landing practice

[Wayne Hicks]

From this SpaceRef dot com article:

 

KSC END OF MISSION LANDING WEATHER FLIGHT RULES

 

The end of mission landing weather forecast is prepared by the NOAA National Weather Service Spaceflight Meteorology Group in Houston for the astronauts, Flight Director and Mission Management Team. All criteria refer to observed and forecast weather conditions. Decision time for the deorbit burn is 70 - 90 minutes before landing. The weather criteria are:

 

 

Cloud coverage of 4/8 or less below 8,000 feet and a visibility of 5 miles or greater required.

 

The peak cross wind cannot exceed 15 knots, 12 knots at night. If the mission duration is greater than 20 days the limit is 12 knots, day and night.

 

Headwind cannot exceed 25 knots.

 

Tailwind cannot exceed 10 knots average, 15 knots peak.

 

No thunderstorm, lightning, or precipitation activity is within 30 nautical miles of the Shuttle Landing Facility.

 

Detached opaque thunderstorm anvils less than three hours old must not be within 20 nautical miles of the Shuttle Landing Facility, or within 10 nautical miles of the flight path when the orbiter is within 30 nautical miles of the runway.

 

Turbulence must be less than or equal to moderate intensity.

 

Consideration may be given for landing with a "no go" observation and a "go" forecast if at decision time analysis clearly indicates a continuing trend of improving weather conditions, and the forecast states that all weather criteria will be met at landing time.

[King Racer]

Thanks for the information Wayne.

 

I realize the Space Shuttle reenters earth's atmosphere as a glider, and, therefore, requires more/better weather information when landing.

I, also, realize airlines provide one of the safest means of transportation, but I would imagine, in the future, and possibly now, better information (i.e., sensors around the perimeters of the runways/airports etc. -anemometers, doppler radar?? etc.) would be relaid to onboard computers that would enable pilots to make better decisions (on marginal days) on final (or before) whether to land or not. I am sure people on this website know more about this topic than I do.

[Wayne Hicks]

For me, the strangest thing was to enter the atmosphere and see 4 knots on the airspeed indicator, knowing the vehicle was doing mach 25.

[King Racer]

Astounding! I can't imagine what it would be like to enter the atmosphere or fly at those speeds. The Space Shuttle is truly a marvel of engineering.

Is the four knots indicated speed a function of the atmospheric density?

If NASA ever plans to take the average guy off the street, in the Shuttle, put my name on the top of the list; I have no problem sitting in the cargo bay area:D

[Neverquit]

For me, the strangest thing was to enter the atmosphere and see 4 knots on the airspeed indicator, knowing the vehicle was doing mach 25.

 

I couldn't find this in the writing Wayne. Sounds interesting to read. Do you have a biography of someone's accounts?

[Wayne Hicks]

I'm not an astronaut, but I felt like one each time I flew in the Shuttle Mission Simulators. These are the highest fidelity simulators NASA has. My job was to train astronauts and flight controllers. Although most of my time was spent driving the simulations from behind the instructor consoles, the job did require us to go into the flight deck and fly the things during off-hours (like, really late at night). The main purpose was to check out new simulation models we had created. But after we were done, we'd get the sim controllers to set us up at 50,000 feet so we could shoot approaches to landing. In the Shuttle, 50,000 feet to landing is about 30 seconds! The Shuttle is amazingly easy to fly except for actually landing the beast. All you do is look through the heads up display and keep the diamond in the flight director box. The preflare (15,000 feet), flare (10,000 ft), and final flare to alpha (5,000 ft) were hard for me. I was never able to land without crashing until after I got my pilot's license.

 

We have two SMSs -- one fixed base (doesn't move) and one motion base (6 degrees of freedom). Just before leaving Houston, I was "rewarded" with full launch and landing sequences in the motion base. Except for full 3G loading and weightlessness -- the motion base can simulate that for a few brief seconds, I was there!

[ZUCZZ]

OK, I admit it! I'm green with envy!

 

But real happy to hear you have such a super job!

[Drew Swenson]

Wayne,

As part of NTPS, I got to go to Nasa as part of the class "field trip" and flew an approach from 50K to landing. I only got one approach---and thought it was very pitch sensitive. I went first and "bobbed" all the way down---smooth landing--just not pretty--very humbling. One of the ASCANs went second---and he was very smooth. Evidently, practice makes perfect.

[Wayne Hicks]

Now that we're totally hijacking the thread, a shuttle commander completes literally thousands of shuttle landings in a variety of simulators. The most accurate is a Gulfstream-2 that is highly modified to simulate the speed and steep glide angle of the Shuttle. The plane’s cockpit has been adapted to closely resemble a Shuttle's flight deck; the left-hand seat features the same hand controls that a Shuttle commander uses during a mission. Several passenger seats in the back of the aircraft have been replaced by a bank of Shuttle-simulating computers. This Shuttlr Training Aricraft (STA) flies at the same speeds, dive angle and approach trajectory as the Shuttle. To emulate the "falling brick" feeling, the STA flies the approach with the gear deployed and the engines in reverse thrust. A shuttle commander must do 1,000 landings with the STA alone before being qualified to land the Shuttle on a mission.