These are speculative ideas but put here anyways according to our publishing ethos, see Open source knowledge.
Hydrogen pipelines
While the hope is that receiver stations will transmit energy to shore via direct electrical cables or other electrical means, if this is not initially possible for whatever reason, we will need to store energy somehow. One method is to convert the electricity to splitting water to produce hydrogen gas, which can be burned to yield clean energy (and water, using the heat of the combustion for distillation!), this was Max(Emiliano)‘s idea. However, liquified hydrogen is insanely difficult to make, and gaseous hydrogen diffuses easily, so we’ll need a way to store hydrogen at room temperature. One method would be to use a solvent; hydrogen gas would need to be dissolved into some kind of solution, which could then hold the hydrogen in liquid form, allowing transport by ship, until it can be extracted at another location. Another, more complex way is for some kind of chemical encapsulation, whereby a molecule “wraps” around the hydrogen ions, keeping them from escaping; this may be a solid or a liquid.
Ocean pumped hydro for receiver stations
We can store energy in our massive oil rig-turned power receiving platforms by attaching massive (but hollow) concrete legs that we fill with hundreds of thousands of tons of water as ballast to keep them stable. We can design these to have multiple chambers/tanks. Now, what we can do is that we can use a portion of the power received from orbit to pump water to a high point, until the tanks are 80% or more full. Then, in case something happens and we need backup power to supply land power grids, we can generate electricity by letting that water out of the tanks through specialized spillways with water turbines, until the tanks drop to about 50% full. The gravitational potential energy of the water will be able to store a lot of energy, and releasing it will consequently be able to generate a lot of electricity, which we can either use as supplemental power to power the systems on the platforms OR use to generate liquid hydrogen that can be burnt in power plants and carried by docking ships.
Speculative mirror designs
We can use use superconducting magnets to generate a strong magnetic field which can be used to circulate ionized xenon gas. The xenon ions are exposed to strong sunlight and circulate through the field until they glow blue-hot. They are arranged in such a fashion that the moving xenon ion cloud produces strong microwave emissions that are amplified in a resonant cavity, creating a very strong laser.
Another idea is to disperse a very thin film of silver halide suspended in a heavy ionized gas (e.g. xenon/argon) trapped within a magnetic field that forms a “mirror” without needing a physical giant mirror, as the magnetic field keeps the silver atoms in place and in a parabolic arrangement. This would not work on Earth (due to atmospheric turbulence), but because space (at GSO orbit) is so empty, this may actually work in space.
SSTO spaceplanes for orbital construction
Summary: the idea is for spaceplane with detachable rocket boosters. The spaceplane uses a ramjet up to about 30km of altitude, then shuts off its ramjet and uses its rocket boosters to quickly and rapidly gain thrust before the boosters detach and fall back to earth. This allows its main rocket engine and thrusters to be fairly small, while delivering much larger payloads than rockets into space, accelerating the construction of our space-based power satellites.
The plan is to create SSTO-like transport spaceplanes for delivering parts for constructing Project Elara’s power satellites into space (and possibly servicing them):
- Lift becomes insufficient ~30km into atmosphere
- So we will design a jet (turbofan) engine that will transition to a ramjet, and then turn off at 30km, and rely on external rocket boosters the rest of the way
- A modified version of the aircraft can be launched from an electromagnetic catapult and does not need the turbofan; it can just use its ramjet
- The external rocket boosters then detach (for this concept design they are non-reusable, but they are relatively cheap and inexpensive because they don’t need to be as big as a typical rocket given they are given a head start by the jet engine)
- If the spaceplane is configured for suborbital mode, then its payload (with attached third stage) is released at this point; if the spaceplane is configured for pure orbital mode (such as docking with ISS or an interplanetary spacecraft in orbit), then its rocket boosters burn for a little while longer
- Upon re-entry the SSTO would slow down in the upper atmosphere, then glide, then finally at ~5-10km altitude it turns its jet engine back on to fly to its runway
Why do this? It integrates the best things about both SSTOs and conventional rockets:
- Ability to operate from runways rather than extremely complex rocket launch pads
- Theoretically safer than conventional rocket (given it takes off like a normal jet) and cheaper than (non-reusable) rockets
- Isn’t as limited by payload constraints of SSTOs because it uses lift and efficient jet engines to gain speed at low altitudes, then uses expendable rockets for the second stage - in fact it should be able to carry more payload than a comparable 2-stage rocket given the boosting effect of the jet engine at low altitudes, allowing the second stage expendable boosters to be smaller
- It works well with economies of scale, which is the best way to achieve inexpensive spaceflight
Engine stages:
- Takeoff-Cruise: turbofan with afterburner (or alternatively electromagnetic catapult, it must get to 300 km/h or above for its ramjet to work)
- Cruise-15km: ramjet
- 15km-70km: scramjet, from 30km onwards boosted by rocket
- Will require active cooling for reentry systems to prevent need for thermal tiling.
The same intake is used by both the turbofan and ram/scramjet. However, the air from the intake is rerouted to the appropriate engine at the appropriate stage.