NASA | Exploration Mission-1 – Pushing Farther Into Deep Space

In the next eight minutes you’ll
experience a twenty-five-and-a-half daymission from roll out to recovery. The
first integrated flight test of theOrion spacecraft and the Space Launch
System rocket, launching from theKennedy Space Center, is about to unfold.
This is the first of many missions tocome that will use the deep-space
exploration system to prepare our team,our ship, and our astronauts for human
operations in deep space. Rollout from the Vehicle Assembly Building signals
that launch is near. Sitting atop the mobile launcher the crawler transporter moves along the crawler way towards thehistoric launch pad 39b at the Kennedy
Space Center at a top speed of 1 mile an hour. After traveling over 4 miles,
the rocket and spacecraft climb up aramp and are positioned over a flame
trench. Once in position, the mobilelauncher is lowered onto support posts
and the crawlers roll away to a safe distance. Final checks are performed at
the pad, including crew cabin closeout viathe access arm sitting over 300 feet
above the surface of the launch pad. The launch date is set and the teams are
prepared for the mission that is about to occur. At sunrise on launch day
engineers in the launch control centerhave already powered up the spacecraft
in the rocket and loaded the core stageand upper stage with cryogenic fuel. As
launch window open approaches finalchecks are performed and when all
systems are go terminal countdown is initiated. The big physics of launch are
about to be put on full demonstration. Umbilical plates weighing hundreds of
pounds await their cue to retract toclear the path of the rocket at liftoff,
some mounted on arms the size oftractor-trailers. The mighty core stage
engines are prepared for engine startas they are thermally conditioned for an
onrush of cryogenic fuel in the heat of ignition. At T-minus 15 seconds sound
suppression is activated, cascading waterinto the flame trench to dampen the
acoustic shock, and as the core stageengines achieve full throttle shock
diamonds appear. At booster ignition theflame trench is flooded with fire.
At first motion all umbilical arms areretracted and the rocket clears the
tower in just seconds. At liftoff thevehicle produces 8. 8
million pounds of thrust and lofts thevehicle weighing nearly 6 million pounds and standing 32 stories tall to orbit. Propelled by a pair of five-segment boosters andfour liquid engines, the
rocket achieves maximum dynamic pressureonly 90 seconds into the mission–the
period of greatest atmospheric force onthe structure of the rocket. Thousands
will gather in Florida to watch our shipget smaller and smaller and leave the
Space Coast behind. Approximately two minutes into the mission
the boosters will have consumed all oftheir solid propellant and are safely
jettisoned. The rocket will continue onguiding itself to orbit with magnificent
precision. Just three minutes into themission the service module fairings are
jettisoned to lighten the vehicle andexpose Orion solar arrays. Just 40
seconds later the launch abort system isalso jettisoned. It is no longer needed:
Orion could safely abort at any time. Once at the desired velocity target the core stage engines are shut down and the core stage separates. The interim cryo propulsion stage with Orion will continue to orbit the Earth. Along the way they will past through the altitudeof the International Space Station at
250 statute miles. During this firstorbit the solar arrays are deployed so
that Orion no longer needs battery power. It can now produce its own power. Following solar array deployment, the arrays are positioned into a load-bearing configuration to preparefor the perigee raise maneuver. The raise
maneuver will ensure an Earth orbit anduse the thrust provided by the interim
cryo propulsion stage. Once the perigeeraise maneuver is complete
Orion systems are checked prior tocommitting to the translunar injection
or TLI maneuver. The TLI maneuver must besuccessfully completed to depart Earth
orbit. The TLI burn is approximately 20minutes in duration and increases the
spacecraft’s velocity over 9,000 feetper second–a speed change faster than a
high-powered rifle bullet travels. Following TLI, Orion is committed to a
lunar trajectory just one-and-a-halfhours after launch. Once complete, the
spacecraft adapter will remain with theinterim cyro propulsion stage and they
will separate from Orion. As Orion departs low-Earth orbit it will fly
through the orbital debris fieldencircling the Earth. Past the global
positioning navigation satellites,past the communication satellites in
geostationary orbit, and through the VanAllen radiation belts on into the deep
space radiation environment. Orion is nowentering in outbound coast phase. The
spacecraft is uniquely designed tonavigate, communicate, and operate in this
deep space environment. The outboundcoast of the Moon will take
approximately 4 days. As Orion approachesthe Moon, the service module will be used
to perform a critical lunar gravityassist maneuver, allowing the ship to
enter a distant retrograde orbit about the Moon. The Moon will get larger and
larger in the window and at closestapproach Orion will be just 62
miles from the surface of the Moon. As the spacecraft flies around the far side
of the Moon we will lose allcommunication back on Earth and for a
period of time Orion will be on its own. Mission Control will await acquisition
of signal and as we lock on a newgeneration will see their first Earth
rise. The spacecraft is now in thedistant retrograde orbit, where its
systems will be tested in the deep spaceenvironment for over a week. Along the
way our ship will travel farther fromEarth than any human-capable spacecraft
has ever gone. At the farthest pointOrion will be some 1,000 times farther
from Earth than the International SpaceStation, at over 270,000 miles away. Teams in Mission Control Houston and at NavalBase San Diego will prepare for Orion’s
return home and the recovery ship willset sail for the recovery zone in the Pacific Ocean. Orion will exit the distant retrograde
orbit with another lunar gravity assistand service module engine firing. Along
the way the trajectory will be adjustedto target the Earth’s thin atmosphere at
over a quarter-million miles away andensure precision landing in the Pacific
Ocean following a direct entry. During the coast home Orion will maintain the desired tail to Sun attitude tooptimize spacecraft cooling and maximize
power production in the deep spaceenvironment. Another 4 days’ return
coast home to Earth. As our home planet fills the windows of Orion an important contribution from ourEuropean partners, called the service
module, has done its job. The service module is jettisoned and separates. Following separation the world’s largest heat shield will be oriented into the direction of travelto prepare for entry interface and an
altitude of 400,000 feet. At entry interface, Orion will hit the
Earth’s atmosphere traveling at a speedof 24,500 miles an hour and
decelerate up to nine timesthe force of gravity. The heat
shield will protect the spacecraft fromtemperatures half as hot as the surface
of the Sun–approaching 5,000degrees Fahrenheit. Orion will continue to decelerate, pass through the soundbarrier, and announce its arrival to the waiting
recovery team with a sonic boom. Following peak heating a protectivethermal cover that sits over the
parachutes will be jettisoned. Thisbegins a series of parachute deployments.
The drogue chute deployment series isdesigned to stabilize and slow the
spacecraft in a period of less than 20minutes–Orion will slow from the speed of Mach32 to 0 at splashdown. The three main
parachutes will deploy and slowly unfurland suspend the 22,000 pound capsule and
allow it to gently descend to thesurface of the ocean. After 25-and-a-half
days, and a total distance traveledexceeding 1. 3 million miles, a precision
landing within eyesight of the recovery ship. Following splashdown Orion will
remain powered for a period of time asNavy divers approach in small boats
from the waiting recovery ship. After abrief inspection for hazards, the divers
will hook up tending lines and a towline. The capsule will be then towed
into the well deck of the recovery ship,and once the capsule clears the stern
gate, the gate will be closed, the welldeck will be drained, and we will bring
our ship home. We invite you to followalong at www. NASA. gov/exploration

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