During the first two-and-a-half minutes of flight, the first stage booster
powers the vehicle to an altitude of about 200,000 feet and a speed of Mach 6.1.
After its propellant is spent, the reusable booster separates and the upper
stage’s J-2X engine ignites and powers the crew vehicle to an altitude of about
63 miles. Then, the upper stage separates and Orion’s service module propulsion
system completes the trip to a circular orbit 185 miles above Earth.
Once in orbit, the crew vehicle and its service module will rendezvous and dock
either with the space station or with a lunar lander and Earth Departure Stage
that will send the astronauts on their way to the
The first launch of Ares I is foreseen for 2012. It will be followed by two
unmanned flights of the Orion Spacecraft. The first manned flight to the
International Space Station is foreseen no later than 2014. The first lunar
excursion is scheduled for the 2020 timeframe.
Length: 93 m (309 ft)
Gross Lift-off weight: 900 t (2 million lbs.)
Payload Weight: 25 metric tons (55,000 lb)
Ares I First Stage
The Ares I first stage is a single, five-segment reusable solid rocket booster (SRB)
derived from the Space Shuttle Program's reusable solid rocket motor, which
burns a specially formulated and shaped solid propellant called polybutadiene
acrylonitrile (PBAN). The SRB is similar to those used on the
but with a fifth motor segment added. ATK Thiokol is the prime contractor for
the Ares I first stage.
The first stage is slightly longer version of the space shuttle’s
pencil-shaped solid rocket booster.
Initial test flight known as Ares I-1, may occur in 2009. The test
flight will use a simulated fifth segment on the first stage motor and a
simulated upper stage.
A newly designed forward adapter will mate the vehicle's first stage to the
upper stage and will be equipped with booster separation motors to disconnect
the stages during ascent.
Ares I Upper Stage
The Ares I upper stage (second stage) is propelled by a J-2X main engine fuelled
with liquid oxygen and liquid hydrogen. The J-2X is an evolved variation of two
historic predecessors: the powerful J-2 engine that propelled the Apollo-era
Saturn IB and Saturn V rockets, and the J-2S, a simplified version of the J-2
developed and tested in the early 1970s but never flown.
Rocketdyne, a division of Pratt & Whitney, will be the main subcontractor for
the J2X rocket engine. Testing of the engine is currently underway at a facility
north of Huntsville, Alabama.
Pad Abort Tests
Pad abort tests and high altitude tests with a Little
Joe II-type system are foreseen from White Sands. They are foreseen
for the early 2009 timeframe.
* Originally, Ares I would have used a 4-segment Solid Rocket Booster (SRB)
for the first stage, with a simplified Space Shuttle Main Engine (SSME) being
used for the second stage; an unmanned version using a five-segment SRB first
stage like that planned for the unmanned Ares V would also have been
constructed. Because of a reduction in size of the Orion spacecraft as proposed,
a decision was made in 2006 by NASA to construct a five-segment booster for both
the Ares I and Ares V.
In addition to the redesign of the Ares I first stage, the possible problems and
expense of converting the reusable, ground-started SSME to a throwaway air-startable
engine led NASA to revise the booster's upper-stage design around the J2X rocket
motor. The J2X is a simpler and more rugged motor designed to be started in both
the air and in vacuum and its projected cost ($20-25 million USD) is less than
half that of the complex SSME ($55 million USD).
* The name Ares I was officially announced on June 30, 2006.
Formerly, the Ares I Rocket was called Crew Launch Vehicle.
Ares I Team and Partners
The Ares I effort and associated element project teams
are led by the Exploration Launch Projects Office at Marshall, on
behalf of the Constellation Program, hosted by NASA’s Johnson Space
Center, Houston and NASA’s Exploration Systems Mission Directorate
Participating NASA facilities include:
1. Johnson Space Center - responsible for the Orion and
flight operations projects
2. Stennis Space Center near Bay St. Louis, Missouri - primarily
responsible for J-2X and stage testing
3. Glenn Research Center’s Plum Brook Station in Sandusky, Ohio -
responsible for vacuum chamber testing of the J-2X upper stage
engine, developing the ascent development flight test upper stage
mass simulator and upper stage power, thrust vector control and
4. Langley Research Center in Hampton, Virginia - responsible for
aerodynamic characterization, ascent development flight test vehicle
integration and Orion mass simulator development and support to
flight mechanics and structure development
5. Ames Research Center in Sunnyvale, California - responsible
for integrated health monitoring, blast modeling and reliability
6. Michoud Assembly Facility in New Orleans - assemble the upper
7. Kennedy Space Center, Florida - home to all Constellation launch
operations and associated ground activities.