J-2X

This "legacy hardware" included the main engines and the solid rocket boosters from the space shuttle and a modernized version of the Saturn V's upper-stage J-2 engine, which would be known as the J-2X.

TIME.com: Top Stories 2011

This "legacy hardware" included the main engines and the solid rocket boosters from the space shuttle and a modernized version of the Saturn V's upper-stage J-2 engine, which would be known as the J-2X.

TIME.com: Top Stories 2011

This "legacy hardware" included the main engines and the solid rocket boosters from the space shuttle and a modernized version of the Saturn V's upper-stage J-2 engine, which would be known as the J-2X.

TIME.com: Top Stories 2011

This "legacy hardware" included the main engines and the solid rocket boosters from the space shuttle and a modernized version of the Saturn V's upper-stage J-2 engine, which would be known as the J-2X.

TIME.com: Top Stories 2011

Additionally, there may be sufficient funds and time to develop such upgrades as RL-60, J-2X, RS-68B and the 5-seg RSRMs in the medium-term without them becoming 'long poles 'in the schedule.

Griffin - No Human Space Flight Review Needed - NASA Watch 2009

Continue J-2X development for use on Ares-V variant; many of our issues with rocket design stem from a lack of choices in production engines.

Dear Mr. Augustine - NASA Watch 2009

Let it fly like a Titan IV and air start the Upper Stage J-2X (as planned).

Phantom Internal Studies - NASA Watch 2009

Ares requires the never-flown J-2X engines, and Ares V requires the RS-68B variant, which has also never flown.

Transition Team Update - NASA Watch 2009

Sooner, with 6x RL-10s (currently in production) or later if you continue developing the J-2X as with Ares I/V.

Today's Video - Profiling the Ares Launch Vehicle - NASA Watch 2009

Ares I and V have nothing in common, save the J-2X engine on the upper stage.

Transition Team Update - NASA Watch 2009