Hera’s incredible adventures in LEGO

The team got in touch with Frans Snik, an astronomer at Leiden University in the Netherlands who has the hobby of designing detailed models of astronomical observatories such as the European Southern Observatory’s Very Large Telescope and Extremely Large Telescope. He also previously branched out into recreating tiny versions of the space-based James Webb Space Telescope for kids to build at events.

“Frans did us proud with a roughly 1:11 scale model of Hera, plus the twin CubeSats the spacecraft is carrying to the Dimorphos asteroid, using 4448 bricks in all,” explains Hera mission documentalist Mark Brophy. 

“It was debuted in public during last October’s ESA Open Day at ESTEC in the Netherlands, just in advance of Hera’s actual launch.

“But this is such a complex model that it would be hard and costly for enthusiasts to build their own. So we also had Frans design smaller LEGO replicas of the cartoon versions of Hera and its two CubeSats, as featured in our Incredible Adventures of the Hera mission series of animations.”

Cartoonish constructions

This multi-part animation series recounts the adventures of the Hera asteroid detective plus its accompanying CubeSats – Milani the rock decoder and Juventas the radar visionary – on their journey through construction, testing and launch, and soon their visit to Mars and its enigmatic moon Deimos.

Frans made LEGO versions of the three cartoon spacecraft (including Hera’s dinosaur mascot), plus the twin asteroids that they are on the way to visiting: the larger Didymos and the smaller Dimorphos, which in September 2022 had its orbit shifted when NASA’s DART spacecraft impacted with it. These asteroids come complete with arms to wave hello to Hera!

“I had the amazing opportunity to see the actual Hera spacecraft a few times when it was located in the Test Centre at ESTEC, and I was very impressed by the number of technical capabilities within such a compact device,” says Frans.

“It was a nice challenge for me to add as much details as possible into the Hera LEGO model. I have also become a fan of the Hera cartoons, which contain even more little details – I have tried to incorporate those into the models as well."

Want to build them? Download our assembly instructions here, including a link to order the LEGO bricks needed.

Scaled-down DIY spacecraft

There is another Hera model available for enthusiasts to build, a scaled-down version of the realistic spacecraft (while also including Hera’s pet dinosaur) which was designed by Hera communication system engineer Paolo Concari in his spare time. After a hard day of working on the spacecraft’s communication system Paolo would go home to resume work on his LEGO equivalent of Hera.

Paolo explains what inspired him to create the model: “While working on the Hera mission, I came across a LEGO model of the spacecraft that someone had created and shared online. But because I know Hera by heart, I couldn’t help but notice some inaccuracies, as well as key details missing – that’s how I got the idea to create a more true-to-life version.”

For the seasoned engineer, used to bringing real space missions to life, this was the first time recreating one using LEGO. He designed the tiny Hera in a 3D modelling tool called STUDIO 2.0 – a program made specifically for LEGO models.

“Creating the model was actually the easiest part – it was the instructions that gave me the most trouble,” Paolo notes. “The whole process was a learning curve, from figuring out how to create the CAD model, to learning how to use Photoshop and bind the assembly instruction booklet.

“When designing a model using the available LEGO bricks, you need to be extra creative. For example, if you look closely, you will see that the thrusters on the side of the model are actually tiny binoculars!”

As with any space mission, LEGO Hera underwent rigorous testing: “My children offered to help and provided me with some very valuable feedback, like when they spotted a mistake in the instructions or found certain steps too complicated.”

The resulting 98-piece model, roughly 280 times smaller than the real Hera, is not just a toy – the mission team has also used it to recreate in their hands the various manoeuvres the real spacecraft would be making.

Want to build it? Download the assembly instructions here and the list of bricks needed here. As a finishing touch, add these solar panel stickers and mission logo.

Note: these models are made for fun and sharing only, not for commercial use, with no involvement or endorsement from the LEGO Group.

About Hera

Launched last October, Hera is ESA’s first planetary defence mission, on its way to visit the first asteroid to have had its orbit altered by human action. By gathering close-up data about the Dimorphos asteroid, which was impacted by NASA’s DART spacecraft in 2022, Hera will help turn asteroid deflection into a well understood and potentially repeatable technique.