Caitlin: Get ready, people!  On Thursday, December 4th, NASA will conduct the first test flight of its new deep space crew vehicle, going farther than any passenger vehicle has in over 40 years, and signaling NASA's return to the astronaut launching business for the first time since the space shuttle program ended in 2011.  Ladies and gentlemen, get ready to meet Orion.  

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Caitlin: The flight of Orion next week will take place without a crew, but nonetheless, it will go farther than any space vehicle has since astronauts went to the Moon.  Unlike any of today's crude spacecraft, Orion is made to go beyond low-Earth orbit.  Low-Earth orbit vehicles like NASA's Space Shuttle and Russia's Soyuz can only reach a maximum altitude of 2,000 km.  With the exception of NASA's six Apollo lunar missions, no crew vehicles have made it out of low-Earth orbit.  

Eventually, Orion will carry astronauts to asteroids, to the Moon probably in 2021, and to Mars and deep-space.  To do that, it will use the biggest, most powerful rocket ever built, known as the Space Launch System, which is still under construction, and will be completed in 2017.  But for next week's exploration Flight Test-1, Orion will hitch a ride on the Delta IV Heavy Rocket, which is the most powerful rocket currently in operation.  The mission will take Orion 58,000km above the Earth, orbiting twice in 4.5 hours.  For perspective, the ISS orbits Earth at an altitude of about 420km.  From that distance, Orion will re-enter Earth's atmosphere at a mind-boggling 32,000km/hr, generating temperatures up to 2,002 degrees Celsius.  

This will only be about 80% as hot as Orion will get when returning from the Moon, but it'll be a crucial test of Orion's state of the art heat-shield.  At five meters in diameter, it's the world's largest heat-shield, made of a single giant piece of ablative material, which redirects heat energy into chemical reactions.  It should be capable of protecting Orion's crew from temperatures as high as 2,800 degrees Celsius.  

The flight will also test Orion's nine parachutes and their ability to slow the capsule in stages before it lands in the Pacific Ocean off the coast of Mexico.  The test will also allow NASA to check completely new systems that will help protect Orion's future human crews.  For example, the new launch abort system will use thrusters to separate the crew module from the rocket in case of emergency.  It'll be tested in a drill near the apogee of this flight.  
And then there's the service module.  It's attached to the crew module and capable of being discarded during the mission.  The service module has propulsion systems that steer and orient Orion in different directions, while also carrying water and oxygen, generating and storing electricity, and transporting cargo.  
Basically, Orion is a whole new breed of vehicle, one that opens the next chapter in human space flight.  Though it looks like a slightly larger Apollo to allow for four crew instead of three, it has very different needs.  Orion is designed for deep space missions, so it needs to support a crew for up to 21 active days and six months at a resting state.  It needs to protect its crew from extreme heat, extreme cold, extreme radiation, and probably things we haven't even encountered yet, which is awesome and it all begins next Thursday, so check back in with us, and we will tell you about it!  

Thank you for joining me for SciShow Space News, if you want to keep exploring the universe with us, don't forget to go to YouTube.com/SciShowSpace and subscribe.

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