How to Build a Time Machine: Lessons from a Top Telescope Engineer

A few weeks ago, I had the incredible opportunity to listen to a talk from a total rockstar in the world of space science, Dr. Alison Nordt. She’s the Director for Space Science at Lockheed Martin’s Advanced Technology Center and was a key engineer on the James Webb Space Telescope (JWST). As part of the Stanford Program for Inspiring the Next Generation of Women in Physics (SPINWIP), she shared how we go from asking a big question to building the amazing instruments that help us find the answers.

Here’s a breakdown of the coolest things I learned.It All Starts with a Question

Dr. Nordt explained that space science works in a cycle, and it always begins with a question. Think of questions like:

• What did the very first galaxies look like?

• What causes dangerous space weather?

• Are there other planets out there like Earth?

You can’t answer these just by looking up at the sky. You need to build a special tool—an instrument—to make the right observations. And here’s the cool part: sometimes, the technology we need doesn’t even exist yet!

She gave a perfect example: the Geostationary Lightning Mapper (GLM). Scientists asked, "What does lightning look like from space?" They built an instrument, and it turned out that certain lightning patterns can predict when a tornado is about to form. A science question led to an instrument that now saves lives by giving more accurate tornado warnings. Science isn’t just about looking at stars; it can have a huge impact right here on Earth.

Building the Ultimate Time Machine: The James Webb Space Telescope

Dr. Nordt spent a huge part of her career working on JWST, and her main focus was the Near Infrared Camera (NIRCam)—basically, Webb’s primary eyeball.

The main question for JWST was: "What did the first galaxies look like?" These galaxies are over 13.5 billion light-years away. Since light takes time to travel, looking that far away is literally looking back in time. JWST is a time machine. But why does it see in infrared?

Dr. Nordt explained it with a simple analogy: the Doppler effect. Just like an ambulance siren sounds higher-pitched coming toward you and lower-pitched going away, light from distant galaxies gets "stretched out" as they move away from us in our expanding universe. Their light shifts from what we can see into the infrared spectrum. Infrared light is basically heat. To see faint heat signals from across the universe, the telescope has to be incredibly cold (around -400°F or 37 Kelvin!). Otherwise, it would be blinded by its own heat. It’s like a firefighter using thermal goggles to see through smoke—JWST uses infrared to see through cosmic dust and look at the birthplace of stars.

One of the biggest engineering challenges was that NIRCam had to be built and aligned perfectly at room temperature, knowing that every single part would shrink a different amount as it cooled down in space. The precision required was mind-boggling.

And the results? We’ve seen galaxies that are far more "grown-up" than scientists expected for being so young. We’ve seen gravitational lensing, where gravity from a massive galaxy cluster bends light and creates multiple images of the same distant galaxy. It's all just incredible.

The Next Big Question: Are We Alone?

JWST was a game-changer, but answering one question always leads to ten more. Webb can see some huge exoplanets, but it wasn't built to find small, rocky worlds like our own. So, the next big question is: Is there another Earth out there? To answer that, scientists are designing the Habitable Worlds Observatory (HWO). This future telescope will need to be 1,000 times more stable than JWST! Its goal will be to do something called "direct imaging"—blocking out the blinding light of a distant star to see the faint little planets orbiting it.

Dr. Nordt showed a simulation of what HWO might see if it were 33 light-years away, looking back at our own solar system. You could actually pick out Earth and Venus. Finding a "pale blue dot" around another star would be one of the greatest discoveries in human history. It’s inspiring to see how one incredible mission like JWST is already paving the way for the next generation of discovery. It’s a powerful reminder that science never stops. It’s a cycle of curiosity, engineering, and storytelling that pushes humanity forward.

A huge thank you to Dr. Alison Nordt for her amazing talk and to the Stanford SPINWIP program for creating such an inspiring opportunity for students like me to learn from leaders in the field.