Michael Laine, the CEO of LiftPort, a commercial advocate of space elevators, says he plans to have a usable elevator anchored in the Pacific Ocean near the equator by April 12, 2018. LiftPort's outer space precursor hit a 1,000-foot benchmark in September 2005, but it clearly has a long climb ahead. Laine also believes his company can bring payload costs down to $400 a pound, a huge reduction from the many thousands of dollars per pound it currently costs to get people and satellites into geosynchronous orbit via rockets.

HEY, HOT STUFF

Step aside, solids, liquids, and gases. Plasma has arrived, and former astronaut Franklin Chang Diaz, who has been to space seven times on conventional chemical rockets, wants to travel with plasma. "If you heat a gas enough, the atoms break apart, and you get plasma. It's a fourth state of matter that's really, really hot. Plasma is everywhere in space," he says. "It's what our stars and sun are, really."

The hotter the exhaust, the zippier the rockets. Right now, rocket exhaust is in the thousands of degrees. "That's a pretty cold fuel," says Chang Diaz. "Plasma exhaust will be millions of degrees hot."

He's talking about fueling an ionically souped-up engine that can shift gears through space and get humans to Mars in three or four months instead of the minimum 10 months projected for chemical rockets. Better travel speed could greatly reduce the wearying weeks of boredom, the bone weakening of weightlessness, and the dangerous levels of exposure to solar radiation that space travelers face on long trips.

The plasma rocket is too hot (by just a few million degrees) to launch from Earth. One idea is to assemble it in space, like the ISS. Current plans to heat the plasma are for the power source to be electrical - possibly converting solar energy for close to Earth and using nuclear reactors for deep space.