Problems with Problems With The Orion Spacecraft #9: Stress

In article ,
Tux Wonder-Dog wrote:
It also reduces the risk of secondary radiation from the pusher plate. That
always bugged me - riding an Orion would be deliberate suicide if you knew
beforehand that you were going to receive a massive overdose of radiation
every time you increased speed.

The smaller Orion designs -- the ones on which the most design detail has
been published, and also the ones with the biggest radiation problem --
did generally incorporate a heavily-shielded "powered flight station", at
the extreme nose of the vehicle, to which the crew would retreat during
engine firings.
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spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

pulse unit *isn't* an omnidirectional device

True, especially in the larger space charges, we have clear information
about how they work and the tightly focused shape of the forward
plasma. Their backward lobe is unfocused.

the pictures and diagrams of the blasts that you photoshop are

Rough drafts, we don't have a drawing of the six times less massize
http://spacebombardment.blogspot.com...-altitude.html

sea level pulse units, so errors like this, at 1.25 seconds, remain to
be corrected.

http://spacebombardment.blogspot.com...launch_27.html

I need to fix the section between the explosion center and the plate to
get the focused, rammed, air to the plate sooner, a torroidal fireball
seems like a good start.

Henry Spencer wrote:

The smaller Orion designs -- the ones on which the most design detail has
been published, and also the ones with the biggest radiation problem --
did generally incorporate a heavily-shielded "powered flight station", at
the extreme nose of the vehicle, to which the crew would retreat during
engine firings.



For the 10 meter diameter design, the report (Vol. III) quotes a crew
compartment radiation shielding weight of 18,170 kilograms.

Pat

Derek Lyons wrote:

This [plutonium gun] is the first stage - it's never loaded on the
craft, but is fired beneath it as it sits on the launch towers. Thus
the size/weight of this unit is not restricted the way the onboard
units are.

OK, so this reduces one of the drawbacks of using a gun. It doesn't
eliminate it, and it still leaves the other drawbacks. Where is the
advantage over using implosion, to justify this?

From other postings, this sounds like it might have just been a test
harness for subjecting a plate to a tiny nuclear explosion. More like
a very powerful pulse neutron reactor, with a particularly large burst
rod inserted really fast. For that, you want a strong neutron source
to ensure predictable predetonation at the moment of first criticality,
giving predictable yield. Plutonium would provide both the fissile
material and the strong neutron source. With uranium, you would need
to add a neutron source to ensure that the system did not go
supercritical by an unpredictable amount before the reaction started.

No. The designs I've seen to date place a fusion device inside a
larger holhraum which focuses the output of the device onto/into the
ablative material that provides the thrust. No alterations to the
tampers at all.

That makes sense. The report that I read was written when this stuff
was still classified due to the military projects like Casaba. So it
was vague about how the focusing was done, except that it was related
to the arrangement of mass around the device.

At any rate, if you used a gun with this, you would have the immensely
thick barrel to work into your design somehow.