Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v12_5/v12_563.txt

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Subject: SPACE Digest V12 #563

SPACE Digest                                     Volume 12 : Issue 563

Today's Topics:
             Re: LNLL Inflatable Stations
             Re: LNLL Inflatable Stations
        Re: Reliability and Insurance (2 of 3)
        Re: Reliability and Insurance (1 of 3)
        Re: Reliability and Insurance (1 of 3)

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Date: 15 Nov 90 02:22:42 GMT
From: sumax!thebes!polari![e-mail]  (Charles Radley)
Subject: Re: LNLL Inflatable Stations


+All things being equal a crew in the LLNL Earth Station will
+not need to be rotated as often as Freedom. Since it will cost
+several hundred million $$ to do a rotation, this is a major
+consideration.
-
US Law allows radiation dose up to 3 rem per calendar quarter for any worker
(29 CFR 1910.96 (b)) provided the lifetime dose is not exceeded.
LLNL is presumably governed by AEC and/or DOE and State of California
radiation regulations which may be different, probably more stringent.
This may determine rotation times, rather than 0-g, and would negate the
benefit of artifical G.  If 90 days is the limit, no point in spinning
the station.
  The Soviets operate at lower altitudes than Freedom is planning, so their
radiation exposure is less.   Plus they probably allow a higher accumulated
dose  than US.
  Going off-line, this will be my last post until ca 27 Nov,
flamethrowers please note.   I shall return  O<~

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

Date: 15 Nov 90 01:44:51 GMT
From: munnari.oz.au!brolga!bunyip.cc.uq.oz.au!iceman![e-mail]  (M Parigi)
Subject: Re: LNLL Inflatable Stations

> In article <[e-mail]>:
In article <[e-mail]>, [e-mail] ("Allen W. Sherzer") writes:
>
> >>In practice the station will need a spun section attached to a despun
> >>section.
> >+As I said, already in there. The airlock is at 0G.
>
> >I would still want to despin the station for EVA which could be fairly often.
>
> And they don't.
>     Allen

    I don't know about you, but if I were an astronaut doing an EVA to fix
a section of the rotating platform (from damage by space flotsam) and had to
get out to the 1 g region, I would first have to spin my body, climb down
the rotating station hanging on to it for dear life, with the whole universe
and earth rotating at 4 times per second above your head, with an uncomfortable
suit on, I certainly wouldn't be in any mood to do any work! I think if the
kevlar shell did get damaged, the only way to get a human on the outside of
the spinning section would be to have it despun!
    Have you thought about this, Allen?


Marco, JCUNQ, oz.
Disclaimer: I admit it, this isn't in my university's best interests.

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

Date: Wed, 14 Nov 90 22:30:00 -0500
From: "Allen W. Sherzer" <[e-mail]>
Subject: Re: Reliability and Insurance (2 of 3)
Newsgroups: sci.space
Cc:

In article <[e-mail]> Wales Larrison writes:
>    However, this does pose some interesting questions.  If, as you
>say, the Delta HLV design is 7 Deltas strapped together, does this
>not imply the reliability to be .98^7 = .86?

No the claimed reliability is much higher. A failure which is
catostrophic with one Delta may not be as bad if there are six
others to take up the slack.

I have seen figures on HL Delta reliability but cannot state
them here. The reliability is near Shuttle levels although I
do not know how the figure was arrived at.

>Also, looking at the
>historical data shows that a significant design change to a launcher
>typically results in a pattern of failure for a few years (shown in
>Delta and Scout upgrades, and in the little bit of data I have on
>Titan history).  How do we avoid the "infant morality" for a major
>design change to a HLV?

Maybe we don't. I don't know the answer. I do know that:

1. It will cost less than one Shuttle flight to develop the hardware
and find out.

2. For HL Delta we aren't making big changes but using well established
engineering methods.

Maybe you're right. Maybe all we get out of this is a way to send up
bulk supplies for a quater the cost of a Shuttle flight. On the other
hand, for a very small investment we just might reduce the cost to orbit
for everybody by an order of magnitude. Isn't it worth the risk?

>    For discussion sakes, lets say .90 for the new, untested HLV,
>and .98 from the shuttle.

Again, this does not agree with the MDAC figures.

>   2) The difference in launch costs.   I will accept the Shuttle is
>never get the economies of scale per individual launch available in
>a HLV.  So the price of an individual shuttle launch will be always
>higher ($/lb) than a HLV.  However, if we can increase the shuttle
>annual flight rate from 4 to the planned 12, then the cost is
>reduced by $2.3 B.

This is *VERY* unrealistic. This is three times the average launch
rate for the last *TEN YEARS*. There is no reason to think this
can be achieved.

BTW, a report in this weeks Avation week said NASA is backing off from
claiming high launch rates. There is a good graph of NASA launch
rate claims and actual for the last ten years.

