PDA

View Full Version : Atlantis lands safely, 100,00ft 2nm final.


gaunty
21st Sep 2006, 11:42
It might be doofy now but I still get the same thrill watching a shuttle landing now as I did with the first one .

Old technology or not, watching a night landing on Nasa TV from the cockpit decelerating from 400 to just under 300mph in the last 60 secs just spectacular 100,000 ft 2nm final.:eek:

And they only get one go.:D

It is still a technological tour de force, wherever you are coming from.

TURIN
21st Sep 2006, 11:49
Yeah me too. Call me sad, but I watched it from de-orbit burn all the way down on NASA TV. Remarkable still.

3202b
21st Sep 2006, 11:54
Well done to Nasa :D

Hmm 100,000ft at 2nm - I doubt that!

Nasa TV and the Nasa website were saying this:

6:18 a.m. -- Now at 3 minutes to touchdown. Twin sonic booms could be heard at the Kennedy Space Center. Pilot Chris Ferguson is now flying on the way to Runway 33, 470 miles per hour, altitude 1,000 feet, 13 miles to the runway.

6:16 a.m. -- Atlantis is on course and at proper speed as it approaches the runway. Altitude 10 miles or 55,000 feet, 32 miles to the runway.

gaunty
21st Sep 2006, 12:46
3202b

You're right of course I got it backward I think what they were referring to was "the 90 degree" position, sorta base turn point.

Energy management the same way we all do it, or should, the deltas are all just that much bigger.

Awesome.

Groundloop
21st Sep 2006, 12:48
Pilot Chris Ferguson is now flying on the way to Runway 33, 470 miles per hour, altitude 1,000 feet, 13 miles to the runway.

Something wrong there, methinks. Stretching a glide from 1000 ft over 13 miles!!!

30W
21st Sep 2006, 12:51
An 18-degree glideslope then...crikey!

Must have been quite heavy then.....

The normal steep glideslope segment of the arrival starts at about 40,000' and 290kts. Glidepath angle from this point generally runs between 18 and 22 degrees, depending on the Orbiter mass at re-entry. Descent rates run at about 18000 - 20000ft/min to maintain this up until the initial flare phase which commences at 1900' AGL, just inside 1nm from touchdown.

This point has a VASI type set up, with the angle variable, and set according to the re-entry mass again as above. Visual following of these apparently can be fun, and at the steeper glideslope angles, has to be done through the overhead windows on the orbiter, as the required point can't be seen through the main windows at this point due to the pitch attitude upon the steep glide.

It's a diffrent world, and wouldn't all pilots love to be part of it!!

I can never get tired of watching the shuttle, a bit like concorde was, it's a very special machine which always catches the eye and interest......

30W

gaunty
21st Sep 2006, 12:57
The airframe noise was really quite impressive too.

EGBKFLYER
21st Sep 2006, 13:31
NASA TV? Can I get that on Sky? Seen everything on Disco Wings now...:O

3202b
21st Sep 2006, 14:14
Yeah you can get it on Sky News by pressing the red button - it's only available at launch and landing time though.

gaunty
21st Sep 2006, 14:16
Or streaming video off the Nasa web.

Lotsa a really interesting stuff there too.

visibility3miles
21st Sep 2006, 14:23
Stretching a glide from 1000 ft over 13 miles!!!

Yes, that is wrong. I have heard the shuttle described as a brick with wings.

I watched one shuttle landing at the Edwards AFB in California in 1984 and was startled at how fast it moves. The first clue you get of its arrival is the sonic boom, then it comes whizzing along for a normal landing.

They wait around thirty minutes or more before the crew disembarks to give them a chance to get used to gravity again, and to shut down the shuttle.

For NASA TV, go to www.nasa.gov.

XL5
21st Sep 2006, 18:35
If the descent profile is known, fly it. Works every time for anything that's airborne and has to come down. PE to KE, energy management, check points on the descent, etc etc. The laws of physics, not the whims of witchcraft. Just trust the gauges and should looking out the window cause discomfort, don't look. Helps of course when the FMC(s) are doing the flying. As for 100,000ft at 2 miles: a brick thrown out the aircraft couldn't achieve that.

30W
21st Sep 2006, 20:14
100,000ft 2 miles from touchdown no, but 100,000ft 2 miles from the field it certainly could have been.......

The Orbiter does not do a straight in approach, but arrives in the overhead at about 100,000ft, where it carries out energy/altitude loss through a series of turns in what's known as the HAC (Heading Alignment Circle), which is designed to bring it to the right point on final for the next segment, the steep glidepath approach described earlier. The subsonic deceleration also occurs overhead the airfield somewhere between 100,000 and 80,000ft.

alexban
21st Sep 2006, 20:18
typical glipe path angle for the shuttle is around 19 deg,so the shuttle will be at 7.5NM at 13,365 feet ,flying a wide arc app with a speed about 424 miles per hour. About 2NM the speed is around 360 miles/hour and the glide path from 18-22 deg .
During flare,the glide path is reduced to 1.5 degrees and the touchdown speed is between 215-226 miles/hr.
The S-turns to reduce speed start at a altitude of aprox 30 miles. At an altitude of 9.5 miles the speed is about 1 mach.All flight till now is done by computers.
The commander takes over after going subsonic (aprox 4 min to landing)
If I remember correctly,at space center in Houston ,there was a simulator where you can enjoy a manual landing with the shuttle,hands-on the side-stick and using the actual instruments...but it is a long time since i've 'flown' it.

