| Saturday,
February 1, 2oo3
This got posted pretty much immediately on
FreeRepublic, and wouldn't be a bad thing to consider on your site.
God rest their souls.
Jim Riticher
The Green Hills Of Earth, Thread for The Shuttle.:
http://www.freerepublic.com/focus/news/833933/posts
The Green Hills of Earth
Let the sweet fresh breezes heal me
As they rove around the girth
Of our lovely mother planet
Of the cool, green hills of Earth.
We rot in the moulds of Venus,
We retch at her tainted breath.
Foul are her flooded jungles,
Crawling with unclean death.
[ --- the harsh bright soil of Luna ---
--- Saturn's rainbow rings ---
--- the frozen night of Titan --- ]
We've tried each spinning space mote
And reckoned its true worth:
Take us back again to the homes of men
On the cool, green hills of Earth.
The arching sky is calling
Spacemen back to their trade.
ALL HANDS! STAND BY! FREE FALLING!
And the lights below us fade.
Out ride the sons of Terra,
Far drives the thundering jet,
Up leaps a race of Earthmen,
Out, far, and onward yet ---
We pray for one last landing
On the globe that gave us birth;
Let us rest our eyes on the friendly skies
And the cool, green hills of Earth.
Robert A. Heinlein
Thank you. That was the old solar system,
and the explorers were more bold than we are today. Or perhaps we were
past The Crazy Years, and understood why it is important to look beyond
the next mountain.
I suppose you've heard by now about Columbia.
Jerry, I've been a NASA fan since I was two; seeing
Apollo 11 sitting on the pad is my first memory. I worked on NASA projects
like my father before me; he tracked Mercury, Gemini, and Apollo thru 13,
and I was on UARS and helped with a couple others...
Tell them we have to go on. Make sure all of fandom
pounds the hell out of their congresscritters to make sure a space
program, be it public or private, is not only going to continue, but
expand. No terrorist, no bureaucrat, no accident should get in the way.
Sure, we should make it as safe as we can... but this stuff happens, and
we learn from it... but we must go on. I don't think the seven who died
this morning would have it any other way.
-- Glenn Stone who would like to make orbit just
once... -- "History will remember the inhabitants of this century as
the people who went from Kitty Hawk to the moon in 66 years, only to
languish for the next 30 in low Earth orbit. At the core of the risk-free
society is a self-indulgent failure of nerve." -- Buzz Aldrin, Apollo
11 astronaut
Of course we have to go on. And we will. The
language spoken in space is not yet determined, but it is certain that
mankind will be there. To the Moon, to the planets, and to the stars. That
is our destiny, even if this generation doesn't know it.
Just heard Dan Rather on CBS saying how many of us
had been hoping to see men on Mars in our lifetimes,and asked a Nasa suit
if this would be a setback.
She said that Mars had never been a nasa project,
and Mars may never happen in our lifetimes.
Dan Rather said, "well some of us will continue
to dream."
Robert A Pierce
It is hardly surprising. Dan Rather and the media
people have more imagination than nearly all of NASA. Fortunately NASA is
no longer thought infallible and there may be alternatives: although NASA
relentlessly grinds down and destroys all rivals, and devotes more effort
to that than to getting us to space. There remain a few people in NASA who
are there to accomplish great things; but most of NASA now consists of the
people who accomplished the extraordinary feat of making mankind's
greatest achievements look dull, then making it impossible to repeat them.
Yet what man has done man can aspire to.
An open letter to the
President:
Mr. President,
I am a graduate of the United States Air Force
Academy, class of 1994, and I am writing to you to urge you to continue to
support our nation's manned space flight program. There will be pressures
on you to slow down or stop funding for the obviously dangerous business
of manned space flight, but you must not let this happen.
I am a fighter pilot for the USAF currently
finishing up a tour of duty as a T-37 instructor, and I am fully aware of
the hazards faced by people in flying and space related jobs. Those who
died today also knew the risks, and they dared to fly despite them because
the benefits to our nation and to all nations of the world outweigh the
risks. We are a pioneering nation and must continue to lead the way in the
ventures that are dangerous, because only those who dare greatly can ever
hope to succeed in great things.
Please don't let the Columbia crew mark the end of
our space program. Instead, let their sacrifices be a call to an even
louder call to greatness. This nation owes much to the scientific
discoveries produced by NASA and it's people, and we owe it to them and
ourselves to fully fund the manned space flight program lest it die and
the pace of scientific advances die with it.
