Space neighborhood: Mars is just a block away

Updated block configuration enables Boeing’s Exploration Upper Stage to take future crews to Earth’s planetary neighbor.

May 01, 2023 in Commercial, Space

EUS launch system with Orion Photo Credit: NASA

While the Artemis II crew was just announced, Boeing teams are already preparing for when the crew will head much further into space than the moon

The moon is the first stop for NASA’s Space Launch System (SLS) rocket as the Artemis missions take off. Beyond that, SLS has its sights set on Mars — Earth’s most intriguing planetary neighbor.

While people have dreamed of exploring Mars for decades, the average distance between Earth and Mars is over 200 times greater than the distance between Earth and the moon.

So, a trip to Mars requires a more capable, in-space vehicle.

More capable than what?

For the Artemis I, II and III missions, the upper stage on the SLS rocket is known as the Interim Cryogenic Propulsion Stage (ICPS). While sufficient to get Orion to the moon, the sustained exploration of lunar space requires more payload than a crew capsule. Meaningful exploration requires more capability and power.

Enter the Exploration Upper Stage (EUS):

EUS will provide the in-space propulsion needed to bring a crewed spacecraft and large payloads to the moon to enable the Moon to Mars objectives, beginning with the Artemis IV mission.

Here’s a look at some key differences between the two upper stages.
Artemis EUS metrics infographic Photo Credit: NASA
What this means:

The EUS makes deep-space missions possible. EUS will support sustainable, scientifically rich exploration, including:

  • Validation missions between Earth and the moon.
  • Exploratory missions to deliver large Earth observation satellites and telescopes to space.
  • Scientific missions to the outer planets and their moons.
Why it matters:

“When people first landed on the moon, the prospect of exploring Mars was merely science fiction,” said Sarah Weis, B1B Deputy Program Manager. “Now it’s within reach, and there’s no limit to all we can learn through space exploration.”



NASA’s Space Launch System – the nation’s next-generation, human-rated rocket – will enable NASA’s Artemis missions and will launch people and cargo to the moon, Mars and beyond. NASA selected Boeing to design, develop, test and produce the core stages, upper stages, and avionics suite for the SLS fleet of rockets. The first SLS rocket – featuring the Boeing-built core stage – successfully launched on Nov. 16, 2022, as part of the Artemis I mission. Production is underway for the Boeing-built core stages, upper stages and avionics for future Artemis missions.