An email arrived in the Observer’s Question Corner mailbox asking what was going on at the southwest corner of Plymouth and Green, where a shipping container emblazoned with a hand-painted yin-yang symbol sits next to a concrete-block wall in an otherwise open field.

“I’ll often spot a couple of cars parked on the old driveway and a few people near the wall or the container, but I drive by too quickly to see what they’re doing,” our correspondent wrote. “This has been going on for at least a year. This doesn’t look like business activity, but like a club, or students use this site for something.”

That’s exactly what it is. But it’s not just any group–a sign on the container identifies it as a “Rocket Propulsion Testing Facility.” U-M students are testing rockets around the corner from Plum Market and Zamaan Cafe.

The container is used by “a University of Michigan student team called MASA (the Michigan Aeronautical Science Association),” emails Michigan Engineering news director Nicole Casal Moore. “They test engines using a custom horizontally-mounted system that points away from populated areas.”

One recent test produced a loud “boom” that set off a “what was that?” thread on At the end of April, Moore writes, a small fire ignited inside the container during an engine test and the Ann Arbor Fire Department responded. Students followed contingency plans. No one was hurt–they operate from outside and behind a wall that’s two cinder blocks thick. The damage was limited to a charred camera and some cables …”

The undergrads “are competing for a $1 million prize to launch a rocket to the edge of space in December,” Moore explains. “MASA took first place in phase 1 of the Base 11 Space Challenge in 2019, and second place in phase 2 in April, 2021. In the final phase, teams aim to launch 62 miles up to the Karman line, where Earth’s atmosphere ends and space begins …”

That won’t be happening from Plymouth and Green, though. They “don’t actually launch anything in the facility,” Moore stresses. “The final launch will take place at Spaceport America in Truth or Consequences, New Mexico.”