How To Add Energy Parameter

I draw a space ship :

Code:

private void spawnSpaceship() {
Rectangle spaceship = new Rectangle();
spaceship.x = MathUtils.random(0, screenWidth-32);
spaceship.y = screenHeight;
spaceship.width = 32;
spaceship.height = 32;
// spaceship.energy = 100; <= this line won't compile
spaceships.add(spaceship);
lastDropTime = TimeUtils.nanoTime();
}

As you can see, spaceship has parameters : x position, y position, width, and height.

I'm a noob and I would like to add an "energy" parameter but this line won't compile :

Code:

spaceship.energy = 100; <= ERROR