shynung

kww.reusabletechnologies.com Where else can you find cheap second-hand space hardware? Other than the side of the road, that is.

I think they used timed programs. As in, the computer knows how much time would pass between ascent MECO and circularization burn start, and simply count down when MECO happened.

The transition from 1G to 0G is trivial. Some people would get space-sickness, from their spatial senses being confused (not knowing where is 'down'), but it's not lethal. It's the transition from 0G to 1G that's problematic. For some reason, the body adjust their internal composure according to current mechanical loads, so if it is put in a 0G condition, the structural parts (bone, muscles) weaken because they no longer have to bear their own weight. I'm imagining that someone who spent too much time in 0G conditions becoming so adapted to the weightlessness in that condition, their bodies are too weak to return to Earth without some sort of exoskeleton to keep it from collapsing under its own weight.

That's if there is such a machine that can do such a feat. The Venera 13 and 14 surface landers, sent by the late Soviet Union in the 80's, survived at most a little over 2 hours, despite being massively overbuilt.

Local TV news station KompasTV announced that they have found one of the emergency doors. Said announcement are being broadcast as I write.

Or use a closed-cycle nuclear thermal rocket. It can be designed to minimize radioactive isotopes in the outgoing exhaust. Though, I have to say that making a single-stage-to-orbit craft is far more difficult than it may seem.

I don't see why the radiation would be a huge concern. Barring an open-cycle reactor, all nuclear fuels and reaction products stays in the reactor. The propellants (either ambient atmosphere or liquid rocket propellant) are merely heated, and spewed out the nozzle. And it doesn't have to be direct heating, either; an intermediary coolant can take the thermal energy from the reactor and subsequently heat the propellant with that energy. Protests against RTGs and nuclear technologies in general are mostly political in nature. As in, people simply don't like anything with the word 'nuclear' in it, regardless of its actual usefulness or safety. Let's just leave it at that, shall we? I don't want anymore pro/anti nuclear argufights.

Well, both nuclear thermal jets and rockets have been studied in Project Pluto and NERVA, respectively. The SABRE engine from the Skylon project is a study of a hybrid jet/rocket engine, even though it hasn't gone very far as of now. Though they did get the precooler part running. Basically, a hybrid nuclear thermal jet/rocket is an amalgamation of these technologies, which is to say that the concept is feasible.

A very slight alteration to my legal name. If you find anyone else using the moniker 'shynung', or a variation of it, out there in the web, there's a good chance it's the same guy as the one typing this post.

Fun fact: there are swans that are black.

Did you know that squirrels communicate with each other using magnetic waves? Brought to you by The Untrue Fact Telling Machine.

Seems interesting. Alright, I'd watch it if you release it.

Secure-Contain-Protect? The one that deals with forbidden artifacts and stuff? I dunno, seemed a bit too implausible for me to be in a science channel.

What's this SCP report you're talking about?

The dV cost of going to graveyard orbit is less than 10 m/s. Just dipping the periapsis under 100km alone would have taken a few km/s.

The British used kerosene and hydrogen peroxide in their Black Arrow rocket, which according to the Wiki, is hypergolic when heated to high temperatures. My guess is that the Black Arrow had a catalyst somewhere in the combustion chamber, to decompose some of the peroxide to hot oxygen and superheated steam, the reaction of which is highly exothermic, in order to ignite the rest of the peroxide, if any, with the kerosene fuel. Both the kerosene and peroxide had nothing but hydrogen, carbon, and oxygen molecules in it, so if done correctly, we'd get a hypergolic rocket with an exhaust gas composition similar to kerosene/LOX rockets. It may not look like much, but it's definitely better than UDMH/N2O4 hypergols which throw off nitrogen oxides by the tons.

I'm wondering how did this discussion went from kerosene-LOX rockets to renewable energy. IMO, we should continue to use kerosene rocket for safety reasons, and then switch to methane when the oil dries up; they're both safer to handle than liquid hydrogen, and can be stored at higher temperatures. Not that it's going to do so in the next few years, anyway. That, and we should limit the hypergolics to exoatmospheric use only.

Actually, the silicone sealant is for the oxidizer's binding agent. The goal is to find one that doesn't react with potassium nitrate in such a way that the binder does not become fuel.

Liquid hydrogen is a tough beast. If not kept below 20 K, it boils away through the tank's walls. And it blows up with the slightest spark if a large concentration managed to spawn itself. Not to mention that a hydrogen flame is almost invisible, one can walk into it and never realize that he's burning until the heat sets in.

If the fuel and oxidizer is in the same solid mix, it'll burn to completion by itself. Frozen_Heart said UK banned those rockets for amateur projects, and plan to get around the ban by separating the oxidizer and fuel. As per his previous posts, the oxidizer will be potassium nitrate, and the fuel will be propane, presumably gaseous.

That's black hydrogen. It does come from natural gas (methane), and contributes to CO2 production as well. If the hydrogen comes from water-cracking plants (electrolyzers), it's an energy storage medium. While locally CO2-free, it's quite energy-intensive, so the CO2 contribution depends on where the energy source ultimately came from.

So? If there is no substitute that proves more profitable than regular old farming, it would still be the prime method. Nuclear, yes. Solar or wind, I doubt it. The latter two takes a long time to get their return on investment.

Now we run into the classic 'Food vs Fuel' problem. This would have solidified the position of the crude oil industry, since it needs less space than energy crops for the same net energy output.

Why not use the plants themselves? Farm them in massive amounts, then process the biomass harvest into fuel. Why bother with inventing the industrial processes when one can make something else make it for him? Now we're back at the ethanol biofuel business model. It's possible, but it would be much more expensive per joule of energy produced. How much would you think it will impact the human population as a whole, facing drastically-increased energy cost in comparison to today's crude-oil fuels? Of course, somewhere, someone will respond by suggesting to use nuclear sources. How much sociopolitical obstacles remain for that option in an energy-scarce future, I have little idea, but judging from today's society, it wouldn't change much different.

Experimental rocket engines, both from the past, present, and the near-future, of all types. Something like NERVA or the recent VASIMR is decent, but if you can find designs that go beyond insane, I think it'd be much better.