>     Similarly, your HLV costs can be claimed as very opimistic. If,
>LLNL is going to pay for a Space Station to completely recover the
>development and financing costs for a HLV, and there is no long-
>term recurring market, I think the cost could be increased.

I'll accept your HLV launch cost for the sake of arguement. However,
I point out that LLNL will be buying ~24 of these launches plus
more for later phases. One byproduct of this may well be enough
of an infastructure to get a real space industry started.

>   3) Engineering for assembly in orbit.  I would assume the
>provisions needed to assemble something on orbit are the connections
>be simple and very easy to do/undo via EVA.

I don't think so. Just because something has field replaceable units
doen't make construction easy. For example, it may be possible to
fix the wing of a 747 at Podunk Regional Airport but that doens't
mean they could build one if given the parts.

The Zenith Star engineers considered sending the payload up on
a Titan and the Shuttle and doing assembly in orbit. This was
considered too expensive because of design changes needed. That
is why they went with the HL Delta and Titan V.

>between the two.
>    Combining all this, gives a set of revised numbers...
>
>Item            HLV          Shuttle
>Payload         $22.5  B       $22.5   B
>Insurance       $ 2.250        $ 0.450
>Launch cost     $ 0.195        $ 1.175
>EVA             $ 0.0          $ 0.002
>Engineering     $ 0.0          $ 0.0       Same between the two
>                --------       ---------
>                 24.945         24.017
>     Which has now reversed....

These two numbers are within 4% of each other. I consider that a
wash. So if we use pesamistic numbers on the HLV and optimistic
numbers on Shuttle they look the same. On the other hand, if we
can't tripple the number of Shuttle flights and MDAC is correct
on HL Delta reliability, the HLV will be the clear winner.

It will only cost us one Shuttle flight to find out.

>I would say the most sensitive part
>of this calculation is reliability since Shuttle total costs come
>out cheaper is HLV reliability is .94 or less (shuttle at .98).
>Based upon the historical patterns for launch vehicle development,
>this might be a reasonable bet.

Agreed.

>     Anyway, I think we've beat this subject to death.  Can we agree
>to disagree on this?  My opinion is that we need a HLV capability,
>and I think it would make sense to apply such to any Space Station
>program - after a good test period (10-20 flights).  I'm just not as
>hard over on killing our current programs in favor of untested new
>programs - without a much better examination of what this entails.
>But I support activities to examine this option.

I can live with this. I wouldn't kill the Shuttle without having
an option in place. I just point out that there is a good chance
that that option is here.

  Allen

--
+---------------------------------------------------------------------------+
|Allen W. Sherzer| I had a guaranteed military sale with ED-209. Renovation |
|   [e-mail]  | programs, spare parts for 25 years. Who cares if it      |
|                | works or not?  - Dick Jones, VP OCP Security Concepts    |

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

Date: 13 Nov 90 03:38:38 GMT
From: usc!elroy.jpl.nasa.gov!zardoz.cpd.com!dhw68k!ofa123![e-mail]  (Wales Larrison)
Subject: Re: Reliability and Insurance (1 of 3)

Allen, you raised some interesting questions...

>Of course, the government usually doesn't buy insurance for the
>payloads it puts into orbit.
   Actually they do.  There are differing ways of getting launch
insurance (or more properly, assurance).  One way is placing a bet
with a broker on the probability of success, which is the normal
commercial insurance method.  This the government does not do.
   However, another form of insurance is "self-insurance" where the
payload originator typically buys an additional satellite.
Government program managers for programs with greater than 1
satellite constellation will typically buy an additional satellite
and keep it on the ground in storage against a possible launch
failure.  This was done for DSCS, DSP, Fleetsatcom, TDRSS, GPS, and
other government programs.  Some commercial firms, Intelsat, for
example, have elected to also do this due to large block buys of
satellites.
   Another way of launch "assurance" is to very intensively control
and monitor the launch operations.  This is what is done for some
classified programs which launch one of a kind superbly expensive
satellites, and is the current way of doing things on Shuttle
launches.

