Ares I

NASA Ares I Rocket will be used primarily to launch the Orion Spacecraft to the International Space Station (after the end of the Space Shuttle flight program in 2010) or to 'park' payloads in Earth orbit for retrieval by other spacecraft bound for the moon or other destinations. The vehicle will also be used to launch the unmanned cargo supply version of the Orion, as well as unmanned satellites weighing at or less than 25 metric tons. Ares-I technology is based on Apollo and Space Shuttle propulsion elements. It is currently in development.

Ares I Rocket Name

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 moon.

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. 

Specs

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 space shuttle, 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.

History

 * 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.

• Constellation Program: Ares I Crew Launch Vehicle: NASA
• NASA - Ares: NASA's New Rockets Get Names:
• Ares I Crew Launch Vehicle First Stage Contract Modification: 4th October NASA Press Release