Index Home About Blog
Newsgroups: sci.space.history
From: henry@spsystems.net (Henry Spencer)
Subject: Re: smaller RTGs (was Re: [CASSINI]...)
Date: Thu, 29 Oct 1998 14:15:40 GMT

In article <TtQZ1.1142$4%.18174526@fozzy.nit.gwu.edu>,
Dwayne Allen Day  <wayneday@gwis2.circ.gwu.edu> wrote:
>I think that you are dramatically overemphasizing the impact that the
>anti-nuclear crowd is having.  When these things are debated in government
>circles, approval is always forthcoming.  There is no evidence that the
>environmentalists have had any impact on this at all.

Yes and no.  At present, there is little or no chance that any particular
RTG-using mission plan will be rejected because RTGs are included.  BUT...
what all this fuss does do, is raise the costs of using RTGs, by requiring
elaborate engineering studies, massive paperwork, layer on layer of
approval, lawyers on standby to fight off lawsuits, etc.  Pointing to the
uniformly successful approval record of RTGs overlooks the missions which
were stillborn because the RTGs they wanted to use cost too much.

For that matter, if cost is the only issue, then why are the Discovery
missions -- where most of the action is now in planetary exploration --
flatly forbidden to use RTGs?  ("No RTGs" is one of the program ground
rules.)  It's not just hardware cost, since total mission cost is quite
explicitly part of the Discovery evaluation criteria.

>The key factor is cost.  You cannot do a fastercheaperbetter RTG--they
>simply cost too much.

A significant -- and growing -- fraction of that cost is paperwork, not
hardware.  Although the RTGs themselves are not cheap, the total program
cost of using them would be significantly lower if they were not so
controversial.  RHUs, which involve many of the same engineering concerns
and manufacturing issues, are relatively cheap.
--
Mass-market software technology has |  Henry Spencer   henry@spsystems.net
been deterioriating, not improving. |      (aka henry@zoo.toronto.edu)


Newsgroups: sci.space.history
From: henry@spsystems.net (Henry Spencer)
Subject: Re: smaller RTGs (was Re: [CASSINI]...)
Date: Thu, 29 Oct 1998 19:02:49 GMT

In article <190_1.1155$4%.18310510@fozzy.nit.gwu.edu>,
Dwayne Allen Day  <wayneday@gwis2.circ.gwu.edu> wrote:
>: what all this fuss does do, is raise the costs of using RTGs... the
>: uniformly successful approval record of RTGs overlooks the missions which
>: were stillborn because the RTGs they wanted to use cost too much.
>
>But how are they getting more and more expensive if the technology has
>been essentially static for years?

Same way as nuclear power plants have been getting more and more expensive
despite essentially static technology:  more paperwork, more reviews, more
procedures, more signatures, more people who have to be briefed, educated,
and convinced.  Final launch approval for the Cassini RTGs came from the
White House, and just getting to that point means many levels of approval
within NASA had to be passed first.  All this takes man-hours, lots of
them, especially since many of the approvers are effectively illiterate
(they won't read documents, someone has to brief them).  That all has to
be paid for even if the result is a foregone conclusion.  (Even if the
people are already on staff, they could be doing something more productive
instead.)

I agree that there's a component of the costs which comes from the
inter-agency relations and the disappearance of non-space customers (and
hence the extremely low production rate).  I don't read that as being the
biggest factor.
--
Mass-market software technology has |  Henry Spencer   henry@spsystems.net
been deterioriating, not improving. |      (aka henry@zoo.toronto.edu)


Newsgroups: sci.space.history
From: henry@spsystems.net (Henry Spencer)
Subject: Re: smaller RTGs (was Re: [CASSINI]...)
Date: Thu, 29 Oct 1998 22:57:00 GMT

In article <s55_1.1165$4%.18388342@fozzy.nit.gwu.edu>,
Dwayne Allen Day  <wayneday@gwis2.circ.gwu.edu> wrote:
>:> ...the disappearance of non-space customers...
>: Who were the non-space customers?
>
>CIA.  Navy.  Possibly Air Force.

