1. Environmentalists first raised concerns about the impact of rocket exhaust, particularly from solid fuel rockets, on stratospheric ozone about eight years ago. 2. Officials said the grated site might have contributed to the fire because it produced unexpected ground effects from the rocket exhaust that slowed and affected the landing. 3. That flaw combined with freezing temperatures to allow a leak of fiery rocket exhaust from an O-ring seal in one of the boosters at liftoff. 4. The laser would destroy not the whole object, but a small corner of it, sending vaporized material shooting off like a tiny rocket exhaust. 5. This hot, low-density matter pushes against the colder, denser matter left in the cloud, much as rocket exhaust accelerates a space shuttle in the opposite direction. 6. The experiment sought to evaluate what would happen if rocket exhaust hits parts of the planned space station. |