Henry Spencer Quotes

Since SpaceX's very beginnings, they have talked about recovering and reusing at least the first stages of their rockets.

Technically and financially, it might still make sense to give up on Ares I and simply write off the money spent on it, but politically, that's probably impossible.

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.

Is manned space exploration important? Yes - not least because it simply works much better than sending robots.

MS-DOS isn't dead, it just smells that way.

Belief is no substitute for arithmetic.

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.

Progress requires setbacks; the only sure way to avoid failure is not to try.

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.

On the technical side, Apollo 8 was mainly a test flight for the Saturn V and the Apollo spacecraft. The main spacecraft system that needed testing on a real lunar flight was the onboard navigation system.

Indeed, "brute force" solutions are often characteristic of advanced cultures, not primitive ones. The Romans and their predecessors spent a long time figuring out how to build arches ... and virtually all our buildings today use post-and-lintel construction, precisely what the arch was devised to replace. We have better materials and more money, and given that, arches are usually not worth the extra complexity.

Liquid oxygen is one of the cheapest manufactured substances on Earth. In large quantities, it costs pennies per kilogram - cheaper than milk or beer.

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.

Speaking of photography, while the Apollo 8 crew shot hundreds of photos, there was one that got everybody's attention: a blue-and-white Earth rising over a gray moonscape.

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.

Rocket engines generally are simpler than jet engines, not more complicated.

Altruism is a fine motive, but if you want results, greed works much better.

The Apollo programme of the 1960s had some weight problems, too; in particular, the lunar lander needed some fairly drastic weight-reduction work.

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.

Testing a parachute drop of a heavy object is not simple.

Large solid rockets have never been a very good way to build launchers that might have crews on top, especially because of the problems in getting the crew away from a failing launcher.

Programming graphics in X is like finding the square root of PI using Roman numerals.

SpaceX does seem to have had a run of bad luck, with its first three launches all failing.

8th Commandment:

"Thou shalt make thy program's purpose and structure clear to thy fellow man by using the One True Brace Style, even if thou likest it not, for thy creativity is better used in solving problems than in creating beautiful new impediments to understanding.

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.

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.

In a small spacecraft, it was hard for the other two guys to sleep when the on-duty man was talking to Mission Control regularly.

The demise of Constellation is not the death of a dream. It's just the end of an illusion.

Politics /n/: from 'poly ticks', short for 'many small bloodsucking insects'.

As plans for the first lunar landing started to be made, nobody had really thought about who would be out first.

Claiming that solid rockets are necessary for a heavy-lift launcher is obvious nonsense.

Reusable rockets promise much easier testing because you should usually get them back, and you can debug as you go rather than having to get everything perfect the first time.

In the first few years, it was at least plausible to come in in the morning and read all the Usenet traffic that had come in, and 15 minutes later be off doing something useful.

A bit of tolerance is worth a megabyte of flamming.

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.

Solid-fuel rockets can't easily be shut down on command.

The key virtue of orbital assembly is that it eliminates the tight connection between the size of the expedition and the size of the rockets used to launch it.

Historically, the U.S.'s big launchers fly seldom enough that their costs are dominated by annual upkeep of facilities and staff, not by the actual cost of each launch. The expensive part is maintaining the launch capability, not actually conducting launches.