GAry 7

Blockquote will do something like this

Or you could just italicise using the “i” tag like this.

The fuel in the Falcon engines is kerosene, not hydrogen. The do give off CO_2_. I just don’t think all the spacelaunches put together contribute significantly compared to just a day of driving in the US.

But I’d love to see some back-of-the-envelope numbers.

however, if we can look at chemistry you will see that in reality this test did not do that. liquid oxygen and hydrogen are two chemically combustible substances that, when combined, produce the highest thrust rate at the cleanest output that we know of.

if you want to imply that nasa is making the earth hotter from green house gases i suggest you turn your ire to china’s cars, to india’s coal plants, and to the hot gas that escapes from your boring brain.

I have a silly question. Does all that thrust affect the earth’s orbit in any way? We have been testing rockets like that for many years and I’ve never heard of anyone being concerned, so I assume it is negligible. Anyone want to do the math for me?

The sheer overwhelming mass of the Earth makes any force we can apply to it completely ineffectual (in any meaningful way). There will be a theoretically calculable change in Earth’s motion round the Sun, but I suspect it’s not measurable by anything we have today, and it’s certainly nothing to worry about.

If you think about it, the Earth has survived countless high-energy impacts from space (much higher energy than anything we’ve done) and it is still in the same, stable orbit it’s been in for billions of years.

I do have an interesting and related story idea I might develop some time which involves parallel Universes and parallel Earths. The key point is that in the vast majority of the parallel universes, Earth is not in exactly the same position in space as our own Earth because the countless minor differences that have happened over millions of years — e.g. plate tectonics may have shifted the continents into a different configuration — add up to a major shift in another Earth’s orbit and position when compared to our own. So you would not be able to cross over from one Earth to another, because you would be stepping out into deep space! (But you could use that problem to your advantage as a really cheap and easy way to launch spacecraft, assuming they can get back into our reality!).

855,000 pounds of thrust = 4 MH.
To compare, each (out of three) space shuttle engine produce 1.8 MN of trust, each shuttle’s buster – 14.7 MH.

Half a million pounds = 226.5 Tons of propellant

And of course don’t let’s talk about what’d happen if the US car park had the same fuel efficiency as the EU one. That’s much too inconvenient.

A propos – I’m getting increasingly fed up with 4x4s. Something’s gonna give before long.

“Now let’s go burn down the observatory, so this never happens again!”