Hawai‘i’s native forests are being quietly overtaken by strawberry guava, an invasive tree that grows in the shaded understory where it is hard to see from planes or regular satellites. To locate these hidden stands, we analysed more than 650,000 laser pulses collected by a space-based scanner on the International Space Station. The laser measures the height and density of vegetation, letting us detect the subtle structural changes caused by guava. Using these measurements, we created a detailed, 25-metre map that highlights where the invader is most likely to be in several forest reserves. We checked the map with thousands of ground and drone photographs. Next, we will add data from an upcoming radar satellite and a thermal sensor that tracks plant-water use, so the system can keep working under clouds and after the laser mission ends. The resulting maps will help managers find and remove guava before it spreads further.