1. Fuel depots. 2-17 times more stuff to the moon or other space missions. Lowering costs for GTO closer to LEO orbit costs
Boeing Propellant fuel depot
2. Lunar concrete would reduce the amount of material needed to build things on the moon by ten times.
A 50 meter telescope could be built from lunar concrete, with the mirror covered with a thin layer of aluminum. It could directly image any potential continents on planets around nearby stars with no atmosphere on the moon to distort the massive light gathering area.
3. Successful Big and cheap rockets by Spacex or others
Spacex is trying to bring costs down to $500-3200/kg to get into space
Spacex Falcon 9 Heavy
Spacex Dragon space capsule
4. Bigelow - inflatable space stations
Bigelows planned habitable private space station
Bigelow Aerospace Lagrange point and lunar plans
The Vasimr 200kw unit is almost flight ready
A 12 MW Vasimr system could send a ship to Mars in less than 120 days one way. A 200 MW Vasimr could go to Mars in 39 days.
1-2MW Vasimr lunar cargo vehicle could transfer up to 39% of the mass from low earth orbit to the moon.
6. Solar electric sail
A simplified picture of the electric sail. An actual system would have 50 to 100 or more 20 kilometer wires. 100 kg spaceships could be accelerated to final speeds of 40-100 km/second. The electric sail is an extremely promising new propulsion technique which is nearly ready to be tested. If electron heating turns out to be successful performance may be increased even more. Costs for solar system missions will go down and new capabilities and performance will be possible.
7. Virgin galactic getting LEO orbit capabilities with SpaceshipThree
Spaceshiptwo at apogee
Virgin Galactic could expand the number of people (passengers) who get to fly by 10 to 1000 times versus the NASA plans. Seats on spaceshiptwo cost $200,000. Virgin Galactic says more than 200 individuals have booked, and another 85,000 have registered an interest to fly. Tens of millions of dollars in deposits have already been taken. If set prices drop to $100,000 each then 85,000 people would generate $8.5 billion in revenue. This could make Spaceshipthree (an orbital system) fully fundable from Virgin Galactic operational profits. Virgin Galactic appears to be offering a path forward to safer (100 times or more safer) and cheaper travel into space for a lot more people.
8. LEO solar power
Low earth orbit (LEO) systems offer the advantage of reducing the scale of the solar power systems. An interesting concept for solar power appears to be on track for testing in Palau by 2012. The Space Island Group is also proposing low earth orbit solar power beamed to multiple locations. Space Island Group hopes to have its first system up by 2010. Space Island group is targeting 10 cents per kilowatt hour (kWh). The Space Island Group has almost completed financing for a prototype system that it claims will be in orbit within 18 months, at a total cost of $200 million. "The satellite will deliver between 10 to 25 megawatts of power," says Meyers. "It will 'site-hop' across base stations in Europe, beaming 90 minutes of power to each one by microwave."
9. Lorentz force propulsion
Successful simulated space conditions test of lorentz force propulsion
Refueling nuclear rockets using lorentz force propulsion
10.Power source breakthroughs: IEC fusion, focus fusion, uranium hydride reactors, Blacklight power
Laser arrays. Technology is possible but not funded.
Space elevators and space piers. Technology will take two decades or more to mature or to be funded.
Tethers. Minor development and projects funded.