Shuttle Main Engine Test to be Webcast

spamacon writes "Periodically, the Space Shuttle Main Engines (SSMEs) get tested, and sometimes the public is invited to witness the event. Well, now they've gone and done it right: this Friday, they are going to broadcast the test over the internet (with audio, so go out and buy that big subwoofer you've had your eye one). The webcast link is here, and a little history of the SSME is located here. If you are in southern Mississississ(stop me!)ippi on Friday, go have a peek. Should be a blast (ugh)."

Comments

Re:Which one?

[Uma Thurman]

Each shuttle engine can be and has been flown on many different shuttles. These numbers are sometimes given in the status reports. Check out this page to see a list of what engines flew on what shuttles. I would post the list here, but it won't get past the lameness filter.

I really love and hate the SSME

[WolfWithoutAClause]

On the one side, they're rocket engines, and they achieve maybe 97% of the theoretical maximum performance you can get from liquid hydrogen/liquid oxygen from these propellents. Cool!

On the other, they're expensive as hell, after 30 years of flying they're only just now looking like they're even close to getting them fully reusable (does it count if you have to remove them and tear them apart after each and every mission 'just to check'), and contrary to what NASA will tell you they aren't the only reusable engine out there (other engines aren't classed as such, mainly by NASA, but have had >2,000 seconds on them during testing, and that's about the same as most of the shuttle engines have, only the other engines probably need less maintenance.)

Oh yeah and they burn hydrogen. Hydrogen gives great exhaust velocity, but it's really seriously not very dense. This makes the tanks, fuel lines, and pumps much heavier, (that external tank costs $100 million, oh yeah and they throw it away each time).

Current thinking is that LOX/LH is about 6% worse overall than LOX/Kerosene for getting to orbit- the rocket needs more delta-v due to the extra vehicle weight and other technical issues and that swamps the extra performance of the hydrogen; oh yeah and LOX/Kerosene may not have needed an external tank to be thrown away because Kerosene is much denser.

All in all. Hey, it works! Anyway, pass the popcorn someone; it's still a rocket engine, and it makes a loud noise. ;-)