1412-009 Haven1 is a GRAVSAT - an orbital living and Farming environment, in LOW GRAVITY (1/10 of Earths gravity) in its living and working environment, fully pressurised, solar powered and fully shielded from solar flares. and a big zero gravity sports volume
Haven1 is the first 1/10 gravity living environment, where "falling" is no longer deadly, and with a farm next door, good chefs, and there are useful things for you to do. At this stage, 1412-009 - a KeroseneRocket remains the best way to get cargo and passengers to orbit, and we plan for a series of 10 ships that are tanks 8m diameter, 12mm thick walled aluminium tube, It is, I believe, the smallest diameter that a permanent crew and farm can live in PERMANENTLY and where visitors can fit in too.
These 8m diameter 30m long tanks are built and tested on Earth, then filled with kerosene and LOX to about 10m deep each, and are the 2x500t reactant mass, that fuel the insertion into orbit of the tank plus its small pointed payload under a pointed cone, and, underneath, the 49 rocket motors in a 7 x 7 point array. It's an SSTO most of the payload IS the tank and its ascent engines (which will be recycled in orbit) a soyez return capsule would make a good tools chest for the point and that part IS already human rated and would become one of Haven1's lifeboat fleet.
50 tonnes of water or other mass shielding has to be supplied on the sun pointing end of each of the 2 or 3 paralell tubes that rotate around each other, with axis at the sun. ie up to 150 tonnes for all 3 shields, but only one is essential
A small amount of reaction mass timed in the 12 seconds of a revolution both maintains alignment and boosts the orbit or changes the spin rate and/or axis by about 1 degree per day
(normally connected by pressure tubes in tension, cable backed. though at the shadow end of each shielded tube, other tubes may be added axially, and still be fully shielded from the sun
The first and main component launched for the first 10 trips consists of an 8m diameter 12mm thick Duralumin tank, about 30m long. (or high) divided to hold 500 tonnes LOX, 500 tonnes kerosene and general cargo. The expected launch cost is $120m per launch at $3m/tonne
4% of 1000 tonnes is 40 tonnes can be got up. Tank weighs 900kg/m plus ends etc. 30 tonnes? 35 tonnes? 25 tonnes?
for shielding we need 50 tonnes of water., etc, for each of the 1,2 or 3 sunward ends. As our "payload" may be only 5-10 tonnes, plus the 35 tonne tank, it's possible tank #5 (or different) may be dismantled to be part of that shielding.
Up to 5 twin habitube ships can be built from 10 launchings - or just one.
"Gravity" is longitudinal - Spinning around the central axis of the tube wastes a lot of agricultural space, so generally a SECOND mission launched tank (and/or some waste mass on a 200metre tether?) becomes a zero-g pressurised area, with shielding (by Earth's mass) for 40 minutes, and "exposed to solar flares" 50 minutes (daylight side of orbit) until it has enough mass shielding
a THIRD
agricultural station, it is the first to provide GRAVITY in an orbital environment, suitable for humans, livestock and plants. In 50 years of access to space, nobody has "bothered" to provide this, yet it is the first step for survival beyond earth's atmosphere. It is part of the larger plan described in UnitedSpaceAgency.com
The FULL SIZE GRAVSATS are much bigger, multi-decked and more substantial, and requires lunar resources to build both its shield 120m x 50m x 1 tonne/square metre = 6000 tonnes and the aluminium for the 4 disks showm.
Because, at the distance that the Earth and moon are from the sun, the sun occupies 1/2 a degree of arc, and there is a square pyramid shadow from the shield. the disks will either need to be smaller as they get further from the shield, or some intermediate "tip shielding" may be required. the configuration of 4 large disks, as shown may need slight size or shielding adjustment. and their direction and/or speed of spin may vary from the 5RPM of the prototype - that would give about standard earth gravity at the rim, but still have a fairly high corriolis force at 30 degrees per second.
a slower spin would reduce corriolis , allowing about 15 degrees per second and 1/4 G (2.5 Metres per second, per second) for greater comfort. rather than the "single deck" (plus hub) of the proto, up to 30 decks could give a considerable "acreage" (up to 4 acres per deck) for agriculture, plus a large low gravity hub area in each of the disks. the two 6M diameter (zero gravity) connecting tubes may be fully shielded or used only in planetary shadow. the extra mass for shielding is probably worthwhile though, and a good idea as with 4 or more disks, and hundreds of people on 300 acres of "land", and possibly livestock full shielding is preferred
Construction of gravsat 2 starts with a smaller disk (or contra-rotating pair of disks, better for stability) behind a smaller shield, and when another is built (constructed in shadow but zero gravity at the right) it is bigger, but initially not fully shielded, then the shield is extended, and the new disk mounted behind it - moving very heavy structures in orbit is EASY!.
"Parking" for transit craft or constructions can be had in the shadow to the right. or "teed off" from the connection tubes /"axles" for ease of access. Power generation is from an aluminium parabolic reflector (not shown) on the LHS that concentrates a LOT of solar energy to a focus for THERMAL collection to run a "conventional" steam turbine generator, with cooling finsin the shadow behind it. many megawatts of power are available, without having orbit-hazardous fragile ceramics exposed to space as in P.V. Photo-Voltaic collectors
Gravsat 2 is a stage towards a rural township - holding many skills, spaces and amenities, and a low G (and zero G) environment ideal for paraplegic and elderly people nursing, as well as "the hardy outgoing" types one usually associates with space fiction - though, of course, GETTING to LEO is (at present) not a trip for the feeble, or frail. It will get better though, with the demand (and funding) for it to do so. this will be expanded on a link from UnitedSpaceAgency.com shortly
Oxford@UnitedSpaceAgency.com