I am. outraged at the university's treatment of a retired professor.. Mark of Excellence The matter of the practical benefits of emeritus status, however, is amoot point at many institutions, especially community colleges, thatlack resources to share with retired faculty members.
Dear publish1000-ga; You posed a great question. The answer is really much simpler than it first appears. The US Space Shuttle uses a rocket propulsion system to get into its final orbit in its approach to Earth. Other than that the Shuttle is essentially falling and during re-entry the aircraft is actually a glider. The reentry speed is largely dictated by the Earth gravitational pull and given the physics of such a reentry the speed is typically approximately 25,405 feet per second (17,322 statute miles per hour).
The fastest spacecraft launched from Earth was NASA's New Horizons mission, which visited Pluto in 2015. In January 2006, the probe left Earth at 36,000 mph (58,000 kph). If such a probe traveled in a straight line to Mars, the time it would take to get to Mars would be: Closest possible approach: 942 hours (39 days)