After the resounding success of the Artemis I mission, why is there an encore after 2 years?

The launch of the Artemis I mission in mid-November was spectacular, and NASA’s Orion spacecraft has performed almost flawlessly since then. If all goes as expected — and there’s no reason to believe it won’t — Orion will splash up in calm seas off the coast of California this weekend.

This exploratory mission provided dazzling pictures of the Earth and the Moon and offered the promise that humans would soon fly into deep space again. So the question for NASA then is when can we expect an encore?

Realistically, the sequel to Artemis I is probably at least two years away. The Artemis II mission likely won’t happen until early 2025, although NASA isn’t giving up hope of launching humans into deep space in 2024.

It may seem strange that there is such a large gap. After all, with its flight in November, the Space Launch System rocket has already demonstrated its capabilities. And if Orion returns safely to Earth, it will confirm the calculations of the engineers who designed and built its heat shield. Should it really take more than two years to finish building a second rocket and spacecraft and complete the certification of life support systems in Orion?

The short answer is no, and the reason for the long difference is a bit absurd. It all goes back to a decision made about eight years ago to plug a $100 million budget hole in the Orion program. As a result of a series of events that followed this decision, Artemis II is unlikely to fly before 2025 due to its eight relatively small flight computers.

“I hate to say that Orion is holding us back this time,” Mark Kirasich, who was NASA’s Orion program manager when the decision was made, said in an interview. “But I’m bringing up the rear. And that’s part of my heritage.”

A long time ago, in a budget far away

About eight years ago, senior officials at NASA and Orion’s prime contractor, Lockheed Martin, had to plug a budget hole. At the time, NASA was spending $1.2 billion a year developing the Orion spacecraft, and although it was making progress in the design, there were still challenges.

NASA’s exploration plans at the time were substantially different from today’s Artemis program. Nominally, the agency was building Orion and the SLS rocket as part of Journey to Mars. But there was no clear plan for how to get there, and no well-defined missions for Orion to fly.

One key difference is that NASA plans to fly the original version of the SLS rocket, known as “Block 1,” only once. After this initial mission, the agency plans to upgrade the rocket’s upper stage, making a version of the rocket known as “Block 1B.” Because this variant was taller and more powerful than the Block 1, it required significant modifications to the rocket’s launch tower. NASA engineers estimated that it would take nearly three years of work after the initial SLS launch to complete and test the reconstructed tower.

So it seemed plausible that the Orion planners might reuse some components from their spacecraft’s first flight on the second. In particular, they focused on a set of two dozen avionics “boxes,” which are part of the electronic system that controls Orion’s communication, navigation, display and flight control systems. They estimated it would take about two years to recertify the flight hardware.

By not needing to build two dozen avionics boxes for Orion’s second flight, the program closed a $100 million budget hole. And as far as the schedule goes, they would have almost a year to work on the launch tower.

“It was just a budget decision,” Kirasich said. “The launch dates were completely different at the time.”