Author Topic: STS-135 Landing Weather Thread (Read 27768 times)

rdale · « **on:** 07/15/2011 12:52 pm »

I normally wouldn't post this far in advance, but I'm on vacation next week so wanted to get it started and let the group take over from here.

Offhand I don't see anything big on the horizon... USAF is actually pretty pessimistic with their shower/storm threat during that morning, but I don't see what warrants that much worry.

USAF Weather Links: http://www.patrick.af.mil/shared/media/document/AFD-070606-012.pdf

Spaceflight Meteorology Group: http://www.srh.noaa.gov/smg/SMG_prod.php?pil=OAV&sid=JSC

National Weather Service: http://forecast.weather.gov/MapClick.php?CityName=Titusville&state=FL&site=MLB&textField1=28.5888&textField2=-80.8202&e=0

NWS Forecast Discsussion: http://www.srh.noaa.gov/data/MLB/AFDMLB

Landing weather rules: http://nasa-ksc.org/outgoing/weather_Rules.pdf (L2 has more info and more recent updates)

DO NOT POST WEATHER.COM OR ACCUWEATHER PREDICTIONS PLEASE. Those are completely automated with no living person ever looking at the output. Computers can't replace humans in every field yet

Eksath · « **Reply #1 on:** 07/16/2011 12:40 am »

RDale,

Thanks for the start of the thread. With sunrise at 6:38am and civil twilight at 6:12am, I am thinking that a 15 approach may be the nominal choice. i.e. keep the light behind the pilot after the last HAC. Do the potential winds direction at that time in the morning, support this,too?

Thanks

Prober · « **Reply #2 on:** 07/16/2011 01:15 am »

I'll still keep my Cameras charged for a quick Edwards trip.

rdale · « **Reply #3 on:** 07/16/2011 01:33 am »

Very rarely would the winds be an issue at that time of the morning, so it'll probably be chosen on other issues like you noted Eksath.

Prober - no need to charge them now, Edwards will not be activated for the initial landing day.

shuttlefanatic · « **Reply #4 on:** 07/16/2011 04:47 am »

Given that lighting conditions are debatably "weather", some related numbers:

KSC July 21-22:
5:08AM Astronomical twilight (negligible atmospheric scattering)
5:41AM Nautical twilight (sea horizon visible)
6:12AM Civil twilight
6:38AM Sunrise

Edwards July 22:
4:12AM Astronomical twilight
4:50AM Nautical twilight
5:25AM Civil twilight
5:53AM Sunrise

Also, per notes in L2, waiting 1 orbit for daylight conditions is not being considered. Approximate landing time on July 22 is roughly 5AM local time for both KSC and Edwards.

Prober, I'll post Edwards landing viewing notes in the viewing thread should that scenario become likely.

Prober · « **Reply #5 on:** 07/16/2011 07:11 pm »

Quote from: shuttlefanatic on 07/16/2011 04:47 am

Given that lighting conditions are debatably "weather", some related numbers:

KSC July 21-22:
5:08AM Astronomical twilight (negligible atmospheric scattering)
5:41AM Nautical twilight (sea horizon visible)
6:12AM Civil twilight
6:38AM Sunrise

Edwards July 22:
4:12AM Astronomical twilight
4:50AM Nautical twilight
5:25AM Civil twilight
5:53AM Sunrise

Also, per notes in L2, waiting 1 orbit for daylight conditions is not being considered. Approximate landing time on July 22 is roughly 5AM local time for both KSC and Edwards.

Prober, I'll post Edwards landing viewing notes in the viewing thread should that scenario become likely.

Thanks, will keep it handy

Orbiter · « **Reply #6 on:** 07/17/2011 10:08 pm »

Take a look what's off Cape Canaveral..
...TROPICAL DEPRESSION FORMS JUST NORTH OF THE NORTHWEST BAHAMAS...
5:00 PM EDT Sun Jul 17
Location: 27.5°N 78.2°W
Max sustained: 35 mph
Moving: S at 2 mph
Min pressure: 1010 mb

Predicted to move away from the launch/landing site by Thursday.

Orbiter

shuttlefanatic · « **Reply #7 on:** 07/18/2011 12:24 pm »

SMG is out this morning with a landing day forecast. No weather constraints for any of the landing opportunities at any sites.

Forecast winds for KSC on Thursday are 240 at 6-9 kts, so a direct crosswind not favoring either runway.

(Tropical Storm Bret is not currently a factor, and will be even further out to sea by Thursday.)

Hog · « **Reply #8 on:** 07/18/2011 01:17 pm »

Sun position at 1st landing opportunity at KSC.

Altitude -8.9°
Azimuth 60.8°
Right ascension 8h 1m 42s
Declination 20° 29' 46"
Range (AU) 1.0161136
Constellation Cancer

brettreds2k · « **Reply #9 on:** 07/19/2011 02:44 pm »

What time is Atlantis due to touch down (Eastern time)??

dsmillman · « **Reply #10 on:** 07/19/2011 02:47 pm »

Quote from: brettreds2k on 07/19/2011 02:44 pm

What time is Atlantis due to touch down (Eastern time)??