An underfunded manned space flight program is a
dangerous program. This should be clear at this point. Please do what is
necessary to ensure that our country does not act the part of the cowards,
afraid to grasp at the heights of human accomlishments.
Respectfully,
Sean A. Long, Capt, USAF
Which pretty well says it all.
Dan Spisak has put this together:
Jan 27, 1967: Apollo 1 fire http://www.hq.nasa.gov/office/pao/History/Apollo204/
Jan 28, 1986: Challenger explosion http://www.fas.org/spp/51L.html
Feb 1, 2003 Columbia breakup http://www.cnn.com/2003/TECH/space/
02/01/shuttle.columbia/index.html
If a heat shield tile indeed had been damaged on
launch is there a contingency plan for having a heat shield tile replaced
in orbit before deorbit?
I get the feeling that if a heat shield tile was
damaged anyone in the shuttle would have to just "ride it out"
and hope it wasn't serious enough damage. Am I right in this assumption?
-Dan S.
I don't know what might be done if we knew a
shuttle tile was damaged. Go back and dock with the space station while
new repair materials are assembled and sent up, I would suppose.
We have not developed much in the way of in-orbit
assembly, largely because we insist on sending up tired old men and women
rather than vigorous young riggers. You don't get to space until you're
over 40 and have a Ph.D., and that isn't conducive to going out and
working your tail off in tough conditions for 12 hour shifts. Pete Conrad
went out and fixed Skylab, but that was a long time ago, and NASA
carefully took a second operational Skylab and put it in the Smithsonian,
and laid the most powerful machine mankind ever made down on its side as a
lawn ornament: lest Shuttle be endangered, and some of the senior NASA
people be laid off.
There are probably contingency plans for known
tile damage but I don't know them.
Mr. Pournelle
It puzzles me to see you suggest that a damaged
Columbia could have been sent to the ISS. The Columbia is the only shuttle
not equipped for docking to the ISS. The other 3 have been modified for
ISS missions by relocating the airlock into the cargo bay while the
Columbia maintains the airlock in the crew compartment. Also, no docking
mechanism was installed in the cargo bay of Columbia as in the other 3.
Lastly, there is no way the shuttle could reach the orbital inclination of
the ISS as it was launched in a completely different trajectory.
The only plausible solution would have been a rescue
mission but logistics keep that option nearly impossible due the the 20
day timeframe required.
Chad Brink [cbrink@sio.midco.net]
Why should you be puzzled? I haven't worked on
those programs for twenty years and more, and I had forgotten. I don't
pretend to infallibility.
Space
Station is still a convenient place to rendezvous and there are certainly
automatic docking systems launched out of Russia: if repair materials were
needed, I would think that it would be easier to get everyone near ISS
than try to do the job in some other orbit. Clearly I haven't done an
actual examination of the orbital inclinations. I am aware that changing
orbit plane is a very delta-vee expensive operation.
I confess I have not been following these missions at
all. Surely SOME shuttles get to ISS? Or have I just been imagining that
the main job of Shuttle is support of ISS and the main demand of ISS is to
absorb shuttle missions? I admit confusion: I presume you know more than I
do on this, and I don't just now have time to look it up.
I do know that after Challenger a number of us
tried to convince the Congress to let North American build a new shuttle
on designs influenced by the problems of the old one, but NASA insisted we
just copy the old systems, warts, defects, and all.
More on Fixing things in orbit: see
below.
Dear Dr Pournelle "Dan
Spisak has put this together:... If a heat shield tile indeed had been
damaged on launch is there a contingency plan for having a heat shield
tile replaced in orbit before deorbit?
I get the feeling that if a heat shield tile
was damaged anyone in the shuttle would have to just "ride it
out" and hope it wasn't serious enough damage. Am I right in this
assumption?
On breaking news this morning the NASA spokesman was
asked essentially this question and one other involving voice recorders I
think... he was barely holding himself together - managed to answer the
voice recorder question ('we do have them but not hardened') and
remembered there was another but not what it was. He confirmed that there
were no options. No EVA was possible; Colombia was not equipped with a
robot arm on this mission; and there was no capability for reviewing the
left wing; even had a distressed tile been evident, there was no
'capability' to repair it.
