New Ventures Society
Spaceship for the Common Man
Initial $10 billion
expansion $20,000 billion
upgrade $6,000 billion
Our objective would be to design and build the first true spaceship. It would be a cross between a B2 bomber, a C5 cargo plane, and the Space Shuttle. It would load up to 100 tons of cargo (or 100 passengers), take off from any airport, fly to 45,000 feet, start the rocket motor, achieve Low Earth Orbit, unload, return to Earth, and prepare to launch again the next day. A prototype design capable of lifting 1 ton to orbit would also be considered.
The first thing in any aerospace design is to develop the propulsion plant.
Currently the only way to reach orbit is with a "disintegrating totem pole" (multi stage rocket). These are very inefficient!!, but they are the only things available.
The energy of an object in orbit is worth about $1 / kg if expressed in terms of energy that it would cost your electric company to produce.
So a 100 kg man would cost $100 to send to orbit. $ 100
Except he would need 1000 kg of environmental support 1,000
10000 kg of structural support (@ $500 /kg) 5,000,000 (thrown away in flight)
100,000 kg of fuel 1,000,000
or just ask the Russians if you can hitch a ride (going fee $ 5,000,000 )
going rate for a satellite is about $ 10,000 / kg
There are efforts to improve this currently in development that hope to reduce to cost to $1,000 /kg
(there are technologies [rotating skyhook, Bifrost bridge] based on the Beanstalk that have potential to drop it to $10 / kg but they have problems either with requiring massive existing orbital infrastructure or reliability )
This project aims to reduce costs to about $100 /kg or roughly the price to fly to Australia.
First (pedantic mode on) let it be said that no one is hiring Rocket Scientists. -- the last one we had (Konstantin Eduardovich Tsiolkovsky) lived in Russia about 100 years ago and developed all the equations related to space flight and conceived of all the modes. single stage, multi stage as well as the beanstalk and this project -- beamed power.
What NASA, the Russians, the Japanese, the Chinese, and the rest use are ROCKET ENGINEERS
All rockets depend on throwing propellant out the rear end. How well they work depends on the momentum of the exhaust which varies with the square root of the Temperature and inversely with the square root of the molecular weight of the exhaust.
So kerosene and liquid oxygen burns at 1600 C giving an Isp of around 3.5 not enough to get to orbit.
Shifting to liquid hydrogen and oxygen burns at 2800 C giving an Isp around 5.5 but has a drawback in that it requires massive insulation and better structural mass which negates most of the Isp increase. So we can make it to orbit with multi stages but just barely. If the Earth was just 25% larger no chemical rocket could get to orbit.
To get better performance we have to cheat. Leave our energy source behind, just carry the propellant and beam the power we need through the air.
Some interesting facts.
We beamed microwave power in tests to a rectenna ( converting back to electricity) as part of the solar power satellite program back in the 1970s
Boeing designed and tested a power plant for jet engines that relied on laser beams from orbit heating a heat exchanger back in the 1970s
My Chemistry lab at Rice built a vortex stabilized plasma torch (25,000 C )(pressurized N2 / O2) (experiment for cheaper nitrates) back in 1962
In 2014 a company demonstrated a microwave powered heat exchanger using He achieving ~ 5.5 Isp (then abandoned the work because of funding)
Ammonia (NH3) will decompose at 1000 C to H2 and N2 (it requires 1000 C and 14,000 psi to form)
Water ( H2O ) will decompose at 2800 C to H2 and O2 (the same temperature as for equilibrium formation)
H2 and O2 will decompose to the monomolecular forms around 4000 C
High temperature ceramics melt in the range 3500 C to 4500 C, mullite (what was used in heat exchanger test) melts at 2200 C.
Sub millimeter microwave systems (~300 GHz) exist and are several orders of magnitude cheaper than lasers.
If we take an array of microwave emitters scattered over an area several miles in diameter we effectively create a tracking phased array radar set that can focus on a spot 10 meters in diameter at orbital heights. Because of absorption by water we need to install this array on mountain tops or in high deserts.
A 1 GW power array will create an intense heat on a ceramic heat exchanger at the focus of the beam. This should result in a temperature around 3000 C . If we pass ammonia through this heat exchanger we will heat the exhaust gasses ( N2 and H2) to 3000 C, far hotter than conventional chemical exhausts. Isp estimated 6.0
If instead of directly heating the propellant, we convert the energy of the microwave beam into electricity and then power a plasma torch we have a spectacular increase. The exhaust gasses ( monomolecular H and O ) come off at 25,000 C (5 times the temperature of the surface of the sun) resulting in 3 times the Isp (9 times the temperature) plus 1.4 times the ISP for the monomolecular form with low molecular weight. . Thus roughly an Isp of 25.
Because of the much higher Isp we could probably use 1/4 the propellant, substituting 10 times the payload.
The operational mode would be as follows.
The spaceship would operate out of an ordinary airport.
Takeoff would be using ordinary jet engines
At around 45,000 feet the spaceship would enter the beam path and switch to the rocket motor.
The spaceship would climb and accelerate along the roughly 400 mile range of a given beam, switching to the next one if necessary.
At low Earth orbit the spaceship would discharge its cargo, then decelerate and use normal braking to return to lower altitudes and speeds.
Landing would be at an airport by jet engine and the craft would turn around, refueling and loading for another flight the next day.
The spaceship would still have the same cost ( ~ $500 / kg) but with continuous use the amortization of the hull will be a small value.
So there is a lot of room to improve