Shuttle TPS tiles dinged

On 20/05/2011 6:10 PM, jacob navia wrote:

by committee. The design decision to fly styrofoam at Mach 2 wasn't
a very bright idea. Each flight proves that. And now, to save money,
they decide to use a badly damaged old external tank to make matters
worse.


It's to avoid having any external tanks left over for posterity to laugh at.

Sylvia.

On 05/20/2011 10:06 PM, Sylvia Else wrote:
On 20/05/2011 6:10 PM, jacob navia wrote:

by committee. The design decision to fly styrofoam at Mach 2 wasn't
a very bright idea. Each flight proves that. And now, to save money,
they decide to use a badly damaged old external tank to make matters
worse.


It's to avoid having any external tanks left over for posterity to laugh
at.

Good one, Sylvia. :-)

The real reason was to allow the last flight to be upgraded from a
launch-on-need rescue flight (STS-335) to a regular mission (STS-135).
Using the repaired tank was an acceptable risk for a rescue flight, but
since flying 135 as a regular mission would necessarily mean that no
subsequent rescue flight would be possible, it was deemed prudent to
swap tanks with 134, given that 135 would still be there to rescue 134,
and give 135 a "pristine" tank.

The level of damage on 134 is pretty low compared to most pre-Columbia
missions (and even most post-Columbia missions). There is only one ding
that even warrants a focused inspection, and the RPM images indicate the
damage is not as bad as that on STS-118, which performed re-entry
"as-is" without incident.

On 5/20/2011 7:55 PM, Jorge R. Frank wrote:

The real reason was to allow the last flight to be upgraded from a
launch-on-need rescue flight (STS-335) to a regular mission (STS-135).
Using the repaired tank was an acceptable risk for a rescue flight, but
since flying 135 as a regular mission would necessarily mean that no
subsequent rescue flight would be possible, it was deemed prudent to
swap tanks with 134, given that 135 would still be there to rescue 134,
and give 135 a "pristine" tank.

That's a little strange in the logic department given, that there was
only a very small chance that 134 would have any problem with the TPS
that would be so severe that it couldn't reach the ISS where 135 could
pick up the stranded crew.
I sort of assumed that Frankentank (as the STS-134 ET was nicknamed) was
saved for the last flight as it could be seen as an excuse for not
flying that added mission, as it was damaged and repaired.
So say you launch STS-135, and it somehow does get damaged during ascent
so severely that it can't get to the ISS...
What are you going to do then? Hope the Russians can launch two Soyuz
rescue ships in a big hurry?
The CAIB said there should always be a rescue Shuttle ready to go on any
flight. Just like the Hubble repair flight with no ISS docking option if
it had problems in orbit, and the ban on night and cloudy day launches
so ascent damage could be observed, the CAIB's recommendations are being
tossed aside one-by-one, and I'm glad to see the next flight will be the
last one from a safety viewpoint.

Pat

It's to avoid having any external tanks left over for posterity to laugh at.

Sylvia.

funny but sad, just look at how nasa engineers have examined old
apollo hardware in museums.

one day some engineer in the future might say wish they had saved one
tank for reference purposes on this question.

besides it would of made a nice display item

On Sat, 21 May 2011 13:06:15 +1000, Sylvia Else
wrote:

It's to avoid having any external tanks left over for posterity to laugh at.

There will still be one flightworthy External Tank leftover... ET-94.
Right now it is being planned for use by SLS as a prototype, but SLS
will probably be killed off next year when Dems and Repubs get into an
election year contest over who can cut the budget deficit the most.

There are also a couple of non-flight ETs around... Marshall and
Kennedy, for example.

Brian

On 22/05/2011 12:11 AM, bob haller wrote:

It's to avoid having any external tanks left over for posterity to laugh at.

Sylvia.

funny but sad, just look at how nasa engineers have examined old
apollo hardware in museums.

one day some engineer in the future might say wish they had saved one
tank for reference purposes on this question.

Perhaps, but there is a clear difference. Apollo was an example of
getting something done, which someone might want to duplicate to some
extent.

I can't imagine that anyone will ever want to build another external
tank covered in foam.

besides it would of made a nice display item

Pretty big, and it would have to be housed. At least NASA will not be
taking me up on my offer to provide a plaque saying "Don't do this again."

Sylvia

On Fri, 20 May 2011 22:55:01 -0500, "Jorge R. Frank"
wrote:

The real reason was to allow the last flight to be upgraded from a
launch-on-need rescue flight (STS-335) to a regular mission (STS-135).

Wouldn't the rescue flight have been STS-334, as it would have been
sent to rescue STS-134?

Dale

On Sat, 21 May 2011 17:53:52 -0800, Dale Carlson wrote:

On Fri, 20 May 2011 22:55:01 -0500, "Jorge R. Frank"
wrote:

The real reason was to allow the last flight to be upgraded from a
launch-on-need rescue flight (STS-335) to a regular mission (STS-135).

Wouldn't the rescue flight have been STS-334, as it would have been
sent to rescue STS-134?

334 would have rescued 133.

Brian

On Sun, 22 May 2011 00:20:20 -0500, Brian Thorn
wrote:

On Sat, 21 May 2011 17:53:52 -0800, Dale Carlson wrote:

On Fri, 20 May 2011 22:55:01 -0500, "Jorge R. Frank"
wrote:

The real reason was to allow the last flight to be upgraded from a
launch-on-need rescue flight (STS-335) to a regular mission (STS-135).

Wouldn't the rescue flight have been STS-334, as it would have been
sent to rescue STS-134?

334 would have rescued 133.

Oh, OK. When these 300 series misions started, I thought they carried
the last two digits of the rescuee mission.

Dale

On 22.5.2011 4:53, Dale Carlson wrote:
On Fri, 20 May 2011 22:55:01 -0500, "Jorge R. Frank"
wrote:

The real reason was to allow the last flight to be upgraded from a
launch-on-need rescue flight (STS-335) to a regular mission (STS-135).

Wouldn't the rescue flight have been STS-334, as it would have been
sent to rescue STS-134?

Dale

No. After the first couple after the Columbia disaster, and excluding
the Hubble SM-4 mission, the Rescue Flights have not been assigned a
300-series number. This is because they would have been done with "Fly
The Next Flight" -approach.

--
Mika Takala