AngelLestat

@Mazon Del and @CatastrophicFailure, very well said. Besides, if we specific talk about Elon, he is also doing Tesla, Solar City, Gigafactory, internet constellation, free superchargers in all USA and China, Hyperloop, etc. Is a man who tries to make a better world, and his ultimate dream is Mars. Rich men in his position only cares about the money they will get if they buy or sell certain company, does not matter if is something good or bad for the world. So the question, why someone will be fan of spacex or elon musk.. is kinda weird considering the facts. But I am ok with that, is just matter of taste.

Ok a mental mistake 60% of the ship is fuel. No it doesn´t, you are taking examples here on earth that are very different from the ones set in the calculations and conditions. It said seriously impeded. And it will be similar to the mars ground in a storm where you can not see much with the spacesuit addiction. Good luck returning to your ship if you are far. That is because you can not separate your experiences from real test. You might remember stand on a ground ramp without fall, but you dont have into account that natural inclined planes are not perfect, they always had small horizontal parts or salients where you can put your foot bending your finguers which would count as an horizontal plane. We do all that instinctively, so your inclined plane example, just exploit from false experiences. The same that how much you can stand in the wind, without spacesuit or with asphalt under you and in a weird posture (not walking) and without different gusts. Just constant wind. Is not what the trailer shows. We are making calculations.. use the metric system.. Why I need to do conversions? Is not my fault. I am already using a languege that is not easy for me. Also, those are your sources? some kids with not real measuments or parameters in the wind? I just tell you one thing.. is super hard to walk on winds with more than 100 km/h without using your hands to grab. And I mean walk.. not crawl. There are not the accurate experiences that I am looking for.. in your 4.2m dinghy or even in your Sonar, none of those has an anenometer, I imagine you check the wind speed with an app in your phone connected to a webpage with data transfer from a no so close beacon. And personally I cant believe you did that in just small sail without using your hands (I cant even do it in 10m sailboat). mmm, not sure about that. But I will not make judgments yet. The only thing that I can see that if I try to calculate the terminal velocity with 0.84 of CdA, and pressure equal to 1000 meters (sky diver) I exceed a little bit from the mentioned in books. But not sooo much to calculate the 30% of that. I can see that the pdf you post, does not calculate the lift force from the lean angle which reduce the friction coefficient. You have another source that explain me that change in the Cd?? I did and read many times drag calculations and I never saw it.. I understand that happens, but not with such change.

Agree, older ICE cars are easier and last longer, and new electric cars as tesla, they are also very complex. You mean steam? it does not count as internal combustion engine.. Can I see the source? Electric motors is not the problem, working batteries may be difficult to find, their lifespan is not much, and not sure how difficult is to make them. On the other hand, reversive fuel cells are not hard to make, (in case you can access to internet to read the instructions in the apocaliptic world), you can use them as batteries or to produce hydrogen from water. You just need to stack many metal sheets, depending the materials you can get, it will depend on the efficiency, being platine the best material. Heh that will depend on the type of apocaliptic world. But if your transport needs is kinda solve, then you dont need to fight for your live in each fuel station you find. You can just concentrate in get food far from others.

I still choose the old 747 and everyone will do the same. This happen with any product, if you buy a new laundry machine or a new PC, or air cooler, is always the same, the first time you press on you are not so sure that all will be ok as you will be if you used all days. Airplanes had very expensive and intensive test, and fly test after leave the factory, And companies who buy it test them again. Then you can transport people, and dont worry about test for a month. Why is different? Is just matter of taste. If you like rockets, you will fan of esa, nasa, spacex, cosmodrome, ULA, etc. If you like cars you will be fan of Toyota, ford, porsche, etc.

In his case of variable thrust, yes how I already point. The graphic that I did is for the moon, which I think is cheap considering the area and easy to enter or exist.

If you read the last Elon musk interviews his goal still is fully reusability, for now he is focus in the first stage only.. But he knows that it needs both stages and fast reusable to accomplish huge prices drop.

1) true. 2) false, new cars engines has very low time expentancy, no more than 25 years, and forget of repair them, the electronic injection system is very complicated. Solar panels said that last 25 year with warranty (keep the solar production under that time), but in fact they can last a lot longer if you are ok with values of 60% or 50% energy production. 3) what? A electric car is much much much easier to make than an internal combustion engine. In fact electric cars (1828) came way before than internal combustion cars (1885), First the electrical car use 90% of the energy input in traction, the internal use 25% of the energy for traction. Also you dont need solar panels, when the car is stop, just connect a wind helix to the same car engine and it would work as generator. Good luck building this: http://garagelatino.com/wp-content/uploads/2013/03/warrantybmw-x6m-engine-parts-exploded.jpg That without take into account the box gear (electrical does not needed), radiatior, etc. 4) why not? An electrical motor who was not used, it can last a lot of years, it doesn´t have any complex mechanism.

