When it comes to getting into space, traditional rocketry is the pits. Gigantic tanks that cost millions of dollars, massive fuel requirements, trajectories that fight against the atmosphere instead of using it to their advantage. Out of the five space shuttles built, two have gone boom. If you're going to build a Lifeboat in orbit, deploy solar power satellites, or visit space hotels, you're going to need a better way to get into space.
 
Luckily, there are numerous ideas, including rocket planes, orbital airships, the space elevator, and the space pier. 3/4 of these ideas already have companies putting serious resources towards their realization. Let's take a look at the details, shall we?
 

 
The rocket plane is currently the idea getting the most attention and funding. All current rocket planes are only capable of taking people to the edge of space and back, rather than going into orbit. Thus, trips on rocket planes are called suborbital space flights. The typical rocket plane launch consists of a larger plane that helps a smaller unit ascend to about 14km, where the air is several times thinner than at ground level, then releasing it.
 
The first rocket plane to reach space, as defined by 100km altitude, was the North American X-15, which was flown almost two hundred times throughout the 60s. SpaceShipOne has also reached space and the more advanced SpaceShipTwo was completed in 2009. Virgin Galactic, the company largely funding the present effort, has stated that if SpaceShipTwo is commerically successful, it will follow up with a craft that will be used for transportation through point-to-point suborbital spaceflight, the SpaceShipThree. This vehicle would provide a 2 hour trip from London to Sydney. This will be followed up with a craft capable of making it into orbit, SpaceShipFour:
 

 
In general, craft that suck material directly from the atmosphere to use for oxidation offer superior specific impulse to traditional chemical rockets:
 

 
In 2006, Virgin Galactic started constructing the world's first purpose-built commerical spaceport, SpacePortAmerica, in southwest New Mexico. Space Adventures Ltd. is partnering with the people behind the Ansari X Prize to plan and eventually build the Ras Al Khaimah Spaceport in the United Arab Emirates, and the Singapore Spaceport in Singapore. Here's what they would look like upon completion:
 

 

 
Spiffy, yes?
 
So what is an orbital airship? Proposed by JP Aerospace, the orbital airship concept is a three-staged process which includes a conventional airship, a permanent sky base, followed by a helium-filled, solar-powered ascender unit that slowly accelerates horizontally until it reaches escape velocity. Here's a look into the middle of the vee of the Y-shaped ascender unit:
 

 
Here's a look at the inside:
 

 
The JP Aerospace website has several videos of both real flights and CG mockups. Problem is, engineers on the sci.space newsgroup confirmed that their plan is physically impossible. You can't gather enough energy with solar cells to overcome the atmospheric drag on the ascender unit. Interesting idea, but seems as if it will require major breakthroughs to be feasible, if ever. Time to move on to the space elevator:
 

 
The space elevator is a concept being championed by the Liftport Group. It's one of the older alternative space ideas, dating back several decades. The proposed contruction method, is to guide an asteroid into geostationary orbit, launch a series of rockets filled with carbon nanotube fiber to it, and lower a thin "seed elevator" to the earth's surface. From this point on, the elevator could be strengthened by using robotic climbers to add additional material to the initial thread.
 
The space elevator concept is very popular, in no small part due to its common presence in sci-fi, Tower of Babel-esque connotations, and the numerous CG mockups floating around on the net. In the short term, it may not be the ideal means of getting to space. To quote extropy list veteran Eugen Leitl:

"I have problems with terrestrial space elevators (much less so with lunar elevators), largely because of need of actively moving the ribbon to avoid perforation by debris, because the tensile strenth required is borderline to what physics gives you, with not much safety margin, and if you fail only once you've wrapped all your infrastructure around the equator."

Forming a continuous rigid strand from earth to space, a space elevator would interfere with all sorts of low earth orbits, and also be an ideal target for terrorists of the future. Once that cable snaps, it would practically take the power of a god to grab the two ends and reconnect them without imminent disaster. An alternative is the Space Pier:

 
The Space Pier is an idea from J. Storrs Hall, a pioneer in the field of nanotechnology and on our Scientific Advisory Board. Essentially, it's a 100km-tall, 300km-structure topped with an electromagnetic linear accelerator. Air resistance at this altitude is lessened by a factor of one million, and the plan is less cumbersome and catastrophe-prone than a taut string that reaches six earth radii from the surface. It would be a compressive tower, that is, standing under its own weight rather than using a geosyncronous counterweight. If one of the legs were K.O.ed by a nuclear terrorist attack, the structure as a whole would still stand. Utility fog distributed around the legs would provide yet another fail-safe. The trip to the top is much shorter than climbing up a 36,000 km space elevator, and the way to low earth orbit is fast and easy. Once in LEO, one could employ ion drives or other techniques to get to GEO or out of the earth's gravity well.
 
RESOURCES

Colonies in space may be only hope says Hawking, an interview by The Telegraph - October 16, 2001
 
Literati Moon-ISRU homepage
 
Shooting for space on a shoestring: Just how cheap can rockets get? by Michael Hopkin, Nature - September 22, 2006
 
REPORTS

Dipping a Toe into the Sea of Space: Are we Columbus or Erikson? by Lifeboat Foundation Scientific Advisory Board member Gregory Benford.
 
AUDIO

Space & Middle East - Howard Bloom (subscription required to hear audio)
 
VIDEO

Blue Beauty: Our Beautiful Earth
 
ONLINE RESOURCES: LIGHT READING

Better Ways to Get into Space by Michael Anissimov - 2006
 
Building a Sustainable Political Consensus for Construction of a Space Elevator - PDF file by James N. Gardner - 2004
 
It is Time to Backup Civilization by Robert Shapiro - 2003
 
Orbital Space Settlement by Al Globus - ongoing project.
 
ONLINE RESOURCES: DIFFICULT READING

Advanced Automation for Space Missions - 1980 NASA feasibility analysis of self-replicating space factories coedited by Robert A. Freitas Jr.
 
An Orbiting Magnetic Arrest System for Rocket-Free Transportation to Earth Orbit - White paper by Phil Putman.
 
BOOKS

High Frontier: Human Colonies in Space by Gerard K. O'Neill - 1977
 
Reinventing Capitalism: Putting Soul In the Machine — A Radical Reperception of Western Civilization by Howard Bloom - 2006
 
Space-Based Manufacturing from Nonterrestrial Materials by Gerard K. O'Neill - 1977
 
The Survival Imperative: Using Space to Protect Earth by William E. Burrows - 2006