My deepest condolences, TC
-- Terry Cole BA/BSc/BE/BA(hons) (tcole@maths.otago.ac.nz)
System Administrator, Dept. of Maths. & Stats., Otago Uni. PO Box 56,
Dunedin, NZ.
So: what must be done?
Dear Dr. Pournelle -
I just saw the news that the Shuttle Columbia is
down in Texas - what am I saying? - that the Shuttle Columbia came apart
during reentry. That the seven astronauts have died. May the Good Lord
have Mercy on their souls, and that they will fly with the angels.
What must be done? Why do we put up with a system
that makes compromises and
I'm sick and tired of NASA. I've been reading your
site for a few years now whenever I get a chance, which is less that I'd
like it to be. I'm sick and tired of bureaucracy and vested interests
being in the way of doing things the right way, of vested interests and
bureaucracy being in the way of reaching the dream. What will this
terrible, terrible accident mean for manned space flight? It means that no
shuttle will fly until everything' s been checked and rechecked and
analysed to the ninth sigma; it means that the Shuttle has to be phased
out and that we have to start doing things right!
I'm an economist and I don't understand the business
of space. I've tried and tried and tried and it just doesn't make sense
economically. It just makes no sense to create high valued equipment and
then just throw it away (one-use rocket engines). It makes no sense to try
for the very, very best when the adequate will do when dealing with
non-human space flight, and it makes no sense not to have the very, very
best when dealing with human space flight. It makes no sense to compromise
on human safety in order to transport satellites into space, it makes no
sense to rely on what essentially is a truck when what we need is an
airplane.
Now, this doesn't mean that space flight can't be
economical! But let's be completely honest: NASA can't do it. NASA is not
equipped to run a space transportation service. NASA is caught in a web of
its own weaving, a web of old technology, contradictory missions and too
damn many people trying to have a part in manned space flight.
It doesn't mean that NASA never can run a space
transportation service, it doesn't mean that NASA can't regain the
priorities it should have.
Here are my thoughts on what needs to be done:
1. We have to reduce the cost per pound into space.
Let's get the Russians back on board and have them restart their assembly
line of those basic, simple rockets for getting bulk up there. I keep on
reading about how western scientists are always amazed with what simple
technology and methods the Russians place their payloads on time and on
target: let's get the prices down by mass production, not a rocket a
month, but rather 100 a year or 1000 a year. This is for basic launching
and development. For national security launches you freeze the current
booster technology for interim purposes.
2. We have to separate satellite and human
transportation. Human space flight needs to be without compromises,
without accepting that there is a residual risk due to the need to take up
significant resources that don't need to be transported with the
astronauts. Design a new spacecraft that deserves the name, with module
designs that allows updates and modifications for efficiency and safety
without having to completely rebuild the shuttle.
3. We can never, ever, ever place our eggs in one
basket. There needs to be at least three designs: one for 3-5 people up to
the space station and back down again within a few days; one for 3-5
people up into orbit and stay there for a while to service satellites and
whatever; one for 50 people for space tourism and for national security
reasons. The first two can be similiar, the last will be the first
commercial space vehicle.
4. We have to take bulk space flight away from NASA
and place it firmly in the commercial realm. No subsidies, no insurance,
no tax breaks: the cold hard rules of commerce have to push the price of
getting a pound in space down. If the Chinese or the Russians can do it
cheaper, than they will be the launchers, just like the South Koreans
build the world's shipping. I know that there are arguments against this,
but we have to get the damned pork out of launch vehicle development and
back into efficiency. We need to get the engineers back in charge of doing
the job, but on a budget (Ariane is also a great example of what goes
wrong
5. We have to turn around NASA and get it back in
the business of technology development and providing for the
infrastructure of doing science in space. Why should NASA do anything but
work as a clearing house for technology, financing key developments that
no one company can afford to do so (or where NASA doesn't want any one
company to have a monopoly to drive prices up); NASA should be
coordinating development, but with the goal of creating a space industry,
of getting humanity into space.
I've said enough now. I'm going to put my thinking
cap on and try to understand how we can honor those who have died today by
making space transportation economical and feasible.
Best regards on this gloomy of days... - John F.
Opie Senior Economist Feri Resarch GmbH
I can solve the space access
problem with a few sentences.
