NARRATOR: Jaime Waydo led the team that designed and built Curiosity's mobility system, the six wheels, suspension and other mechanisms that allow the rover to roll over terrain. This system also had to function as Curiosity's landing gear.

JAIME WAYDO: The rover touches down at almost three feet a second, which doesn't sound that fast, but some of those loads are 2,500 pounds, going into each individual wheel. And what the wheels don't absorb goes into the suspension. We're just trying to make sure that all of those precious science instruments are safe.

NARRATOR: They needed a way to make the system as strong, yet as light as possible. Inspiration rolled in on two wheels.

JAIME WAYDO: If you look at the modern bicycle, they do amazing things with shaping the tubes of the bicycle frame, for the stiffnesses they want, in every direction. And so, we talked to a bicycle company that makes titanium bikes, and they helped us build the suspension tubes.

NARRATOR: Curiosity's wheels were redesigned as well.

JAIME WAYDO: We ended up taking a bicycle wheel and making it as strong as possible and taking that to the extreme and making it, basically, a Martian bicycle wheel.

NARRATOR: Curving titanium spokes and a pliable aluminum skin would make the wheels tough but resilient.

Waydo and her team would test their new system in stages.

JAIME WAYDO: We're going to do our final countdown and then we'll test.

NARRATOR: They used a model rover, without its wheels, to check the mechanisms that release the mobility system during the sky crane maneuver. The rover has just six seconds to pop its wheels into place for touchdown.

JAIME WAYDO: That test was really focused on making sure that, as mobility is deploying, there's nothing that's going to hang up, that all of the cables can move smoothly and they're not going to catch on each other.

NARRATOR: Small pyrotechnics would release the latches that hold the system close to the rover's body.

ADAM STELTZNER: I don't think any of us really thought it would be as violent, as noisy or as herkedy-jerkedy of an event. From amongst a human perspective, there was a lot of, "Oh, my god, is that, is that right?"

JAIME WAYDO: It's not graceful. But it's what you do to get 200 pounds of hardware to go 60 degrees in six seconds and be ready for landing.

NARRATOR: Waydo's team used a stripped-down rover model to measure the stresses of touchdown.

This simulation was also a test of Waydo's nerves.

JAIME WAYDO: My hands are sweating, and my throat is getting dry, and I'm looking at it going, "Oh, my goodness. Oh, my goodness." And then, they let it go, and she hit, and it was so hard. And I was like, "You can't do that to our baby! That's too much! That's too hard!"

ADAM STELTZNER: It's like that old Vaudeville joke, right? It's not the fall that kills you, it's the landing, right?

JAIME WAYDO: That's extremely brutal. And then, you realize, "No, we designed her for that. She's good for that. It's okay." But that tangible, visceral, "What does landing look like?" is much different on a computer simulation than, than the first time you see it for real.

TOM RIVELLINI: Congratulations, Jaime.

ROB MANNING: The great thing about landing on your wheels is that you're ready, you've landed! Now, you can drive around the surface of Mars and go do great science and do some exploration.