As the Artemis II spacecraft launched on April 1 at 6:35 p.m. ET, millions of people watched the massive rocket propel into the sky. To the public, that launch lasted a few minutes–but behind that fleeting moment was years of engineering, problem-solving, and testing. The mission marked a major milestone for NASA, making Artemis II the first time humans have returned to the moon since Apollo 17 in 1972. Beyond its historical significance, the launch reveals how complex modern space missions are today, and the engineers who made it possible.
While most viewers focused on liftoff, Chris Ranieri, an aerospace engineer and director at The Aerospace Corporation, was watching something more specific.
“I watched the big white side boosters,” he said in an interview with Eastside.
Those boosters provide most of the thrust that the rocket uses during the first few minutes of flight, one of the most stressful parts of the mission. Shortly after liftoff, they separate, allowing the rocket to lose weight and continue its climb.
“There is also an event called ‘Max Q’ early in flight, where there is the highest atmospheric pressure pushing on the booster. They actually throttle down the thrusters around this point to keep the pressure manageable,” Ranieri said.
Much of the technology behind Artemis II is built on decades of innovation in earlier space programs and missions.
“All of the engines on the first stage came from the Space Shuttle program, and most flew to missions to space before.”
As the rocket ascends, it undergoes a process called staging, in which the first set of engines is abandoned after running out of fuel. A second stage then ignites, continuing the journey into space. This process improves the flight’s efficiency by clearing excess weight. Yet, reaching orbit is only the beginning.
Once in space, the risks beyond Earth become less visible, but far more dangerous.
“There are a lot of unseen risks to the mission once in space. There are micrometeoroids and space debris that can be super small but hit Artemis/Orion at almost 10 miles per second relative speed which could puncture the hull if it’s not thick enough,” Ranieri said. “There are also times when the vehicle can’t see Earth and they can’t talk to Earth anymore to troubleshoot any issues”
In addition to high-speed debris, astronauts must navigate increased radiation exposure and temporary periods when they have no way of communicating back to Earth. The Orion spacecraft is designed to withstand such conditions, as it is equipped with shielding systems that allow it to independently operate when contact is unavailable. These systems are designed and tested for years in advance because once the crew is beyond low Earth orbit, there is no emergency return option.
For Ranieri, the complexity of these challenges is what makes aerospace engineering so compelling.
“It really is many different disciplines together as you can focus on lots of different topics like structures, thermal, fluids, trajectories, dynamics, electronics, power, communications, etc. It is hard to get bored doing aerospace engineering”
As Artemis II pushes human exploration further, it also highlights the importance of expertise behind the scenes. What appears to be approximately a 10-day journey is, in reality, the result of years of preparation and countless decisions.
