A set of NanoRacks CubeSats is photographed by an Expedition 38 crew member after deployment by the NanoRacks Launcher attached to the end of the Japanese robotic arm. The CubeSats program contains a variety of experiments such as Earth observations and advanced electronics testing. International Space Station solar array panels are at left. Earth's horizon and the blackness of space provide the backdrop for the scene. - 

NASA is increasingly reliant on private contractors to get goods to and from space. Here are four ways the rich are trying to get richer in the final frontier:

1. Transportation: SpaceX has a launch set for March 16 to supply the International Space Station. NASA now depends on private firms to ferry stuff up to the astronauts on the station.

2. Space Tourism: Virgin Galactic says it may be able to launch its suborbital space tourism operation later this year. Tickets for a flight aboard Virgin's SpaceShipTwo cost hundreds of thousands of dollars. Still, Virgin Galactic is already booked up for years.

3. Asteroid Mining: Some investors want to get into the mining of asteroids. It hasn't been done, but it would involve building some sort of platform on an asteroid, then scooping out valuable platinum, iron and cobalt.

4. Garbage Collection: There's a lot of space junk out there. It's moving fast, and it can do some serious damage to a passing spacecraft. Now there's research on Pacman-like space vehicles that could "eat" the space garbage.