How to Fix the Foam?

[For background haller`s link (thank you!)]
http://www.orlandosentinel.com/news/...home-headlines

.... the agency is quietly acknowledging that there's no way it can prevent
debris from hitting the orbiters. Engineers now are trying to decide what
kinds of strikes -- and how much damage -- is acceptable.
....
But a NASA manager, who would speak only if he weren't identified,
acknowledged that agency personnel are worried about the appearance of
accepting some debris hits -- particularly in the wake of the Columbia
disaster.

"Nobody has a problem with it technically, but a lot of people are
concerned about it politically," the manager said.

[Good God. I read it four times, still shaking my head. Anyone
got it better?]

....

In 1988, shuttle Atlantis was raked with a hardened insulating material
that broke off the nose cone of a solid rocket booster. It sustained 707
hits, with 298 an inch or larger that required extensive repair. One
insulating tile was knocked off, and the orbiter's metal skin was partly
melted.

"It looked like we had been shotgun-blasted," said retired astronaut
Robert "Hoot" Gibson, who commanded that flight, recalling video images
taken of the damage from the shuttle's robot arm while Atlantis was in
orbit. "I looked at those pictures and said 'We are going to die' to myself."

Gibson said the reaction from mission managers was not what he expected.

"They said, 'OK, you guys. We've looked it all over. No problem; normal
re-entry.' "

In 1997, Columbia landed with 308 foam hits and gouges. Engineers blamed
a new foam formula.

....

Then, last October, a large chunk of foam fell off the tank during the
launch of Atlantis and dented the lower portion of a solid rocket booster.
The foam came off the so-called "bipod ramp," a hand-done buildup that
protects the area where the shuttle mates with the tank. The size of the
chunk worried NASA engineers -- but their concern vanished when Discovery
launched without incident the next month.

So when Columbia was hit by foam that detached from the same region of
the tank, there was little alarm.

"My understanding is that ultimately every person that we are aware of,
every single person and individual and group and part of the team in
the organization, was in agreement that we didn't have a safety-of-flight
issue," LeRoy Cain, Columbia's launch and landing director, told reporters
last week.

....

NASA managers are promising that a similar chunk of foam won't come off
again.
....

Paul Czysz, a professor emeritus of aerospace at St. Louis University,
said NASA's priority should be to stop all debris from hitting shuttles
rather than deciding which hits are acceptable and which should be
prevented.

"I think that's an exercise in futility," he said. "I think they ought
to kick themselves in the hind end and solve the problem by not letting
stuff fall on the shuttle."

end
-----------------------------------


Well, I see several ways to look for a fix:

1. Build a modern ET by state of the art material (those foam was from the
1960s Saturn V, today microspheres are much better) with insulation
inside the hull. Ok, takes two years at least.

2. Mix foam with fibres or spray some fibres atop the foam. Or put a fiber
laminate atop the foam. Ok, if you have to keep the same mass you loose
thermal insulation. But the only duty of the foam is to prevent ice
accumulation, not to prevent LH2/LOX boiling. Some IR beamers at the
pad could keep the ET surface above freezing.

3. Launch without any insulation. Keep one at the pad what falls away at
lift off. If this was gaseous capsuled there would be no ice in the
insulation what possibly hits the shuttle at very slow speed. Could work.
During ascent the ET would generate a snow trail. Because of high vibration
no real chunks of ice expected. If the snow still shaves the tiles (I think
so) a metal or composite solid wind-sheet one meter (or less) atop the tank
covering the shuttle side could help.

Well, 1) is a certain one, 2) a fast one and 3) difficult but promissing a
lighter tank then before perhaps.

Any more suggestions?


## CrossPoint v3.12d R ##

On 28 Jul 2003 09:20:00 +0200, wrote:

Any more suggestions?

Ummm... http://cbsnews.cbs.com/network/news/space/current.html
07:15 p.m., 07/11/03, Update: Final CAIB news conference:

NASA engineers now plan to launch future shuttles without any such
foam insulation, using heaters instead to prevent ice buildups before
launch.

"No shuttle is going to fly with a bi-pod ramp again, so you're not
going to see this happen again, I don't think," Gehman said.

