Any time you want an extra measure of protection and safety for yourself or a loved one, visualize the following:

A clear, silver-tinted, egg-shaped shield, all around yourself or the other person. This shield is invisible to others, but, of course, they will sense its presence.

Visualize this frequently, during the course of time you wish to invoke it (yes, if you like, it can be used daily, or even all the time).

This is particularly handy for a child going off to school or camp, for yourself during a dentist or doctor visit, for a loved one in a hospital or on a plane, a familiar at the vet, etc. It doesn't have to be a particularly dangerous mission in order to invoke this shield - or it can be.

So if you and/or a loved one are off on an experimental space shuttle mission or diving 20,000 leagues under the sea, I would say this shield is a requirement. As you visualize it, use the following (or your variation):
                              Words of Power For Creating a Protective Shield:

The One Power

Working for and through me,

Hereby manifests and creates

The Invisible Protective Shield

Of The Goddess

According to Free Will,

And for the Good of All,

Nothing and no one

Can negatively penetrate This Shield.

(Name) is now impervious to all harm,

I (he, she) am (is) now divinely protected,

And perfectly safe,

In all time and all space,

And so mote it be!