TightSlot
21st Sep 2006, 20:35
I was in an Orlando hotel room when the last one (i.e. not this one) landed and heard the news anchor saying "... and the citizens of Osceola and Orange counties should be hearing the orbiter any time..." - I opened the window, and sho' nuff heard my wake up call. It was a double sonic boom - why is this a double boom? (or did I hear an echo?). Does this mean twice the speed of sound?

It raised a goose bump or two, and gave the visit to KSC a couple of days later something of an edge.

alexban
21st Sep 2006, 20:52
Double sonic boom-created by the nose and the wings of the shuttle,or so I've heard..

TURIN
21st Sep 2006, 20:59
Two booms. Two shock waves. One attached to the nose and one to the tail of the aircraft. I think.:ok:

no sponsor
21st Sep 2006, 21:15
I think the airframe noise you are referring to are the chase planes which follow it for the final part of the descent.

I was sad too - I watched the whole thing from de-orbit burn. It was impressive to hear that at 3300 miles to go when she was at around 90 miles in altitude it was only 30 mins to touchdown.

For those who have not visited the nasa home page, the downloads of the launch from this, and previous mission, from the solid rocket booster cameras are very impressive.

visibility3miles
21st Sep 2006, 21:20
I heard two sonic booms too for a shuttle landing.

You get one boom when a plane goes to mach one, and two when it is supersonic (>greater than mach one.)

From wikipedia:
As an object moves through the air, it creates a series of pressure waves in front of it and behind it, similar to the bow and stern waves created by a boat. These waves travel at the speed of sound, and as the speed of the aircraft increases the waves are forced together or 'compressed' because they cannot "get out of the way" of each other, eventually merging into a single shock wave at the speed of sound. This critical speed is known as Mach 1 and is approximately 1,225 kilometers per hour (761 mph) at sea level.

In smooth flight, the shock wave starts at the nose of the aircraft and ends at the tail. There is a sudden rise in pressure at the nose, decreasing steadily to a negative pressure at the tail, where it suddenly returns to normal. This "overpressure profile" is known as the N-wave because of its shape. The "boom" is experienced when there is a sudden rise in pressure, so the N-wave causes two booms, one when the initial pressure rise from the nose hits, and another when the tail passes and the pressure suddenly returns to normal. This leads to a distinctive "double boom" from supersonic aircraft. When maneuvering, the pressure distribution changes into different forms, with a characteristic U-wave shape. Since the boom is being generated continually as long as the aircraft is supersonic, it traces out a path on the ground following the aircraft's flight path, known as the boom carpet.

GEnxsux
21st Sep 2006, 23:04
I think the airframe noise you are referring to are the chase planes which follow it for the final part of the descent.

I was sad too - I watched the whole thing from de-orbit burn. It was impressive to hear that at 3300 miles to go when she was at around 90 miles in altitude it was only 30 mins to touchdown.

For those who have not visited the nasa home page, the downloads of the launch from this, and previous mission, from the solid rocket booster cameras are very impressive.

I think the main reason for the 30mins is for the venting of the v.toxic substances used for the hypergolic RCS OMS system. You can see gas escaping after it comes to a standstill from the 2 'rocket pods' either side of the tail fin.

keepin it in trim
22nd Sep 2006, 00:50
Still a fabulous machine, I always think of buzz in toy story, "it's not flying... it's falling with style!":)

ChicoChico
22nd Sep 2006, 04:18
You have to watch the video from Atlantis' solid rocket booster camera - keeps filming from liftoff till the booster splashes down in the ocean!

panda-k-bear
22nd Sep 2006, 13:49
The Udvar-Hazy Center is well worth a visit to see the orbiter technology demonstrator Enterprise. What an amazing piece of kit! The size impressed me, though the short stroke of the gear making it sit so low that the fuselage is at about head or even chest height makes it that much more imposing.

DelaneyT
23rd Sep 2006, 20:27
It might be doofy now but I still get the same thrill watching a shuttle landing now as I did with the first one ..l.:eek:



... 90 seconds before touchdown the Shuttle is at 425 mph & 13,000 feet -- a 22 glide slope and a rate of descent approaching 22,000 feet per minute.

At 17 seconds the glideslope is shallowed from 22 to 1.5. At 14 seconds prior to touchdown the landing gear is lowered and then touchdown occurs at ~200 mph.

...takes a little practice for the pilot to keep ahead of the aircraft in that fast approach & landing:ooh: