Atlantis on Pad 39A (APOD 09 Feb 2008)

npsguy · Post by **npsguy** » Sat Feb 09, 2008 11:37 am

Nice image. The tiles on the shuttle are looking a little 'aged'.

emc · Post by **emc** » Sat Feb 09, 2008 12:10 pm

Yes, very nice image.

The support structure is incredible. It is cool how the structure "clam shells" onto the shuttle. (It took me a few minutes of study to realize the giant cylindrical "door hinge". )

I wonder if the angled "almost appears to be suspended" white rectanglar structure near center is an emergency escape "slide"?

orin stepanek · Post by **orin stepanek** » Sat Feb 09, 2008 1:51 pm

This http://apod.nasa.gov/apod/ap080209.html is a most awesome sight. I'm saving it as a desktop Item. Did you see the man standing below the clamshell and observing the shuttle? It really puts the size of the shuttle into perspective.
After blowing the picture up; I see there are 2 guys standing inside the clamshell.
Orin

emc · Post by **emc** » Sat Feb 09, 2008 3:31 pm

Yes, I noticed the two men. Looks like the upper fellow is looking into the camera???

The two men posing in the structure reminded me of M.C. Escher's 'Relativity' http://www.mcescher.com/Gallery/back-bmp/LW389.jpg

BMAONE23 · Post by **BMAONE23** » Sat Feb 09, 2008 5:11 pm

I see a total of 5 people standing on the structure

AWSOME

emc · Post by **emc** » Sat Feb 09, 2008 5:36 pm

You're right! but now I think I see more??? maybe 7

rafa · Post by **rafa** » Sat Feb 09, 2008 7:14 pm

One point that I have always wondered about Where does the Shuttle stands when it is upright on the pad? It seems clear that the orbiter "hangs" from the bipod and the tail suport on the External tank (flimsy as the look). The ET is not suported anywhere on its base, so it also "hangs" from the two SRBs. That means that whole weight of the loaded vehicle rests just on the skirts of the SRBs. They must be really strong. Is that so, or is there any other support point that I am mising, such as the big gray box in front of the Atlantis starboard wing??

Rafa

checkthree · Post by **checkthree** » Sun Feb 10, 2008 1:15 am

Wow, I just wrote about how its launch has been delayed in my science class.

iamlucky13 · Post by **iamlucky13** » Mon Feb 11, 2008 8:12 pm

rafa wrote:One point that I have always wondered about Where does the Shuttle stands when it is upright on the pad? It seems clear that the orbiter "hangs" from the bipod and the tail suport on the External tank (flimsy as the look). The ET is not suported anywhere on its base, so it also "hangs" from the two SRBs. That means that whole weight of the loaded vehicle rests just on the skirts of the SRBs. They must be really strong. Is that so, or is there any other support point that I am mising, such as the big gray box in front of the Atlantis starboard wing??

Good question, and yes. The Solid Rocket Boosters support the entire stack. If you think about it, this actually makes sense. With 5.6 million pounds of combined thrust (the shuttle's main engines only contribute 1.2 million pounds together), the entire assembly is "supported" by the SRB's in flight, as well as on the pad. In fact, before the external tank is fueled, the stack only weighs about 3 million pounds (4.6 million fueled).

The stack is nearly balanced, but the 240,000 pound orbiter hanging on the side does give it a slight tendency to tip. I'm not sure if there are additional supports around that box, or if the hold-down bolts (which are blown as soon as the SRB's ignite) are able to support that...it's only 5% of the fully fueled weight.

One of the challenges in designing the external tank was making it lightweight enough to go almost all the way to space, yet strong enough to support the two SRB's hanging on the side and the shuttle on the back. Considering it weighs only 60,000 pounds, but supports 6.8 million pounds of total thrust and holds 1.6 million pounds of fuel, I'd say the engineers did an amazing job on a seemingly simple piece of hardware.

emc wrote:I wonder if the angled "almost appears to be suspended" white rectanglar structure near center is an emergency escape "slide"?

That's actually a cover to protect the wing from inclement weather when the rotating service structure is closed over the orbiter. This cover is why a severe hailstorm which caused enough damage to the foam on the tank on STS-117 to warrant a rollback to the vehicle assembly building for repairs left the delicate thermal tiles basically untouched.

The tower escape system is on the other side of the fixed service structure. If they had to use it, they'd unbuckle, blow the hatch, run across the gantry, jump into a pair of 4-person gondolas, and be whisked down a 1200 foot long zipline into the safety of a concrete bunker. I saw a video of this once on an IMAX screen. It made me dizzy just watching it.

I can't seem to find any good pictures of this escape system from afar, but here's one showing the rotating service structure in the closed position:

emc · Post by **emc** » Mon Feb 11, 2008 8:29 pm

Here is a link to a little more info for the RSS... The structure is impressive, I can only imagine how much more it would be in person!

http://en.wikipedia.org/wiki/Image:STS- ... nchpad.jpg

NoelC · Post by **NoelC** » Tue Feb 12, 2008 5:34 pm

...And for all the design and refinement that's gone into this, the whole thing's being retired in a few short years.

Is there a follow-on vehicle in the plans yet? Or is NASA just dropping the ball and walking away from the game?

-Noel

iamlucky13 · Post by **iamlucky13** » Tue Feb 12, 2008 6:36 pm

Yes, there is definitely a follow-on vehicle in the works. As opposed to a large, winged craft carrying cargo and crew together but limited to earth orbit, NASA will start with a small manned capsule very similar in appearance to the Apollo spacecraft for crew duties. Then they will develop a larger cargo launcher slightly bigger than a Saturn V. The idea is to be able to use a family of related craft to support low earth orbit operations and missions to the moon, near earth asteroids, or the Lagrange points, as well as have technology capable of supporting a Mars mission, if that is ever made a priority. See here:

http://www.nasa.gov/mission_pages/constellation/main/

Shortly after the conclusion of the Columbia Accident Investigation Board, which recommended that the shuttle be retired following the completion of the ISS in 2010, President Bush announced the Vision for Space Exploration that directed NASA to develop the new vehicles to support current operations and allow for a return to the moon and possibly Mars.

The program is called Constellation. The manned spacecraft is the Orion and it will be launched on the Ares 1, which uses both shuttle and Apollo-derived technology. The cargo launcher will be called the Ares V and use Shuttle and Delta IV rocket technology.

Unfortunately, Bush and congress have consistently failed to come through with the funding to make this a reality in a timely manner, and there will be approximately a 5 year delay between the retirement of the shuttle, and the availability of the Orion spacecraft and Ares I launcher. The current political candidates have expressed varying degrees of support for the new vehicle, which poses a threat of yet another NASA project being abandoned midstride, only this time we won't have an existing spacecraft to fall back on if the politicians bail-out again.

neufer · Post by **neufer** » Tue Feb 12, 2008 7:24 pm

NoelC wrote:Is there a follow-on vehicle in the plans yet? Or is NASA just dropping the ball and walking away from the game?

Back to the Future:

bystander · Post by **bystander** » Tue Feb 12, 2008 7:50 pm

NoelC wrote:Is there a follow-on vehicle in the plans yet? Or is NASA just dropping the ball and walking away from the game?

There is the Crew Exploration Vehicle to replace the shuttle and ISS escape vehicle. Orion is primarily a lunar exploration vehicle.

Correction, it seems the CEV is the Orion. Except for servicing the ISS, it seems NASA is abandoning the shuttle mission.

http://scitech.quickfound.net/astro/ori ... links.html