Shuttle Q&A Part 5

#800 by psloss on 23 Nov, 2009 19:31
Quote from: Danny Dot on 23 Nov, 2009 19:01
I think NASA used to scrub "all the time" before the first stage flight profile data could be uplinked to the shuttle while it was sitting on the pad (DOLILU).
Do you recall approximately (or specifically) when that was first used? I recall some delays for a few launches in the RTF1 period, but those were with longer launch windows and some flights were able to launch later in the window for the day.
#801 by jhf on 24 Nov, 2009 05:40
Is the ODS used today for docking with ISS substantially similar to the one used for Shuttle-Mir? Is the same hardware still in use?

Wikipedia (I know, I know) says there's a difference between the Mir-type APAS and the APAS used aboard ISS, but it almost sounds like the main difference is that the new system isn't truly androgynous anymore -- i.e. that the APAS on the PMAs aren't capable of acting as active docking collars.

It's a lot of supposition on my part, I suppose, but it would make a lot of sense if the passive APAS-95 units on the PMAs were compatible with the (truly androgynous) APAS-89 units, but not other passive APAS-95 units: the Russians could have put the same sort of APAS on Zarya as on Kristall, and the old ODS would have continued to work.
#802 by Jim on 24 Nov, 2009 10:57
Quote from: jhf on 24 Nov, 2009 05:40
Is the ODS used today for docking with ISS substantially similar to the one used for Shuttle-Mir? Is the same hardware still in use?

It is the exact same one(s), don't remember how many were there.
#803 by joncz on 24 Nov, 2009 12:55
When the shuttle performs its separation burn from the station, does it depart retrograde or prograde?

I'm wondering when it makes its pass overhead later that evening, who is in trail?
#804 by Lee Jay on 24 Nov, 2009 13:41
Quote from: joncz on 24 Nov, 2009 12:55
When the shuttle performs its separation burn from the station, does it depart retrograde or prograde?

I'm wondering when it makes its pass overhead later that evening, who is in trail?

Retro, which puts the shuttle in the lead and ISS in trail (retro = lower, lower = faster).
#805 by smith5se on 25 Nov, 2009 05:57
Out of curiosity, if un-docking and fly around occurs over the portion of the Earth that it is currently night time, is this visible to see? I would assume the large bright light that is shuttle/ISS connected would change a bit...

Has it ever been seen?
#806 by MKremer on 25 Nov, 2009 08:58
Quote from: smith5se on 25 Nov, 2009 05:57
Out of curiosity, if un-docking and fly around occurs over the portion of the Earth that it is currently night time, is this visible to see? I would assume the large bright light that is shuttle/ISS connected would change a bit...

Has it ever been seen?

The undocks and flyarounds are always planned so the station can be viewed and photographed in daylight.
#807 by Lawntonlookirs on 25 Nov, 2009 12:33
I was just checking Heavens Above on the ISS Height Profile and noticed that they did show the 1.5 k re-boast that was performed yesterday. However, I also noticed that the ISS had an altitude of almost 358 km around 1/10/09, and prior to yesterdays re-boast the altitude was 340 km, which is a drop of 18km. During that perior they had a couple of re-boast in July, which raised the ISS about 2.5km.

With the 27 min burn yesterday to raise the ISS the 1.5km, what is the maximum re-boast that has ever been done? Also related somewhat to the same question, what is the min altitude the ISS can get too before it needs a re-boast.
#808 by Jorge on 25 Nov, 2009 16:51
Quote from: Lee Jay on 24 Nov, 2009 13:41
Quote from: joncz on 24 Nov, 2009 12:55
When the shuttle performs its separation burn from the station, does it depart retrograde or prograde?

I'm wondering when it makes its pass overhead later that evening, who is in trail?

Retro, which puts the shuttle in the lead and ISS in trail (retro = lower, lower = faster).

Today SEP2 was posigrade. This is done to preserve re-rendezvous capability after Late Inspection.
#809 by Jorge on 25 Nov, 2009 16:53
Quote from: MKremer on 25 Nov, 2009 08:58
Quote from: smith5se on 25 Nov, 2009 05:57
Out of curiosity, if un-docking and fly around occurs over the portion of the Earth that it is currently night time, is this visible to see? I would assume the large bright light that is shuttle/ISS connected would change a bit...

Has it ever been seen?

The undocks and flyarounds are always planned so the station can be viewed and photographed in daylight.

They're planned so that only the *flyaround* part is in daylight. Undocking is at midnight -2 minutes so that sunrise occurs at flyaround start, but as a result the Vbar backout is in darkness.
#810 by ChrisC on 25 Nov, 2009 21:17
Hi ... I posted this Monday night in the STS-129 viewing thread but didn't get any responses there, so I'll try it here.

I'm in Florida, 150 miles south of KSC, and will be driving up to KSC on Friday morning. I can not drive up sooner than that. With nominal landing time around 9:45am, I was wondering how close to KSC I would need to get to hear the sonic boom. Here are some random quotes that I got from Googling around.

