PakledHostage

I thought we resolved that misunderstanding on the previous page?

That's a weak argument and you know it. It speaks more to the gullibility of the media and the willingness of celebrities to sing for their supper than anything else. Orion EFT-1 was an unmanned engineering test flight. It was analogous to checking to ensure that HMS Endeavor's dinghy would float while planning Cook's first mission to the south Pacific. In the 18th century, people could easily grasp that a ship's tender may be the means of getting from land to the mission's mothership and back, but it wasn't going to take the crew all the way to Australia. The media and much of the public didn't seem to understand that point about Orion. My point is that funding is limited. I am not disputing that there is some benefit to the ISS, but putting all of our eggs in one basket is a bad idea. A manned mission to Mars or Venus may be great spectacle but a great spectacle doesn't justify the inevitable leaching of funding away from other valuable projects. And don't over-estimate the public's interest in manned space flight. Even by the time of Apollo 13, much of the general public stopped caring about manned lunar missions. The networks didn't even carry Apollo 13's television broadcasts. A small fraction of the money that gets spent on the ISS and manned space flight would fund several robotic planetary science missions. If Voyager, MSL, Spirit, Opportunity, Cassini/Huygens, Hubble, Kepler, Rosetta/Philae are any indicator, the scientific return and inspirational value of those robotic missions will be very high, even when compared to that of manned missions.

I don't. Look at how much attention Rosetta and Philae have received recently. And MSL. And Spirit & Opportunity. Hubble. Kepler. I grew up during the Voyager grand tour era. I wasn't the only one who was captivated by it. Every couple of years we were treated to beautiful new images of our solar system. Short of something going wrong, I don't recall the manned space program ever being as prominently in the spotlight as the robotic planetary science missions. As I said above, missions like EJSM, TSSM, etc get canceled for lack of funding while missions like HORUS don't even proceed beyond the feasibility study stage. Don't tell me that a balloon and/or boat on Titan wouldn't captivate the public. Or that a mission to Jupiter's moons or an orbiter about Uranus wouldn't inspire kids. Likewise, a robotic balloon in Venus' clouds would send back photos to fire the imagination. These things are possible with a fraction of the funding that currently gets allocated to the ISS and an even smaller fraction of the money that would be needed to send people to Mars or Venus. In an environment where budgets are tight, I would rather that money be spent where it yields the biggest PR and scientific ROI. That, to me, is clearly the robotic missions.

Good point. Why do we have people on the ISS? There is a disproportionate amount of money spent on the ISS. Just a fraction of it would fund missions like EJSM -Laplace, TSSM, etc. I can't help but think we'd learn more from robotic missions like those than we do from flying people on the ISS.

In what context are we talking about "the Earth dying"? Current estimates are that the Earth has between 500 million and 1 billion years of habitability left for macroscopic life. To put that in context, the Cambrian explosion (the emergence of most animal phyla in the fossil record) only happened about 540 million years ago. We have a lot of years yet before evacuating the Earth is even remotely necessary. Even if we screw it up horribly with some sort of environmental disaster or are hit by a big space rock, we've got a better chance here than anywhere else we can reach. Rome wasn't built in a day. There are only so many financial resources that the world community can afford to dedicate to space exploration. While they may not be as glamorous as manned missions, robotic missions are a proven means of maximizing scientific ROI.

Sorry, can't. It petered out before it rotated around to my part of southern Canada (BC). You can see the z component of the local magnetic field direction flip from negative to positive in the top plot (red line) of ACE data in the image below. It happened about the time that I posted the POES forecast above. That's effectively a light switch...

Currentspace weather conditions, as given by NOAA POES site. Red indicates a 100% chance of seeing auroras. It is forecast to increase in intensity over the next few hours.

I am not sure. I like how the story leaves a lot to the imagination... The moments of madness/hallucinations mixed with moments of lucidity. We don't know any more than the character itself does in its addled state as it slowly succumbs to the elements.

Or a socket wrench? There was a story in the news this morning about how a 3D model of a socket wrench was recently emailed up to the ISS where they "printed" it. I am not sure how useful the result would be for wrenching anything, but it is an interesting story.

Whether you celebrate Hanukkah, Christmas, Kwanzaa, Yule or even Saturnalia, a lot of music gets played at this auspicious time of year. Not all of it is serious. Here are a couple of fun examples. Share your own favorite weird, quirky or funny seasonal pieces.

I laughed, I cried... It was better than Gravity! No seriously. It was very well done.

Here's another version (sufficiently nerdy for this forum) version: Happy holidays everyone!

