It has been more than a generation since NASA built a spacecraft to transport astronauts
into space but man is now ready to take another giant leap in space exploration.
NASA is planning on sending humans far further than they have ever been before by building the Orion Spacecraft.
The Orion spacecraft is designed to meet the evolving needs of human deep space exploration
for decades to come. Humans have not ventured into space beyond Low Earth Orbit since man's landing on the moon.
Low Earth Orbit is an orbit around the Earth
with an altitude ranging from 160 km to 2,000 km above the earth.
Low Earth Orbit is where the Space Shuttle flew and the International Space Station now flies. It is where spy satellites
and Earth observing satellites fly. It is where the Hubble telescope and many communication satellites fly.
It is also where most of the "space junk" is located.
Orion breaks through this Low Earth Orbit and ventures into interplanetary space on extended duration
deep space missions. Destinations include near-Earth asteroids, our own Moon, the moons
of Mars and eventually Mars itself. The Orion Multi-Purpose Crew Vehicle (MPCV)
provides an entirely new human space exploration capability, beyond low Earth orbit.
In addition to deep space missions, Orion is also capable of transporting crew and cargo
to the International Space Station. It is also a back-up system for the ISS.
It can rendezvous with a lunar landing module and be a departure point in low-Earth orbit
from which crews can venture out to and return from the moon and Mars.
Orion can remain docked at the International Space Station for up to six months. It also has the ability to
stay in orbit around the moon unattended, without an astronaut on board, for the duration
of a lunar surface visit that could last up to six months.
Orion consists of a cone-shaped Crew Capsule, a Service Module, and a spacecraft adapter.
Other components include a Space Launch Abort System, and for extended interplanetary travel,
a Deep Space Habitat. Orion features dozens of new technological
advancements and innovations, many of which were derived from experience with the space
shuttle program, and are incorporated into the spacecraft's design. Even new manufacturing
techniques have been developed for Orion such as a self-reacting friction stir welding system
which provides stronger and more durable joints. Some of the component parts are produced using
3D printing including a baffle and rocket injector. Since Orion is a re-useable craft,
its life support, propulsion, thermal protection, and avionics systems have been developed so
that they can be upgraded as new technologies and innovations become available in the future.
Orion's heat shield is an extremely critical part of the spacecraft.
Orion's capsule shape allows it to land in water, like the Apollo missions did, when it returns to earth.
A capsule without wings makes it a lot simpler to provide heat protection during re-entry.
Due to speeds of around 27,000 MPH required for re-entry from deep space missions, Orion's
Heat Shield needs to protect the capsule from temperatures near 5,000 degrees Fahrenheit,
more than half of the surface temperature of the sun...temperatures capable of melting iron, steel or chromium.
The heat shield's skeleton gives the spacecraft
the strength to withstand the craft's impact with the water's surface when it splashes down in the Pacific Ocean.
Orion's heat shield, at 16 1/2 feet in diameter,
is the largest heat shield ever constructed. A heat resistant material, called AVCOAT,
covers the heat shield. This is a glass-filled epoxy-novolac honeycomb system matrix applied
to the heat shield skeleton. The honeycomb shape gives the heat shield strength and resistance to cracking.
Avcoat is the only man-made ablative material that exists today that can handle
the extreme temperatures of high speed re-entry following a deep space mission.
The heat shield is designed to be consumed as Orion re-enters earth's atmosphere. The ablator heat shield
material therefore burns off during re-entry, carrying heat away from the capsule's structure,
and providing a layer of cooling between itself and the capsule. Since the Space Shuttle could
never have left low earth orbit with its wings and tail, its heat tiles worked fine for heat
the levels that it encountered during its returns from low earth orbit. But tiles like
on the Space Shuttle would not be strong enough for Orion's heat shield which encounters
heat levels significantly hotter than the shuttle ever did.
The non-heat shield surface of the capsule however, called its back shell, is covered
with AETB-8 tiles which are the latest generation of heat shield tiles.
These tiles also protect the capsule from the debris environment or space junk that Orion could encounter
while in low earth orbit. Up to now, long duration spaceflights for
Americans have lasted about six months and have taken place entirely within low-Earth orbit.
Since Orion takes astronauts to destinations beyond low-Earth orbit, astronauts will travel
outside the protective shield of the Earth's atmosphere and magnetic field.
Without the protection that the Earth provides, the crew and systems of Orion would be exposed to the
full spectrum of space radiation. As astronauts venture into interplanetary space they will
also have to cross the Van Allen Belt, a tightly packed field of radiation around the Earth
that protects earth from charged ions. NASA has had to develop methods of protection from
significantly more radiation than astronauts have experienced in the past.
Orion will be able to use materials already stored inside the spacecraft such as water, food, equipment
and other supplies which have been shown to offer additional protection against radiation
in addition to the spacecraft itself. Since these items are already stored near the heat
shield, this provides a temporary shelter in the aft bay close to the heat shield.
Several radiation sensors are located on board to record levels of radiation.
Orion may look a lot like the Apollo capsule in shape but the comparison stops there.
Orion is larger than Apollo and has been referred to as Apollo on steroids.
