Most famous spacecraft are born inside sprawling, high-tech facilities, but the Loki Lego Launcher that brought 10-year-old Kimberly and 12-year old Rebecca Yeung to fame was made right in their garage workshop.

The Yeung sisters gained national attention after successfully launching two homemade balloons to the edge of space, and meeting former President Barack Obama at the White House Science Fair. Now they’re at it again — building the Loki Lego Launcher 3.0, this time working with NASA and other citizen scientists to study the Aug. 21 solar eclipse.

But before heading down to Glendo, Wyo., along the path of totality, the girls have a lot of work to do. I caught up with them at their Seattle home, where they work on the launcher between camps and other summer activities.

When I arrived, I found their task list on the workbench. First on the list? “Prepare Loki and the Lego minifigure.” Sure enough, R2-D2 and Rey, the Loki Lego Launcher’s former passengers, were sitting on the table next to their soon-to-be successor.

Three Lego minifigures sit on the workbench inside the Yeung sisters’ garage-turned-workshop. (GeekWire Photo / Chelsey Ballarte)

The girls set up a poll on their website to let their fans choose which mini figure to send into the eclipse. The contenders were Amelia Earhart, Hermione Granger and Merida from Disney’s Brave.

“Amelia Earhart won with 176 votes,” Kimberly said. “And it was very largely in her favor,” Rebecca added. On her journey, the Amelia Earhart mini figure will be holding a custom map that shows the real Earhart’s flight path.

The girls then did a test run of their battery-operated Eagle flight computer and checked the test data in their dad Winston’s computer.

The flight computer aboard the Loki Lego Launcher.(GeekWire Photo / Chelsey Ballarte)

As with any pre-launch preparations, the girls hit a few speed bumps trying to record GPS data, but after a few adjustments, the computer was in the clear and locked onto a satellite.

“It recognizes the GPS, temperature pressure sensor and the voltage current sensor, which is exactly what we want,” Rebecca said.

The next thing on the to-do list was testing the solar panels, which the Yeung sisters accomplished by moving the Loki Lego Launcher out into the sun and back into the cover of their workshop. Data showed the system was fully operational.

“There was a really noticeable difference from when it was in the shade and when it was in the sun, which is going to be great in the path of totality,” Rebecca said.

Rebecca (left) and Kimberly (right) work on the Loki Lego Launcher. (GeekWire Photo / Chelsey Ballarte)

Rebecca had learned about the eclipse at school and thought it would be an interesting time to create the Loki Lego Launcher 3.0. Then they learned that NASA had already started gathering citizen scientists for the Eclipse Ballooning Project, so they teamed up with the Montana Space Grant Consortium to capture footage of the eclipse from above and send bacteria samples into the stratosphere.

“We thought it was really cool that we had the same idea as the people from NASA,” Rebecca said.

The Yeungs headed up to the balcony to test the parachute. Despite being on the second floor, the parachute’s long cords hung pretty close to the ground, but the sisters improvised and made themselves taller with the help of cushions from a balcony chair.

Showing a positive attitude in the face of challenges, both Kimberly and Rebecca were all smiles when, test after test, the wind kept the parachute from opening properly. But after adding some weight to the bottom, the bright orange parachute and gently landed on the driveway below. “It took a lot of tries,” Kimberly said.

Kimberly Yeung studies their mission binder to decide what to do next. (GeekWire Photo / Chelsey Ballarte)

In the coming weeks, the Yeung sisters plan on testing their SPOT GPS tracker, and once everything is configured, weigh their payload and make flight predictions.

As with any launch group, the “Yeungstuff Space Program,” as they call it, requires an incredible amount of teamwork and collaboration, something Kimberly and Rebecca excel at.

Throughout the day they worked together through all disagreements on how to move forward. Their father Winston only intervened to guide them through their problem solving. “What’s the problem that you’re trying to solve?” he asked the sisters. “Why is that important?”

The Yeung family workshop is just a small taste of the facilities Rebecca and Kimberly have been to. Following the success of their other ballooning missions, they were invited to tour NASA’s Jet Propulsion Laboratory in California, Vulcan Aerospace and the labs at University of Washington.

It’s certainly recommended to see the total solar eclipse in person, but if cloudy weather blocks the view, you can watch a live stream from the University of Montana that will alternate among the view from the Loki Lego Launcher and other weather balloons.

Like what you're reading? Subscribe to GeekWire's free newsletters to catch every headline

Job Listings on GeekWork

Find more jobs on GeekWork. Employers, post a job here.