The wonderful and terrifying implications of computers that can learn:

I hadn't heard about 2014 OL339, thanks. Perhaps an even more relevant example of a non man-made object being captured by the Earth is 2006 RH120. It was most recently in Earth orbit between September 2006 and June 2007. According to Wikipedia, the object made four Earth orbits of about three months each before being ejected after the June 2007 perigee.

I don't agree. They've already described how they use the "report post" feature to serve as an extra set of eyes. I think it works well. Indeed, I think the mods here do an excellent job! But even good things need to be done in (for lack of a better word) moderation... Sometimes the subject of a thread may, strictly speaking, be "verboten" but I don't see why we shouldn't be allowed to continue a discussion if it is done in a mature and polite manner. A science labs discussion about global warming may get heated and turn to politics or a discussion about evolution may devolve into a religious debate, but I believe that those controversies are often healthy. Maybe we won't change our own minds or those of our opponents, but perhaps someone else lurking on the thread will start to ask the right questions? And while I don't think the particular thread that spawned this discussion was a good example of the type of thread that should be allowed to continue, I would have been happy to hear the perspectives of some of our Russian friends about what is currently happening in their country. It has implications, not only for global political stability, but also for their space program. Edit: I feel the need to add that I didn't realise that the locked thread I was thinking about when I wrote the above was actually started by Kerbtrek. Hopefully my comments make more sense in that context.

Perhaps they are charging what the market will bear? Why should they sell launch services for $10 million when customers are willing to pay close to ten times that?

For what it is worth, I think this community is more than a forum about a space related game in which you shoot little green men out of the atmosphere. That may be the foundation of the community, but the game attracts a certain type of person. While there are certainly some in this community who are socially awkward, for the most part we get along surprisingly well. There are topics that I would love to hear people's opinions about, given that we come from such varied backgrounds. You might argue that other forums might be better suited to some of those discussions, but I feel a kinship with the sciencey nerds who call this place home. I would like to hear their opions, not those of some random [rate of change of acceleration with respect to time] on the internet. I suspect that I am not alone in this regard.

I think you should go see a doctor...

I didn't say that no progress was possible. Only that you shouldn't expect much more than incremental progress in the current paradigm of chemical rockets.

No, because I am an aerospace engineer and it is my professional opinion. Likewise, Nibb is a professional in the aerospace industry. You can accuse me of making an argument from authority, but at some point you have to trust the experts. The limitations are well understood by physicists, chemist and engineers and it doesn't take a rocket scientist to know we're already bumping up against them.

Because you are misrepresenting Nibb's argument. There are limitations to physics, chemistry, materials science, etc. that set an upper limit to what is possible with rockets. With any mature technology, you reach a point where only incremental improvements are possible. You can't extrapolate out from someone's realistic engineering judgement about a mature technology to accuse them of arguing that all efforts at technological progress are futile.

Straw man argument much?

But that re-emphasizes my point. Help us understand where you're hung up and we'll try to help you raise your skills to the requisite level. ZetaX's post contains some good information to get you started. A typical scientific calculator has a "ln" button and an "ex" button (it is often even the same button). Just try it out. Kryten is being facetious but he's also illustrating the absurdity of your question. You need to understand some basics before you can proceed with what you're trying to do.

So you want a means of calculating delta-V using nothing more than about grade 6 or 7 level math, is that it? If so, that's a bit of a strange request. There is a price of admission... Why not pony up? We're not talking complex math here. We're talking plug and chug. There are many helpful people here who can probably help you raise your math skills to the requisite level. It may seem intimidating but that doesn't mean it is hard.

The horizontal stabilizer's angle of incidence (angle relative to the wing) is often negative (nose down), but it is important to be aware that the geometric angle of attack isn't necessarily the aerodynamic angle of attack. The wing produces downwash that changes the apparent angle of attack that the horizontal stabilizer experiences. The amount of downwash changes with the circulation (not to be confused with lift) produced by the wing. On large aircraft like airliners, the horizontal stabilizer's angle of incidence can even be changed in flight. There is a large screw jack (or two) at the front of the trimmable horizontal stab that pivots the stabilizer as required. Also, symmetrical airfoils are perfectly capable of producing lift. You don't need camber. What you do need is a sharp trailing edge. All airfoils have one, regardless of whether they are symmetrical, cambered or are composed of a single membrane that has no relevant thickness (like a sail). This is because the kutta condition occurs when an aerodynamic object has a sharp trailing edge. A consequence of the Kutta condition is circulation about the wing which is fundamental to the production of lift (and downwash, see above).