NASA's Orion Program kicked off its critical design review at the agency's Johnson Space Center in Houston the week of Aug. 3, a major program milestone that will ensure the spacecraft's design is ready for its deep space missions atop NASA's Space Launch System (SLS) rocket.

Orion, which successfully flew about 3,600 miles into space last year during an uncrewed flight test, is being developed to send astronauts to new destinations in the solar system, including an asteroid and on toward Mars. During its next mission, Orion will venture to a distant lunar orbit beyond the far side of the moon.

"Our team across the country has been working incredibly hard to develop a spacecraft capable of expanding humanity's frontier in the solar system," said Mark Geyer, Orion Program manager. "Since even before flying Orion in space last year, we've been moving at full steam toward our first flight on SLS, and this review gives us a chance to make sure all systems and their designs meet our requirements and are in sync before we continue pressing ahead."

The review is a months-long process where engineers delve into the details of the spacecraft's systems and subsystems to evaluate their maturity and involves thousands of documents. The milestone is a rallying point for those with technical stakes in successfully building and flying future Orion missions to ensure all elements are in sync before moving ahead with full-scale fabrication, assembly, integration and testing.

It will include an evaluation of common aspects of the spacecraft for Exploration Mission (EM)-1 and the spacecraft for EM-2, the first Orion mission with astronauts, such as the spacecraft's structures, pyrotechnics, Launch Abort System, guidance, navigation and control and software, among many other elements. Systems unique to EM-2 will be addressed at a later critical design review for the mission in the fall of 2017.

Not only will Orion technical experts take a close look at the spacecraft, but engineers working on SLS, which recently completed its own critical design review, the ground systems needed for launch and other elements needed to execute successful missions, such as mission operations and safety and mission assurance, will be on hand during the review to provide insight.

"We're working through our critical design review now so that we can balance evaluating individual components with the hardware manufacturing needs we have to start our assembly and integration activities," said Geyer.

The Orion Program's critical design review is targeted for completion in late October.