PBS's "Nova" and MER

Scott Ferrin wrote:

No, I was saying that aligning it onboard a ship was. Meaning if that
can get that kind of alignment on a ship, in a shipyard, why do they
need a perfect floor?


Probably because constructing the floor that way, one time, allows them to
use precise measurements to/from that floor or to use mechanical guages
(essentially templates) based on measurements to/from any point on that
floor for EVERY rocket they ever build there. Remember, the Boeing Delta
IV plant in Decatur was brand new construction, designed at a time of much
rosier predictions for the commercial launch market. Spending a million on
the floor to save manufacturing/tooling costs and assembly time for each of
potentially hundreds of boosters (some of which may well be further
variants of the ones built now) over a couple of decades was probably worth
the trade off.

Of course, living is a sound-bite world, the Boeing PA flack says, "Gee
whiz, we've got the flattest floor in the free world!" instead of
explaining the cost-benefit analysis with pie charts and graphs.

--
Herb Schaltegger, B.S., J.D.
Reformed Aerospace Engineer
Remove invalid nonsense for email.

On Wed, 07 Jan 2004 10:29:14 -0600, Herb Schaltegger
lid wrote:

Scott Ferrin wrote:

No, I was saying that aligning it onboard a ship was. Meaning if that
can get that kind of alignment on a ship, in a shipyard, why do they
need a perfect floor?


Probably because constructing the floor that way, one time, allows them to
use precise measurements to/from that floor or to use mechanical guages
(essentially templates) based on measurements to/from any point on that
floor for EVERY rocket they ever build there. Remember, the Boeing Delta
IV plant in Decatur was brand new construction, designed at a time of much
rosier predictions for the commercial launch market. Spending a million on
the floor to save manufacturing/tooling costs and assembly time for each of
potentially hundreds of boosters (some of which may well be further
variants of the ones built now) over a couple of decades was probably worth
the trade off.


Seen as an investment that makes sense.

Scott Ferrin wrote:
No, I was saying that aligning it onboard a ship was. Meaning if that
can get that kind of alignment on a ship, in a shipyard, why do they
need a perfect floor?

Because having a perfect floor make designing and building your
assembly jigs and tools easier, and removes the need for constant
re-checking of the jigs and tools. This is handy because then they
can use any jig or tool anywhere in the assembly facility. (For the
same reason shipyards are moving to level assembly facilities,
essentially floating drydocks, rather than the more traditional
inclined ways. Rather than having multiple sets of jigs and tools,
one for each building way, they can have fewer sets, all identical.)

Also, the cleaner your baseline is, the easier it is to reach final
alignment. Clean enough, and all you need is minor tweaks. Dirty,
and it can take considerable work just to get a rough alignment. If
the shipyards could arrange to build every ship exactly the same and
perfectly aligned, they'd do so as it could save considerable
man-hours in the alignment of the numerous systems on board that
require it.

D.
--
The STS-107 Columbia Loss FAQ can be found
at the following URLs:

Text-Only Version:
http://www.io.com/~o_m/columbia_loss_faq.html

Enhanced HTML Version:
http://www.io.com/~o_m/columbia_loss_faq_x.html

Corrections, comments, and additions should be
e-mailed to , as well as posted to
sci.space.history and sci.space.shuttle for
discussion.

Mary Shafer wrote:
We've had fresh-outs who were experts on a particular topic fairly
soon after they joined a project. It's a sink-or-swim process that
makes them the expert, of course, but that's what happens when you're
understaffed and spread too thin.

That happens in the military too, even without sink-or-swim. Show an
aptitude or interest in something, especially something others regard
as onerous or boring, and you are the go-to guy forever.

(Course, had I known this, and known that my topic would result in me
supervising tests that had to be performed at night, and were
invariably scheduled on a liberty night...)

