Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_5/V15NO513.TXT

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Date: Sun,  6 Dec 92 05:00:03
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #513
To: Space Digest Readers
Precedence: bulk


Space Digest                Sun,  6 Dec 92       Volume 15 : Issue 513

Today's Topics:
                              big SSTOs
                      DC-1 staff and spaceports
                           How many DC-Xs?
                             Lunar flight
                 Mars: "unusual" landforms, lat/long
                    NSSDC Data on CD-ROM (2 msgs)
                         physiology in zero-G
                        reliability and losses
                            Saturn V fates
                           shuttle downtime
                     Shuttle replacement (4 msgs)
           Terminal Velocity of DCX? (was Re: Shuttle ...)
                           total power loss
                     unpowered landings (2 msgs)

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Date: Sun, 6 Dec 1992 00:50:32 GMT
From: Henry Spencer <[e-mail]>
Subject: big SSTOs
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>> h> Generally correct.  There's no obvious upper limit...
>
>There are obvious upper limits that have to do with the overhead necessary
>to support the weight of a really large SSTO. Look in Serways Fresman Physics
>book for an explanation that is somewhat relevant.

I assume you're thinking of the square-cube law?  Try flying them from water
instead of land; that eliminates the concentrated support loads.  Look at
some of the proposals made for building solar power satellites with Earth
materials (a dumb idea, but it was investigated in some detail).  Some of
the freighter designs for that were SSTO.

"Obvious" upper limits should always be taken with a grain of salt until
you've had some smart engineers spend a while trying to work around them.
Too often there are hidden assumptions.  I still remember the interesting
paper which "proved" that you could not build 64kbit dynamic memory chips
with optical lithography... published at roughly the same time as the
first commercial announcements of such chips built that way...
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

------------------------------

Date: 6 Dec 92 01:30:27 GMT
From: Henry Spencer <[e-mail]>
Subject: DC-1 staff and spaceports
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>How many people does it take to operate the liquid hydrogen and liquid
>oxygen plant? You've got to have one everywhere DC takes off.

What on Earth for?  Just buy from the local commercial suppliers.  I'm
not sure how widespread liquid hydrogen suppliers are, but every hospital
gets liquid oxygen trucked in.

>You probably need one or two hundred people on the ground to service
>a DC, plus the paper pushing types to back them up. That's for one or
>two flights a week with no need for repair service...

For cargo flights, why should it take more than for SR-71s?  That was
about 50/plane, for eight aircraft flying about one mission a day total.
Hmm, union rules might bloat that some.

Airlines need about three times that many, most of whom sell tickets and
otherwise look after passengers.

>... Seems to me you'd want a single, or maybe
>two launch bases rather than dozens...

If you only have a few DC-1s, sure.  If you have lots of them, and lots
of customers, you'll want more.  See previous comments about markets.

>You'd probably like them to be at a
>low latitude too to take advantage of the increased payload you can lift
>launching East from a low latitude site...

Why?  If your payload to orbit is (say) 10klbs, and your customer's bird
only weighs 8klbs, you've got margin for higher latitudes.  The pressure
to absolutely maximize payload, and use every gram of it, is an artifact
of astronomical prices and long lead times for launches.  With much lower
costs and shorter response times, convenience -- in particular, avoiding
the hassles of scheduling and verifying compatibility of multiple payloads
on a single flight -- will take priority sometimes.

There certainly will have to be one low-latitude spaceport, at least, for
the folks who are shipping stuff up in bulk and want the lowest possible
cost/kg.  Not everybody will make that their highest priority.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

------------------------------

Date: Sun, 6 Dec 1992 00:28:34 GMT
From: Henry Spencer <[e-mail]>
Subject: How many DC-Xs?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (David Becker) writes:
>How many DC-Xs are being built?  Are our eggs in one basket?

Exactly one is being built.  It's a demonstrator and test vehicle for some
of the key technologies involved in SSTO; its most crucial functions will
be fulfilled after only a few flights, so there was no big reason to build
more than one.

Yes, all the eggs are in one basket.  Realistically, (a) there wasn't money
for more, and (b) any major failure at this point would probably scuttle
the DC-Y program regardless.  Cross your fingers.

>Have "pathfinder" mockups been built to test facilities?