--
Dave

Can they fix the last astronaughts?
wrote in message
news:am9obmNvbGQ=.9cb0cd000dcfb33df866aaa368bbf38f @1059521597.cotse.net...
Foam? They'd better wait about another century. Maybe then they'll
have something stronger than Elmer's Glue to hold the **** together.

wrote:

[For background haller`s link (thank you!)]
http://www.orlandosentinel.com/news/custom/space/orl-
asecdebris27072703jul27,0,3462010.story?coll=orl-home-headlines

.... the agency is quietly acknowledging that there's no way it can
prevent
debris from hitting the orbiters. Engineers now are trying to decide
what
kinds of strikes -- and how much damage -- is acceptable.
....
But a NASA manager, who would speak only if he weren't identified,
acknowledged that agency personnel are worried about the appearance of
accepting some debris hits -- particularly in the wake of the Columbia
disaster.

"Nobody has a problem with it technically, but a lot of people are
concerned about it politically," the manager said.

[Good God. I read it four times, still shaking my head. Anyone
got it better?]

....

In 1988, shuttle Atlantis was raked with a hardened insulating
material
that broke off the nose cone of a solid rocket booster. It sustained
707
hits, with 298 an inch or larger that required extensive repair. One
insulating tile was knocked off, and the orbiter's metal skin was
partly
melted.

"It looked like we had been shotgun-blasted," said retired astronaut
Robert "Hoot" Gibson, who commanded that flight, recalling video
images
taken of the damage from the shuttle's robot arm while Atlantis was in
orbit. "I looked at those pictures and said 'We are going to die' to
myself."

Gibson said the reaction from mission managers was not what he
expected.

"They said, 'OK, you guys. We've looked it all over. No problem;
normal
re-entry.' "

In 1997, Columbia landed with 308 foam hits and gouges. Engineers
blamed
a new foam formula.

....

Then, last October, a large chunk of foam fell off the tank during the
launch of Atlantis and dented the lower portion of a solid rocket
booster.
The foam came off the so-called "bipod ramp," a hand-done buildup that
protects the area where the shuttle mates with the tank. The size of
the
chunk worried NASA engineers -- but their concern vanished when
Discovery
launched without incident the next month.

So when Columbia was hit by foam that detached from the same region of
the tank, there was little alarm.

"My understanding is that ultimately every person that we are aware
of,
every single person and individual and group and part of the team in
the organization, was in agreement that we didn't have a safety-of-
flight
issue," LeRoy Cain, Columbia's launch and landing director, told
reporters
last week.

....

NASA managers are promising that a similar chunk of foam won't come
off
again.
....

Paul Czysz, a professor emeritus of aerospace at St. Louis University,
said NASA's priority should be to stop all debris from hitting
shuttles
rather than deciding which hits are acceptable and which should be
prevented.

"I think that's an exercise in futility," he said. "I think they ought
to kick themselves in the hind end and solve the problem by not
letting
stuff fall on the shuttle."

end
-----------------------------------


Well, I see several ways to look for a fix:

1. Build a modern ET by state of the art material (those foam was
from the
1960s Saturn V, today microspheres are much better) with insulation
inside the hull. Ok, takes two years at least.

2. Mix foam with fibres or spray some fibres atop the foam. Or put a
fiber
laminate atop the foam. Ok, if you have to keep the same mass you
loose
thermal insulation. But the only duty of the foam is to prevent ice
accumulation, not to prevent LH2/LOX boiling. Some IR beamers at the
pad could keep the ET surface above freezing.

3. Launch without any insulation. Keep one at the pad what falls away
at
lift off. If this was gaseous capsuled there would be no ice in the
insulation what possibly hits the shuttle at very slow speed. Could
work.
During ascent the ET would generate a snow trail. Because of high
vibration
no real chunks of ice expected. If the snow still shaves the tiles (I
think
so) a metal or composite solid wind-sheet one meter (or less) atop
the tank
covering the shuttle side could help.

Well, 1) is a certain one, 2) a fast one and 3) difficult but
promissing a
lighter tank then before perhaps.

Any more suggestions?


## CrossPoint v3.12d R ##