Re: Opinions: Would Shuttlecam have detected the damage?

[Jorge R. Frank]

"Tristaine Brahms" > wrote in
:

> The cam on that flight was on the right-wing side of the orbiter. I
> keep wondering if STS-107 had used a Shuttlecam on the LEFT-wing side
> of the shuttle, would it have detected the damage to the RCC?

Possibly. It depends on the size of the initial hole. It wasn't detectable
in the ground-based ascent images, so the CAIB's working theory is that the
hole was initially small, then grew later.

> If so,
> would it have been thought serious enough to warrant a TAL abort?

Only if you want to kill the crew quicker. The reentry heating for a TAL
abort is about as bad as that for a nominal entry.


--
JRF

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[Jon Berndt]

"Jorge R. Frank" > wrote in message

> "Tristaine Brahms" > wrote in

> > If so, would it have been thought serious enough to warrant a TAL
abort?
>
> Only if you want to kill the crew quicker. The reentry heating for a TAL
> abort is about as bad as that for a nominal entry.
>
> --
> JRF

ECAL? I can't recall offhand what the boundaries are.

Jon

[Jorge R. Frank]

"Jon Berndt" > wrote in
:

> "Jorge R. Frank" > wrote in message
>
>> "Tristaine Brahms" > wrote in
>
>> > If so, would it have been thought serious enough to warrant a TAL
> abort?
>>
>> Only if you want to kill the crew quicker. The reentry heating for a TAL
>> abort is about as bad as that for a nominal entry.
>
> ECAL? I can't recall offhand what the boundaries are.

Tough call. I suppose you can "force" an ECAL any time prior to the single
engine TAL boundary by manually shutting down two SSMEs, but that sounds a
little drastic...

Besides, isn't ECAL still considered a contingency abort, and therefore
lower in priority than all the intact aborts, including RTLS? RTLS would be
a tough enough call as it is; imagine the pucker factor...


--
JRF

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[Roger Balettie]

"Jon Berndt" > wrote:
> In any case, I would think that snap abort decisions based
> on feared debris strike damage would be a tricky thing.

That's the bottom line... and the answer would be "no".

As you point out, any ascent abort involves serious risk. The trick is to
weigh (in realtime) the risk of the perceived event (visualized only by a
grainy and vibrating camera) against the long-studied risks of an ascent
abort and subsequent landing. Unless there was some significant telemetric
evidence of a problem, an abort would most likely not be called for such an
event.

Roger
--
Roger Balettie
former Flight Dynamics Officer
Space Shuttle Mission Control
http://www.balettie.com/

[Greg D. Moore \(Strider\)]

"Roger Balettie" > wrote in message
. ..
> "Jon Berndt" > wrote:
> > In any case, I would think that snap abort decisions based
> > on feared debris strike damage would be a tricky thing.
>
> That's the bottom line... and the answer would be "no".
>
> As you point out, any ascent abort involves serious risk. The trick is to
> weigh (in realtime) the risk of the perceived event (visualized only by a
> grainy and vibrating camera) against the long-studied risks of an ascent
> abort and subsequent landing. Unless there was some significant
telemetric
> evidence of a problem, an abort would most likely not be called for such
an
> event.

Makes sense. When one thinks about it. Orbit is a rather benign
environment compared to re-entry.

In orbit you have plenty of time to do things. As long as you're not losing
life support, it seems to me that orbit is a much better abort option at
some point.

That way if you DO have a massive strike, you proceed uphill, check it out.
EVA if necessary and then take time to plan your contingencies.


>
> Roger
> --
> Roger Balettie
> former Flight Dynamics Officer
> Space Shuttle Mission Control
> http://www.balettie.com/
>
>

[Allen Thomson]

"Greg D. Moore \(Strider\)" > wrote

> Makes sense. When one thinks about it. Orbit is a rather benign
> environment compared to re-entry.

Speaking of that, what's the thermal environment during a
trans-Atlantic abort like compared to normal orbital reentry?

[Boris Nogoodnik]

"Jon Berndt" > wrote in message
...
> "Jorge R. Frank" > wrote in message
>
> > "Jon Berndt" > wrote in
>
> > > ECAL? I can't recall offhand what the boundaries are.
> >
> > Tough call. I suppose you can "force" an ECAL any time
prior to the
> single
> > engine TAL boundary by manually shutting down two SSMEs, but
that sounds a
> > little drastic...
> >
> > Besides, isn't ECAL still considered a contingency abort,
and therefore
> > lower in priority than all the intact aborts, including
RTLS? RTLS would
> be
> > a tough enough call as it is; imagine the pucker factor...
>
> ECAL (East Coast Abort Landing) is more desirable than RTLS,
when it is
> possible. I believe it is only possible on high inclination
launches (ISS).
> Also, depending on if you launch at the beginning of a window
(prior to
> in-plane) or at in-plane or later towards the end of the
window, some ECAL
> sites may be unreachable, if I am not mistaken. However, I am
wondering if
> that could be fixed by launch profile design.
>
> In any case, I would think that snap abort decisions based on
feared debris
> strike damage would be a tricky thing. If there was good
RocketCam type
> footage and a much improved ground-based coverage during
ascent, it could be
> good. But calling for an abort entials risk in itself of
course, and
> reflight. How do you judge in realtime something like that
and arrive
> quickly at the "right" answer - the one that provides the
lowest overall
> risk?
>
> Jon
>
>

Don't you think that may be some sensors can do a better job
monitoring structural integrity? And if I remember it
correctly, cameras were mounted on SRBs (?). Actually SRBs look
like a better place for them.

