What will replace the space shuttle?

STS-135 is the last planned space shuttle mission, it's set for June 28, 2011 and after it is finished all of the space shuttles will be decommissioned and NASA won't have any kind of vehicle to ferry astronauts to and from space.

So now that the aging space shuttle fleet is being decommissioned what is NASA going to use in it's place? NASA is going to need some kind of transport vehicle to shuttle people and supplies back and forth between Earth and the International Space Station.

So until NASA comes up with something new, here are the options that they will be using in the near and distant future.

Constellation Program
The constellation program was destined to replace the space shuttle program. The primary space vehicle was called Orion, and the rocket to take it there was the Ares. Orion wasn't designed to be a shuttle, it's a capsule, not unlike the old Apollo capsules that took people to and from the moon. It will be lifted upon an Ares rocket, and then descend to earth with a heat shield and parachutes.

The US government had cancelled this program in 2010 due to budget concerns, however as of the beginning of 2012 the vehicle is still under development, with the first orbital test flight scheduled for 2014.

Private Corporations - NASA's bet on the future
NASA knows that they spent WAY too much money on the space shuttle, it was one of the most complex and complicated things mankind has ever built. So they are looking to the private sector to help innovate and reduce costs and complexity. The private sector is already making strides in space exploration in both lifting up satellites (Space-X) into orbit and transporting people into low-earth orbit (Scaled Composites).

So let's have a look at some of the successes already in place and upcoming projects that the private sector is working on.

SpaceX is a company founded by dot-com zillionaire Elon Musk. They have already launched multiple payloads into space for both private companies and governments.

SpaceX has been developing a manned spacecraft called Dragon, when launched this would be the very first ever private spacecraft launched into orbit and recovered.

Scaled Composites is a company founded by the famed aeronautical designer and engineer Burt Rutan. They're flagship is the "SpaceShip One" which was the first private space craft to venture into low earth orbit twice in a 6 month period. This won them the X-Prize.

Scaled Composites is now teaming up with billionaire Richard Branson and his Virgin brand to create Virgin Galactic. This company will use the next version of this spaceship to ferry people back and forth into orbit, creating the age of the space tourist.

There are some great strides being made with private space flight, but it's still very much in it's infancy. So until spacecraft created by the private sector matures a bit NASA and the US space program is going to  have to rely on foreign nations and the spacecraft that they use to get American astronauts to and from space.

Here are some of their options:

The Russian Soyuz space capsule is one of the most successful spacecraft of all time. The Soyuz has become the most frequent launched of all spacecraft. It is also by far the most reliable spacecraft ever created. This is amazing because the design hasn't changed too much since it was introduced in the 1960's.

The Shenzhou is a Chinese spacecraft, and it's design resembles the Russian Soyuz capsule. China is the only country other than Russia and the United States to have a currently operation spacecraft.