Mad Rocket Scientist

My copy has already arrived, so I guess I should review it: Obviously, the book is hilarious. Here's a few excerpts: The book itself (I got the softcover) is nice, they made new cover art which is fine, although not as nice as the original. It does include the image of the test firing and the engraving from the original, although in the front rather than the back and in black and white rather than color. The font is a little small, but not too bad. The chemical formulas have been typeset rather than scanned, except for one, which is odd, but not a problem. There are a few typos I've notices, but nothing major, and they may have been in the original as well. I would recommend it even if you have no knowledge of chemistry, (I have very little) since the stories are still funny and interesting.

I really like that weird jackdaw, but I have no idea what niche it could fill. Maybe roll control if it was gimballed? It's too bad roll control is so easy in stock KSP.

I think methane was chosen because carbon, hydrogen, and oxygen are readily available almost everywhere in the solar system, while ammonia is relatively rare.

It is unexpected, I think @NecroBones figured that one out right after the forum was updated to the new software.

Sort of. You need to write the html (or generate it) and then paste it into the editor with the inspector. But the bordercolor attribute seems slightly broken, but you might be able to get it to work with some fiddling.

SpaceX has stated that they want to make their operation carbon-neutral someday, which would mean producing methane from CO2 in the atmosphere. In fact, they could even become carbon negative, which, although it wouldn't really make much of a dent in atmospheric CO2, would be a great precedent.

OK, thanks. The Boring Co. youtube just posted this:

I think you mean üm̈läüẗ.

This: Although I believe they don't count posts in forum games.

That makes sense, I just prefer the lighter side of the show. And I agree, some of the early writing wasn't very good, the way Clara seemed to hold it against the doctor for changing was particularly unbelievable. But I do like the over-the-top-ness and how gregarious and unselfconscious his portrayal of the doctor is.

What about Cyberpunk 2077? That looked more interesting than those to me. Fallout 4 was kind of boring, so I probably won't but 76, at least not until it goes on a >50% off sale, and I've never played an Elder Scrolls Game. If there's a sale on a bundle of the older ones when VI releases I might grab those.

Doctor Donna, of course. But since that's not an option, Peter Capaldi. Am I really the only one who likes Peter Capaldi? And there are Christopher Eccleston fans? Well, let me justify my preference for Capaldi: first of all, I'm excluding the first half season after the regeneration, as those are often the weakest for any doctor, and were especially bad for Capaldi. I think Capaldi just edges out David Tennant and Matt Smith (who I would rate slightly above David Tennant, but possibly only because of writing and story quality), because first of all, I think he captures the quirky and dramatic nature of the doctor better than the others, who played the doctor straighter. Second, as an older actor, the writers can avoid a companion-doctor romance more easily, which I think is better as those romances always have to end badly, and I think they make the companion's character more flat, as there is nothing going on with them outside of the adventures they have with the doctor. I'm also ignoring the old doctors, since I've seen very few of those episodes.

Bring coal, then make coal gas and liquefy to make a steampunk coal powered rocket engine. Brass fittings not included.

I think the book said it was something like an extra 15% for boiloff. It seems like around 0.1%-0.5%/day, depending on how heavily insulated the tanks are, is normal. That seems good enough for initial operations.

The Case For Mars talked about using some feedstock hydrogen hauled from earth to make CH4 and H2O, then splitting the H2 off and recycling it through the process. It used 6 tons of hydrogen to make 108 tones of CH4-O2 propellant, and avoided needing ice mining the moment you arrive.

Honestly I don't expect to see anything but twitter ramblings about rocket roadster until after the model 3 production is well sorted out. Based on this: It won't be just a braking boost, but a set of thrusters to help the car accelerate quicker, go faster, and turn faster. Based on some earlier things Elon said, the roadster v2 is probably limited in speed and handling by traction with the road through the tires, rather than power from the motors. This would also help overcome the advantage of lightness for handling in gas cars. If you're talking about noise, Elon said this: I agree that this system would be impractical and silly for the vast majority of driving, but I think that's true of any car that's this expensive and powerful. Anyway, to avoid turning this into a Tesla Motors thread: Does this mean using water carried along with the mission or mined from ice on Mars to capture CO2, or capturing water vapor (ice crystals?) from the martian atmosphere?

