Shuttle TPS tiles dinged

On 21.5.2011 10:24, Pat Flannery wrote:
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?

There is a good plan to return the crew with Soyuzes as soon as
possible, and that has been agreed with the Russians for STS-135.

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.

The above plan does fulfill the intentions of CAIB. Night launches were
only approved after it was proven that the on-orbit inspection results
(OBSS and RPM) will catch all dangerous damages, and the engineering
data on the tank foam shedding performance was collected. I see no
problem with this, from a safety standpoint.

--
Mika Takala

On 22.5.2011 21:50, Pat Flannery wrote:
As far as the last mission goes, it's not a problem.
However on the ones prior to that, seeing in detail what went wrong
during ascent could mean that you could spot a problem that needs to be
corrected on the rescue mission, so that it doesn't occur on that one also.
The last thing you would want is two Shuttles marooned in orbit.


Yep, but the ET umbilical well has also been equipped with a digital
camera and a flash unit, so footage of the ET and where the foam has
been lost, is available also for those occasions where there is a night
launch. Also, if the launch is at night, the ET is photographed by the
astronauts, and the foam losses can be documented that way. And those
could occur at daytime on a night launch, mind you.

Its all good to have all kinds of cameras looking at the launch, and
even better if its a daytime launch, but only the information about the
foam losses (where and when) is important - the rest is just "nice to
have". 'When' -part is only important during the time from liftoff to
around 2 minutes, where a piece of foam could cause damage (there is no
atmosphere to slow the foam down to hit the shuttle at any significant
speed after that), and that can be seen by the ET and SRB cameras even
at night conditions. Don't forget that NASA also has X-band radars to
look at foam shedding. 'Where' is easily obtainable by the ET umbilical
well and crew handheld cameras.

--
Mika Takala

On 5/22/2011 2:03 AM, Mika Takala wrote:

The above plan does fulfill the intentions of CAIB. Night launches were
only approved after it was proven that the on-orbit inspection results
(OBSS and RPM) will catch all dangerous damages, and the engineering
data on the tank foam shedding performance was collected. I see no
problem with this, from a safety standpoint.

As far as the last mission goes, it's not a problem.
However on the ones prior to that, seeing in detail what went wrong
during ascent could mean that you could spot a problem that needs to be
corrected on the rescue mission, so that it doesn't occur on that one also.
The last thing you would want is two Shuttles marooned in orbit.

Pat

On 21.5.2011 10:24, Pat Flannery wrote:

The CAIB said there should always be a rescue Shuttle ready to go on any
flight.

The CAIB recommended no such thing. They recommended in-flight repair
capability (R6.4-1) but made no recommendations on rescue. NASA
implemented LON rescue as part of its "Raising the Bar" effort.

and the ban on night and cloudy day launches
so ascent damage could be observed,

Not only did the CAIB *not* recommend such a ban, I have it straight
from the panelist who wrote the ascent imagery recommendation (R3.4-1)
that it was very carefully worded not to even *imply* such a ban, and he
was surprised that NASA implemented one anyway for the first few flights
as part of "Raising the Bar".

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.

Someone badly needs to read the CAIB report, slowly, for comprehension.

For convenience, all the recommendations are collected in Chapter 11,
starting on page 225.

On 05/22/2011 04:20 AM, Mika Takala wrote:
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.

That's right. Once the CSCS duration of the shuttle-ISS stack exceeded
the interval between launches, and NASA decided to launch rescue flights
with the nominal payload complement, the need for separate STS-3xx
designations went away. It came back for STS-335 because it started out
as a rescue-only mission.