There's nothing harder for a mom than letting go.

A mom is a human Star Wars defense system, scanning the skies for incoming threats and blasting them to smithereens. And then one day your kid walks through the shield and off to college, and you don't know his friends or where he's hanging out. You're forced to let go.

Last summer was my time to let go. My son, Owen, started at Penn State in the fall. But before he left, we took a cruise to the Caribbean - one last vacation together - and signed up for adventurous excursions, including a thrilling zip-line ride.

That's generally not my game. I hate to plunge, and zip lines involve plunging. But Owen is an active kid, and I wanted to spend as much time with him as possible. The zip line also had a timely appeal: It was all about letting go. I knew I could use the practice.

So one day we landed at Labadee, Haiti, where the Dragon's Flight zip line launches you from a mountain and swoops you over water at 40 to 50 m.p.h. for 2,600 feet (half a mile), landing you on a beach.

The view from the launch tower was spectacular. Our ship floated majestically off to the left, a white jewel in the blue cove. Water and sky married in the distance, and tiny people dotted the beach below.

I looked down the five zip-line cables, the umbilical cords that tethered us to a safe landing. The landing spot was so far away that the cables disappeared in the distance. Oh, goodness.

When the guide pointed to me, I reluctantly climbed up to the launch platform. I realized Owen was in the same group. We'd fly together.

The guide clipped me to the slim cable, had me squat on the platform, and asked whether I was ready. I lied and said yes. "Lift your feet," he ordered, and I shot off the tower and into blue air.

I barely remember the first moments. There was a heartstopping terror for sure, but it was brief. I was flying, and that was that.

And then, suddenly, I felt wonderful. I was actually

in

all that light and color - not a middle-aged woman with stress and emotional baggage, but a body free-flying through space. I started whooping as I raced down the cable: WhoooooHOOOOOOOO.

I sped over the treetops, and the soft white waves came closer and closer. Then a hook grabbed my clips, and a giant spring provided a soft landing. I think I was still whooping a little.

My goodness, what a ride. I could do this. I could send my child into the world.

Still exhilarated, I asked Owen about his ride. It was good, he said, but he wished he had had some kind of control.

I did a double take. My teenage son wanted a control - was he having a little trouble letting go, too?

"Yeah, a control," he said, "so you could go faster."

Sheila Young lives in Ellicott City, Md.