There are hardly any facilities needing testing for DC-X.  I'd expect at
least partial mockups for DC-Y and DC-1, assuming they happen.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

------------------------------

Date: 05 Dec 92  10:24:24
From: [e-mail]
Subject: Lunar flight
Newsgroups: sci.space

Inquiring minds want to know:

A Soyuz capsule costs about $7 million, and has a mass of 7 tons.

The new Proton KM launcher (due in 1995) will cost about $30 million,
and be able to  send 7.5 tons in a lunar trajectory.

Why isn't there talk of a circumlunar flight, paid for by the USA, and crewed
with US astronauts? We could send US astronauts around the poles of the moon
during the Clinton Administrations' first term......

The enhanced Proton KM, the one with a LH2 escape stage should be able to send
10 tons to the Moon, perhaps enough to put the Soyuz in lunar orbit.
With a little ingenuity, we might be able to develop a lunar landing mission
architecture with this system, for an extremely small amount of money.

--- Maximus 2.00

------------------------------

Date: Fri, 04 Dec 92 10:06:39 PST
From: Author <[e-mail]>
Subject: Mars: "unusual" landforms, lat/long
Newsgroups: sci.space

>     I examined that particular region with the Mar Digital Image
>     Model (MDIM) CD-ROMs which the Mars Observer project generated
>     from the Viking 1/2 orbiter data (which we distribute for the
>     Planetary Data System) and found the site to be particularly
>     unexciting. (I'm pretty certain that I found the "face", but
>     the resolution on the MDIM CD-ROMs appears to be less than
>     ideal for seeing much "detail". I suspect that it might be
>     better on the original images from Viking (which we also
>     distribute), but have not had the time to explore those yet.)

You say that you distribute the original Viking images, how could I
obtain these.

Greetings Peter

----------------------------------------------------------------------------
[e-mail] (Author)                      Stycx BBS [phone]
The responsibility for chance...lies within us. We must begin with ourselves,
teaching ourselves not to close our minds prematurely to the novel,
the suprising, the seemingly radical.                        -Alvin Toeffler



------------------------------

Date: Sun, 6 Dec 1992 07:49:21 GMT
From: Ron Baalke <[e-mail]>
Subject: NSSDC Data on CD-ROM
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Ryan Korniloff) writes...
>>Xref: mnemosyne.cs.du.edu sci.space:27435 alt.sci.planetary:363 alt.cd-r
>m:6194
>>Path: mnemosyne.cs.du.edu!mercury.cair.du.edu!copper!vexcel!ncar!ames!el

>>>Has anyone looked at these images?  Are the pictures very detailed and
>>>diverse?
>>
>>Yes.  Keep in mind the images are the raw unprocessed data from Voyager.
>>The images are black and white.
>>
>Black and white!? Well, I understand that Voyager's camras took 3 pictures
>to make a complete color image - in a green, then red, then blue (was it
>yellow??) filter. Then, on the ground, the images were processed to make
>the color image.

This is true, except the color filters normally used by Voyager are orange,
green and blue.  From a scientific viewpoint, the raw data is more important.
As new image processing techniques are developed, you can always go back
to the original data and squeeze out more information.

>Can this be done with IMDISP or any other image
>displaying software?

With IMDISP, no.  I have looked into it, and it is not a trivial process.
First, the three images have to lined up properly. Second, you have to account
for differences between the images due to spacecraft movement and planet/moon
rotation.  Third, you have to adjust for the orange filter (Voyager didn't
have a red filter).  The only software I know of that does all of this
is VICAR, which was developed by the Image Processing Lab at JPL.

>I was relly excited with the prospect of purchasing
>CD-ROMs of the images. Now I'm not so sure it would be worth it for me.
>Is it the same for Magellan??

The Magellan images are different.  Its images were derived from radar
bounced off the surface of Venus.  You cannot get a true color image from
the Magellan data.  Magellan did not have a camera - it would
of been useless on a cloud shrouded planet like Venus.  So yes, the Magellan
images are black and white, too.  However, in some of the press released
photographs, a yellow-orange color palette was applied to the image.
This color palette came from a Venera lander image from the surface of
Venus.

>And what about the Mars Observer in the
>future? Are thoes images going to be in B/W?

