Last Comments…maybe

I doubt this will get posted on The Space Review. If so, then fine. If not, also fine. I am not happy about doing this, but I want it out there.

A “true” Space Station provides a Near Sea Level Radiation 1 Gravity (NSLR1G) environment for long duration missions Beyond Low Earth Orbit (BLEO). Dosing and debilitation causes permanent damage to astronauts and cuts short their careers in space due to rapid accrual of a career dose. This is the single critical obstacle to humans living in space and the most difficult to overcome. Because astronauts will still be dosed transiting to and from this protected environment, and the effect of the heavy nuclei component of galactic cosmic radiation on lesser shielding schemes, the amount of shielding is not negotiable and far beyond what people interested but not knowledgeable would guess. To meet this requirement these stations will likely have 4 distinct features.

1. The “true” Space Station would be constructed using “Fat Workshops”, which are double-hulled upper stages with a 17-foot outer envelope to be filled with a cosmic ray water shield. Such a construct only becomes efficient on a scale much larger than NewSpace-everything-cheap accepts as practical. The numbers automatically generate shock, outrage, and wailing and gnashing of teeth. I will leave it to space enthusiasts with an open mind to calculate the tons of water needed for a sphere with a 17 foot outer envelope and an inner envelope equal in diameter and totaling 68 feet. The concept really starts providing an adequately spacious crew compartment at around 100 feet. This is actually about how large one Shuttle concept, the Chrysler SERV was.
2. The “true” Space Station would utilize a Tether Generated Artificial Gravity (TGAG) system several thousand feet long spinning at around 1 RPM to provide 1G of artificial gravity. The reasoning behind such long tethers is simple in that tether materials are so strong that the savings in weight for a partial gravity rating are not great, and the Fat Workshops used are already rated to withstand max Q launch stresses so there would no savings in that either. The multi-tether system would allow a crew compartment to travel from the end of the tether at one 1G to the center at zero G for various purposes such as docking and transferring personnel. As long as an equal mass was also relocating to keep the system balanced this would keep the tether system operating smoothly and water can also be used to dampen oscillation.
3. The “true” Space Station would utilize thousands of tons of water not only as a Cosmic Ray Water Shield (CRWS) and as a dampening and balancing mass in the tether system, but also in a closed loop life support system providing years of breathable air, purified water, and basic calories. “The European Space Agency is coordinating an international research project called the Micro-Ecological Life Support System Alternative, or MELiSSA. The goal of the project is to create a completely closed life support system that could be used for space travel. MELiSSA is an artificial ecosystem modelled on an aquatic ecosystem. The MELiSSA system would contain living plants and algae.”
4. The “true” Space Station would require an Ultra Heavy Lift Vehicle (UHLV) to launch the Fat Workshops to the vicinity of the Moon where they could be loaded with lunar-ice-derived-water launched from the Moon using 23 times less energy than from Earth. Eventually rail guns, or mass drivers as Gerard K. O’Neill called them, might be used. Once a construction pipeline for these Space Stations is operating the next step would be to provide them with Nuclear Propulsion as only nuclear energy can efficiently move these large masses. Nuclear Thermal is a dead end and the only presently feasible and practical system is Nuclear Pulse. Unfortunately, while transporting packaged bomb pits safely is possible using human-rated capsules with escape towers, it is politically problematic. However, advances in ThermoPhotoVoltaics and overpowering ion thrusters may make Nuclear Electric a viable option in the near future.

I think the wet workshop concept was the path to take (with the Shuttle) and design based on the Chrysler SERV would have made it work. The problem with the SERV was of course it was SSTO. With an outer ring of engines, an inner ring, and a single central engine, I believe the SERV would have worked quite well. The outer ring could have been F-1A’s with their kerosene propellent load incorporated into the ring and used splash doors and parachutes to be recovered at sea. A J-2 inner ring would have required a heat shield to reenter and then also been recovered at sea. The central engine might have also been heat shielded and been parachute-air-recovered with a helicopter. And eventually the rings might have been propulsively landed Phil Bono style. After the engines were jettisoned the roughly spherical tankage would have been made into a crewed platform. Eventually such workshops would be used as crew compartments docked with Earth Departure Stages and leave LEO for….out there.