From: Gary LaPook
Date: 2016 Sep 18, 00:21 -0700
On "Impossible Engineering" tonight on the Science channel the show was about the Orion spacecraft being built at NASA to carry astrodauts to Mars. It will have a computer controlled camera that will make measurements between celestial bodies to navigate the Orion to Mars. But, since there is concern of a failure in this very complex system the astronauts will also carry a sextant which would provide sufficient accuracy to get them home.