Plutonium on Next Atlas V - Bad Idea?

The next Atlas V will carry plutonium in RTGs on
the Pluto New Horizons probe.

"http://www.spaceflightnow.com/atlas/av007/050814pluto.html"

This will be the seventh Atlas V, but it will
also be the *very first* Atlas V flown in the
"551" configuration, with five solid boosters
and a five meter fairing. According to the
report above, a recent environmental impact
summary stated that the "mean probability of a
plutonium release during the flight is about
1 in 300".

Atlas V has had six successful launches, but
only three have flown with solid motors, and
there have been problems with the Atlas V solid
motor development effort. One of the early solid
motors failed during a ground test. I think I
recall reading that Aerojet has had to certify a
new "B" solid motor model to reduce acousitic
loads. No Atlas V has flown with more than three
solids to date.

This launch will have to be approved by President
Bush. I suspect we will be hearing a *tiny* bit
more about this in the coming months.

- Ed Kyle

Launch the thing. Quit being a woosy about nuclear power and let's get
real reactors into space. More and purer plutonium (100kg), has been
spilled in the United States from making atomic bombs than would be
theoretically lost in the worst case of one of these birds. Full steam
ahead!

On 14 Aug 2005 20:00:08 -0700, "Ed Kyle" wrote:

The next Atlas V will carry plutonium in RTGs on
the Pluto New Horizons probe.

Should you care to calculate how large your solar panels have to be,
out at Pluto's distance, then you will see that RTGs are the only real
choice. Hopefully, they stuck in an extra RTG or two, when out past
Pluto it would be going out a long way.

"http://www.spaceflightnow.com/atlas/av007/050814pluto.html"

This will be the seventh Atlas V, but it will
also be the *very first* Atlas V flown in the
"551" configuration, with five solid boosters
and a five meter fairing.

Well that is not uncommon, when they can swap the parts around as
needed.

According to the
report above, a recent environmental impact
summary stated that the "mean probability of a
plutonium release during the flight is about
1 in 300".

Atlas V has had six successful launches, but
only three have flown with solid motors, and
there have been problems with the Atlas V solid
motor development effort. One of the early solid
motors failed during a ground test. I think I
recall reading that Aerojet has had to certify a
new "B" solid motor model to reduce acousitic
loads.

So they had an early design problem and have since fixed it.

No Atlas V has flown with more than three
solids to date.

Well this one is going to Pluto.

This launch will have to be approved by President
Bush. I suspect we will be hearing a *tiny* bit
more about this in the coming months.

Yes, but not that much. Due to past launches the public now sees that
there is little risk here. And should this rocket like explode during
launch, then they can go and pick up all the pieces.

Also, since this is the one probe that NASA did not want to build, but
due to public (and scientific) protest, congress forced them to build
it anyway, then it would be an odd notion for the public to now
protest over the very hardware that they forced NASA to build.

You got it. You live with it.

Cardman.

Cardman wrote:
On 14 Aug 2005 20:00:08 -0700, "Ed Kyle" wrote:

The next Atlas V will carry plutonium in RTGs on
the Pluto New Horizons probe.

Should you care to calculate how large your solar panels have to be,
out at Pluto's distance, then you will see that RTGs are the only real
choice. Hopefully, they stuck in an extra RTG or two, when out past
Pluto it would be going out a long way.

"http://www.spaceflightnow.com/atlas/av007/050814pluto.html"

This will be the seventh Atlas V, but it will
also be the *very first* Atlas V flown in the
"551" configuration, with five solid boosters
and a five meter fairing.

Well that is not uncommon, when they can swap the parts around as
needed.

According to the
report above, a recent environmental impact
summary stated that the "mean probability of a
plutonium release during the flight is about
1 in 300".

Atlas V has had six successful launches, but
only three have flown with solid motors, and
there have been problems with the Atlas V solid
motor development effort. One of the early solid
motors failed during a ground test. I think I
recall reading that Aerojet has had to certify a
new "B" solid motor model to reduce acousitic
loads.

So they had an early design problem and have since fixed it.

No Atlas V has flown with more than three
solids to date.


I agree that RTGs are needed for this mission.
What I am wondering is if it is a good idea to
launch them on an unproven launch vehicle
configuration. An Atlas 551 is a much different
animal than the 401 that launched last week. At
568 tonnes, it weighs 235 tonnes more (70% more)
than 401 at liftoff. Its SRBs provide 635 tonnes
(1.4 million pounds) more thrust than the 401's
428 tonnes. Only seven of these, the world's
largest single-grain solid rocket motors, have
flown to date - and never more than three have
flown at a time.

- Ed Kyle

Cardman wrote:
On 14 Aug 2005 20:00:08 -0700, "Ed Kyle" wrote:

This launch will have to be approved by President
Bush. I suspect we will be hearing a *tiny* bit
more about this in the coming months.

Yes, but not that much. Due to past launches the public now sees that
there is little risk here.

I suspect the "public" who live near the Cape
wouldn't agree with the "little risk" bit. They
remember quite clearly Titan 4A-20, Delta 241,
and Delta 259, all of which blew up within
eye and ear shot of the Cape during the past eight
years.

- Ed Kyle

On Sun, 14 Aug 2005, stork wrote:

Launch the thing. Quit being a woosy about nuclear power and let's get
real reactors into space. More and purer plutonium (100kg), has been
spilled in the United States from making atomic bombs than would be
theoretically lost in the worst case of one of these birds. Full steam
ahead!

Go to work cleaning up Hanford and don't be woosy about protective gear,
etc.

On 15 Aug 2005 06:51:17 -0700, "Ed Kyle" wrote:

Cardman wrote:
Yes, but not that much. Due to past launches the public now sees that
there is little risk here.

