Nibb31

This post from an IBM engineer on the NSF forums is really interesting: http://forum.nasaspaceflight.com/index.php?topic=27043.0

Man, you're so funny.

I don't think the LES had grid fins, at least the unmanned prototypes didn't, but other than that, it probably worked like Soyuz (which is not how BobCat made it) Note the the Block A and Block B were half grey and half white. I'm not quite sure why... probably to monitor roll during the ascent, like the checkered pattern on US rockets. Downloading it now...

"Better" would depend on their actual purpose. The best form would depend on the requirements: function, budget and timeframe.

No it isn't. The most expensive part is the payroll for the people who will be building, designing, handling, integrating, testing, monitoring, maintaining, etc... These people are mostly highly qualified engineers and techs and are expensive to hire. By reusing the first stage, you only reduce some of the manpower required to build the first stage. All the other work still needs to be done.

I guess it pretty much stemmed from the question "why would we want to build gigantic space habitats in the first place?".

You're right, it's probably less than that.

Not sure where you're picking that conspiracy theory attitude. Our planetary resources are a finite pie where 10% of the population eats half of the pie and the rest wants a larger share. Either we keep on multiplying and everyone gets a smaller share, especially those who eat the most but don't want to give up their share, or we can take measures to reduce population and everyone can keep on having a decent piece of the pie. We can't keep on with exponential demographics forever. At one point, there will a rebalance between population and resources will be unavoidable. Either we handle it now pacifically, or the problem is going to handle itself dramatically and it won't be pretty. You might hope that technology manages to increase the size of the pie, or that we manage to become more efficient by losing less crumbs when slicing it, but those gains will not allow the pie to grow at the same level as the world population, ie: exponentially. Au contraire, productivity and efficiency gains usually tend to follow the laws of diminishing returns. In other words, economical growth is far from following the same curve as demographic growth. Even if population growth slows down dramatically, we will still be over 10 billion by 2040, with a majority of that population aspiring to the same standard of living as Europe or the US. Either you deny them that level of wealth and face the consequences of an increasingly unfair imbalance, or you give up a large part of your wealth so that they can have some. Either way, something is going to crack, and it won't be pretty when it does. Sending a few thousand people into space won't make a difference. We might have the technology to deport billions of people into space in several centuries, but space colonies of that scale simply aren't an option at this point. We have to find a solution for the problem now if we don't want to face a violent reduction in population in the next century. Strawman argument and hyperbole.

You can go all Nazi, or you can just put an end to pro-natality programs and subsidies, educate populations, and make contraceptives freely available for the entire world. Bringing the world population back down to 4 or 5 billion over several decades would improve the quality of life for populations everywhere. That is a something that we could initiate now without having to wait 200 years to develop space technology. Because if we continue growing, we might not have the resources left to do anything much in 200 years.

I don't see how reusable will decrease launch prices by 75%. The larger part of the cost of launching a rocket is in the infrastructure, the R&D, the personnel... The actual material for building new hardware is only a minor part of the cost. You still need to pay for the launch facilities and the people on the ground who handle all the launch activity, the testing, the integration, the admin overhead... Even a cost reduction of 20% seems optimistic, and that's just for the launch part of the space project, which usually includes development of a payload, ground stations, monitoring, etc...

Already posted and discussed here: http://forum.kerbalspaceprogram.com/showthread.php/47269-Animation-Of-Proposed-Asteroid-Redirect-Mission

What do you mean by everything? are you talking about personal information or appliances ? I think that just about everything about you is on a computer that is already connected to the Internet, so the cat is already out of the bag.

If we can build a self-sufficient colony on the Moon or Mars, then we can live anywhere, including our own home planet after a cataclysmic event. Even a scorched Earth where all vegetation has burned down will always be more hospitable than Mars. There will always be water, resources, and the basic building blocks of life.

Rocket science is about compromise. You can't have a perfect rocket.

