Getting To The Moon

Lunar Trailblazer is different from most planetary missions. Like its sister NASA SIMPLEx missions, Lunar Trailblazer is a “rideshare mission”. Kind of like choosing an Uber/Lyft-pool ride, NASA is taking advantage of the fact that most large missions launch with extra mass capacity on the rocket to bring material to space. To allow more spacecraft “seats” on the ride, launch providers use ESPA rings, a standard add-on with ports to host smaller spacecraft like Lunar Trailblazer.

Credit: Lockheed for Lunar Trailblazer

Here’s an ESPA ring and the standard volume available for a payload spacecraft. With its solar panels folded safely for launch, ~200-kg Lunar Trailblazer fits comfortably in ESPA volume. We link via a standard commercial-off-the-shelf part called a “lightband” (a Mark II Motorized lightband, to be exact).

As a small spacecraft, Lunar Trailblazer cannot do a direct burn and deceleration like the Apollo spacecraft. This is even though around two-thirds of Lunar Trailblazer’s volume is its fuel tank. Instead, Lunar Trailblazer uses a low-energy transfer trajectory that is distinct for each and every launch date. It can take between 4-7mo depending on the launch date to get to the Moon but it is a fuel efficient means of traveling. The trajectory computed by our navigation team at JPL for a 26 February 2025 trajectory is below.

The trajectory computed for a 26 February 2025 launch date.
Credit: NASA/JPL for Lunar Trailblazer

Rideshare Integration

Lunar Trailblazer is a small satellite that launched to space alongside other missions, making it a “rideshare mission”. Because Trailblazer needs to work with many parties, including the launch company (SpaceX) and the primary mission that purchased the launch (Intuitive Machines), rideshare integration was an important part of getting the Lunar Trailblazer mission to space. Rideshare integration is a term that encompasses all aspects of connecting the spacecraft with the rocket. This includes the hardware that physically and electronically attaches the satellite to the rocket, making sure the spacecraft meets the requirements set by the launch company, scheduling steps along the way, communication about constraints with the teams from other spacecraft sharing the rocket, and acquiring certifications and paperwork to make sure everything is safe, legal, and follows best practices for launches.

Lunar Trailblazer worked with a company called Maverick Space Systems, who made rideshare integration possible. Founded in 2019, Maverick has completed rideshare integration for over 30 launches. During the Trailblazer mission, they advised on, designed, and built pieces needed for the physical and electronic connections between Trailblazer and the rocket. They also coordinated scheduling of pre-launch installations and post-launch deployments to make sure there are no conflicts between the many parties involved, and coordinated paperwork and compliance.

At launch, Lunar Trailblazer was attached inside the rocket fairing with a connector called an ESPA ring. Credit: Isabelle Adamczewski (PCC/Caltech)

Lunar Trailblazer presented unique challenges for Maverick Space Systems, says David Hobbs, integration manager for Trailblazer, compared to previous missions. NASA and the Lunar Trailblazer project had certain requirements for the spacecraft, and the job of Maverick was to find a way to follow those while working within the boundaries of the commercial launch contracts. There were also two other rideshare payloads adjacent on the ESPA ring, the payload adapter within the rocket fairing that holds the secondary payloads. All had a say in the logistics of how Trailblazer was integrated into the rocket. Also, Trailblazer is a more complex satellite than some small missions. It has toxic propellant, carefully folded solar panels, several antennas, and science instruments that needed protection from contaminants – each presenting complexities in working with, testing, and attaching to the rocket.

Despite the complexities, Hobbs says he enjoys the challenge of “fitting the square peg in the round hole”. This turn of phrase is apt: literally, Lunar Trailblazer’s cube-shaped spacecraft connects to the ESPA’s circular port. Making sure Trailblazer and other missions get what they need from the rocket company and everyone else is no easy feat, but Hobbs likes working with people and building relationships along the way. Maverick completed the integration successfully in February 2025.