CMESS Space Line: Ring Booster and Space Bus Blueprint by Kaveh Dimitri Salahi

The CMESS Space Line is a civilian transport system that carries ordinary passengers above the atmosphere and sets them down in another city, often on another continent, in well under an hour of flight time. It rests on one new piece of hardware: a reusable ring booster. The ring is a doughnut-shaped rocket stage made from a circle of Super Tanks, the nested spherical fuel tanks developed earlier for the roadster. Rocket engines face backward around the bottom of the ring to lift it, smaller thrusters face forward to brake it, and side thrusters steer it and hold it steady. The passenger vehicle, a road-going space bus, sits in the open centre of the ring and is held there by rigid arms that close on it from every side. Movable petals at the front of the ring swing forward and close around the bus to form a pointed nose and a heat shield. The ring and the bus share the same ten-layer heat shield design, so both can survive the heating of the climb and the much stronger heating of the return. The ring does all of the hard work of the flight. It holds the liquid hydrogen and liquid oxygen, it supplies the thrust, it steers the stack, and it lands the stack at the far spaceport by angling down onto a platform built for it. The bus never carries rocket fuel. That single rule shapes the whole system: the vehicle full of people has no fuel tank, no main engine and no combustion anywhere near the cabin. When the stack lands, capture arms on the platform lock the ring in place, the rigid arms open, the bus lowers its wheels and drives out, and a waiting bus drives in. The same ring is refuelled and flies the new bus back. A ring therefore works like a shuttle on a fixed route, moving buses in both directions, and it is never thrown away. The bus is a pressurized cylinder about 14 metres (46 feet) long and 2.55 metres (8.4 feet) wide, which keeps it within the width allowed for buses on public roads. In its road form it is a quiet electric coach with retractable wheels. In its flight form its front sections extend forward from all sides and close into a nose cone, so that the bus and ring together take the shape of a rocket. Passengers travel in ordinary clothes. The cabin holds sea-level air pressure, carries its own oxygen and air supply that is entirely separate from any rocket propellant, and uses doors and seals designed so that cabin pressure pushes them shut. Windows of a layered glass called Aegis Glass line the cabin, and sliding armoured shields cover them whenever the bus is climbing through or falling back into the air. The shields open only after the bus is above the atmosphere, so passengers can see the black sky and the curve of the Earth. The planning version of the system carries 20 passengers per bus. A typical flight climbs to a peak height of 150 to 250 kilometres, well above the 100-kilometre line where space is generally said to begin, and stays below the radiation belts that start near 1,000 kilometres. Short routes of up to about 1,500 to 2,000 kilometres use the ring that travels with the bus, called the Carrier Ring, on its own. Longer routes add a second, larger ring underneath, called the Lift Ring, which does the first part of the climb, separates, and flies itself back to its home spaceport. With both rings, a 20-passenger bus can fly from Toronto to London in about 30 to 40 minutes and from Toronto to Sydney in about an hour, compared with roughly seven hours and twenty or more hours by airliner. How the design arrived here The system went through three versions before reaching its current form, and each change came from a number that would not work. The first version launched the roadster from a tall tower down an evacuated track, around a U-shaped curve and up a ramp, with a target speed of about Mach 3, or roughly 1 kilometre per second. Even a perfect track could only supply a small part of the speed needed, because reaching space and coming down far away takes something close to 6 to 9 kilometres per second once air drag and gravity are counted. The rest had to come from fuel inside the roadster, and a roadster has room for only about half a tonne of hydrogen and oxygen. That much fuel gives a twotonne car a speed change of under 1 kilometre per second, which is a small fraction of what the trip requires. The second version moved the fuel into an external ring and dropped the track. The third version, recorded here, kept the ring and replaced the roadster with a bus, because a booster large enough to lift any crewed vehicle is far more useful lifting twenty people than two. The roadster’s systems were carried forward into the bus: the layered heat shield, the retractable wheels, the separation bulkhead idea, the Homing emergency system, Aegis Glass with its sliding shields, and the private diagnostics and two-stage inspection rules.