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1. #FUEL CELL CONSTANT SURFACE AREA WHEN BURNING SHAPE ROCKET FULL#
2. #FUEL CELL CONSTANT SURFACE AREA WHEN BURNING SHAPE ROCKET PLUS#

#FUEL CELL CONSTANT SURFACE AREA WHEN BURNING SHAPE ROCKET FULL#

Campbell goes on to say that a good shadow shield would probably have an interaction length on the order of a few centimeters at the 2.2 MeV energy of D-D fusion, so a few meters of neutron shielding would reduce the dose by something like 40 orders of magnitude. By way of comparison, the shadow shield on an old NERVA nuclear rocket was only about 0.25 meters thick.Īssuming that the centrifuge arm is indeed 150 meters long, it can spin at a safe no-nausea 2.5 RPM and produce a full gravity of acceleration. This can be dangerous over the 12 or so days of continuous thrust (the 226 days between thrust events would probably allow any acute radiation injury to heal - but the chronic stuff will accumulate from different burns).ĭr. He goes on to say that even with a perfect shadow shield enough neutron radiation would scatter around it if a heat radiator, another spacecraft, space station, or asteroid was outside of the shadow and close to the ship. (Doing my own calculation, assuming a person with a body mass of 68 kilograms, a cross section of 0.445 m 2, who is 480 meters away from 4.4 GW of neutrons, I figure that with no shadow shield they will be exposed to about 10 grays per second, or a LD35 lethal dose of 2 grays in 1/5 second) At a measly distance of 480 meters the 4.4 GW of neutron radiation will still be strong enough to give everybody on board the ship a lethal dose of radiation in about 1/5 of a second. Not against 4.4 gigawatts of neutron radiation it isn't. Luke Campbell points out that the engine is going to need one heck of a shadow shield, because distance attenuation ain't gonna do diddly-squat. parts of the radiator extending out of the shadow will suffer neutron embrittlement.ĭr.parts of the radiator extending out of the shadow will suffer neutron activation.parts of the radiator extending out of the shadow could scatter deadly radiation onto the passengers.The heat radiators are triangular, so that they can stay inside the shadow cast by the anti-radiation shadow shield. There are absolutely huge heat radiators because the engine has to get rid of 2.8 freaking Gigawatts of waste heat. That means a mass-flow rate of 0.96 kg/s. Adam Crowl calculates if the jet-power is 4.8 GW and the mass-ratio is 5/3 for a return to Earth mission, then an exhaust velocity of ~100 km/s and a total delta-vee of 51 km/s. I hope so, it would be nice to have some solid figures to work with instead of all this conjecture and assuming.įor the Terra-asteroid run, the vehicle would boost for 11 days, coast for 226 days and brake for 13 days to rendezvous. The report Scott found only mentioned the ship in passing, he has filed a FOIA request for another report that might go into more details.

#FUEL CELL CONSTANT SURFACE AREA WHEN BURNING SHAPE ROCKET PLUS#

Treet these numbers with grave suspicion, they could be off by an order of magnitude plus or minus. Reading the dimensions off my model it says the ship is roughly 480 meters long, has a diameter of 400 meters at the tips of the heat radiators, and the centrifuge has a 150 meter radius. Hard to do since the drawing of the "shuttle" is just a smudge. I made a quick and dirty 3D model in Blender and scaled it to with the assumption that the fly in the corner is indeed a 37 meter Space Shuttle. The pods on the ends of the centrifuge arms may or may not be shuttle external tanks, 47 meters long and 9 meters in diameter. That looks as if it was supposed to be a 37 meter long Space Shuttle. In the first picture, note the fly-like object in the upper left corner. The tail of the ship is in the lower right corner, with the engine. In case it is not clear, the nose of the ship is in the upper left corner, with the tanks on girders. The spacecraft was a fusion powered rocket designed to transport miners to the asteroid belt. Scott Lowther discovered it in a 1981 Boeing report Controlled Ecological Life Support System: Transportation Analysis. This little gem is from Aerospace Projects Review Blog.