What Is Orion?

Artist's rendering of the Multi-Purpose Crew Vehicle on a deep space mission. Image credit: NASA

Orion ("o-rie-un") is a new NASA spacecraft for astronauts. The spacecraft will play an important part in the future of human space exploration. It will carry astronauts farther into the solar system than ever before.





What Will Orion Do?

Orion is the Multi-Purpose Crew Vehicle, or MPCV. It will carry astronauts into deep space and then return them home to Earth. Orion will be able to travel to the moon, Mars or an asteroid. If necessary, the MPCV will transport cargo and crew to the space station.

NASA is developing a huge rocket called a heavy-lift launch vehicle. Orion will launch on top of this rocket. The heavy-lift launch vehicle will carry Orion beyond low Earth orbit, where the International Space Station orbits, and even past the moon.

Orion has three main parts: the launch abort system, or LAS; the crew module; and the service module. Astronauts will sit in the middle section, the crew module. If an emergency occurs during launch or the climb to orbit, the LAS would activate in milliseconds. It would propel the crew module from the top of the rocket to safety. The LAS looks like a tower on top of the crew module. Beneath the crew module is the service module. It holds the power and propulsion systems. Solar array panels on the service module will track the sun to collect energy. This power will allow the spacecraft to remain in orbit for months at a time.


How Was Orion Designed?

NASA uses new technology and lessons learned from other missions to build new spacecraft. The Orion spacecraft is similar to NASA’s Apollo capsule. Apollo was the space program that carried astronauts to the moon in the 1960s and 1970s. The spacecraft could carry three astronauts. The shape of the MPCV looks like the Apollo capsule, but the new vehicle is bigger. Instead of the three-person Apollo crew, Orion will carry four astronauts.

When returning from deep space, a spacecraft re-enters Earth's atmosphere at a very high speed with high temperatures. A new version of the Apollo heat shield will keep the astronauts safe as the crew module returns home. Orion will land in the ocean when it returns. NASA used lessons learned from Apollo and space shuttle parachutes to design the MPCV parachutes. The updated parachutes will help the vehicle land safely in water. Orion will use its more modern technology in many other areas, such as computers, electronics, life-support systems and propulsion systems.

Launch Abort System
The launch abort system (LAS), positioned on a tower atop the crew module, activates within milliseconds to propel the crew module to safety in the event of an emergency during launch or climb to orbit. The system also protects the crew module from dangerous atmospheric loads and heating, then jettisons after the Multi Purpose Crew Vehicle (MPCV) is through the initial mission phase of ascent to orbit.
Crew Module
The crew module is the transportation capsule that provides a safe habitat for the crew, provides storage for consumables and research instruments, and serves as the docking port for crew transfers. The crew module is the only part of the MPCV that returns to Earth after each mission.
Service Module
The service module supports the crew module from launch through separation prior to reentry. It provides in-space propulsion capability for orbital transfer, attitude control, and high altitude ascent aborts. When mated with the crew module, it provides the water, oxygen and nitrogen needed for a habitable environment, generates and stores electrical power while on-orbit, and maintains the temperature of the vehicle's systems and components.
This module can also transport unpressurized cargo and scientific payloads.Image credit: NASA

Why Doesn't NASA Use the Space Shuttle?

The space shuttle was an amazing spacecraft that served NASA for 30 years. From 1981-2011, the space shuttle flew 135 missions. The shuttle carried satellites to orbit; transported parts, cargo and crew to build the International Space Station; and helped NASA learn about living and working in space.

However, the space shuttle was not designed to travel beyond low Earth orbit. For instance, it could not stay in space for much more than two weeks at a time. When a spacecraft returns from a deep space mission, it will return at high speeds. The space shuttle was not built to resist the high temperatures of a high-speed return.


When Will Orion Fly?

Before a spacecraft can fly, NASA must test it to make sure that it will do the job well and work safely. Parts of Orion already have been tested. For example, NASA has conducted water landing tests of the crew module. The first test flight of the MPCV is scheduled for 2014. The flight test is called Exploration Flight Test, or EFT-1. This flight will launch from Florida without a crew. It will fly two orbits around Earth. The orbits will reach an altitude higher than any spacecraft for humans has flown since 1973. The test vehicle will make a high-energy re-entry through Earth's atmosphere and land off the coast of California.

more here