Be it enacted by the Congress of the United
States:
The Treasurer of the United States is directed to
pay to the first American owned company (if corporate at least 60% of the
shares must be held by American citizens) the following sums for the
following accomplishments. No monies shall be paid until the goals
specified are accomplished and certified by suitable experts from the
National Science Foundation or the National Academy of Science:
1. The sum of $2 billion to be paid for
construction of 3 operational spacecraft which have achieved low earth
orbit, returned to earth, and flown to orbit again three times in a period
of three weeks.
2. The sum of $5 billion to be paid for
construction and maintenance of a space station which has been
continuously in orbit with at least 5 Americans aboard for a period of not
less than three years and one day. The crew need not be the same persons
for the entire time, but at no time shall the station be unoccupied.
3. The sum of $12 billion to be paid for
construction and maintenance of a Lunar base in which no fewer than 31
Americans have continuously resided for a period of not less than four
years and one day.
4. The sum of $10 billion to be paid for
construction and maintenance of a solar power satellite system which
delivers at least 800 megaWatts of electric power to a receiving station
or stations in the United States for a period of at least two years and
one day.
5. The payments made shall be exempt from all US
taxes.
That would do it. Not one cent to be paid until
the goals are accomplished. Not a bit of risk, and if it can't be done for
those sums, well, no harm done to the treasury.
I had Newt Gingrich persuaded to do this before
he found he couldn't keep the office of Speaker. I haven't had any
audiences with his successors.
Henry Vanderbilt points out that having a prize,
say $1 billion, for the second firm to achieve point (1) above will
get more into the competition, and produce better results. I agree. For
more on Prizes see next week.
Mr. Pournelle:
What is wrong with NASA, what must be done to fix
it, idle speculation on the cause, etc. will all have its day. Perhaps we
could wait a day or two. I think today should be reserved for respect and
honor of the dead. Bureaucracy will still be with us tomorrow and can be
tackled then. Whether you wish to edit your "current mail" is
your prerogative of course, but I would hope it is not how you would want
today remembered.
Thank you for your courtesy,
Richard Micko rmicko@clipperinc.com
That is one view. But while people are thinking
about the subject, perhaps a better way to honor heroes is to try to
accomplish their work. It's what we did back in the days when we'd name a
new street at the base and fly the next day. And we have waited far too
long to fix the dream.
And we have this:
BTW, I do know the Columbia was refurbished with
new, improved tiles. I was wondering if the cause of the disaster is new
parts badly installed. Perhaps your more knowledgeable readers can
comment.
Oleg
Dear Dr Pournelle:
Back in the '80s I worked for the Industrial
Measurement Technology division of Carl Zeiss, Inc. The company made the
highest end of high-end Coordinate Measuring Machines (CMMs). CMMs
automatically measure three-dimensional parts and Zeiss' was the best at
measuring complex three-dimensional contours such as those of aircraft
wings and (aircraft and ship) propellers. You got what you paid for.
The skin of the space shuttle's orbiter is covered
with refractory tiles. Since the surface of the orbiter is of a complex 3D
contour, each tile has to be machined to match the specific place where it
will be positioned.
One of our salesman complained that they (I don't
recall now if he named NASA, the contractor or whether he used just the
generic 'they') decided to go with an less expensive CMMs. According to
him, the refractory tiles were measured at three points, and if those
three point were within tolerance, it was assumed that the fit was was
good.
I offer this for what it is worth. Caveat lector.
I know not one thing about this. I haven't looked
at space operations in any detail since Reagan left the White House.
An eyewitness acoount:
I watched the reentry from Mojave, CA at about 0553
this morning. Although there was some light haze (clearly visible when
viewing Venus and Jupiter with 10x50 binoculars while waiting for the
event), I was able to see an orange dot leaving a glowing trail behind it.
At about the time of closest approach [about 220 miles according to
published data] the brightness flared for an instant and a small speck
(possibly a tile?) came away from the main body, drifting backwards
relative to it. Over about ten seconds, it dimmed and went out, then
perhaps thirty seconds later the shuttle flared again but no debris was
visible. It appeared intact until I lost sight of it in the dawn glow a
minute later.
No commentary, just the facts (or speculation) as I
saw them...
-- Doug Jones, Rocket Engineer XCOR Aerospace
Does anyone know (1) the cohesion strength of
shuttle tile, and (2) the stagnation temperature about mach 25 which is
about what they'd be doing when you saw that? Stony asteroids come in and
when the front pressure exceeds their strength of cohesion they break up
so that all the energy is released at one whack: often kilotons of energy
as in Tunguska.
