| Answer the Challenge Question at http://www.physicscentral.com/sots for cool prizes! NASA Astronaut Don Pettit uses his off-duty time to practice his microgravity yo-yo skills. |
| nasa sots don physics aps yo-yo sphere the space science physicscentral Premiere_Elements_10 off pettit gravity |
| Views: 205035 | 2012-08-09 |