Yes, and this is true for Galileo, too.  In fact, all of the cameras
carried by  planetary spacecraft were black and white cameras.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | The 3 things that children
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | find the most fascinating:
|_____|/  |_|/       |_____|/                     | space, dinosaurs and ghosts.

------------------------------

Date: Sun, 6 Dec 1992 08:15:51 GMT
From: Ron Baalke <[e-mail]>
Subject: NSSDC Data on CD-ROM
Newsgroups: sci.space,alt.sci.planetary,alt.cd-rom

In article <[e-mail]>, [e-mail] (Kenneth Porter) writes...
>> Yes.  Keep in mind the images are the raw unprocessed data from Voyager.
>> The images are black and white.
>
>So where does the color come from that we see in the news? Is the
>original data in color and the CD just omits it, or is the color
>synthesized somehow?

The images were taken with various color filters.  By combining images
(normally 3 images) taken with different color filters, you get the
color.

>And does the retrieval software have all of the neat histogram stuff
>that we saw as the images came in live? It would be cool to play with
>false color on these images.

IMDISP can display the histograms.  Also, it has 11 built-in color palettes,
along with about 30 other color palettes that can be loaded in from files.
The program also allows manipulation of the color palettes.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | The 3 things that children
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | find the most fascinating:
|_____|/  |_|/       |_____|/                     | space, dinosaurs and ghosts.

------------------------------

Date: Sun, 6 Dec 1992 01:40:58 GMT
From: Henry Spencer <[e-mail]>
Subject: physiology in zero-G
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Dave Michelson) writes:
>>Wups, my mistake:  what I meant was "no facilities for solid wastes".  Urine
>>disposal they did have, but it wasn't until Apollo that even the stick-on
>>baggies became available for bowel movements.
>
>You're not kidding, Henry.  You did make a mistake...
> [stick-on baggies in use on Gemini]
>There is no detailed summary as to who used the bags and when... However,
>another NASA SP summarizing Gemini EVA results indicates (in a long table)
>that the defecation bags were carried aboard GT-12, a flight of relatively
>short duration.
>
>I just couldn't imagine the flight surgeon allowing astronauts to sit around
>in "dirty diapers" for several days anyway...

I've seen it mentioned as a problem that did occur on Gemini.  However, my
immediately-available references don't say when the transition to the baggies
was made.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

------------------------------

Date: 6 Dec 92 01:35:24 GMT
From: Henry Spencer <[e-mail]>
Subject: reliability and losses
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Pat) writes:
>... this is a good question.  in the X-15, 4 (i think) planes were
>built.  and i think 2 were lost in testing...

Nope.  They built three, and had to do major repairs at times, but only one
was a complete loss, after the program's only fatal accident.  The count may
look like four at an incautious glance, because number 2 got a major rebuild
at one point to become the only X-15A.

>will DC-X build 3-4
>prototypes?  or will the whole basket be on one ship?

DC-X, the suborbital technology demonstrator, is building only one.  I don't
know what the DC-Y proposal is for, but if I were doing it I'd try for two.
Two is a reasonably common number for major experimental programs.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

------------------------------

Date: 6 Dec 92 01:15:47 GMT
From: Henry Spencer <[e-mail]>
Subject: Saturn V fates
Newsgroups: sci.space.shuttle,sci.space

In article <[e-mail]> [e-mail] (Brian Stuart Thorn) writes:
>     I was under the impression that once Shuttle got final approval
>     in 1972, the Saturn program was terminated completely. Shuttle
>     modifications to KSC began immediately after the SkyLab 1 launch,
>     if memory serves. While the SkyLab Saturn 1Bs and ASTP were flying,
>     NASA was already busy tearing up Launch Pad 39A for Shuttle mods.

I hadn't thought it was that prompt, but I don't have good references
on this one.  The tail end of Apollo is ill-documented.

>>Finally, to add further confusion, bear in mind that the second set of
>>Apollo cancellations scrubbed not Apollos 18 and 19, but Apollos 15
>>and 19...
>
> Do you mean that the Apollo 18 mission was targeted for Hadley, not 15?
> Why did the pass over the Apollo 15 LM, hardware problems? Is this the
> LM now on display at the Smithsonian?