And a question about abort while in the atmosphere. Orbiter
designed to separate in space with the ET empty and engines off.
How risky is separation during early stages of accent? I am
sure they thought about it, but nobody ever done it before.

[Michael R. Grabois ... change $ to \s\]

On 9 Jul 2003 12:41:16 -0700, (Allen Thomson) wrote:

>"Greg D. Moore \(Strider\)" > wrote
>
>> Makes sense. When one thinks about it. Orbit is a rather benign
>> environment compared to re-entry.
>
>Speaking of that, what's the thermal environment during a
>trans-Atlantic abort like compared to normal orbital reentry?

Roughly the same. On a TAL you get up into the 3-400kft altitude range, above
any significant atmosphere. The period of peak heating on a TAL vs NEOM
(Nominal End Of Mission) is similar.

[Michael R. Grabois ... change $ to \s\]

On Wed, 09 Jul 2003 21:18:52 GMT, "Boris Nogoodnik" > wrote:

>Don't you think that may be some sensors can do a better job
>monitoring structural integrity?

The problem isn't so much of embedding sensors all over the place, it has to do
with the bandwidth of the data being transmitted to the ground. With all the
telemetry that MCC requires, there's literally no room for other information in
the data stream. There are many parameters that MCC would see while the shuttle
is in orbit that it doesn't even see during ascent because there's so much SSME
data, for example.

>And if I remember it
>correctly, cameras were mounted on SRBs (?). Actually SRBs look
>like a better place for them.

The camera we saw a few missions ago was mounted on the ET. In fact, I think it
even looked down on the right bipod area.

>And a question about abort while in the atmosphere. Orbiter
>designed to separate in space with the ET empty and engines off.
>How risky is separation during early stages of accent? I am
>sure they thought about it, but nobody ever done it before.

Very risky, probably unsurvivable. The maneuver is called "fast sep" and
involves getting the orbiter off the ET/SRB stack at once. The risk of
recontact is apparently quite high. However, an uncertain death beats a certain
death all the time, so it's theoretically available.

[Jorge R. Frank]

(Allen Thomson) wrote in
om:

> "Greg D. Moore \(Strider\)" > wrote
>
>> Makes sense. When one thinks about it. Orbit is a rather benign
>> environment compared to re-entry.
>
> Speaking of that, what's the thermal environment during a
> trans-Atlantic abort like compared to normal orbital reentry?

About the same, order-of-magnitude wise.

--
JRF

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check "Organization" (I am not assimilated) and
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[Jorge R. Frank]

"Boris Nogoodnik" > wrote in -
russian.org:

> Don't you think that may be some sensors can do a better job
> monitoring structural integrity?

Unless you just concentrate on a few areas (and there you fall into the
trap of "re-fighting the last war"), you're talking lots of sensors, lots
of weight, and lots of bandwidth to telemeter it all down.

> And if I remember it
> correctly, cameras were mounted on SRBs (?).

There have been flights with cameras on the SRBs, as well as one flight
with a camera on the ET.

> Actually SRBs look
> like a better place for them.

The SRB camera views I've seen were only useful post-SRB sep; they were too
close to the ET to see much of it. So they wouldn't provide good views of
debris shedding.

> And a question about abort while in the atmosphere. Orbiter
> designed to separate in space with the ET empty and engines off.
> How risky is separation during early stages of accent? I am
> sure they thought about it, but nobody ever done it before.

Possible (it's called "fast sep") but extremely hazardous, especially
during first stage. You'd do it only if the alternative was certain death.

--
JRF

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[Diane Wilson]

In article >,
says...
> "Brian Gaff" > wrote
>
> > Hmm, I somehow doubt if any normal camera shot would have shown
> > the problem. Seems to me that the panel or seal was cracked
> > and not dislodged until later in the mission.
>
> A couple of months ago there was mention of a left-wing internal
> temperature rise seen in the instrumentation recorder data just
> after the foam strike. I haven't seen anything more on it, but
> would think it's more consistent with an actual hole letting in
> aerodynamic heating, er, heat than just a crack.
>
The last I saw on this sensor reading was that it was too small
to draw any strong conclusions from, and it was in a range where
the sensor did not have good sensitivity anyway.

They may revisit this data now that we've seen a demonstration
of how big a whole can be blown in an RCC panel. On the other
hand, the aerodynamic environment at impact time was past
max Q, and at much lower speed, so the amount of heating would
still be very much open to question---especially since part of
the RCC debris may not have detached until day 2.

Diane