If the shuttle tiles are strong enough -- they
can't burn since they are a ceramic -- then there may be pieces strewn
across the country from Marin County CA to Fort Worth.
It wouldn't take many pieces of tile breaking
loose to cause severe control problems, which would get progressively
worse. Clearly they had a lot of time to see this coming.
Hi Jerry-
The sample tiles that I've handled seem plenty
strong enough to survive the mechanical stresses. Consider: they usually
do well even when being dragged along by the mass of the shuttle itself,
instead of being allowed to slow down quickly before the air density
builds up. The compressive strength has to be at least ten psi, so a
single tile could take hundreds of gees without crumbling. If what I saw
this morning was a tile coming loose, it certainly landed intact. Also,
some of the photos of the Texas debris on line appear to be tiles.
-- Doug Jones Rocket Plumber XCOR
So there will be tiles west of Texas, possibly
nust north of Mojave.
And mail on other
subjects...
Dear Dr. Pournelle: Thought you
might be interested in this review: http://206.183.2.199/Articles/ReadArticle.asp?ID=5826
It's a review of a book on industrial policy - the
short form is that manufacturing IS important. Nothing that you haven't
said, but very neatly summarized.
V/r: Mike McDaniel
Thanks. Manufacturing is extremely important, and
we're losing far too much of it.
On Going to Space
The debate on SSTO (Reusable
space ships, or Single Stage to Orbit) continues. Note that despite the
tone of some of these letters, SSTO is not absurd, and has the support of
many experienced rocket engineers, including the late Max Hunter. For
political reasons NASA has always said it was too silly to study -- else
why hadn't they ever done anything as simple as the DC/X as a research
vehicle?
The report of the Council which recommended X
projects leading to an SSTO vehicle, go here.
The basic rocket equation discussion of the concept is here.
There's math in there, but not too much. The concept of X projects and
their importance for getting to space, look here.
I have repeated this short introduction below.
Eventually I will collect all this material into a single debates or
reports page.
Subject: SSTO, nice idea but impractical
Jerry: I like a lot of your ideas concerning the
privatization of space flight. However, I think trying to build a single
stage to orbit vehicle using chemical rocket engines is a futile task
because the minimum, theoretical mass ratio of any rocket rises
exponentially with the ratio of delta vee divided by exhaust velocity.
Depending on the aerodynamic characteristics of your vehicle and the
acceleration profile, the delta vee is about 10km/sex. The best
hydrogen-oxygen rocket engines have an exhaust velocity of 460 which would
require a minimum mass ratio of 8.8. Of course this calculation ignores
the mass of rocket engines and structural mass such as fuel tanks. Given
the extremely low density of liquid hydrogen, the tankage mass is going to
be pretty high even if you are using balloon tank construction, much less
the far more robust structure that would be needed for a fly back orbiter.
Alternative fuels such as liquid methane or propane don't have a ISP as
high as hydrogen, but they are a lot less bulky and easier to work with.
These fuels would require a minimum mass ratio of about 20.
While the SSTO vehicle concept is seductive, I
believe that it simply isn't feasible unless we have major advances in
propulsion technology such as a super sonic combustion ramjet which would
have an ISP of a thousand or more because it uses the atmosphere as a a
source of oxidizer. Rather than try to develop a revolutionary STS, lets
try to make evolutionary improvements on the system we've got. The first,
most profitable step would be to replace the SRBs with liquid fueled,
flyback boosters which actually land on NASAs air strip rather than just
falling into the ocean. These modular, fly back boosters would be designed
to have dimensions comparable to the shuttle SRBs so that they could be
used to upgrade the existing STS. Note that these modular, liquid fueled,
flyback boosters could be used to build heavy lift assemblies with two,
four, six or even eight boosters grouped around a payload capsule, liquid
fuel tank, and a set of SSMEs packaged in a reentry vehicle.
Alternatively, one of these fly back boosters could be used to launch a
minishuttle. The next, more obvious step is to build a next generation
orbiter that would also be only an evolutionary rather than revolutionary
improvement over the exhisting orbiter, but would be compatable with the
existing STS.
James
Crawford [mailto:odusprop@earthlink.net]
Well, thank you for showing me that I (and Max
Hunter before he died) have been wasting my time for decades. Will you
forgive me if I point out that it may not be as clear cut as you seem to
think?