I don't remember the targeting assignments, but the crucial fact here is
that there were two flavors of Apollo missions involved.  Apollo planning
identified several mission types alphabetically, building up to type F
(dress rehearsal -- Apollo 10) and type G (first landing -- Apollo 11).
These designations were continued, skipping I because of confusion with
the numeral 1.  Missions immediately following Apollo 11 were type H,
basically G plus the full surface-experiments package and some other
small improvements.  The last five sets of hardware, allocated to Apollos
16-20 originally, were type J, with both CSM and LM significantly upgraded;
notably, a J LM had a surface stay time of several days.

The Sept 1970 cancellation scrubbed the last H mission (15) and the last
then-extant J mission (19).  Given the short hiatus that followed 13,
and the general stretchout of mission schedules to ease budgets and give
more time for science analysis, the first J hardware could be ready for
mission 15... and with only three missions left, nobody wanted to keep
an H mission at the cost of a J mission.

So at the end of Apollo proper, one set of H hardware and two sets of
J hardware were surplus, plus some pre-H CSMs from earlier in the program.
I don't remember exactly which CSMs got used for Skylab.

I've seen a list of where the various bits ended up, but I don't have
it handy.  Don't remember which LM is in the Smithsonian.

> By the way, what about Apollo 20?

It was killed slightly earlier, in Jan 1970.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

------------------------------

Date: Sun, 6 Dec 1992 00:41:22 GMT
From: Henry Spencer <[e-mail]>
Subject: shuttle downtime
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Michael V. Kent) writes:
>>If you're willing to accept data from other programs as indicative, the USAF
>>figures that large solid rocket motors generally have a 1-2% failure rate...
>
>Wouldn't Castor IV-A's count as solid rocket boosters?

Not as large ones, especially since they're not segmented like the Shuttle
and Titan solids.

Smaller solids, especially ones that don't have thrust vectoring, do indeed
have a better record.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

------------------------------

Date: Sun, 6 Dec 1992 00:00:54 GMT
From: Paul Dietz <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (John S. Neff) writes:

> Several times a year there are accidents involving tank trucks carrying
> gasoline or propane, sometime the consequences are very serious. I cannot
> recall hearing of any accidents involving shipments of LH2 or LOX. Why is
> that?

I could imagine several reasons.  Most obviously, the volume of
gasoline shipment is much larger than that of liquid hydrogen
shipments.  Other reasons might be: gasoline or vaporized propane tend
to stay near the ground, while vaporized hydrogen rises.  Liquid
hydrogen has less heat of combustion per volume than gasoline.
Cryogenic tanks could be stronger than gasoline tanks.  Driver
training might differ.

    Paul F. Dietz
    [e-mail]

------------------------------

Date: 6 Dec 92 00:02:02 GMT
From: Pat <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Brian Stuart Thorn) writes:
>
> I wouldn't be too quick to blame the spy-satellite shortage on the
> Space Shuttle. Afterall, the USAF/CIA had bought Titan 34D to be a
> backup for the Space Shuttle, which was well behind schedule. Both
> the primary (Shuttle) and backup (Titan) systems failed in 1985-86.
> The KH-12 was waiting for a launch from Vandenberg, tentatively
> scheduled for September, 1986 at the time of Challenger, but there was
> very little chance of meeting that schedule. They couldn't "have kept
> on flying 11s" because there was no launcher available after two
> Titan failures (Sep 85 and Apr 86, both carrying 11s, I think) and
> Challenger (Jan 86).
>

Unfortunately a lot of this stuff is classified so it's a little
hard to tell,  but if we made 11's with a little more regularity,  we
would have had fewer problems.  also i think because the 12 was coming
on line,  they had stopped making 11's making the loss of 2 titans
even worse.  We may not have had a launcher for the 11,  but i don't think
we had any 11's left either.

> The GOES shortage is the fault of the Delta booster. GOES had been
> pulled off the Shuttle manifest long before the Challenger accident,
> and the loss of GOES (5? 6?) was due to an extremely rare failure of
> the Delta booster. A 1-in-30something bad break.
>

But once again, we had stopped building GOES, because GOES-NEXT was coming
along.  we shouldnt stop building something until the next version
is flying.  While i dont think much of the shuttle, until the DC-1
is running, we shouldnt scrap it.  in 1997, when we get a DC-1 built
then we can decide to scrap teh STS.


