How to reach the moon, again

The crew is expected to travel approximately 695,081 miles, or about 1.12 million kilometers, in a 10-day mission that loops around the Moon in a figure-eight trajectory before returning to Earth for splashdown.

At its core, Artemis II is an engineering validation mission.

According to NASA, astronauts are testing the Orion spacecraft’s systems in deep space, including life support, propulsion, navigation, and thermal control. The crew will also perform manual piloting, conduct trajectory adjustments, and evaluate how the spacecraft operates at lunar distances.

The mission represents the first human flight beyond low Earth orbit since the Apollo era, a milestone that underscores both the complexity and ambition of modern spaceflight.

“It’s an essential ingredient for us to not only continue to operate beyond low Earth orbit but eventually get to Mars,” said Alec Gallimore, a professor of aerospace engineering.

The engineering challenge begins with sheer energy requirements.

To reach low Earth orbit, spacecraft must travel at about 18,000 miles per hour. Reaching the Moon requires roughly 24,000 miles per hour — a jump that significantly increases energy demands.

“That jump is enormous,” Gallimore said, noting that energy requirements scale with the square of velocity.

To achieve this, NASA’s Space Launch System stands 322 feet tall and weighs approximately 5.75 million pounds when fully fueled. Much of that mass is dedicated to propellant, reflecting the immense energy needed to push a relatively small crew capsule toward the Moon.

The Orion spacecraft itself is a combination of legacy design and modern upgrades.

Its crew capsule, built by Lockheed Martin, will return to Earth, while the European-built service module provides propulsion, power, and life support systems.

The service module carries oxygen, water, and solar arrays capable of generating over 11 kilowatts of power, while 33 onboard engines manage trajectory and maneuvering in space.

One of the mission’s key technological upgrades is its communication system.

The Orion Optical Communications System will use laser-based transmission to send data back to Earth at speeds of up to 260 megabits per second, enabling near real-time 4K video from lunar distances — a significant leap from the limited bandwidth of the Apollo era.

Safety engineering also plays a central role.

Northrop Grumman developed critical components of the Launch Abort System, including an abort motor capable of producing 400,000 pounds of thrust and accelerating the spacecraft to 500 miles per hour in just two seconds.

The system is designed to pull the crew capsule away from the rocket in the event of an emergency, while additional features protect against lightning strikes and structural stress during ascent.

“Whenever we send humans to space, the stakes are much higher,” said Adam Lyons, chief engineer for the abort motor.

The spacecraft is also equipped with 32 cameras and imaging systems to support engineering analysis, navigation, and public outreach, while a small plush indicator named “Rise” will signal the onset of zero gravity during flight.

Beyond the hardware, Artemis II is also about proving operational readiness.

The crew will test manual control of the spacecraft, evaluate onboard systems, and simulate mission-critical procedures that will be essential for future lunar landings and eventual missions to Mars.

Koch emphasized the broader vision of the mission, describing it as a step toward sustained human presence beyond Earth.

“We will explore. We will build. We will build ships. We will visit again,” she said.

Each launch comes at a significant cost. A 2021 report by NASA’s inspector general estimated that each Artemis launch, including the Space Launch System and Orion capsule, costs about $4.1 billion.

But for engineers and mission planners, Artemis II is less about the price tag and more about proving that deep space travel is once again possible.