5:56 AM EDT

brettreds2k · « **Reply #11 on:** 07/19/2011 03:14 pm »

I cant believe they are doing a night landing for the final landing ever, That sucks!!

MarekCyzio · « **Reply #12 on:** 07/19/2011 03:16 pm »

Quote from: Hog on 07/18/2011 01:17 pm

Sun position at 1st landing opportunity at KSC.

Altitude -8.9°
Azimuth 60.8°
Right ascension 8h 1m 42s
Declination 20° 29' 46"
Range (AU) 1.0161136
Constellation Cancer

So it looks like the shuttle will be fully illuminated by the sun above 55K feet (12K feet / 2 degrees). It will be quite difficult to snap a good photo of it

shuttlefanatic · « **Reply #13 on:** 07/19/2011 04:08 pm »

Quote from: MarekCyzio on 07/19/2011 03:16 pm

So it looks like the shuttle will be fully illuminated by the sun above 55K feet (12K feet / 2 degrees). It will be quite difficult to snap a good photo of it

Unfortunately, it's worse than that. The approximation is 12K meters / 2 degrees (http://curious.astro.cornell.edu/question.php?number=388), and the higher you go, the less it helps. My estimate is closer to 50 _miles_ for full illumination ("sunrise").

If it were only 55K feet, that's roughly the altitude of the shuttle as it goes subsonic, directly overhead. At least in the drier, clearer air out west, it's possible to spot it at that point, and even easier if it were lit up. Given that 55kft ~ 11 miles ~ distance from launch pad to Port Canaveral/Titusville, that gives a rough idea of its apparent size at that point.

Incidentally for the weather thread, this morning's weather sheet continues to indicate no forecast weather violations for landing:

Quote

U.S. LANDING SITES - EOM - THURSDAY 07/21/11

SHUTTLE LANDING FACILITY...KENNEDY SPACE CENTER FL
KSC FEW020 FEW070 SCT250 7 24006P09

Danderman · « **Reply #14 on:** 07/20/2011 11:45 pm »

So, what is the weather like in Florida? I am on standby in case the shuttle lands in California, so I guess I should be paying attention.

Lee Jay · « **Reply #15 on:** 07/20/2011 11:56 pm »

U.S. LANDING SITES - EOM - THURSDAY 07/21/11

SHUTTLE LANDING FACILITY...KENNEDY SPACE CENTER FL
FIRST OPPORTUNITY
KSC FEW050 SCT250 7 24004P06

SECOND OPPORTUNITY
KSC FEW050 SCT250 7 26002P03
WIND LGT VRB

EDWARDS AIR FORCE BASE CA
EDW SKC 7 22007P11

NORTHRUP STRIP...WHITE SANDS SPACE HARBOR NM
NOR FEW080 SCT250 7 12006P09

FLIGHT RULE VIOLATIONS:
KSC ... NONE
EDW ... NONE
NOR ... NONE

shuttlefanatic · « **Reply #16 on:** 07/20/2011 11:56 pm »

Mark: 10 hours until landing, and about 1 1/2 hours until crew wake at 9:29PM Eastern.

I bid Atlantis and crew a safe entry and landing, and will save further comment for when they are on the ground.

Quote from: Danderman on 07/20/2011 11:45 pm

So, what is the weather like in Florida? I am on standby in case the shuttle lands in California, so I guess I should be paying attention.

Warm and humid, as usual, and favorable for landing. I'll post updates to the weather thread as needed, but it's not really been needed. Edwards isn't activated for Thursday, so there won't be anything to stand by for tonight.

shuttlefanatic · « **Reply #17 on:** 07/21/2011 12:07 am »

Quote from: Lee Jay on 07/20/2011 11:56 pm

...

Note: I believe the issue time for this forecast was 3:30AM CDT - that's the most current on the SMG site. There was supposed to be an update issued at 5P, but I haven't seen it yet... Not that I expect anything to change.

jcopella · « **Reply #18 on:** 07/21/2011 12:47 am »

From Orlando, about 50 miles (as the crow flies) from the SLF, it's a beautiful summer evening. Warm & on the humid side as is the norm, but calm, almost no wind, and just a few high cirrus.

MarekCyzio · « **Reply #19 on:** 07/21/2011 12:58 am »

The weather is amazing.

shuttlefanatic · « **Reply #20 on:** 07/21/2011 04:04 am »

Very likely the final formal SMG weather forecast for the shuttle program.

