LA Times: Critic says Space shuttle is "Inherently Unsafe"

Ian Woollard wrote:

Another subtle problem is that it carries 7 people.

Whilst that doesn't directly affect the death rate, it means that when a
problem is found (aka 'everyone dies') you've lost 7 people. If the
vehicle had the same reliability but only carried 1 person then you've
only lost 1 person; but after you've fixed the
design/operational/manufacturing bug, you can carry on launching, with
improved reliability. By the time you've launched the same number of
people- less people have died.

That's nice, until you consider that one person can't carry out the
typical shuttle on-orbit mission....

Even Columbia's *first* flight had a crew of two.

In sci.space.policy Paul F. Dietz wrote:
Jonathan Silverlight wrote:

I know fluorine is an alternative to oxygen, and probably not as
difficult to keep cold, but I can't see them using it for a shuttle-size
launcher. Are there any other alternatives?

The boiling point of fluorine is *lower* than that of oxygen.
It's not a practical oxidizer for several reasons (cost, reactivity,
toxicity, lack of availability). Other oxidizers have lower
Isp that LOX or higher cost or both.


Didn't Japan have a couple of hydrogen-fluoride rockets? But yes, it is
really nasty stuff and there doesn't seem tobethat many good reasons
to use it

Paul


--
Sander

+++ Out of cheese error +++

Sander Vesik wrote:

Didn't Japan have a couple of hydrogen-fluoride rockets? But yes, it is
really nasty stuff and there doesn't seem tobethat many good reasons
to use it

AFAIK, liquid fluorine has never been used in any deployed rocket system
(chlorine pentafluoride may have been, though.)

Experiments have been performed with fluorine as a propellant
in engines on test stands, including a test of a H2/F2/Li tripropellant
variant of the RL-10 that set a record for Isp.

Paul

In sci.space.policy Joann Evans wrote:
Jonathan Silverlight wrote:

The insulation on the tanks also prevents icing, which is a problem
with any cryogenic propellant, not just hydrogen (consider all the ice
cascading off those old Atlas launchers.)

I know fluorine is an alternative to oxygen, and probably not as
difficult to keep cold, but I can't see them using it for a shuttle-size
launcher.

Or much of anything else, considering that much of the exhaust will
consist of hydrofluoric acid....

No, it will be superheated hydrofluoric acid. So not only will everybody
in a considerable radius need to be wearing a hermetic suit, it needs
to be a special hermetic suit. And there are probably lots of additional
problems with construction materials, unles syou just scratch and rebuild
anything that was on the launch pad.

--
Sander

+++ Out of cheese error +++

On Mon, 01 Sep 2003 00:19:41 GMT, Michael Walsh
wrote:


Liquid Oxygen, a common oxidizer throughout the space launch industry,
must also be insulated.

That just isn't true. Most launchers don't bother to insulate the
oxygen tanks.

Ariane 5 insulates it. Delta IV insulates it. Atlas 5 insulates it.
H-2 insulates it...


Brian

"Richard Schumacher" wrote in message
...
Large solid rocket boosters. In solid rockets the structure of the solid
fuel is crucial, yet it cannot be tested or even adequately inspected
before each use.

X-ray and ultrasonic inspections are used and do the job just fine, thanks.

And, solid boosters of this size cannot be made in one
piece, requiring joints between sections.

A monolithic SRB was pitched by Aerojet that would have used their existing
production facilities. Handling issues were the only stumblers, and they
could have been overcome.

Unpowered gliding landing. A modest wind gust at the wrong moment will
cause the orbiter to break landing gear; at the shuttle's landing speed
this will destroy the shuttle.

Everybody always screams about this, but they never consider the number of
unpowered landings made in the history of flight - most being intentional
and safely completed. There's nothing unsafe about unpowered landings if
sufficient safety margins are applied.

"Fixing" any of these amounts to putting bandaids on broken legs. Some of
them cannot be "fixed" at all without designing a new vehicle. NASA has
proven itself incapable of doing that job and should not be given billions
of dollars to waste trying it.

While it's true that Shuttle bandaids are not the answer, I think your
soapbox is rotting out from under you.

-Kim-

Brian Thorn wrote:

So is everything [inherenty unreliable]. Get over it.

Aircraft have become several orders of magnitude safer and more reliable than
they were originally. The Shuttle is several orders of magnitude more
dangerous and less reliable than a launcher needs to be.

Yet it has basically the same reliability as every other major space
launch vehicle.

The reason airliners are reliable is that many millions of aircraft
have been built, many billions of takeoffs have occured, and many thousands
of persons have been killed in plane crashes.

So far, only a few thousand launches to orbit have occured (summed over all
launch vehicles.) When the experience base has expanded by six orders of
magnitude launchers will have become as reliable as airliners.

Paul

Kim Keller wrote in message
...
"Richard Schumacher" wrote
in message ...

In solid rockets the structure of the solid fuel is crucial, yet it
cannot be tested or even adequately inspected before each use.

snip

While it's true that Shuttle bandaids are not the answer, I think
your soapbox is rotting out from under you.

I have a question for you, Kim. I don't want you to take it
in a derogatory way, because when you were functioning
as a shuttle technician, most of the shuttle group worshiped
you for your website's visual contributions.

Do you have an engineering degree, or any four-year degree?
All I'm looking for is a simple yes or no. I don't think I'm
asking too much, under the circumstances. I understand that
you're functioning in an engineering capacity on the OSP now.

--
John Thomas Maxson, Retired Engineer (Aerospace)
Author, The Betrayal of Mission 51-L (www.mission51l.com)

Craig Fink wrote:
You forgot that it is a non-robust entry vehicle built out of aluminum,
which melt and burns like butter when exposed to the high temperature
plasma. A graphite epoxy structure would hold up much better than aluminum.
Carbon doesn't sublime until 6500 F.

Tell me Craig, which epoxy were you planning to use exactly? Epoxy is a
polymer glue. Every formula I am aware of falls apart below about 500C.

Craig Fink

"Rand Simberg" wrote in message

Even if it's not fully reusable, it's an issue. OSP will be very
expensive to replace, and I doubt that they plan to build any more of
them than they did Orbiters. So, yes, NASA's plans are to do the
exact same thing again.

You may have answered this already, perhaps more than once. If so, if you
can just give an idea of when and I'll try to find it, but have you written
up your view on what should replace shuttle? Here? In one of your columns?

Jon