In general, people who wanted to put long-lived electronics packages in
places where they couldn't conveniently be reached for refuelling.  For
example, there were RTG-powered instrument packages in the Himalayas
watching the Chinese nuclear-test site.
--
Mass-market software technology has |  Henry Spencer   henry@spsystems.net
been deterioriating, not improving. |      (aka henry@zoo.toronto.edu)


Newsgroups: sci.space.history
From: thomsona@netcom.com (Allen Thomson)
Subject: Re: smaller RTGs (was Re: [CASSINI]...)
Date: Fri, 30 Oct 1998 02:19:04 GMT

In article <F1M2F0.L69@spsystems.net> henry@spsystems.net (Henry Spencer) writes:
>In article <s55_1.1165$4%.18388342@fozzy.nit.gwu.edu>,
>Dwayne Allen Day  <wayneday@gwis2.circ.gwu.edu> wrote:
>>:> ...the disappearance of non-space customers...
>>: Who were the non-space customers?
>>
>>CIA.  Navy.  Possibly Air Force.
>
>In general, people who wanted to put long-lived electronics packages in
>places where they couldn't conveniently be reached for refuelling.  For
>example, there were RTG-powered instrument packages in the Himalayas
>watching the Chinese nuclear-test site.


An interesting Cold War story that awaits its final telling.

As I heard it, one such package, perhaps the first, perhaps the last,
collapsed off the Himalayan ridge where it had been set and tumbled
down into the valley below.  Where, one supposes, it still rests, melting
a bit of snow from season to season.

And then there was the Pelton Memorial Sea of Okhotsk cable tap pod,
which seems to have come to rest in a GRU or KGB museum.  Minus, one
hopes, the RTG power supply.



Newsgroups: sci.space.history
From: henry@spsystems.net (Henry Spencer)
Subject: Re: Re Apollo 13 LEM re-entry.
Date: Tue, 2 May 2000 00:24:53 GMT

In article <UPXO4.3185$Px3.82704@news2-win.server.ntlworld.com>,
Phil Bulmer <phil.bulmer@virgin.net> wrote:
>> On 27 April NASA said that air sampling  above the SNAP-27 flask
>> splashdown area showed no trace of radiation
>> above that already present in the atmosphere...
>
>All this took place in the weeks after the splashdown. Does anyone monitor
>the area now?

Not that I've heard of.  Do bear in mind that the air sampling done at the
time conclusively established that the plutonium cask did not burn up on
reentry.  Any monitoring now would be of the water, not the air, and since
(as I recall) plutonium dioxide is not noticeably water-soluble, any
leakage into the ocean would be extremely slow.

>Call me an old cynic but can the claims from a potentially
>embarrased AEC of 30 years still be holding true today?

Why should the AEC have been embarrassed?  It was NASA that screwed up.
Bear in mind that such things were not given as much weight 30 years ago
as they would be now; the US had stopped atmospheric nuclear testing only
a few years earlier.

>> and this indicated that the cask had survived the heat of entry
>> and sank to the bottom intact..
>
>The LEM was a very flimsy structure, would anything else have survived
>re-entry?

It seems unlikely.  I would guess that the batteries would probably be
next in durability after the plutonium cask, and I doubt they'd have
survived a high-energy reentry.
--
"Be careful not to step                 |  Henry Spencer   henry@spsystems.net
in the Microsoft."  -- John Denker      |      (aka henry@zoo.toronto.edu)


Newsgroups: sci.space.history
From: henry@spsystems.net (Henry Spencer)
Subject: Re: Re Apollo 13 LEM re-entry.
Date: Tue, 2 May 2000 00:45:06 GMT

In article <r5IO4.2735$Px3.69102@news2-win.server.ntlworld.com>,
Phil Bulmer <phil.bulmer@virgin.net> wrote:
>I've just finished reading Apollo 13 (I take it this is 'Lost Moon' under a
>different name???)

