Landing practice for the space shuttle...

[gn85]

I was just watching the news this morning and they were saying how the astronauts were doing practice landings with the small Grumman jets.  The reporter was saying that the space shuttle comes in considerably faster than a normal plane.  Of course he didn't actually say at what rate the space shuttle or these practice jets come in at.  Anybody have an idea??

[ozzy72]

On final she'll be a little faster but not significantly. But I believe during re-entry she can get up to Mach 20something. I'd have to check that but she is FAST!

[gn85]

Yes, I know it's moving pretty fast when it re-enters.  Takes a whole continent to scrub off speed.

The way the reporter was talking, it sounded like he was referring to rate of decent moreso than actual airspeed.

[OTTOL]

Unless they've changed things....they used to use a Gulfstream II (not a Grumman) to practice landings. The aircraft has it's weight-on-wheels switches "squat switches" rigged to ground mode and they deploy the T/R's to duplicate the shuttle's steep descent profile.

[Rifleman]

From Nasa KSC HERE, you can get more of the mission profile..........

The approach and landing trajectory capture phase begins at the TAEM interface and continues to guidance lock-on to the steep outer glide slope. The approach and landing phase begins at about 10,000 feet altitude at an equivalent airspeed of 290, plus or minus 12, knots 6.9 nautical miles (7.9 statute miles) from touchdown. Autoland guidance is initiated at this point to guide the orbiter to the minus 19- to 17-degree glide slope (which is over seven times that of a commercial airliner's approach) aimed at a target 0.86 nautical mile (1 statute mile) in front of the runway. The spacecraft's speed brake is positioned to hold the proper velocity. The descent rate in the later portion of TAEM and approach and landing is greater than 10,000 feet per minute (a rate of descent approximately 20 times higher than a commercial airliner's standard 3-degree instrument approach angle).

At 1,750 feet above ground level, a preflare maneuver is started to position the spacecraft for a 1.5-degree glide slope in preparation for landing with the speed brake positioned as required. The flight crew deploys the landing gear at this point.

The final phase reduces the sink rate of the spacecraft to less than 9 feet per second. Touchdown occurs approximately 2,500 feet past the runway threshold at a speed of 184 to 196 knots (213 to 226 mph).

TAEM=Terminal Area Energy Management

[JBaymore]

19 degree glideslope  :o  :o  :o

Flys like a brick.

I remeember lading that thing back in "Orbiter" days....... it just falls out of the sky.

best,

.................john

[Felix/FFDS]

Unless they've changed things....they used to use a Gulfstream II (not a Grumman) to practice landings.  

Technically, as I understand it, Grumman did start out the Gulfstream series - first with the G-159 Gulfstream I, then the G-1159 Gulfstream II ...  with the passing of time, etc. the business aircraft became a separate business, Gulfstream American, etc. etc.  So calling them "Grummans" may not be current, but not completely incorrect?

[gn85]

Thanks for the great answer.  I was thinking of trying this with flight sim.  Wow, that does come out of the air like a stone.  It's a little decieving to watch on TV.  

[MattNW]

[quote]19 degree glideslope

[jrpilot]

What would happen if they had to do a go around?, since there speed would drop very fast.

[gn85]

What would happen if they had to do a go around?, since there speed would drop very fast.

Don't think there is such a thing as a 'go-around'.  Can't engage engines obviously.  They have 10,000 ft. of runway and don't exactly have to worry about 'traffic'.

[Ivan]

Buran had a planned go-around capability... the one that was parked in Sydney has the engine stuff for flight testing, but a go-around system most likely would look the same

[beaky]

What would happen if they had to do a go around?, since there speed would drop very fast.

gn85 is right: Landing the Orbiter is a one-shot deal, because at that point, it's a big glider. But between the flight control computers and the skill of the pilots, they usually make very precise landings; don't think there's ever been an overrun or anything like that, despite the fact that it comes over the fence at speeds in excess of 200 mph.
Here's a link I found to an article about the Gulfstream program...
http://www.aviationnow.com/content/ncof/lo_nfm05.htm

[Chris E]

yeah, once they are coming in, they are coming in, no stopping it, no go arounds, nothing

[beefhole]

They have 10,000 ft. of runway and don't exactly have to worry about 'traffic'.

They've gotta have more than 10,000' at the landing sites-I know Titusville is 15,000.