Just before noon on Monday, every person in the Theodore von Kármán Auditorium at NASA’s Jet Propulsion Laboratory (JPL) in California sat on the cusps of their seats. They stared straight ahead at a video screen showing a live view from inside JPL’s mission control center. On-screen, rows of engineers also sat entranced, transfixed by their computer consoles as a flight controller announced altitude measurements over an intercom.

“Altitude 400 meters. 300 meters. 200 meters. 80 meters. 60 meters.”

And then, a few moments later, the final call: “Touchdown confirmed.”

Straightaway, the engineers and those in the auditorium erupted into cheers and applause. In jubilation, many threw their hands in the air or threw their arms around their colleagues. Some had come prepared with elaborate celebratory handshake routines. It was the outcome that everyone had been hoping for: NASA’s latest spacecraft had successfully touched down on the surface of Mars, and it had seemingly made it down in one piece.

“Touchdown confirmed.”

Everyone in the von Kármán Auditorium had gathered together to watch as this lander, called InSight, reached its final destination. Unlike some of its predecessors, InSight won’t rove around on the planet’s surface. Its mission is relatively simple: sit on Mars and listen for quakes. The seismic waves from these wobbles will help planetary scientists decode the structure of Mars’ interior, similar to how ultrasounds show us what’s inside a person’s body.

But it’s been a very long road to get to this point. InSight has been in development for the last decade at Lockheed Martin and JPL, and it suffered an additional two-year delay after engineers found a defect in one of its main instruments. The problem was ultimately fixed, culminating with the lander’s launch this May. The vehicle then traveled through space for the last six and half months, so that it could make the plunge into Mars’ atmosphere on Monday.

Members of the press, planetary scientists, engineers, social media influencers, and even a few celebrities started streaming into JPL early on Monday morning to “watch” the landing live, though we all knew we wouldn’t actually see the event — at least not visually. There aren’t any cameras on Mars to record spacecraft coming in for landings. And it wouldn’t really be live, either. Right now, one signal of light takes more than eight minutes to reach Earth from Mars. So, in reality, we had all come to hear that the landing had succeeded from the mission team eight minutes after the touchdown actually occurred.

But despite not having any real-time visuals of the landing, JPL did have something worth the trip: lots and lots of scientists milling about the sunny government campus. Those on the InSight team could be easily spotted, thanks to their matching maroon button-down shirts sporting the InSight mission logo. And they all vibrated with a mixture of jubilance and anxiety. Some of the scientists, including the lander’s principal investigator, Bruce Banerdt, have been working on some form of this mission for decades now, waiting for this day. But a Mars landing is always a scary prospect, with the fear of a crash hanging heavy in the air.

landing anything on Mars is the worst

That’s because landing anything on Mars is the worst. Compared to landing spacecraft on Earth or the Moon, Mars is considered “the worst of both worlds.” Unlike the Moon, Mars has an atmosphere that causes spacecraft to heat up to intense temperatures on the way to the ground, which makes shielding a requirement. And while this atmosphere does help slow down vehicles, the air is still quite thin — about 1 percent the density of Earth’s atmosphere — so it doesn’t slow down spacecraft enough. A parachute alone won’t cut it, and thrusters are usually needed as well to lower a vehicle down gently. The heavier a spacecraft becomes, the harder it is to land on Mars.

Fortunately, InSight is a relatively light spacecraft at just 789 pounds, and NASA has decades of success with putting vehicles of even bigger sizes on the surface of Mars intact. The InSight team designed the lander to perform a complicated landing routine that’s meant to be performed in just six and a half minutes. But even with years of preparation, sometimes Mars can get the better of a spacecraft.

In the hours leading up to the landing, the InSight scientists spoke with curious visitors about what to expect. NASA’s administrator Jim Bridenstine was on hand, too, doing rounds of on-camera talks while standing in front of a full-scale model of the InSight lander. By this point, talking was all they could to stay occupied. InSight was more or less on autopilot. The last commands had been sent to the lander, and the team could only hope their hard work would pay off.

As the scheduled landing drew closer, everyone at JPL started shuffling to the various locations where they needed to be. The InSight team took their places at mission control, while I and other members of the media gathered into the von Kármán Auditorium to watch a live stream of the engineers. If all went according to plan, we’d get something of a countdown for the landing. Along with InSight, NASA launched two tiny satellites called MarCO that would attempt to send back data of the landing as it happened. The MarCO probes were experimental, though, so it wasn’t a guarantee that we’d hear from them.

In the minutes leading up to the landing, we heard a hopeful phrase from mission control: “MarCO Bravo has locked on to carrier. MarCO Alpha has also locked on the carrier.” Mission control exploded into applause. I exchanged a few smiles with other space reporters in the room. “That’s a good sign!” I said, surprised. The MarCO satellites were receiving signals from InSight, and that meant we’d know how every step of the landing process would go, which is a luxury past Mars missions didn’t have.

“You’ve missed a lot of different holidays and important events to make this a success. And today, it was all worth it.”

From that point on, it was a smooth ride — for InSight and for us in the auditorium. Thanks to the MarCO satellites, we had confirmation of every major event. When InSight deployed its parachute, the room applauded. When it locked onto the ground with radar, everyone cheered. And then, when it was just meters away from the surface, everyone held their breath until we got that final call.

Hours later, the same von Kármán Auditorium was packed with InSight team members, press, and fans. The top scientists and InSight project manager Tom Hoffman walked in, hands raised in triumph, while the audience cheered and clapped. Hoffman thanked all of the scientists and engineers in the room who worked countless hours to make a six-and-a-half-minute landing possible. “You were working on Thanksgiving, but not just Thanksgiving,” he said. “You’ve missed a lot of different holidays and important events to make this a success. And today, it was all worth it.”