Whereas Apollo carried 3 astronauts, Orion can carry as many as 6 crew members to and from
the International Space Station and is capable of landing 4 astronauts on the moon.
The crew capsule can withstand the vacuum of space and keeps out salty ocean water upon
returning to Earth protecting critical components. It provides a habitat for the crew, storage
for consumables, and holds the majority of Orion's electronics.
The crew module is the only re-useable part of Orion that returns to Earth after each mission.
This is the green interior pressure vessel that makes up the core of the crew capsule.
The Capsule's Avionics are described as the "brains" of the spacecraft.
Orion has advanced systems in electrical power, flight control, life support, and communications.
Due to the extreme distances of long duration missions, Orion's advanced navigation and
tracking systems will enable Orion to maintain orientation and communication with the Earth.
Its systems move data at a rate 1,000 times faster than systems on the shuttle and the ISS.
The capsule contains what is called a "glass cockpit".
It is a digital control system evolved from several airplane cockpit designs
including Boeing's 787 multifunction flat-panel multicolor displays. It is outfitted with
an "auto-dock" feature allowing the spacecraft to dock with the International Space Station
automatically, yet has a provision for the flight crew to take over in an emergency.
The Orion Service Module serves as the primary power and propulsion component of the spacecraft,
and is discarded at the end of each mission. It carries rocket engines for propulsion and
large solar panels for generating electrical power. It is attached below the crew capsule,
and provides life-sustaining water, oxygen and nitrogen needed for a habitable environment
and maintains the temperature of the vehicle's systems and components.
Both the Crew Module and Service Module are constructed of the aluminum lithium alloy
that was used on the space shuttle's external tank.
14 foot protective fairing panels cover the capsule and service module protecting those
components during launch and are jettisoned after the spacecraft reaches 560,000 feet above the earth.
Orion's Ultra-Flex solar arrays support
all of the electrical power needs for both earth-orbiting and deep space missions.
Rechargeable lithium-ion batteries store that power for use when the vehicle is away from sunlight.
The solar arrays are 10 times as rigid as conventional rigid panel arrays, yet are micro-thin.
Each of the 2 circular solar arrays spans 19 feet in diameter and provides over 6,000 watts of power
... enough to power six three bedroom homes.
The spacecraft adapter connects the Crew Capsule and Service Module to the launch vehicle and
protects service module components during launch and ascent into orbit.
The Orion MSA diaphragm is a light weight composite structure that protects astronauts
in the crew capsule from hazardous gases produced by the upper stage launch engines. It sits
between the propellant stage of the rocket and the crew capsule.
The crew capsule and service module join with a Deep Space Habitat for longer deep space
missions, which can last up to 900 days. The crew quarters of the Deep Space Habitat provide
the crew with radiation and storm shelter protection during Solar Particle Events.
They provide, in addition to living quarters, storage areas, science stations, and a galley for
food preparation, including a microwave and refrigerator for food heating and storage.
Upon returning to Earth after deep space missions the capsule will splash down in the Pacific Ocean.
Once the heat shield has done its job of getting Orion through the atmosphere, parachutes
will take over for the landing. A forward bay cover protects the crew during launch,
flight, and re-entry, but must be jettisoned to allow Orion's main parachutes to deploy.
After returning from a deep space mission, the forward bay cover is jettisoned at an
altitude of 23,000 feet. Drogue parachutes initially slow down the
spacecraft and then three smaller pilot parachutes are deployed. Next come the three main parachutes.
They measure 116' across and weigh 300 pounds each and together can cover a football field.
In the event of emergency on the launch pad or during launch, an escape system called
Launch Abort System separates the Crew Module from the launch vehicle using a solid rocket-powered
launch abort motor. This abort motor is more powerful than the Atlas booster that launched
astronaut John Glenn into orbit in 1962. The launch abort system, positioned on a tower
atop the crew module, activates within milliseconds to propel the crew module 500' in the first
3 seconds and to safety in the event of an emergency during launch or climb to orbit.
The Launch Abort System consists of 3 motors: The Main Abort Motor, The Attitude Control Motor, and The Jettison Motor.
Orion is launched into space by NASA's Space Launch System,
an advanced, heavy lift vehicle which provides an entirely new capability
for science and human exploration beyond Earth's orbit and into interplanetary space.
The SLS is NASA's first exploration-class vehicle since the Saturn V rocket took American astronauts
to the moon over 40 years ago. The core (center) stage stands over 200 feet tall
with a diameter of 27.5 feet. It carries cryogenic liquid hydrogen and liquid oxygen
that feed the 4 RS-25 engines for the SLS. Two solid rocket boosters add to the configuration.
Orion is the safest, most advanced spacecraft ever built. It is flexible and capable enough
to take humans to a variety of destinations including landing on an asteroid, and into
interplanetary space. After the December 2014 test flight, an unmanned
Orion may circle the Moon by 2017 and the first manned mission by 2021.
Landing on an asteroid could take place during the late 2020s and a landing on Mars by the 2030s.
If humans can't make it to near-Earth objects, they can't make it to Mars so landing on
an asteroid would be the next step necessary toward a human landing on Mars.
The Orion spacecraft is capable of carrying astronauts on diverse expeditions beyond Earth's
orbit, ushering in a new era a human space exploration.