I will say it again (what a constructive discussion!): a space colony does nothing for our long-term survival because there is hardly anything that we couldn't survive as a species. As for "advancement", that's a totally subjective argument which is based on your own bias of what our "goal" or "purpose" or "destiny" is. The human race is extremely diverse and what you consider "advancement" might be a step sideways or backwards to other people from other countries, other cultures, with other priorities... It's ultimately meaningless. Scientists don't agree with you that an asteroid will destroy the entire human race. At least two studies state that an asteroid impact is survivable for humanity as a species: http://en.wikipedia.org/wiki/Impact_winter#Survivability The references to the actual scientific papers are in the Wikipedia article. As such, no matter how many times you say it again, you cannot claim that a space colony is essential for survival of our species, because our species is clever enough to survive pretty much everything without it.

Yeah, and I love that they fit it with 100MW laser, just in case they run into some Klingons on the way to Mars. Ridiculous is an understatement.

Wasn't that what you were proposing for a Mars base in that other thread? Scientists estimate that it took 10 years for the dust to completely settle after the Chicxulub event. It would probably take much less before you get the same amount of light you would get on Mars (Mars gets about 40% of the daylight level of Earth). You wouldn't need to live underground either, you would just need air filtering. And we have this great invention called electricity for lighting. I'm not saying it wouldn't be a cataclysmic civilization-ending event. I'm saying that although many species would go extinct, not all of them would. A lot of biodiversity was lost, many individuals died, but many species of flora and fauna survived the various extinction events. Those that didn't disappeared in the years after the impact because they were unfit for their new environment. Humans can more easily adapt to a new environment than other species, so there certainly would be a number of survivors. Bla bla bla... One is actually easier than the other, and it's not what you think it is. But you are missing the point, which is that there is hardly any cataclysmic event in the foreseeable future that would wipe out 100% of humanity or 100% of life on Earth. Life is extremely resilient and humans are tough. Therefore a space colony as an insurance policy for survival of the species doesn't hold. And statistically speaking (which is what insurance policies are about after all), if this sort of event occurs at a scale of several million years, there really is no rush because whether we do it in 20 or 2000 years makes no difference on the geological scale. The problem is that you have decided that you want a space colony, probably because of the romantic appeal of science fiction, and you are now looking for a reason to have one. You might as well just admit that you want one because it's cool, because there really is no real justification for one.

Surely if we can build self-sufficient colonies on Mars or in orbit, with hydroponic farms and shielded habitats that could sustain that many people, we could maintain the same closed-loop life support on Earth, couldn't we? Besides, if we had the technology to send 80000 people to Mars, we would probably have the technology to detect and divert an asteroid in the first place. Even if a Chicxulub asteroid hit us today, many of us would die, but we would certainly survive as a species. We have particle filters for breathing, we can build shelters or dig ourselves underground. Pretty quickly we would get power generators up and running that would provide heat and light. We could build hydroponic farms like we would on Mars. If we detect the asteroid in advance, we could prepare by stockpiling food and supplies and start building shelters. It wouldn't be fun, but there is no doubt that a small number of us would survive, and life would still be easier than on Mars. Even if it killed 99.9% of the world population, there would still be 8 million of us left, which was the total human population only 8000 years ago. That's more than enough for the species to survive, and 100 times larger than your Mars colony.

The dinosaurs didn't have our intelligence. They couldn't shelter, warm themselves, or grow crops. We could find ways to work around the lack of sunlight with artificial light and heating, we could build filtering systems to preserve our lungs from the dust. Sure, there might be a cataclysmic famine, we might lose a few billion fellow humans in the process, our culture and society might be destroyed, and we might even face a bottleneck event, but more than enough members of the species are likely survive to preserve the genetic pool. A few hundred more people on the Moon or Mars wouldn't make a difference if it's the species you're worried about. And so what if we don't? Sure, the longer we live the better, and it's worth putting up a fight, but we are all going to die one day, and so is our species. It's just something that we've got to accept.

