"Curiosity Mars "landing" BIGGEST HOAX EVER!!!" | |
Engineer User ID: 694654 United States 08/13/2012 06:16 AM Report Abusive Post Report Copyright Violation | OK, this is giving me big red flags: NASA has sent no less than 3 probes to Mars to measure atmospheric density, they have this data. But where is it? I can't find it, can anyone else find it? This is the most critical set of data anyone can have, and at the low densities on Mars, even small errors have a significant impact on velocities - a little less density, and we are truly dealing with a real vaccuum where Curiosity is not possible, a little more, and NASA can make untrue claims. If we look at: [link to www.google.com] we can see that everybody is saying the atmospheric density of Mars is LESS THAN 1% of EARTH. But if we use the model that NASA provides to the public, we get densities far above 1% ... We can also see that many universities and aerospace organizations have been attempting to figure out the densities at various altitudes right up until the "last minute" - which seems a little risky, because they know it is highly variable at all places all of the time, yet very crucial to any kind of successful outcome. And it is not a linear model. Anyway, let's see what their public mathematical model produces, from the link previously provided: First, we know: 0.00237 slugs/ft^3 (Earth, @ sea-level) 0.0000237 slugs/ft^3 (Mars, @ datum, if 1% of Earth's) Now: @1ft 14.62*e(-.00003*1)/(1149*((-25.68-.000548*1)+459.7)) .000029 OOPS! That is quite a bit MORE THAN 1%, eg, .0000237! Why is that? @1000ft 14.62*e(-.00003*1000)/(1149*((-25.68-.000548*1000)+459.7)) .000028 @5000ft 14.62*e(-.00003*5000)/(1149*((-25.68-.000548*5000)+459.7)) .000025 @10,000ft 14.62*e(-.00003*10000)/(1149*((-25.68-.000548*10000)+459.7)) .000021 @ 25,000ft 14.62*e(-.00003*25000)/(1149*((-25.68-.000548*25000)+459.7)) .000014 @25,000ft (need to switch models at this altitude) 14.62*e(-.00003*25000)/(1149*((-10.34-.001217*25000)+459.7)) .000014 @30,000ft 14.62*e(-.00003*30000)/(1149*((-10.34-.001217*30000)+459.7)) .000012 @50,000ft 14.62*e(-.00003*50000)/(1149*((-10.34-.001217*50000)+459.7)) .000007 @50,000ft (using low altitude model) 14.62*e(-.00003*50000)/(1149*((-25.68-.000548*50000)+459.7)) .000006 OOPS! That's much less than the "high-altitude" model, why are they giving us a "high-altitude" model that ADDS EXTRA AIR DENSITY? Why is that? The density should fall off more rapidly, like light from a bulb, heat from a heating source, a radio transmission from an antenna, like gravity, or air pressure out of a gun, wouldn't you think? Any ideas? @100,000ft 14.62*e(-.00003*100000)/(1149*((-10.34-.001217*100000)+459.7)) .000001 GRRR! Need more decimal places! I will make 10. @100,000ft 14.62*e(-.00003*100000)/(1149*((-10.34-.001217*100000)+459.7)) .0000019333 @200,000ft 14.62*e(-.00003*200000)/(1149*((-10.34-.001217*200000)+459.7)) .0000001531 @300,000ft 14.62*e(-.00003*300000)/(1149*((-10.34-.001217*300000)+459.7)) .0000000186 @350,000ft 14.62*e(-.00003*350000)/(1149*((-10.34-.001217*350000)+459.7)) .0000000149 @375,000ft 14.62*e(-.00003*375000)/(1149*((-10.34-.001217*375000)+459.7)) -.0000000235 OOPS! Negative air density at only 71 miles altitude. OK, so, I guess that is the end of the line for this model. CONCLUSION: NASA has sent no less than 3 space probes to measure the air density of the Martian atmosphere. Additionally, other institutions and organizations have done much work to make these measurements by other means, and to correct them as much as possible, considering the fluctuating nature of the Martian atmospheric density, and the critical nature of such data. Atmospheric density at various altitudes is probably the most critical set of data one would need for a mission like this, and yet, it is nowhere to be readily found. NASA has put forth a mathematical "model" to describe this data, but the model adds more density to the atmosphere, even in contradiction to the words of NASA's own scientists when interviewed. If anything, NASA would want a model that leans toward more pessimistic values, to ensure greater engineering success, but their model does the opposite, and actually adds density to the atmosphere, not only at low altitudes, but at high altitudes as well. This is not a frivolous misrepresentation, because with such a low air density, fudging the numbers makes a large difference between plausible success, and certain failure. |