I dont buy this, but in case ULA wants to sabotage a spacex mission, then it would be much easier to bribe one or two spacex technician to add a complication in the last test procedure. Which also sound kinda crazy unless spacex find strong evidence.

A 400km/h wind is not normal, I will said that is very rare, when you work all days in calm enviroment you tend to lower the guard. Maybe things are anchored but as Jesrad said there is a thing called abrasion, which can set free objects, there is always things out of your control. More in chaotic scenaries like this. More mass against what object? A human? no even close. The human body has a density close to the water.. A space vehicle even if the 100% of the vehicle volume is full of fuel, it would not have the same density than a human, fuels are lighter than water. And a better estimation for a mars vehicle points to 15% of the volume would be fuel (in case your transfer vehicle is in orbit). So yeah, that is a very low density vehicle, which nobody would include in the design "safe to launch on 400km/h winds", because had that case into account would make the vehicle very inefficient. You was very sure under your own calculations, now that more accurate calculations show you wrong, the results needs to be ignored? And again, being in asphalt and without spacesuit is not the same.. And the Beaufort scale description match. 30 degrees is a lot. Let me remind you: Also not sure if the force distribution between the box and the angle of the person standing is equal. But I can said for sure that if you are on a dust ground in that inclination you go down. Grass and tire are 2 flat surfaces?? please.... Also, in mars all water that might be under the dust is freeze.. You have that into account too? I can give you 0.4 in the coefficient, that stills makes my point. Or even higher if the static friction over a short time is overcome and becomes kinetic friction. Which is wrong like I point. Call someone good with physsics, he will choose what is the best propper way to solve this. haha, you are really desperate to change the values more into your favor. Why is so difficult to accept that your first "reality" concern was not so accurate as you thoght in the begining? Yeah, I imagine they use all kind of instruments to measure the wind speed, with asphalt under their feets and without astronaut suit, also with all kind of weird positions. Yeah we should take into account this instead an international wind scale. You dont have any idea what are you talking about.. that wind speed is terminal velocity. So you need to counter your same weight with only your feets on the ground.

You can not simul gravity or its effects on the body just lifting extra mass. A force applied to few external points of your body has nothing to do with a constant acceleration applied to each atom of your body.

The main goal is achieve reusability, once spacex achieve that, then the ratio of possible failure will drop considerably. Is like I said before, you will feel more secure flying in a 747 that fly often, or in a new 747 which never was in the air? That is the thing that happen with rockets right now, there is not way to fully tested them (also is very expensive even try to test them to reduce chances of failure), until you dont press the launch button nobody knows.

Ok Nibb31, I understand you, but I cant answer you.. because I cant use the P word. this forum is starting to looks like the Tabu game.

That is what I never understand from many apocaliptic movies as madmax and waterworld.. If everyone is trying to survive and get the last resources.. Why you need to burn all that fuel just to try get more fuel? A solar electric vehicle in those movies would rock. Why try to get oil which would be very hard (more taking into account that you can not use crude oil, you need to refine it). But you can use thermal machines with vapor, or wind.. in those worlds renowable energy is a lot easier to get and you dont need to fight with others to get it.

But you already said that you are side-on, so if it turn you can be on front again, at least for one moment.. Arms at side? Spacesuit remember... Yeah me too, if you are sit in the sailboat there is not much trouble because only 1/3 of your body is expose, but if you want to remove the genoa, then you are screw. At least you do it walking in 4 legs holding with your 2 arms. I dont know what you want me to said.. first the OP said that it would be like a 45km/h wind in earth, I said not, we need to take into account the gravity. I made all calculations and I prove that we are in the limit to be drag by the wind. But... you two still think that is not real... In brief: 400km/h wind, taking into account that drag is square... is not joke.. even with much lower density, because the gravity is very low too.

heh thanks, I had the same surprice when I think about it for first time, I look in internet, but nothing even relative similar, so the only way to show what I mean was to draw it. About mods, I am bad on that. But it would be fun to see the physics work. Yeah, in his example with variable trust, your idea fits better. But the picture example confuse more than help