Looking like the rocket powered tesla is for real. Use this link to read all of Elon Musk's tweets and replies without a twitter account: https://twitter.com/search?f=tweets&vertical=default&q=from%3Aelonmusk&src=typd This was posted on reddit, it seems to be a similar concept:

It is limited by door size. There are four, two each on side. The doors are 456 ft or 141.7 m tall, and for the lower 113 ft or 34.4 m is 149 ft or 45.4 m, and the remaining height is 76 ft or 23.2 m. I've seen references to the lower part of one of the doors being widened by 40 ft or 12.2 m for the space shuttle, and a cutout for the tail being added in the upper part, so it can stay closed while a shuttle goes through.

https://dsl.richmond.edu/historicalatlas/138/c/ Select table of contents in the checkboxes on the left to compare years. 1869 was when the transcontinental railway was completed, so everything not specifying travel mode is talking about stagecoachs.

MalwareBytes does not like CubeUpload, FYI. When you upload an image to imgur, it creates an "album" automatically. With one image, it's just a bandwidth-hogging wrapper, but if you upload multiple images at once, or use the "add another image" button, it adds that to the album. This is what it looks like if we... Copy and paste what is already in the address bar right after upload: https://imgur.com/a/WCnc3uk Copy everything after /a/ in the URL, then post it into the imgur button in the editor (IIRC this is broken): RMB > open link (or image, or copy image address) in new tab > copy url > paste in editor: RMB > copy image > paste in editor: (Note that with the above, there appears to be no difference whether or not you zoom in) Get share links > embed in HTML > paste in editor: <blockquote class="imgur-embed-pub" lang="en" data-id="jVziRV1"><a href="//imgur.com/jVziRV1">View post on imgur.com</a></blockquote><script async src="//s.imgur.com/min/embed.js" charset="utf-8"></script> Get share links > BBCode > paste in editor: Get share links > Markdown > paste in editor: [Imgur](https://i.imgur.com/jVziRV1.png) In the forums editor: Insert other media > insert image from url > paste a direct link to the image (ending in .jpg, .png, etc): Selecting the image from the thumbnail view on you account (YourAccountName > images) you can also directly copy the direct link. And you can copy resized versions of the image. You can also do this by appending a letter to the image id (numbers and letters before .png) i.e. https://i.imgur.com/jVziRV1.png is original https://i.imgur.com/jVziRV1s.png is small and square https://i.imgur.com/jVziRV1b.png is bigger and square https://i.imgur.com/jVziRV1t.png is a small thumbnail https://i.imgur.com/jVziRV1m.png is a medium thumbnail https://i.imgur.com/jVziRV1l.png is a large thumbnail https://i.imgur.com/jVziRV1h.png is huge thumbnail You can also resize by edit on imgur, but I prefer to use the forum's resize tools instead if I need to. In short, it matters very little which of imgur's many layers of sharing systems (and at least two redesigns) you use.

This is what I have hung in my bedroom. Except there's some extra stuff on the bottom.

I initially answered this with a bunch of math for cost, but after almost finishing, I realized alternating receiving slugs between the side of the orbit which would accelerate the receiver station and the side which would decelerate it would lose some of the energy, but require zero fuel. I kept the math for if it was always decelerating anyway: So if the figure from the OP of 1.729 GJ/kg is right, and the cost per joule from here of 2.8 * 10^-8 $/joule ($28/GJ), each kilogram coming in is worth $48.412 USD, assuming no losses in recovery. According to this, mass driver efficiency is about 50% with current technology, and my understanding is that that's the same whether you're launching or decelerating. So each incoming kg is worth $24.26 USD, minus 15.7 MJ/kg for launch = 31.4 MJ for efficiency losses = $0.8792 USD is $23.3808 USD profit, per kilogram. So that means if you have a 1 ton station (which seems on the light side for something like this) every time you need to boost the station by that much, you've made $233.81 USD. With a specific impulse of 450 s, you'd need to launch 193 kg of fuel from earth. so with current $/kg to orbit this would be impossible, however if fuel was transported from the asteroid belt, with reusable tugs, this could easily be possible with existing technology. SSTO/fully reusable rockets might be able to get the cost down to $1/kg to orbit someday too. Using NTRs with Isp's of 900 s would drop the fuel requirements to 92 kg, however ion engines would probably have too low of a thrust to counteract the stream of slugs. Interestingly, it appears that adding or removing mass from the station would not actually make a difference. If it was ten times heavier, it would be affected 1/10 as much, but need 10 times more fuel. I think it it essentially the oberth effect. Mass just has more energy the lower it is in a gravity well.

He also says: So it is unclear if they actually intend to spin it up or not. That would be better, but anyone who wanted to use the rotating room would have to reacclimate to the already discussed coriolis forces.

Thanks, I was looking in "backup drives."

Think a standard electric motor, but unwrapped and extended. They're called linear motors, and are used on some roller coasters to "launch" the coaster train. If you want to know more about the applications to space, look up "mass driver."