After retrieving a few balloons (since she'd seen what happened to Professor Flamsteed's balloon and she didn't want to have to go back and forth), Heather tapped herself on the head with her wand. "Aquatraxi Gravita." Grabbing a blue balloon, she placed it a couple of feet in front of her, then took a few steps toward it. And ended up with wet shoes. Luckily, they were waterproof.

So, one balloon down. She placed a red balloon in the same place as before, then tried walking to it. Hmmm, wet face this time. Maybe she should recast the spell....?