LIVE: STS-120 Flight Day 13 - Transfers - Hatch Closure

[psloss]

sts1canada - 4/11/2007  7:43 PM

Thanks Philip for the STS-84 reminder, I forgot about that one, however these descending node entry opps. are very rare for the STS program, good job in finding that one!

There's been some discussion in the Q&A thread(s) on descending node entries and what plays into why those aren't flown as much now.  

Here's the ground tracks for 51.6, from the RTF implementation plan.

[Chandonn]

Punkboi, that graphic is too awesome!

Now, if the trajectory follows the 41-G descent trajectory I'll have to find some excuse to go outside at work Wednesday...

[John2375]

STS-74 also landed descending trajectory - I remember seeing a film w/spectacular footage of them coming in over the Canadian Rockies - really amazing!

How does this affect their sleep cycle?  are they basically landing at the end of their 'day' in stead of the beginning?

[Jim]

it is actually better since the cycle isn't affected.  However a waveoff might cause an extension of the day

[psloss]

John2375 - 4/11/2007  7:52 PM

STS-74 also landed descending trajectory - I remember seeing a film w/spectacular footage of them coming in over the Canadian Rockies - really amazing!

How does this affect their sleep cycle?  are they basically landing at the end of their 'day' in stead of the beginning?

Yes, as did STS-79 -- I'm going through the MCC status reports:
http://science.ksc.nasa.gov/shuttle/missions/sts-79/news/sts-79-mcc-21.txt

This probably should end up in the Q & A thread, but here's a few existing posts (I'll add to this momentarily):
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=8406&start=61#M151127
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=6156&start=931#M180132
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=6156&start=931#M180311

[Bubbinski]

Chandonn - 4/11/2007  5:49 PM

Now, if the trajectory follows the 41-G descent trajectory I'll have to find some excuse to go outside at work Wednesday...

But are shuttle entries visible overhead from the ground, in broad daylight, at peak heating?  I've seen the shuttle reenter at night.

[Andrewwski]

How far could one be from the track on the descending track to see it, if seeing it is possible?

[MKremer]

Bubbinski - 4/11/2007  7:50 PM

Chandonn - 4/11/2007  5:49 PM

Now, if the trajectory follows the 41-G descent trajectory I'll have to find some excuse to go outside at work Wednesday...

But are shuttle entries visible overhead from the ground, in broad daylight, at peak heating?  I've seen the shuttle reenter at night.

Yes, you just won't be able to see much of the long-lasting spectacular glowing trail behind like during darkness.

[ratman]

Chris Bergin - 4/11/2007  7:44 AM
Certainly is great work if this is a working OBSS as suggested, as they expected it to last no longer than five hours.

The chart makes you wonder: what is the equilibrium temperature for an object on orbit ? (let's say it's white and insulated like OBSS). Looks like OBSS would stabilize around -50 C - which is a bit strange considering that average Earth surface temp is +14 C...

[Lee Jay]

ratman - 4/11/2007  7:14 PM

Chris Bergin - 4/11/2007  7:44 AM
Certainly is great work if this is a working OBSS as suggested, as they expected it to last no longer than five hours.

The chart makes you wonder: what is the equilibrium temperature for an object on orbit ? (let's say it's white and insulated like OBSS). Looks like OBSS would stabilize around -50 C - which is a bit strange considering that average Earth surface temp is +14 C...

Greenhouse effect.

[ratman]

Lee Jay - 4/11/2007  9:18 PM
Greenhouse effect.

Thanks - that seems to be right. Looks like radiative equilibrium reflects average temp somewhere in the atmosphere - surface temp is much higher...
Sorry for the offtopic.

[Jim]

ratman - 4/11/2007  9:14 PM

Chris Bergin - 4/11/2007  7:44 AM
Certainly is great work if this is a working OBSS as suggested, as they expected it to last no longer than five hours.

The chart makes you wonder: what is the equilibrium temperature for an object on orbit ? (let's say it's white and insulated like OBSS). Looks like OBSS would stabilize around -50 C - which is a bit strange considering that average Earth surface temp is +14 C...

The earth is a smaller portion of the "sky" than deep space. And there is the occasional sun viewing

[ETEE]

psloss - 5/11/2007  12:47 AM

Here's the ground tracks for 51.6, from the RTF implementation plan.

It appears that the ascending deorbit opportunities have more banking options than the decending ones.  Is this why ascending configurations are preferred?

[John2375]

And didn't STS-79 also make an overhead RIGHT turn to Runway 15 - very unusual, don't think that's been done before

[collectSPACE]

jmjawors - 4/11/2007  1:57 PM

Scott reports an MMOD strike on one of Discovery's windows.

[psloss]

John2375 - 5/11/2007  8:03 AM

And didn't STS-79 also make an overhead RIGHT turn to Runway 15 - very unusual, don't think that's been done before

Not that unusual...descending node entries (well, high-inclination ones) are more unusual.