Quote

NOAA/NATIONAL WEATHER SERVICE
SPACEFLIGHT METEOROLOGY GROUP / WS8
LYNDON B. JOHNSON SPACE CENTER
HOUSTON TX 77058
1100 PM CDT WEDNESDAY JULY 20 2011

LANDING FORECAST FOR STS-135

EXPECTED LANDING DATE: 07/21/11
TIME: 0957Z
SITE: KENNEDY SPACE CENTER...FL

U.S. LANDING SITES - EOM - THURSDAY 07/21/11

SHUTTLE LANDING FACILITY...KENNEDY SPACE CENTER FL
FIRST OPPORTUNITY
KSC FEW050 SCT250 7 24003P04
WIND LGT VRB

SECOND OPPORTUNITY
KSC FEW050 SCT250 7 26002P03
WIND LGT VRB

EDWARDS AIR FORCE BASE CA
EDW SKC 7 22007P11

NORTHRUP STRIP...WHITE SANDS SPACE HARBOR NM
NOR FEW080 SCT250 7 12006P09

FLIGHT RULE VIOLATIONS:
KSC ... NONE
EDW ... NONE
NOR ... NONE

U.S. LANDING SITES - EOM+1 - FRIDAY 07/22/11

SHUTTLE LANDING FACILITY...KENNEDY SPACE CENTER FL
KSC FEW030 SCT250 7 21002P03

EDWARDS AIR FORCE BASE CA
EDW SKC 7 22007P11

NORTHRUP STRIP...WHITE SANDS SPACE HARBOR NM
NOR SCT100 BKN250 7 13006P09

FLIGHT RULE VIOLATIONS:
KSC ... NONE
EDW ... NONE
NOR ... NONE

THE NEXT SCHEDULED FORECAST WILL BE ISSUED AS NEEDED

KSC...KENNEDY SPACE CENTER...FL
ICAO ID IS KTTS
EDW...EDWARDS AIR FORCE BASE...CA
ICAO ID IS KEDW
NOR...NORTHRUP STRIP WHITE SANDS SPACE HARBOR...NM
ICAO ID IS KE28 (KHMN IS NEARBY)

HOETH/WILEY/HOOD

psloss · « **Reply #21 on:** 07/21/2011 07:06 am »

Latest reported observation at the SLF:

METAR KTTS 210655Z VRB01KT 10SM CLR 24/22 A2995 RMK SLP144 N2901/02 C2601/02 S1601/03

Only thing that might be worth worrying about (maybe) is the dewpoint spread. Not hearing that mentioned in what PAO Rob Navias is relaying in terms of weather conversations, so maybe not.

psloss · « **Reply #22 on:** 07/21/2011 07:20 am »

Weather brief/tagup for Entry FD in 44 minutes at four minutes after the hour.

(Edit: that's the schedule, but it may happen sooner.)

psloss · « **Reply #23 on:** 07/21/2011 07:23 am »

Latest from about 10 minutes ago:

SPECI KTTS 210710Z 26001KT 10SM CLR 24/23 A2995 RMK SLP142 N2601/02 C3301/02 S2802/03

shuttlefanatic · « **Reply #24 on:** 07/21/2011 07:27 am »

Up until the last observation, the temp/dewpoint spread was trending slightly better than yesterday, when it was 1C all night through sunrise. An observation of shallow fog was recorded yesterday at the 1055Z observation (6:55A local).

If that's as bad as it gets this morning, it's probably not a problem. Shallow fog is fog with a depth of less than 6 feet. Given cockpit elevation, they may be able to see right down through it.

psloss · « **Reply #25 on:** 07/21/2011 07:31 am »

Landing time is well before that, too, so less likely to see anything until after. Agreed that it's not likely to be an issue.

Edit: 725Z obs

SPECI KTTS 210725Z 30002KT 10SM CLR 24/23 A2995 RMK SLP142 N3002/02 C3401/02 S3102/02

psloss · « **Reply #26 on:** 07/21/2011 08:03 am »

METAR KTTS 210755Z 28002KT 10SM CLR 23/23 A2994 RMK SLP141 N2802/03 C3401/02 S2902/02

Weather briefing coming up for Entry FD; probably last one. About 25 minutes from Go/No-Go on the burn.

shuttlefanatic · « **Reply #27 on:** 07/21/2011 08:05 am »

Noting the latest observation has temperature = dewpoint.

From PAO commentary, air is described as "dry" so perhaps no real concern for fog this morning.

psloss · « **Reply #28 on:** 07/21/2011 08:11 am »

Quote from: shuttlefanatic on 07/21/2011 08:05 am

Noting the latest observation has temperature = dewpoint.

From PAO commentary, air is described as "dry" so perhaps no real concern for fog this morning.

Yes, and the Wx briefing was so short, it sounds like they're going to go ahead and give the crew an early go for the deorbit burn.

psloss · « **Reply #29 on:** 07/21/2011 08:36 am »

About 13 minutes to the burn; latest obs:

SPECI KTTS 210825Z 31002KT 10SM CLR 23/22 A2995 RMK SLP142 N3102/03 C3402/02 S2902/02

shuttlefanatic · « **Reply #30 on:** 07/21/2011 09:15 am »

Less than 45 minutes to go. Observations being reported every 15 minutes, but not much change. The latest:

KTTS 210910Z 27002KT 10SM CLR 23/22 A2995 RMK SLP142 N2702/03 C3301/02 S2902/02

shuttlefanatic · « **Reply #31 on:** 07/21/2011 10:06 am »

For the record, the weather at landing:

KTTS 210957Z 00000KT 10SM CLR 23/23 A2995 RMK SLP142 N0000/02 C3501/02 S0301/02