Author Topic: Discovery Returns To Earth (Read 843 times)

eagl · « **Reply #45 on:** July 17, 2006, 08:27:06 AM »

You're right Shrimp... They get right around 3 minutes from field in sight until touchdown... Not much time to make or correct any errors. I imagine they do a little bit of training so it doesn't seem so fast

Chairboy · « **Reply #46 on:** July 17, 2006, 08:28:11 AM »

The pfft pfft pfft sound comes from the APUs. When operating, they use an evaporative cooling system. Water is sprayed onto the radiator plates to take the heat away, and the end result sounds like a steam engine. Watch a night landing in infrared some day and you'll see the puffing from the base of the tail.

The reason people hang back in the beginning has to do with the hydrazine that fuels the APUs. Toxic stuff, they check to make sure there isn't a leak first. watch closely, and you'll usually see a couple trucks with big fans that pull up. They are there to keep the poisonous cloud (if it exists) away from the astronauts/groundcrew.

Dunno why my NasaTV feed was so far ahead of yours, Eagl, I used the one linked to in the beginning of this thread.

eagl · « **Reply #47 on:** July 17, 2006, 08:28:26 AM »

raider they showed an IR image earlier that clearly showed a puffing exhaust over the left OMS rocket housing. My guess is that they have an APU running.

And some guy just honked his horn too...

Masherbrum · « **Reply #48 on:** July 17, 2006, 08:28:57 AM »

eagl · « **Reply #49 on:** July 17, 2006, 08:29:22 AM »

Chair,

It's probably because I was having connection probs last week and told windows media player to buffer 99 seconds of video

RAIDER14 · « **Reply #50 on:** July 17, 2006, 08:32:44 AM »

Quote

Originally posted by eagl
raider they showed an IR image earlier that clearly showed a puffing exhaust over the left OMS rocket housing. My guess is that they have an APU running.

And some guy just honked his horn too...

they gave the shuttle a horn???

shuttle looks big even though its the size of a DC-9

RAIDER14 · « **Reply #51 on:** July 17, 2006, 08:34:28 AM »

APU shutdown

eagl · « **Reply #52 on:** July 17, 2006, 08:38:37 AM »

They're stripping down! I KNEW that was the party bus!

AquaShrimp · « **Reply #53 on:** July 17, 2006, 08:42:35 AM »

I dont want to get corny here, but when Nasa switches to capsules again, it just wont be quite as exciting. Example:

"Yeah, I rode the capsule down, chutes deployed at 80,000 feet. Quite an uneventful landing." OR

"We re-entered Earths atmosphere doing Mach 25. We were doing S-turns to slow this unpowered behemoth down. Busting through the clouds at 10,000, and I had less than 180 seconds to make a perfect approach, because theres no go-arounds flying a dc-9 sized glider with a 10,000 fpm sink rate."

Chairboy · « **Reply #54 on:** July 17, 2006, 08:58:14 AM »

While it may not be sexy, having a capsule means that the low clouds are a non-issue.

Shuttles take off (and try to land) on clear days only. Capsules can take off in almost anything. Blizzards, rain showers, fog, the works. Same with landing.

A Ford Trimotor scud running through valleys, finding the airfield using roads, then making a nail-biting approach through low vis might be exciting, but I'll take a 737 casually flying the ILS any day).

AquaShrimp · « **Reply #55 on:** July 17, 2006, 09:06:00 AM »

I was just talking about the excitement factor.

But neither capsules nor shuttles take off in bad weather. Because the exhaust trail is capable of grounding the rocket, causing a lightning strike.

But I'm all in favor of getting rid of the shuttle. Its payload is so limited because it in itself is an orbiting space station.