Lockheed thought it possible enough to spend
billions. Now the X-33, which was no X program, was a flawed concept. I
knew that at the time, but the only power I had was to be able to kill it,
and had I killed it, it would inevitably have been thought to be the right
way and it would have worked if that S.O.B. Pournelle hadn't killed it. So
I did nothing, and the money was wasted.
But it needn't have been.
Two stages, both recoverable, are one path.
Operationally that is a far more complex route. But the USAF/SDIO Project
Have Region, which was classified but the results were declassified, built
cross sections of structures for a single stage to orbit vehicle and test
their strength; and concluded that the mass ratio needed for an SSTO
vehicle could be achieved with present structure.
As to the rocket equation, please credit me with
knowing what it is. Indeed, my SSX
paper is mostly a reflection on the rocket equation. What we don't
know without further testing is the payload. Start with a 600,000 pound
Gross Liftoff Weight (GLOX : a fully fueled vehicle ready to launch)
Single Stage to Orbit ship. Of that, 90% is fuel and oxidant: it has to be
or it won't achieve orbit. (This percentage may be higher: that's one of
the things we have to learn by flying. It depends on a number of
inter-related factors.) Of the 10% or 60,000 pounds left, about 90%
will be structure, tankage, fairing, landing gear, crew life support,
seats, controls, and enough fuel to get back down. That leaves 10% or
6,000 pounds for payload: useful stuff we wanted to put in orbit. But of
course that is a third decimal place number, and we don't know any of this
to three decimal places: which is why we have to fly some of these birds.
Some believed and a few still believe that the actual payload will be
zero, or even negative (the ship won't make orbit). But then before DC/X many experts said it couldn't be controlled at low speeds:
there wasn't enough control authority in those flaps. That turned out not
to be the case.
It's possible that SSTO can't be made to work;
certainly that was the conventional wisdom until 1986 or so, when a bunch
of us including the Aerospace Corp engineers who told the Air Force SSTO
couldn't be done concluded that we had been wrong: it can be done. We
don't know quite how much payload it may have. Gordon Woodcock played with
the numbers for days, worrying particularly about the rings holding
cylindrical tankage together as weighing too muck, before concluding that
it could be done, and it would have a positive payload; and he signed the report.
When then Vice President Quayle asked us why, if this was the right way to
go, why we hadn't tried it before: "Do you have new engines?" -- Max
Hunter said, "No sir, we weren't smart enough before. Now we
are."
It may be that an SSTO would have to be too big
to have a respectable payload (clearly the larger the ship the more likely
it will be to have a payload at all). We won't know until we fly. The SSX
was intended to let us fly: we could bore holes in the structure where it
was overly strong, and, as Max put it, nickel and dime it into orbit.
At worst we'd know precisely how to design a two
stage to orbit system with both stages recoverable -- which was what
Boeing proposed for solar power satellites some 40 years ago. We knew that
would work then: it will still work now.
One thing DC/X did convince us of was that
hydrogen is an impractical rocket fuel. It's an operational nightmare.
Fortunately, it's possible to use methane, and Max Hunter had converted to
methane or propane before he died. Propane might need a "zero"
stage, probably jet engine powered, to get it to 50,000 feet where the
drag has essentially vanished. A "flying ring" zero stage is not
difficult to design and build. It does add an operations step we'd rather
do without, but it may be needed.
We won't know these things until we fly some
more.
You will excuse me but the notion of trying to
design a new system to use parts of present shuttle strikes me as, uh,
well, highly undesirable, and the kind of thing I expect NASA bureaucrats
to come up with.
The discussion continues below.
On fixing things in orbit,
Peter Glaskowsky observes:
You wrote:
> I don't know what might be done if we
knew a shuttle tile was damaged.
This has happened before. On Columbia's first launch
for STS-1, it lost 16 tiles. At the time, they just went ahead and landed
the thing, and of course it survived. The small tiles are meant to be
individually expendable; losing one or maybe more won't cause the loss of
the vehicle. The large black carbon tiles on the nose and wing leading
edges are not expendable, but the routine inspection on orbit by our
reconnaissance satellites would have detected this sort of problem.
