Re: They said the APU fire is normal?

On Mar 29, 6:23 pm, Who Needs Fenders? <yea.ri...@xxxxxxxxx> wrote:
max...@xxxxxxxxxxxxxx wrote:
I'm not even so sure about the idea that one can "see the [APU] heat
being exhausted in the infrared for every night landing."

See: <http://tinyurl.com/2lr94x>

You must remember, in that shot, Discovery is still traveling at well
over 100 knots--the exhaust is being dissipated by the slipstream
between the vertical stabilizer and the OMS/RCS pods (if you view the
visible light version of the "on fire" landing, even during rollout, the
flames are dragged back along the body).

But, that being said, if you look at video of that same landing (STS-114http://tinyurl.com/25sg39), you can start to see the APU exhaust
"strobing" at the about the 1:16 mark.  And it looks like the still
image was taken just between "puffs" of exhaust some where around the
1:46-1:50 range of the video...  by that time, the puffs are quite
clearly visible (in IR).

I'm on the dial-up and have never been able to get YouTube to work for
me here. Would you be so kind as to compare the video at the link
below to the one you reference and tell me if they are the same? (Use
FIND "APU fire" to locate it.)

http://groups.msn.com/SpaceCowboySaloon/sts9.msnw

Now, changing gears here: I'm wondering if we're all "arguing" about
this just because the commentator used the word "normal" to describe the
fire.  I wonder if he should have said the phrase "not unexpected".  As
described elsewhere, the exhaust is flammable... maybe this is the first
time it stayed alight all the way to the ground--every other time, the
slipstream was able to put it out well before going sub-sonic...

"Not unexpected" is still a bit lenient, in my opinion. I doubt if
aerodynamic flow will assist NASA much in explaining an APU anomaly
noticed while on orbit.

Regardless, I would expect the design/testing of the exit orifice to
guarantee continued expulsion under all expected conditions, unless
shutdown is ordered.

JTM
.

Relevant Pages

  • Re: They said the APU fire is normal?
    ... You must remember, in that shot, Discovery is still traveling at well over 100 knots--the exhaust is being dissipated by the slipstream between the vertical stabilizer and the OMS/RCS pods (if you view the visible light version of the "on fire" landing, even during rollout, the flames are dragged back along the body). ... And it looks like the still image was taken just between "puffs" of exhaust some where around the 1:46-1:50 range of the video... ...
    (sci.space.shuttle)
  • Re: They said the APU fire is normal?
    ... image was taken just between "puffs" of exhaust some where around the ... After looking again at a fairly old IR landing video, ... an airflow theory of my own that offers a different explanation. ...
    (sci.space.shuttle)
  • Re: OT: LOOK AT THIS VIDEO OF THE NEW FORD DIESEL-FLAMES OUT THE TAILPIPE
    ... The video means Nothing, they don't even know where it came from! ... After exhaust emission systems introduced oxygen to ... thoroughly burn any unburnt traces of fuel, ...
    (rec.games.pinball)
  • Re: Sad RV Story
    ... Hugh wrote: ... I watched the video as well as read the story. ... how her boyfriend must feel and the rv'r whose exhaust killed her. ... campfires must have blocked any exhaust fume smell and CO has no ...
    (rec.outdoors.rv-travel)
  • Re: fire !
    ... It's the APU (Auxilliary Power Unit) exhaust that you're seeing, ... IR camera. ...
    (sci.space.shuttle)