Mission

General discussion about F-SIM Space Shuttle.

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Mission

UNREAD_POSTby JCM » Mon Aug 19, 2013 5:07 pm

Is there anything else than the approachs ?
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Re: Mission

UNREAD_POSTby Sascha » Tue Aug 20, 2013 1:50 pm

Right now there are only final (from about 9,000 ft) and full (up to about 50,000 ft) approaches.
This is the only part of the flight that’s actually controlled by a human—the atmospheric re-entry is done by the autopilot.

There’s a lot of variation though (landing site, wind and weather, time of day), and you can e.g. perform a minimum-entry-HAC approach (chosen when the orbiter is low on energy) or other emergency landing procedures (e.g. a stuck speed brake).
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Re: Mission

UNREAD_POSTby brahmanknight » Thu Aug 22, 2013 11:12 pm

I'm still the most interested in specific flying conditions during shuttle landings.

I do fly some as faithfully as I can, especially the last 10 or so. Those last flights have pretty easy to find landing ground tracks. Before STS 114, they get harder ( but not impossible ) to find.

Like this for sts 135, a night landing
Image
With the weather conditions being...
0 Kts
Visability 10 miles ( equal to 25 miles on the game )
No clouds
74 degrees F
Pressure 29.95 inches

I'd love to see that for every mission, if we don't get alternate runways first.
Last edited by brahmanknight on Sun Sep 01, 2013 7:58 am, edited 2 times in total.
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Re: Mission

UNREAD_POSTby brahmanknight » Thu Aug 22, 2013 11:38 pm

Or for STS 133
Image
Daytime
Winds: 150 degrees ( SSE ) 17 Knots Gust 24 knots
Visibility 10 miles
No clouds
Temp: 80 degrees
Pressure: 30.17 inches

Note: Close in aim point was used due to high headwind.
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Re: Mission

UNREAD_POSTby Walle2815 » Sat Aug 31, 2013 9:49 am

brahmanknight wrote:Note: Close in aim point was used due to high headwind.

Do you mean Minimum Entry Point? If you do, the graphic shows rather a long-final approach. If it was a Minimum Entry Point approach, the shuttle's trajectory before entering the HAC would cut the runway — what is called "to do a field vertical" (at least I think it is correct from the French version) in aviation, one of the typical possible maneuvers carried out by a plane in the process of getting aligned on the runway and land: field vertical - put oneself rear wind - go around - short final.
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Re: Mission

UNREAD_POSTby Sascha » Sat Aug 31, 2013 4:12 pm

No, there are two aim points for the outer glide slope (that’s why there are two sets if PAPI lights too).
Currently F-Sim uses the outer aim point only, but I plan to make the close in aimpoint selectable too.
Actual selection depended on vehicle weight and I guess weather too.
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Re: Mission

UNREAD_POSTby Walle2815 » Sun Sep 01, 2013 8:07 am

Oops! Right! My mistake, sorry.

Found on the Nasaspaceflight forum:

"The nominal and close in aimpoints are energy management tools. From the crew’s perspective they are both flown the same way (i.e. maintain about 300 knots on the steep outer glide slope and initiate the pre-flare as you descend thru 2000 feet - still about a 1.3G pullout).

The close in aimpoint simply moves the outerglide slope 1000 feet closer to the runway threshold (6500 feet away verses 7500 feet) while still targeting the same touchdown energy (i.e. airspeed). This in turn adds 1000 feet of downrange energy to the orbiter’s current energy state. This change will results in a higher speedbrake setting. Depending on the exact value of the new speed brake setting most of the added energy will either be bleed off or the orbiter will land 1000 feet further down the runway.

The close in aimpoint is used for low energy/high head wind scenarios.

These aimpoints are not to be confused with NEP/MEP (nominal/minimum entry point) which in simple terms is the location of the top end of the glide slope - more specifically the tangent point of the HAC and the final approach path. The NEP is 7 nautical miles from the runway at 12,000 feet altitude and the MEP is 4 nautical miles away at 6,000 feet altitude.

Either of these entry points can be selected as enegy management tools as well.

Mark Kirkman"

By the way, it seems very few flights — if any — were landed using MEP, but I don't know any. If you do, could you tell me which ones were? I'd be interested to see it on the actual space shuttle, if it was on video coverage and preferably not a night landing, of course.
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Re: Mission

UNREAD_POSTby Sascha » Sun Sep 01, 2013 9:05 am

I’m not 100% sure, but I think the MEP HACs were never used.
They are a kind of emergency scenario. If the shuttle is very low on energey, they'd first select a direct (non overhead, i.e. < 180 degree) HAC. If there's still to little energy, the guidance software could even change the HAC radius. So I think the MEP HACs were I kind of last resort.
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Re: Mission

UNREAD_POSTby desktopsimmer » Sun Sep 01, 2013 5:03 pm

To the best of my knowledge the MEP HACs have never been used, even with the STA. All 'off nominal' approaches have been flown in the simulators. Even losing an STA is expensive.
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Re: Mission

UNREAD_POSTby Sascha » Mon Sep 02, 2013 11:24 am

To answer the original question: Yes, I do plan to add historic mission presets in a future version. I can’t promise anything at this time though.
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