>First of all, let's look at the cost of doing the same thing with
>the Shuttle compared to the HLV:
>
>Item            HLV          Shuttle
>Payload         $22.5  B       $22.5  B
>Insurance[1]    $ 1.125B       $ 1.125B
>Launch cost[2]  $ 0.150        $ 3.5  B
>EVA[3]          $ 0.0          $ 0.002B
>Engineering[4]  $ 0.0          $ 2.25 B
>                --------       ---------
>                $23.775B       $29.377
> [...Notes left out..]
    Hmmm... interesting point.  However, I think you've been very
optimistic about the HLV, and very pessimistic about the Shuttle.
Let me do a sensitivity analysis, and play at being optimistic
about the shuttle, and pessimistic about the HLV.
   The difference in cost given here is driven by three two factors:
1) an assumption the long-term reliability of the two systems - a
yet undeveloped, "paper" HLV will have the reliability of the
Shuttle, 2) the difference in assumed launch costs, and 3) the
difference for engineering costs for assembly in orbit.
    1). Reliability - the shuttle is, I believe, currently 44/45
(.978). Looking at the equivalent past history of ELVs, the Scout
failed 11 of the first 49 launches (1960-66, r=.78), Delta had 3 of
the first 43 fail (1960-1966, r=.93), and Atlas had 9 of the first
42 spacelaunches fail (1962-1977, r=.79) [Sorry, couldn't quickly
find the data for the Titan program history].  Since each  system is
now showing reliabilities in the range of .94-.98, I would conclude
the shuttle system is going through a common trend in space
launchers, known as "infant mortality" where design flaws are found
and fixed, and the system reliability increases.  Rather than throw
in some mathmatical mumbo-jumbo trying to project an increased
reliability for the shuttle, I think we can say the Shuttle system
reliability should increase with time, if the pattern found in
historical launch programs is followed.
                                        (cont)



--
Wales Larrison
Internet: [e-mail]
Compuserve: >internet:[e-mail]
--------------------------------------------------------------------------

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

Date: Wed, 14 Nov 90 21:48:03 -0500
From: "Allen W. Sherzer" <[e-mail]>
Subject: Re: Reliability and Insurance (1 of 3)
Newsgroups: sci.space
Cc:

In article <[e-mail]> Wales Larrison writes:
>>First of all, let's look at the cost of doing the same thing with
>>the Shuttle compared to the HLV:

>>Item            HLV          Shuttle
>>Payload         $22.5  B       $22.5  B
>>Insurance[1]    $ 1.125B       $ 1.125B
>>Launch cost[2]  $ 0.150        $ 3.5  B
>>EVA[3]          $ 0.0          $ 0.002B
>>Engineering[4]  $ 0.0          $ 2.25 B
>>                --------       ---------
>>                $23.775B       $29.377

>    Hmmm... interesting point.  However, I think you've been very
>optimistic about the HLV, and very pessimistic about the Shuttle.

I can accept that the HLV numbers are optimistic however this
is the best estimate of the companies involved in building them.
Shuttle numbers however, I don't think are pesimistic. That
number is based on ten years of experience with the system. I
see no reason to expect them to drop anytime soon.

>Let me do a sensitivity analysis, and play at being optimistic
>about the shuttle, and pessimistic about the HLV.
>   The difference in cost given here is driven by three two factors:
>1) an assumption the long-term reliability of the two systems - a
>yet undeveloped, "paper" HLV will have the reliability of the
>Shuttle, 2) the difference in assumed launch costs, and 3) the
>difference for engineering costs for assembly in orbit.

Your description of the designs as 'paper' in not totally
correct. No the launcher does not exist today but the baseline
hardware does and the engineering methods have been used by both
the US and USSR with great success. It is a paper design in the
sense that the Boeing 777 is also a paper design. In other words,
the emotional conotation of the words you use is unwarented and
by itself is not evidence  that the design cannot be realized.

>    1). Reliability - the shuttle is, I believe, currently 44/45
>(.978).

I think this is incorrect. It is more like 35/36.

>Looking at the equivalent past history of ELVs, the Scout
>failed 11 of the first 49 launches (1960-66, r=.78), Delta had 3 of
>the first 43 fail (1960-1966, r=.93), and Atlas had 9 of the first
>42 spacelaunches fail (1962-1977, r=.79) [Sorry, couldn't quickly
>find the data for the Titan program history].  Since each  system is
>now showing reliabilities in the range of .94-.98, I would conclude
>the shuttle system is going through a common trend in space
>launchers, known as "infant mortality" where design flaws are found
>and fixed, and the system reliability increases.  Rather than throw
>in some mathmatical mumbo-jumbo trying to project an increased
>reliability for the shuttle, I think we can say the Shuttle system
>reliability should increase with time, if the pattern found in
>historical launch programs is followed.


I suspect this is true but it may not be. It could be that the
complexity of the design and limited tolerences involved in
operations set an upper limit on reliability. This also begs
the question of weather this reliability is worth the billions
spent on the program. Might we have been better off spending
these billions on safer and cheaper ELV's?


   Allen

--
+---------------------------------------------------------------------------+
|Allen W. Sherzer| I had a guaranteed military sale with ED-209. Renovation |
|   [e-mail]  | programs, spare parts for 25 years. Who cares if it      |
|                | works or not?  - Dick Jones, VP OCP Security Concepts    |

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

End of SPACE Digest V12 #563
*******************