"I live 100miles south of the Cape just north of West Palm Beach (across from Lake Okeechobee) and even though the Shuttle is still invisible at 80,000ft there the house rattles from the double sonic booms as it goes over. Anywhere in West Palm, Stuart, Vero Beach, Melbourne and up to Titusville you'll know when it goes over."

"Altitude is irrelevant; when coming in over the US on past missions, it could be heard even at 40 miles altitude during entry." (that's 200,000+ feet)

"Those who live near and around the Kennedy Space Center are accustomed to hearing the double booms of a returning shuttle, but those located under and close to the Shuttle path, perhaps all the way back to the Pacific coast, may also hear the booms as well. "

"From a location in the nation's midsection or over the northwest United States, where the altitude of the shuttle will be in the range of 100,000 to 200,000-feet, it will take time for the shock wave to propagate down to the ground. Sound travels at roughly 1,100-feet per second, so depending on where you live relative to the track, it could be anywhere from 90 to 180 seconds after the shuttle has passed on by before you hear anything."

Obviously those last two are from a landing of a mission whose groundtrack took it across the US, which isn't likely this time, but they do illustrate that the sonic boom is apparently still heard even when the shuttle is that high up, thousands of miles away from KSC.

Can someone comment on these are all accurate?

What about crossrange distance? If the groundtrack is coming across the peninsula on a northeast track (like this one), are they going to hear it in West Palm Beach?
#811 by Sesquipedalian on 26 Nov, 2009 01:50
What exactly does the double sonic boom sound like? I don't think I've ever heard even a single sonic boom.
#812 by rdale on 26 Nov, 2009 02:41
A boom, then another boom? I'm not sure how else to describe it - you might do a YouTube hunt.
#813 by Pedantic Twit on 26 Nov, 2009 02:44
Quote from: Sesquipedalian on 26 Nov, 2009 01:50
What exactly does the double sonic boom sound like? I don't think I've ever heard even a single sonic boom.
Quote from: rdale on 26 Nov, 2009 02:41
A boom, then another boom? I'm not sure how else to describe it - you might do a YouTube hunt.

At 2:50. BANG BANG.
http://www.youtube.com/watch?v=AAirZUdQB6g#t=2m48s
#814 by Hungry4info3 on 26 Nov, 2009 08:53
Is there a orbiter bible anywhere for download? L2 I'm guessing?
#815 by DaveS on 26 Nov, 2009 10:21
Anyone know where I can find the PLB camera pan/tilt angles for FCS C/O?
#816 by daniela on 26 Nov, 2009 12:29
Quote from: MKremer on 25 Nov, 2009 08:58
Quote from: smith5se on 25 Nov, 2009 05:57
Out of curiosity, if un-docking and fly around occurs over the portion of the Earth that it is currently night time, is this visible to see? I would assume the large bright light that is shuttle/ISS connected would change a bit...

Has it ever been seen?

The undocks and flyarounds are always planned so the station can be viewed and photographed in daylight.

In orbital daylight. Of course that does not mean that the bright ISS and shuttle are visible in the dark sky in a "convenient" location of earth, but that should happen regularly.
Please keep in mind that the station and shuttle don't remain visible for long, and it's even worse if you want them high enough on the horizon to do quality photos.
#817 by mdo on 26 Nov, 2009 15:39
Quote from: smith5se on 25 Nov, 2009 05:57
Out of curiosity, if un-docking and fly around occurs over the portion of the Earth that it is currently night time, is this visible to see? I would assume the large bright light that is shuttle/ISS connected would change a bit...

Has it ever been seen?

Assuming that Earth bound viewing is the same for docking as well as undocking - let me report that I watched the pair the other week just a few minutes prior to docking. Even with the naked eye one could discern both objects as separate light sources. ISS actually appeared slightly rectangular in shape and about as bright as Venus. It was shortly after sunset, my vantage point being a light polluted balcony in midtown. The NASA SkyWatch service http://spaceflight.nasa.gov/realdata/sightings/ can be used to check for overlaps between the sightings list for a given location and the time of undocking.
#818 by ChrisC on 26 Nov, 2009 16:28
I'm really hoping someone can weigh in on the range of the sonic boom, asked here yesterday:

http://forum.nasaspaceflight.com/index.php?topic=17437.msg510131#msg510131
#819 by Ford Mustang on 26 Nov, 2009 17:35
Quote from: smith5se on 25 Nov, 2009 05:57
Out of curiosity, if un-docking and fly around occurs over the portion of the Earth that it is currently night time, is this visible to see? I would assume the large bright light that is shuttle/ISS connected would change a bit...

Has it ever been seen?

I've seen the two (Shuttle and Station) very shortly after undocking. It was about 5:50am, and the sun was just rising so the two were very bright in the sky. You could definitely tell that there were two objects in close proximity to each other. It was hard to tell at first, but you could see the very small gap getting slightly (fractionally) bigger, was easier to tell with binoculars.. Don't have pictures as I didn't have a camera, but it was beautiful.