Orion models in detail #1 880 ton Orbital Test Vehicle

On page 55 of Project Orion 4 1959 ship designs are described in detail.


The first is the 880 ton Orbital Test Vehicle

ISP: 3000-6000 sec : Research cause of variation by factor of 2.
Plate diameter 80 ft
Acceleration: 2 g
Frequency: .5 to 1 hertz
Vacuum yield: .8 - 3 kt : Variation by a factor of 4, 2 squared.
Theory- pulse focus was uncertain in '59, later plate capture estimates were 60%.
So this design varied from 30% to 60% capture with '59 pulse units, later designs would allow 60+% capture.

Sea level yield: 30 tons
Loft to 125,000 ft. yield 20 kt. (Calculate yield curve)
Yield to Orbit: .45 MT to 1.8 MT
430 KT / 600 Pulses = .71 kt each <- We'll use this size for analysis.
1.78 MT / 600 Pulses = 3 kt each

16.6 m/s pulse

880 tons total
370 tons bare propulsion
300 tons payload to orbit
210 tons pulse units
525 Lbs each
47.6 (m/s) / ton

170 tons to Luna
42.3 (m/s) / ton

80 tons to lunar surface and back
50 (m/s) / ton

50 m/s / ton / 16.6 m/s/ pulse unit = 664 lbs per vacuum pulse unit

800 * 525 lbs = 210 tons
600 * 664 lbs + 200 * x lbs = 210 tons = 420,000 lbs
200 * x lbs = 21,600 lbs
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x = 108 lbs per sea level pulse ( only air as propellant)
Implied ISP about 15,800 seconds.
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On orbit the 670 ton ship has 4.87 kt. of energy.