The "extinction of the species" argument always sounds a bit weird to me. We have been on Earth for 200000 years, and the Earth has been around for 4.5 billion years. We are 8 billion individuals. I can't think of any cataclysmic event that would totally wipe out Humanity without leaving at least a few million survivors around the world. That is a much larger population than could be sustained by any self-sufficient space colony before many centuries. As far as survival of the planet, we are safe for at least a few million years. Evolution alone will have turned us into something much different than the modern human species by then anyway. So whether we build colonies in space in 20 years or in 2000 years won't make much of a difference for our survival as a species. And even if we are wiped out, what difference does it really make? It's not like we will be there to cry about it. We are just a tiny little spec of life in a remote corner of the universe that has only existed for a tiny fraction of a time. Nothing lasts forever, so why should our species? There is no reason to believe that we have some kind of mythological destiny or purpose or that we have more of a right to survive than the dinosaurs. If we what we recognize as modern humans ever disappears or evolves, then nature and life will find a way to fill the void with something better suited to the environment that we'll leave behind us. I'm ok with that.

Ariane 5 is overpowered for its main mission of launching GEO sats. It has to launch two at a time, which lacks flexibility, and causes Arianespace to lose deals because customers have to wait for a second customer to show up. This is why Ariane 6 will be smaller. Also, the GEO market isn't growing because the main use for GEO comsats is satellite TV broadcast, which is getting a lot of competition from DSL broadband and 4G wireless these days. The trend is to replace older sats with smaller, cheaper, and higher bandwidth sats with a longer lifespan. "Build it and they will come" doesn't always work in the real world. If you open an airline to the middle of the desert, people won't queue up to buy tickets. There needs to be at least some kind of prospective market, and specifically for transportation services there needs to be a destination. The payload capacity of rockets like Ariane or Proton hasn't been an incentive for larger commercial payloads to appear. Economy of scale means that most comsats nowadays use the same busses from 2 or 3 major suppliers (Boeing, LM, Astrium...), which are standardized to a specific size and purpose. The only customers for large payloads are low volume institutional launches for either scientific or military payloads. Elon still doesn't have unlimited funds. SpaceX is a launch service provider, like ULA or Arianespace, not a space program. They build rockets but they still need someone to pay for the stuff that goes on top. "Colonizing Mars" would cost hundreds of billions and there is no ROI for commercial investment. I have no doubt that SpaceX will have an Super Heavy offering in its catalog, available in case a customer wants it, but I doubt that it will ever be needed.

The question is why? What would be the purpose of putting so many people in orbit? If it's to deal with overpopulation, the main problem is finite resources, not real estate, and using up resources to build these would only make things worse. These colonies would rely on importing everything from Earth and would cost much more than colonizing Siberia or the Sahara desert. It would make more sense to build colonies where the resources are easy to get to.

The RTLS (Return to Launch Site) manoeuver was quite dangerous and only done in the simulator. There is an orbiter video of one here: As you can see, it involved waiting for SRB separation, pitching to turn around (with a full tank), burning retrograde to reverse the trajectory, and rolling the orbiter to drop the tank. Pretty hairy... The Transatlantic Abort (TAL) was for aborts that would occur later on in the flight and was preferred over the RTLS. The TAL sites were a select list of landing strips, usually in France or Spain, depending on the launch profile, that were long enough for the Shuttle to land and were manned by NASA personnel during each launch. A C130 was dispatched with the equipment for safing the Shuttle and crew after landing. Other abort modes are discussed here: http://en.wikipedia.org/wiki/Space_Shuttle_abort_modes

Your orbits seem to be on wildly different planes. You first have to align your planes (by burning normal or antinormal at the ascending or descending nodes). Once your planes are lined up, it's just a matter of timing your Hohmann Transfer.

The Kosmos panels lag like crazy on my rig. Also, overuse of struts is usually bad too.