Correct -- it was re-titled to tie in with the movie.

>and towards the end it mentions that the LEM was
>scheduled to re-enter the atmosphere over the Pacific near New Zealand. The
>concern about the LEM was its cargo of uranium...

This is an outright error in the book, and so flagrant that it must have
been deliberate, to minimize public fuss:  the material in question was
plutonium, not uranium.  Specifically, it was plutonium-238 dioxide.

>The uranium was encased in a ceramic which was designed to survive any
>failure during liftoff or the ensuing journey away from earth. In theory it
>could survive re-entry.

There's little doubt that it did, since air sampling in the area afterward
didn't find any trace of it.

>What did finally happen to it? Presumably it rests (assuming it survived the
>trip back through the atmosphere) at the bottom of some very deep water.

Right.  That was a constraint on the landing site, in fact:  bringing the
plutonium cask down in deep water was highly desirable, simply to make
sure that some diver or fishing boat didn't unsuspectingly haul it up a
decade later.
--
"Be careful not to step                 |  Henry Spencer   henry@spsystems.net
in the Microsoft."  -- John Denker      |      (aka henry@zoo.toronto.edu)


Newsgroups: sci.space.history
From: henry@spsystems.net (Henry Spencer)
Subject: Re: Early RTG launches
Date: Fri, 11 Aug 2000 14:54:47 GMT

In article <slrn8p5pd9.5qr.ijk@force.stwing.upenn.edu>,
Ian Kaplan <ijk@force.stwing.upenn.edu> wrote:
>I caught a claim on 'The Learning Channel' (gods have mercy on their
>souls) last night that an early NASA launch carrying a plutonium power
>source had gone wrong, leading to Earth contamination...
>What (if anything) is the incident he was referring to?

In 1964, a Navy navigation satellite (nothing to do with NASA, please
note) powered by an RTG failed to achieve a stable orbit, and burned up on
reentry.  Its RTG burned up, as it was designed to do.  The "Earth
contamination" that resulted was minor compared to that of the 36 US
atmospheric nuclear tests of Operation Dominic, two years earlier.

After that, it was decided that RTGs should survive reentry rather than
burning up.

When a NASA Nimbus weather satellite had a launch failure in 1968, its
RTGs were fished off the ocean bottom -- intact -- and refurbished and
launched on a later Nimbus.
--
Microsoft shouldn't be broken up.       |  Henry Spencer   henry@spsystems.net
It should be shut down.  -- Phil Agre   |      (aka henry@zoo.toronto.edu)

Newsgroups: sci.space.history
From: henry@spsystems.net (Henry Spencer)
Subject: space nuclear tests (was Re: Follow Up program to Apollo)
Date: Fri, 13 Oct 2000 13:42:03 GMT

In article <39e69e31@derwent.nt.tas.gov.au>,
Justin Wigg <justinwigg@yahoo.com> wrote:
>In an attempt to drag this on topic, a Thor missile being used in the
>Pacific high altitude tests blew up on the pad on Marshall Island.  Does
>anyone know if the warhead was totally destroyed and whether there was any
>radiation pollution...

That program had several launch failures, resulting in considerable
contamination of Johnston Island and surrounding waters.  There was
considerable cleanup needed after the on-pad failure, in particular.

>I know those plutonium capsules were as solid as a
>rock but would be interested in exactly what kind of blast they could
>withstand...

Nuclear bombs are not the same situation as RTGs.  Their plutonium can't
be armored to the same extent, and it is necessarily in a case with large
amounts of chemical explosive.  Violent destruction of one of them almost
always *does* involve uranium or plutonium or both getting spread around
the immediate neighborhood.
--
Microsoft shouldn't be broken up.       |  Henry Spencer   henry@spsystems.net
It should be shut down.  -- Phil Agre   |      (aka henry@zoo.toronto.edu)


Index Home About Blog