They don't seem to have any good mechanism for
repairing tiles. Going to the ISS probably wouldn't help much, and they
probably don't have enough delta-V to get there on missions like STS-107
that didn't go to the station. I don't think there are enough consumables
in orbit at any given time to support a large Shuttle crew for the time it
would take to scramble a new launch with repair equipment.
. png
and
Notes from the NASA briefing at 12:30pm PST today.
Shuttle program manager Ron Dittemore said flatly,
"We do not have the capability to perform a spacewalk and do tile
repair."
That being said, I suppose the astronauts would put
on a suit and tie on a rope and go out the airlock if they had no other
hope. I don't think they could do anything about a missing tile, but if
one was loose, there might be some theoretical opportunity for improvised
repairs.
Later in the conference, Dittemore said they didn't
request or receive imagery to evaluate the condition of the wing. In a
previous case, on-orbit pictures they received from "other
assets" weren't useful in analyzing the loss of the drag-chute door
during launch.
. png
Apparently they didn't want to know if the tiles
were damaged: there was nothing they could do anyway:
Seven brave souls were lost today as Columbia broke
apart in the Texas dawn, and our hearts go out to the surviving families.
Many Americans take STS operations for granted, and most assume that the
program was "fixed" after the Challenger loss in 1986. NASA?s
afternoon news conference made me realize that this is far from the truth.
Shuttle Program Manager Ron Dittemore made some
startling admissions during the news conference:
1) The shuttle managers were aware of possible
damage to Columbia?s left wing from a piece of insulation shed by the
external tank. Dittemore reviewed the launch tapes and described the
impact as an "explosion" that caused the debris to
"disintegrate into a cloud". Technical analyses were ordered,
and the conclusion? There was no safety issue, only some manufacturing
problems to be resolved.
2) There is no ability to repair missing tiles on
orbit. A missing tile on the underside of the wing or fuselage is a
single-point failure mechanism.
3) Shuttle managers made a decision NOT to image
Columbia on orbit to see if any damage was apparent. The rational for not
investigating or imaging potential damage was that "nothing could be
done about it".
I was stunned by these admissions from high-level
officials. Were they watching the reentry with their fingers crossed? They
knew the left wing was impacted and possibly damaged, and yet they decided
NOT to investigate any further before ordering the deorbit burn.
Incredible.
I fear this is likely the end of our shuttle program
because when politicians realize its reliability is a charade, the funding
will dry up. NASA needs to replace the shuttle with a modern system.
Unfortunately, it took a tragedy like this to make people pay attention.
James McSheehy Grand Junction, CO
I fought for better space suits for many years,
but I could never get an Administrator to put better suits at high enough
priority: Even the good ones fought the alligators rather than drain the
swamp. Without decent EVA suits you can't do on orbit assembly; and
without young and strong riggers going to space you won't get a hard day's
work out of your crew. Forty year old PhD's are just not going to work
that hard in horrible conditions. Depend on it.
If we routinely thought of doing EVA and worked
with 10 to 12 pounds of air rather than 3 pounds of pure oxygen, we'd have
ways to fix such problems.
They didn't want to look because they wouldn't be
able to do anything about it??? That's the wrong perspective. The more
information you collect, the more options you have. Or at least the fewer
questions you have to answer after you fail. Engineering works that way.
(See Henry Petroski's articles and books.)
I guess I've seen that attitude here in the UK. They
often don't test for diseases they won't treat due to budgetary
restrictions. It still seems dumb. -- --- Harry Erwin, PhD, Senior
Lecturer of Computing, University of Sunderland. Computational
neuroscientist modeling bat bioacoustics and behavior. <http://www.cet.sunderland.ac.uk/~cs0her/index.html>
Indeed.
Oh, I have slipped the surly bonds
of earth
And danced the skies on laughter-silvered wings;
Sunward I've climbed, and joined the tumbling mirth
Of sun-split clouds...and done a hundred things
You have not dreamed of...wheeled and soared and swung
High in the sunlit silence. Hov'ring there,
I've chased the shouting wind along, and flung
My eager craft through footless halls of air.
Up, up the long, delirious, burning blue
I've topped the windswept heights with easy grace
Where never lark, or even eagle flew.
And, while with silent, lifting mind I've trod
The high untrespassed sanctity of space
Put out my hand, and touched the face of God.
'High Flight' by John Gillespie Magee, Jr.
Goodbye and Godspeed, crew of Columbia. We will never forget you.
Andy
Amen.
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