> Lets not forget that the Shuttle's replacement, Titan IV, has not been
> a model of efficiency. Shuttle has flown 23 missions in the time its
> taken Titan IV to fly 6. And folks call the Shuttle 'the hangar queen'!
> USAF/CIA reportedly has a new spy satellite in orbit, thanks to the
> Space Shuttle. Sure Titan is cheaper, but what good is a cheaper system
> that doesn't get off the ground? (The latest Titan is presently getting
> a massive dose of Rust-oleum. Discovery's payload is orbiting.)
>

I am sure with a little work the IV will get flying with out difficulty.
Ariane IV or was it the III  went 0/7???  for a long time.  they were
popping into the ocean with distressing frequency.  new versions can go
through pangs.  i am sure DC-X and DC-Y will have a lot of trouble,
but being well designed like the X-15, we should not have too many losses
of craft.


ctually this is a good question.  in the X-15, 4 (i think) planes were
built.  and i think 2 were lost in testing.  will DC-X build 3-4
prototypes?  or will the whole basket be on one ship?  and are they building
a ground test vehicle.  kinda a pathfinder/Structural test Article/
ground flyer????  for the shuttle program, i heard they built like
5 test articles including the pathfinder.  Henry,alan?  any input????

------------------------------

Date: Sun, 6 Dec 1992 00:14:46 +0000
From: Anthony Frost <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space


  > In article <[e-mail]> [e-mail]
  > (Henry Spencer) wri tes:

  >> In article <[e-mail]> [e-mail]
  >> (Brian Stuart Thorn) wr

  > ites:

  >>> I was wondering if anyone else was going to mention that
  >>> gaffe. I mean, TEN PEOPLE??? Okay, you've crewed the fire
  >>> truck... now who's going to fuel the DC? :-)


  >> How many people does it take to connect a couple of hoses
  >> and push the buttons to start the pumps?

  > Following commercial airliner practice, 7.

  > How many people does it take to operate the liquid hydrogen
  > and liquid oxygen plant? You've got to have one everywhere
  > DC takes off. I doubt

[etc... deleted]

Yes but... OK, your figures give a couple of hundred people, the point is
though that half an hour ago those people were dealing with a different
aircraft. In half an hours time they will have finished with this one and
dealing with the next in the queue. If you only fly one unit of a launcher
then you can assign every member of a ground crew to that particular flight,
but as you said, follow standard airline practice and it takes 7 people to
fuel an aircraft. Assuming a reasonable standard of training, say it takes a
couple of hours to fuel the DC-1 due for tuesdays launch to re-supply SSF,
the rest of the day they are refueling the flight crews T-38, the cargo 747
which brought in the payload pallet for the flight, etc... In the mean time,
the cleaning crew are working on the honeymoon special which just landed,
air traffic control are diverting an incoming cargo flight to allow for last
tuesdays SSF resupplies flight to land. Operation of the flights has been
contracted to Aeroflot after competetive tendering and their lawyers,
Accountants, etc are looking after the details...

Someone else said if you had to pay for all of the support crew for a flight
in the price of a ticket, you'd never travel by air. True if it takes two
air traffic controllers, 14 refuelling operatives etc..., but it doesn't.
The ATC is handling dozens of other flights at the same time, more if you
are mid-route. Refuelling will be carried out many times a day by the same
crew and so on...

  > a year at airline pay scale. But that doesn't include the
  > cost of the fuel plant at each airport, or the launch cradle
  > facilities, or payload clean rooms, or office space.

What does a refinery cost, or an airport departure gate and its associated
security bits and pieces, or a maintenance hanger etc...

          Anthony

------------------------------

Date: Sun, 6 Dec 1992 01:48:03 GMT
From: Henry Spencer <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Michael V. Kent) writes:
>two different approaches, really.  Many simple things vs. a few complex, and
>there are benefits and drawbacks to each.
>
>Which approach is better?  Well, they've gone head-to-head twice.  The first
>was Apollo, the second was Desert Storm.  Draw your own conclusions.

Desert Storm is hardly a reasonable comparison, given that Schwartzkopf (sp?)
himself stated that the results would have been identical if the two sides
had swapped equipment beforehand.

As for Apollo... the Soviets came within a hairsbreadth of sending cosmonauts
around the Moon before Apollo 8, and last I heard, it's still not clear why
they didn't -- the hardware was ready.  They were behind on the capability
to make an actual lunar landing, but not that far behind.