D.
--
The STS-107 Columbia Loss FAQ can be found
at the following URLs:

Text-Only Version:
http://www.io.com/~o_m/columbia_loss_faq.html

Enhanced HTML Version:
http://www.io.com/~o_m/columbia_loss_faq_x.html

Corrections, comments, and additions should be
e-mailed to , as well as posted to
sci.space.history and sci.space.shuttle for
discussion.

On Wed, 07 Jan 2004 20:45:47 GMT, (Derek
Lyons) wrote:

Scott Ferrin wrote:
No, I was saying that aligning it onboard a ship was. Meaning if that
can get that kind of alignment on a ship, in a shipyard, why do they
need a perfect floor?

Because having a perfect floor make designing and building your
assembly jigs and tools easier, and removes the need for constant
re-checking of the jigs and tools. This is handy because then they
can use any jig or tool anywhere in the assembly facility. (For the
same reason shipyards are moving to level assembly facilities,
essentially floating drydocks, rather than the more traditional
inclined ways. Rather than having multiple sets of jigs and tools,
one for each building way, they can have fewer sets, all identical.)

Also, the cleaner your baseline is, the easier it is to reach final
alignment. Clean enough, and all you need is minor tweaks. Dirty,
and it can take considerable work just to get a rough alignment. If
the shipyards could arrange to build every ship exactly the same and
perfectly aligned, they'd do so as it could save considerable
man-hours in the alignment of the numerous systems on board that
require it.

D.


After seeing that show on the carrier construction I felt it was a
miracle they could get everything lined up at all :-)

Scott Ferrin wrote:

Also, the cleaner your baseline is, the easier it is to reach final
alignment. Clean enough, and all you need is minor tweaks. Dirty,
and it can take considerable work just to get a rough alignment. If
the shipyards could arrange to build every ship exactly the same and
perfectly aligned, they'd do so as it could save considerable
man-hours in the alignment of the numerous systems on board that
require it.


After seeing that show on the carrier construction I felt it was a
miracle they could get everything lined up at all :-)

g It's a *big* job. (Counts on fingers.... ) I can think of a dozen
or more things just on my boat that required accurate alignment.

D.
--
The STS-107 Columbia Loss FAQ can be found
at the following URLs:

Text-Only Version:
http://www.io.com/~o_m/columbia_loss_faq.html

Enhanced HTML Version:
http://www.io.com/~o_m/columbia_loss_faq_x.html

Corrections, comments, and additions should be
e-mailed to , as well as posted to
sci.space.history and sci.space.shuttle for
discussion.

"Andrew Gray" wrote in message
. ..
(It'd be an interesting detail to see a list of what *is* sitting in the
clean rooms with no definite plan for the future...)

As to *unclean* rooms, I seem to recall reading many years ago (10+) that
the Navy reclaimed a satellite that had been hanging in the Smithsonian for
several years and successfully flew it.
--
If you have had problems with Illinois Student Assistance Commission (ISAC),
please contact shredder at bellsouth dot net. There may be a class-action
lawsuit
in the works.

Derek Lyons wrote:

Because having a perfect floor make designing and building your
assembly jigs and tools easier, and removes the need for constant
re-checking of the jigs and tools.

....and anyone wanting to see The World's Flattest Floor should tune into
History Channel's "Modern Marvels- Hangers" episode that will be run at
noon EST today (the 8th) and rerun at 6 PM EST.
This shows both it and the Shuttle hanger.

Pat

(Derek Lyons) writes:

[...]

g It's a *big* job. (Counts on fingers.... ) I can think of a dozen
or more things just on my boat that required accurate alignment.

Ooh, could we get a shot of these six-fingered hands?!?

"Chris Jones" wrote in message
...
(Derek Lyons) writes:

[...]

g It's a *big* job. (Counts on fingers.... ) I can think of a dozen
or more things just on my boat that required accurate alignment.

Ooh, could we get a shot of these six-fingered hands?!?

Let me guess, you don't count in binary on your fingers?