I suspect the "public" who live near the Cape
wouldn't agree with the "little risk" bit. They
remember quite clearly Titan 4A-20, Delta 241,
and Delta 259, all of which blew up within
eye and ear shot of the Cape during the past eight
years.

So what are they going to do?

Watch this launch, while licking their lips, eagerly wanting this
rocket to explode. And should it really do so, they will all rush out
of their houses, race to be the first to get to these RTGs, crack them
open, and then to quickly feast themselves on the plutonium contents?

The officials can then try beating them back with sticks. :-]

My point is that paranoia always works wonders to turn a small problem
into a seemingly much large one.

And if someone did find an RTG by accident, and to carry it all the
way to their local police station, then I doubt that their radiation
exposure would be very much anyway. Not the best idea to hide it under
their bed though.

The point is that they should just keep away from these RTGs, when
longer term exposure would be unhealthy. And you can be certain enough
that if this launch did go bang, then the first thing that these
official would do would be to secure these RTGs.

Cardman.

Any launch can fail.

If they have to launch plutonium, and they do, then it should be
encased that it can survive a launch pad explosion.

Same as man rating - you have provisions that the crew can survive if
the rocket explodes. It's a bit easier, since a lump of plutonium
dioxide is less fragile than an astronaut, and can be encased in
titanium or what ever is needed.

I used to work in nuclear litigation from the plaintiff side. My job
was to build databases to help aggregate and let the attorneys search
all of the documents discovered in cases. People have no idea of the
amount of plutonium that was spilled into the environment and how many
people, workers, residents, etc, sacrificed unknowingly their health
and their lives so that we could maintain an effective strategic
deterrent. You could probably make the argument that the entire
Columbia River system has been contaminated with plutonium and other
radioactive and poisonous systems from Hanford. There were
experimental, controlled releases, there were numerous accidents, and
bad stuff got into the environment. Same as for Rocky Flats, Fernald,
and others. At Rocky Flats, they actually had very serious fires, and,
they had some really goofy cleanup procedures. They put a bunch of
nasty stuff into the ground and put a big concrete "pad" on top of it,
but then you had earthworms and insects eating radioactive stuff and
spreading it around to the surrounding community.

All in all, even though Chernobyl has gotten a lot more publicity, even
unclassified documents show that the total amount of radioactivity
released by our nuclear weapons program was -MORE- on a nationwide
basis. Hanford alone released the same amount, just over 50 years, but
when you are talking about stuff whose halflife measures in decades at
a minimum, a few decades doesn't matter. Those of us over 30 have
strontium 90 in our teeth and the only metal they can use to make
certain geiger counters with comes from salvage from pre-1945 - all
other metal is now mildly contaminated and I think they harvest scrap
from the German High Seas Fleet that scuttled itself after World War I.

With all of that, life in the United States goes on. And for that
reason, I think that given that we can absorb a certain amount of
radioactive punishment, that we are living in a "worst case" already,
and the potential gain from nuclear powered space craft, we may as well
explore other planets. Unless you can invent a nonnuclear technology
with a specific impulse of 3000, nuclear powered spacecraft are the
only feasible way that we can truly get to Mars or to other planets -
by making the travel time measured in weeks, or months, and not years.

I support not only the use of RTGs in space, I also think it was a
mistake to cancel Prometheus and the plan to build a nuclear plant in
space, and I hope free enterprise will someday pick up the slack or
that NASA will come to its senses. Yes, we risk maybe a 1000 people
dying from an accident, but, the gain is the ability to spread
humanity, over time, to other planets, and manage the risk of human
extinction because of a catastrophic natural disaster on earth. It's
worth it.

On 15 Aug 2005 06:22:36 -0700, "Ed Kyle" wrote:

I agree that RTGs are needed for this mission.

Well, then going to Pluto does not allow much choice in your launch
vehicle. Considering velocity and launch cost that is.

What I am wondering is if it is a good idea to
launch them on an unproven launch vehicle
configuration.

The hardware used seems quite good. The well proven and reliable
Russian RD-180 engine. Both the 4 and 5 meter nose cone fairings have
both been flown. And so that only leaves the 5 SRBs, which is the
maximum number of their between 0 to 5 options.

An Atlas 551 is a much different
animal than the 401 that launched last week.

Yes, both these are different ends on this same scale, where this 551
launch is the most powerful Atlas V launch to date.

Here is what they have launched so far...

Atlas V(401), Hot Bird 6, August 21, 2002
Atlas V(401), HellasSat 2, May 13 2003
Atlas V(521), Rainbow 1, July 17, 2003
Atlas V(521), AMC 16, December 17, 2004
Atlas V(431), Inmarsat 4-F1, March 11, 2005
Atlas V(401), Mars Reconnaissance Orbiter, August 12, 2005

All successful launches. Two used the 5 meter nose cone. Three made
use of SRBs. And all used the single RD-180 engine, when there is also
a two engine option.

So the only real extra risk is from using 2 more SRBs than with any
previous launch. And well lets just say that this rocket would be
designed for this very option, where lesser requirements just scale
back on this.

At 568 tonnes, it weighs 235 tonnes more (70% more)
than 401 at liftoff.

Maybe that is because apart the usual two stages of the Atlas V
design, then the New Horizons launch will also make use of a Star 48B
third stage. This additional stage is what gives it that higher escape
velocity.

Its SRBs provide 635 tonnes (1.4 million pounds) more
thrust than the 401's 428 tonnes.

Why bother to compare it to their smallest 401 configuration, when the
proven 431 and 521 options compare better?

Only seven of these, the world's
largest single-grain solid rocket motors, have
flown to date - and never more than three have
flown at a time.

Yes. And all with a successful launch.

So in January 2007 this successful New Horizon's launch will increase
this number to twelve.

Cardman.