It’s early morning on my second day at Marum Crater, and as I drift in and out of sleep, I try to place the incongruous buzzing that seems to have awoken me. I unzip the tent’s vestibule and peer outside, where a small drone hovers in the distance, four blades whirring in synchrony and small camera pointed back toward camp. “Let’s get going,” urges Simon Jardine, the man behind the joystick, punctuating his flyover with a well-intentioned cackle. “There’s a fiery pit of lava to go explore!"

For all his joie de vivre, Jardine is a master drone builder and pilot whose skills have produced remarkable footage for shows like Australian Top Gear, the BBC's Into the Volcano, and a range of music videos. His company Aerobot sells camera-outfitted drones, including custom jobs that require unique specifications like, say, the capacity to lift an IMAX camera. From a sprawling patch of coastline real estate in Queensland, Australia, Jardine builds, tests, and tweaks his creations; the rural tranquility is conducive to a process that may occasionally lead to unidentified falling objects.

Simply put, if you’ve got a drone flying challenge, Jardine is your first call.

Sam Cossman, the adventurer who put this expedition together, got Jardine on board early in the planning process. "I met Simon on my first expedition to Vanuatu," he recalls, "one morning when we had both awoken early to catch first light." After leaving their respective trips and following each other's work, the mutual admiration grew. "When I decided to return to the volcano," says Cossman, "I knew Simon would be an integral part of the expedition because of his familiarity with the terrain, the extreme flying conditions, and his level of expertise."

*****

I take a final sip of tea, revealing a gravelly deposit of the pervasive volcanic sand at the bottom of the mug, and join Cossman and Jardine on the crater’s edge. We’re plotting an ambitious drone flight across the crater, one that will capture footage of the full scene with unprecedented detail. Plugging the resulting imagery into 3-D rendering software from Pix4D will generate a model of the tiered crater system, providing a key resource for geologists and hazard assessment teams who are working to understand more about the volcano's fiery temperament.

"I have flown in some really crazy places," says Jardine, recalling his past work in caves, around big waves, and underneath the Sydney bridge. But the vast scale, whirling winds, corrosive fumes, and intense temperatures of Marum Crater presented new challenges. The previous day, Jardine had taken the plunge into the crater itself in order to get footage of the lava lake at closer range than would be practical for human participants. "The bottom of Marum Crater was definitely the most insane place to fly a copter, especially a plastic one," he says. "The hardest part of flying was the hot air rushing out and cold air getting pulled into the lake. The machine would surge forwards and I would pull back on the stick. Then the hot air would blow in my face 10 times hotter than a hairdryer, and I could see the copter blasting back at me, so I'd push forwards on the stick, and so on. It was like playing tug-of-war with a drunk drone."

As a scientist, I was particularly encouraged by the idea of having additional vantage points. From the aerial perspective, it’s possible to quantify the thicknesses of past eruptive layers – the iron-rich red bands, the columnar basalts, the cobble conglomerate – to reconstruct the events that formed the crater. Filming my own sampling efforts was critical in assigning metadata to particular rocks. When a lava lake is gurgling a few meters away, time is of the essence, and making simple measurements is not practical. Information like the size and spatial distributions of recently erupted rocks, the precise distance from the eruption, and the relationship between rock color and age are all discernible from the drone and GoPro footage.

Looking forward, Cossman is also eager to use drones in a more exploratory sense. “We were initially on the hunt for a new vent and potential lava lake that we believed existed in a neighboring crater,” he recalls. “I believed the drones would carry a great sense of utility for our exploration by serving as our eyes in the sky for this unfamiliar terrain, helping to identify the new volcanic feature and to inform the safest and most direct descent route.” For now, that descent will have to wait, but when it does happen, it will likely be faster and more efficient – and thus potentially less hazardous – than previous efforts.

*****

Jardine's flight around, over, and through the crater was ultimately successful, though not without robotic casualties. One drone fell out of the sky and clattered down the rock wall, shedding propellers along the way. Many of the cameras and other electronics suffered from the pervasive acidic vapor, corroding over the course of hours. But after several flights that push the batteries, the navigation system, and Jardine’s skills to the limit, we’ve covered the entire kilometer-wide crater. The resulting 3-D imagery, shown below, represents the highest resolution map of the crater to date, and offers an alluring vision of the future of technology-assisted exploration.

Another fully immersive model – in which you can walk around the crater, leap down its vertical faces, and stand on the shore of the lava lake – is currently in the works. Says Cossman: “we’ve imported the high definition model it into a virtual environment, so I can literally invite people in and give them a virtual tour in real time.”