I can think of a few other comparisons, like Skylab/Fred vs Salyut/Mir,
that aren't so favorable.  And *they* didn't have to borrow a weather
satellite from the Europeans because they'd run out of their own.  Indeed,
note that the US's only fully-functioning TOMS ozone mapper is aboard
a Russian spacecraft...
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

------------------------------

Date: Sun, 6 Dec 1992 00:38:44 GMT
From: Henry Spencer <[e-mail]>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Matthew DeLuca) writes:
>>>The FAA, which legally defines "airliner" for purposes of US aviation,
>>>reportedly disagrees.
>
>>Details, please, Henry!  Did you see this in AW&ST?
>
>Henry is exaggerating a bit.  The truth of the matter is that when the idea
>of certifying the DC-1 as an airliner was proposed to the FAA, they didn't
>immediately reject it out of hand.  That's all that has been said on the
>matter.

I don't think I was exaggerating -- the claim I was responding to was
essentially "no way could DC-1 ever be certified as an airliner, the whole
idea is ridiculous", and the FAA apparently does disagree with that.  They
don't think it's ridiculous.

Matthew is basically correct, however:  they won't say anything more than
"it doesn't sound impossible" until they see a whole lot more detail and
think about it hard.  That won't happen right away.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

------------------------------

Date: 6 Dec 92 01:00:02 GMT
From: Henry Spencer <[e-mail]>
Subject: total power loss
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Pat) writes:
>... In gimli, i thought they could fly
>without gauges as long as the flight computer was operating.?

If my -- somewhat dim -- memory is correct, the 767 has two gauge systems.
With both operating, no problem.  With one operating, you're still okay to
fly, *if* you do dipstick tests beforehand to verify that the total fuel
load matches the gauges.  With both out -- as on the Gimli 767 -- you can't
fly with passengers, even with dipstick tests.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

------------------------------

Date: 6 Dec 92 00:32:59 GMT
From: Pat <[e-mail]>
Subject: unpowered landings
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>>
>>Total power loss is extremely rare in multi-engine turbine aircraft.  It
>>also appears to be quite rare in multi-engine rockets.
>
>Yes, the usual failure mode is a nasty explosion near or on the pad.
>Current rockets of DC size and larger have a failure rate of about
>1 in 100, and that's with a standing army doing zero defects preparation
>and inspection. Flight testing may reduce that in DC by as much as one or
>two orders of magnitude, or it might not reduce it at all, we have
>no experience to guide us. If the failure rate of DC drops to 1 in
>1000, or even 1 in 10,000, optimistic I think, that's still *wonderful*
>for a *spacecraft*. However, that's still orders of magnitude worse than
>airliner reliability rates. There's no credible evidence that DC will
>approach airliner reliability rates with airliner grade servicing and
>at airliner costs.
>

Yes there is.  gary, the DC will not stress itself like a rocket,
it will stress itself like an airplane.  if the engines are 40%
more robust,  that should provide significant safety improvements.
Rockets fly at redline,  look at the shutlle.  it runs at 104% and
i think the turbopumps let go at 111%, that's only a little
room for degradation.  the DC will try running it's engines at
only 60-75% of max power.

military jets have a lot more trouble then civilian jets because they have
such narrow margins.  best thing is wait and see.
>Overselling of this program is dangerous in a way that even the most
>aggressive overselling of Shuttle was not. That's because one failure
>of your *airliner safe* system will likely kill it dead, dead, dead.
>
>Gary


we will see.

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Date: 6 Dec 92 00:56:26 GMT
From: Henry Spencer <[e-mail]>
Subject: unpowered landings
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>>Total power loss is extremely rare in multi-engine turbine aircraft.  It
>>also appears to be quite rare in multi-engine rockets.
>
>Yes, the usual failure mode is a nasty explosion near or on the pad.

Please cite examples of liquid-fueled rockets that have done that recently.
(Glorified roman candles, like the Titan SRBs, are irrelevant to SSTO.  We
know they are unreliable.)

Most of the liquid-rocket failures I can think of recently have been
fairly benign problems with one engine, like the Centaur ignition failures
and the last Ariane failure, which lost payloads only because of the lack
of engine-out capability.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

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End of Space Digest Volume 15 : Issue 513
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