Is not so easy, wind is not always constant over surface, you have gust and different angles of attack. I can also make the math to calculate the force needed to turn you, we have only one foot on the ground when we are walking, it does not need much, which may leave us in front to the wind. Also if we bow forward, does only helps to avoid turn over our back, but in that angle, we get another drag component that points up, that counter our weight which reduce our friction. And once the static friction force is overcome, then the friction coefficient is reduce by almost half. Ok, then tell me what is the right friction coefficient value for a dusty grave ground as mars? I try to did my best estimation taking into account the examples that I had http://www.engineeringtoolbox.com/friction-coefficients-d_778.html For example: car tire and grass is 0.35, leather and metal is 0.4, carbon and steel 0.14, I dont know. Even if we choose 0.4, we are in the limit.. And in my experience, grass has more friction than dust grounds. If you use the decimals and you fix the force which is 235 (not 223), the wind speed would be 19.5m/s or 70km/h Now add the spacesuit and stop imagine you on asphalt. In fact, that wind speed match the Beaufort scale, which points that at force 8 wind, 17.2–20.7 m/s "Some twigs broken from trees. Cars veer on road. Progress on foot is seriously impeded." https://en.wikipedia.org/wiki/Beaufort_scale Now if we watch and we add the extra momentum from the flying object, all match fine with reality and calculations.When people criticism movies, is because something is very far from reality. But at least I dont see much of the point with your number 1) statement from the OP.

please, lets keep the "I hear from a friend" source rumors out of this discussion.

This will be similar to what I imagine to get 1g on the moon:

Not we dont, but he achieves better cost, there is not question about that. ??? Where do you get all this? from the crystal ball? Also it does not have any logic.. Yeah.. lets make them work for nothing.. just to waste time in design a rocket that we would never use. It would create jobs.. that is the strategic.. we can sent them to paint rocks in the desert too, that also produce jobs. So if they give that money to spacex, that would not create new jobs? Yeah, because no matter who is behind this decision, for sure would become elected again, after all is a brillant idea dont you? (Just to clarify, I am being ironic..) That those companies may be more important for some senators, yes. Sure. But why those companies will have hundreds of unemployed if from the first time you choose spacex? Also, their role in the current SLS develop is very small. In this link talks about 5 Billions by launch, but you need to add the development cost. http://www.thespacereview.com/article/2330/1 And we know that is highly unlikely that at that cost exceed the 4 or 5 launchs. Why? Because NASA does all wrong. For example they made orion to land on Sea, this for sure will remove all the possible of reusability, why they choose that if it only takes 1/40 of the mass to make it able to land on land. And you can take infinities of NASA decisions which does not have any logic or long term goal. Never saw it, but not sure if I can take a comedy as a strong source

Ok, I was not happy with the KerikBalm estimations and conversions.. so lets calculate all in mars conditions without correlations with earth. What is the force needed to drag a person in mars? Fs= μmg Fs = force of static friction μ= coheficient of static friction (0.3 dust terrain) m=mass = 80kg (with spacesuit) g= gravity in newtons. (3.7m/s2) Force of the wind in a person on mars: Fd=1/2ÃÂv2CdA Fd= force of the wind p= density of the atmosphere = 0.0165kg/m3 (half between your value and mine, also we need to consider the dust in the air) V= wind speed = 111 m/s = 400km/h Cd*A = drag coheficient * body area = 0.84 m2 (source), it is a bit higher due spacesuit --> 1m2 Friction Force= 88 Newtons Force of the wind= 101 Newtons. Conclusion: weeeeeeeee bye bye..

If they have a reusable launcher this would not happen, this is the problem when you do a new rocket and there is not way to fully test it before launch. How do you will feel if you fly in a new 747 (which never fly)? All agencies had their launch fails, some of them a lot of accidents involving many lives. I guess there is none agencie or space company with an exception in this.. So lets not make this bigger than it is. Besides from the begining, the crew test dint begin until the 2017, so there still 2 years left of testing for that.. Also, errors is what teach us more.

twitter: Elon Musk â€Â@elonmusk Falcon 9 experienced a problem shortly before first stage shutdown. Will provide more info as soon as we review the data. -------------------------------- He musk be in shock

that is dragon version 1, Not sure if it has abort system. I guess not.

Damn, my power is lost due a storm, and my phone connection wouldn't be enough to the stream

For example 4 launchs of the SLS with orion will cost 41 billions dollars, 10 billions by launch. Elon musk said that can do it at 300 millions by launch with its XX future launcher (or whatever its name). And in fact, after those lauchs will not be useless or outdated, contrary to the SLS and Orion to keep lauching missions. So you are saying that if NASA from a begining said I give you half of what would cost to us, and profits after that are yours.. You think a private company will not take that contract? Or I misinterpreted the comments? PD: good data about the CCdev, I will read it later.