The Orion capsule uses an escape system quite like that of the Apollo spacecraft in the 1960s and 70s: an 'escape tower' containing a solid-fuel rocket that will pull it up and away from Ares I in a pinch. Henry Spencer More Quotes by Henry Spencer More Quotes From Henry Spencer My one concern is that when money gets tight, it's easy to cut R&D funding that isn't tied to a specific project - look at what's happened to NASA's aviation research. Henry Spencer look money research easy Sure, there were hopes that Constellation's systems could later be adapted to support more ambitious goals. But Apollo had those hopes, too. It didn't work in 1970, and it wasn't going to work in 2020. Henry Spencer goals more support work Supplying fuel for a Mars expedition from the lunar surface is often suggested, but it's hard to make it pay off - Moon bases are expensive, and just buying more rockets to launch fuel from Earth is relatively cheap. Henry Spencer hard space moon earth The communications delays between Earth and Mars can be half an hour or more, so the people on the ground can't participate minute by minute in Mars surface activities. Henry Spencer more half earth people The Moon may not be quite as appealing as Mars, but it's still a complex and poorly understood world, with many questions still unanswered. Henry Spencer questions mars moon world In 1960-61, a small group of female pilots went through many of the same medical tests as the Mercury astronauts and scored very well on them - in fact, better than some of the astronauts did. Henry Spencer small better group medical NASA has never had a problem finding capable people to be astronauts. NASA's problem was, and still is, finding ways to cut the list of capable applicants down to a manageable length. Henry Spencer down never problem people Spaceflight, especially in the Mercury spacecraft, clearly wasn't going to be much like flying an airplane. Henry Spencer going like airplane flying Not until the space shuttle started flying did NASA concede that some astronauts didn't have to be fast-jet pilots. And at that point, sure enough, women started becoming astronauts. Henry Spencer women flying space enough Since SpaceX's very beginnings, they have talked about recovering and reusing at least the first stages of their rockets. Henry Spencer stages about first very Solid-fuel rockets can't easily be shut down on command. Henry Spencer shut down command rockets Whether solid rockets are more or less likely to fail than liquid-fuel rockets is debatable. More serious, though, is that when they do fail, it's usually violent and spectacular. Henry Spencer fail more serious space Past experience, on the shuttle and the Titan rockets, suggests that large multi-segment solid rockets have a probability of failure of 0.5 to 1 per cent. Henry Spencer probability failure experience past Sometimes people wonder why aeroplanes are so cheap and rockets are so expensive. Even the most superficial comparison shows one obvious difference: aeroplane engines use outside air to burn their fuel, while rockets have to carry their own oxidisers along. Henry Spencer burn space sometimes people Liquid oxygen is one of the cheapest manufactured substances on Earth. In large quantities, it costs pennies per kilogram - cheaper than milk or beer. Henry Spencer milk oxygen earth beer Trying to build a spaceship by making an aeroplane fly faster and higher is like trying to build an aeroplane by making locomotives faster and lighter - with a lot of effort, perhaps you could get something that more or less works, but it really isn't the right way to proceed. Henry Spencer fly you effort way As plans for the first lunar landing started to be made, nobody had really thought about who would be out first. Henry Spencer nobody first thought who The original specifications for Apollo navigation called for the ability to fly a complete mission, including a lunar landing, with no help from Earth - none, not even voice communications. Henry Spencer fly mission voice earth