Launch can mean many things. The two immediate things that come to mind are launching a boat or the launch of a rocket, space shuttle or something equivalent.
In most people lives launch could mean something entirely different. Many of us launch a new business or campaign within our jobs or business. In general, launch means to me a beginning. Passover is in the spring. The spring is the launch of new life. Flowers bloom, snow melts off, the weather starts to get warmer and animals come out of hibernation.
For those that live in colder climates, it can also be the launch of getting back in shape. The warmer weather gives us a chance to get outside, be more active and launch into a healthier lifestyle.
The launch into Passover provides Jews with a chance to have to be disciplined. Going an entire week without any yeast products or anything leavened is a challenge. It can often be the launch needed for other things in life.