lateral component. Edit: yep there's some movement 'downwards' relative to the shuttle's axis. Probably due to the orientation angle of the main engines.

https://www.youtube.com/watch?v=Lq_shHu4lAs

2 stroke

Found this interesting myself so I looked this up

Frangible nuts secured the solid rocket boosters (SRB) of the space shuttle, which were bolted to the mobile launcher platform (MLP) until liftoff. On the shuttle, they were separated using a NASA standard detonator or NSD. The space shuttle used two NSDs for the frangible nut atop each of the four 28" long, 3.5" diameter bolts holding each SRB to the MLP. Once detonation occurred, the shuttle lifted free of the MLP. The broken nut and any shrapnel from detonation was captured by energy absorption material, such as metal foam, to prevent damage to the shuttle. In case of NSD failure, or incomplete clearance of the nut from the bolt, the SRB had ample thrust to break the bolt itself and launch unhindered.

postitnote

tricky D wrote: »

You can see it rocking at launch in this video. I also thinks it doesn't quite go straight up with some lateral component. Edit: yep there's some movement 'downwards' relative to the shuttle's axis. Probably due to the orientation angle of the main engines.

https://www.youtube.com/watch?v=Lq_shHu4lAs

Listening to that through headphones, the noise on main engine start has just such a beautiful low frequency noise to it. That instant, deep grumble has made my hair stand on end.

Sorry for gushing, but it's just lovely. :P

Maximus Alexander

postitnote wrote: »

Listening to that through headphones, the noise on main engine start has just such a beautiful low frequency noise to it. That instant, deep grumble has made my hair stand on end.

Sorry for gushing, but it's just lovely. :P

This one sounds even better - skip to about 50 seconds.

https://www.youtube.com/watch?v=uuYoYl5kyVE

postitnote

It'll probably annoy the wife, but i'm playing this through good speakers when I get home:-)

Cheers for that!

ps200306

postitnote wrote: »

Listening to that through headphones, the noise on main engine start has just such a beautiful low frequency noise to it. That instant, deep grumble has made my hair stand on end.

Sorry for gushing, but it's just lovely. :P

I saw the STS-34 launch in the flesh (Atlantis, carrying the Galileo spacecraft). Even from several miles away that ragged rumble felt like someone punching you repeatedly in the chest!

nokia69

ps200306 wrote: »

I saw the STS-34 launch in the flesh (Atlantis, carrying the Galileo spacecraft). Even from several miles away that ragged rumble felt like someone punching you repeatedly in the chest!

Cool

thats something I really want to do, see an SLS, Falcon Heavy or a Delta IV heavy launch in the flesh, or any big rocket I suppose

Any one know what are the best launches to watch live, is the cape better than Vandenberg, whats the closest you can get to the action

Capt'n Midnight

very slightly off topic

you think of rockets as fragile but the the take off mass of the Shuttle and boosters was over two thousand tonnes. And take off was up to 3g.

Then again Agena, Atlas and Blue Streak have very thin skins and had to be pressurised to avoid collapsing.


I used to worry about the fuel burnt before lift off. But then I realised that it was weight that wasn't carried.


Many rockets are held down and only released at full power.
But the Soyuz rests on L shaped brackets. Those arms are only held closed by the weigh of the rocket itself. Once it lifts off they pivot back away.

ps200306

Capt'n Midnight wrote: »

you think of rockets as fragile but the the take off mass of the Shuttle and boosters was over two thousand tonnes. And take off was up to 3g.

Exactly. And that entire weight -- equivalent to 6,000 tonnes given the acceleration -- is entirely supported after launch by the exhaust nozzles on the main engines and SRBs. So it's not all that surprising that it rests on fairly skimpy bits on the launch pad since it must do so in flight with much greater weight.