starship-design: Antiproton Catalyzed Microfission/Fusion Engines and Pathfinder class ships

["L. Parker" <lparker@cacaphony.net>]

There seem to be a lot of new members on the group and I have condensed some
of the ideas I have posted with some supporting evidence as well as a new
conclusion for their benefit.

As most of you who have been here awhile know, I currently believe that the
ACMF engine is the most likely candidate for spacecraft propulsion for the
next twenty or thirty years. I have been studying the limited information
available on the engine in an attempt to define a ship around it. The first
thing I have considered is total dry mass requirements of the exploratory
vessel in order to compare them with the payload mass fraction of the ICAN
II concept vehicle which was based on a single ACMF engine.

The table below gives the mass distribution of the ICAN vehicle.

Component 			 	     Mass
					 (metric tons)
Ion Driver 					100
Thrust Shell 				 20
Spacecraft Structure 			 30
Antiproton Storage Rings (20) 	  5
Neutron Shielding 			 45
Power Processing and Radiator 	100
Payload 					100

Total Dry Mass 				400

Using this as a guideline I compared it to several existing classes of
research and exploration vessel; the U.S. Navy's USNS Pathfinder (T-AGS 60)
Oceanographic Ship, the Research Submarine USS Dolphin (AGSS 555), and the
Deep Submergence Craft NR-1. These vessels are designed to perform research
and survey operations far from support for extended periods of time and
should be a representative sample of what kind of mass requirements such an
exploration vessel would need. There are some obvious differences and
exceptions because of the difference in their environment and missions, but
I think on the whole the differences with respect to mass requirements will
balance out.

Here is a summary of the basic characteristics of the comparison vessels:

General Characteristics, NR-1 Deep Submergence Craft
Primary Function: Deep submergence research and engineering vehicle
Hull Number: NR-1
Class: no class; this is a one-of-a-kind ship
Builder: General Dynamics (Electric Boat Division)
Power Plant: One nuclear reactor, one turbo-alternator; Two motors
(external), two propellers, Four ducted thrusters (two horizontal, two
vertical)
Length: 150 feet (45.72 meters)
Displacement: 400 tons (360 metric tons)
Diameter: 12 feet (4.18 meters)
Maximum Operating Depth: 2,375 feet (724 meters)
Crew: 2 officer, 3 enlisted, 2 scientists
Armament: None
Date Deployed: Oct. 27, 1969

General Characteristics, Research Submarine
Primary Function: Deep submergence research and development submarine
Hull Number: AGSS-555
Class: No class; this is a one-of-a-kind ship
Builder: Portsmouth Naval Shipyard
Power Plant: Diesel/Electric; Two GM 12-cylinder, 425 HP engines
Length: 165 feet (50.3 meters)
Displacement: 950 tons (861.8 metric tons)
Diameter: 18 feet (5.5 meters)
Operating Depth: 3,000 feet (915 meters)
Crew: 5 officer, 46 enlisted, and up to 5 scientists
Armament: None
Date Deployed: 17 August 1968

General Characteristics, Pathfinder Class
Builders: T-AGS 60 to 64; Halter Marine Moss Point, Miss
Power Plant: Diesel electric, twin screw propellers driven through Z-drives,
6,000 shaft horsepower; 1,500 horsepower bow thruster
Length: 328.5 feet (100.1 meters)
Beam: 58 feet (17.7 meters)
Displacement: 4,762 tons (4,329 metric tons)
Speed: 16 kts (18.4 mph, 29.6 kph)
Range: 10,400 nautical miles (12,000 miles, 19,300 kilometers) cruising
Ships: No Homeports assigned
USNS Pathfinder (T-AGS 60)
USNS Sumner (T-AGS 61)
USNS Bowditch (T-AGS 62)
USNS Henson (T-AGS 63)
To Be Named (T-AGS 64)
Crew: 25 ship's crew and 27 scientists