Engineer User ID: 694654 United States 08/13/2012 06:37 AM Report Abusive Post Report Copyright Violation | [link to en.wikipedia.org] If the atmosphere had a uniform density, it would terminate abruptly at an altitude of 8.50 km (27,900 ft). It actually decreases exponentially with altitude, dropping by half every 5.6 km (18,000 ft) or by a factor of 1/e every 7.64 km (25,100 ft), the average scale height of the atmosphere below 70 km (43 mi; 230,000 ft) |
Engineer User ID: 694654 United States 08/13/2012 06:50 AM Report Abusive Post Report Copyright Violation | If NASA is only going to hand us liar-cheater data for atmospheric density on Mars, there isn't much that can be done to verify any claims of (plausible) success. This is why they cannot be trusted. Is the Martian atmospheric density a matter of national security or something? Nonsense. Martian rover video game. I hate putting effort into things only to run into BS/NONSENSE, but that is my experience with govt. Spend money to find ways to spend more money and tax more things to hire more cronies. |
Anonymous Coward User ID: 9872711 United Kingdom 08/13/2012 06:58 AM Report Abusive Post Report Copyright Violation | Americans are weird. They are capable of putting a car on the Moon yet at the same time they have people who claim: Quoting: Dutch Girl "Curiosity Mars "landing" BIGGEST HOAX EVER!!!" [link to www.landoverbaptist.net] I`m always very careful about making blanket statements like 'Americans are weird' based on one Americans opinion. Would the following video depict your average Dutchman? Jesus Christ...what the fuck was that? Please tell me every was in on the joke? That was a joke, right? |
Engineer User ID: 694654 United States 08/13/2012 07:34 AM Report Abusive Post Report Copyright Violation | IF NASA WON'T RELEASE VALID DATA OF MARS' ATMOSPHERIC DENSITY AT VARIOUS ALTITUDES - F-EM! THEY ARE JUST SCAMMERS! THAT'S THE BOTTOM LINE! I lean toward "they won't release it" because: 1) if they do release it, and it is true data, it will be shown that Curiosity is a SCAM, a VIDEO GAME for "SCIENTISTS". 2) if they do release it, and it is false, a 3rd party will uncover their fraud someday when they send probes to Mars. PROVE ME WRONG - FIND THIS DATA!!! Yes, I am pissed! Always the same old story! I wasted many hours on this garbage, hoping I would find some amazing truth, but no ... JUST MORE BS/NONSENSE FROM US, INC. IT'S OUR MONEY, IT'S OUR DATA! WE PAID FOR IT ALL! |
Engineer User ID: 694654 United States 08/13/2012 08:31 AM Report Abusive Post Report Copyright Violation | |
Engineer User ID: 694654 United States 08/13/2012 10:23 AM Report Abusive Post Report Copyright Violation | What a few hours of needed sleep will do ... Let's see how the bogus Mars atmospheric "model" stacks up to the 1% figure: @ 1% Earth density sqrt(2*7500*.39/(.0000237*.75*3.1416*26^2)) = 393.6629039055 ft/s @ "NASA model" density sqrt(2*7500*.39/(.000029*.75*3.1416*26^2)) = 355.8766635654 ft/s So, "NASA model" takes off 40 ft/s. To the best of my memory, NASA claims 220 mph |
Anonymous Coward User ID: 21789839 Portugal 08/13/2012 10:27 AM Report Abusive Post Report Copyright Violation | |
Engineer User ID: 694654 United States 08/13/2012 11:20 AM Report Abusive Post Report Copyright Violation | Let's see what the "NASA Atmospheric Model" (NAM) does to the speed of things: @ .67% of Earth ("less than 1%"): sqrt(2*7500*.39/(.0000159*.75*3.1416*26^2)) = 480.6184193229 ft/s (328 mph) @ 1% of Earth: sqrt(2*7500*.39/(.0000237*.75*3.1416*26^2)) = 393.6629039055 ft/s (268 mph) @ NAM model: sqrt(2*7500*.39/(.000029*.75*3.1416*26^2)) = 355.8766635654 ft/s (243 mph) NAM takes away 40 ft/s from the speed. About 10%. And the error can easily become much greater at higher altitudes. No way to know without the data. "Following the parachute braking, at about 1.8 km (1.1 mi) altitude, still travelling at about 100 m/s (220 mph), the rover and descent stage dropped out of the aeroshell." 220 mph = 322.67 ft/s Using NAM (assuming free-fall from rest), at 1.1 mi, 5808 ft, we have air density of: 14.62*e(-.00003*5808)/(1149*((-25.68-.000548*5808)+459.7)) = .000025 slugs/ft^3 (greater than 1% of Earth @ sea-level). sqrt(2*7500*.39/(.000025*.75*3.1416*26^2)) = 383.2908968626 ft/s (261 mph) But NASA claims 220 mph, EVEN LOWER than from "free-fall", So, either air density or Cd (drag coefficient) is wrong. What kind of drag coefficient would make that work out to 220 mph, assuming NAM is correct: sqrt(2*7500*.39/(.000025*1.05*3.1416*26^2)) 323.9399322821 ft/s (221 mph) What kind of thing has a Cd of 1.05? Cube, face-on = 1.10 Disk, face-on = 1.10 OK, so, NASA is telling us that Cd for the Curiosity assembly is 1.05 instead of .75, so how does that change all the velocity equations? @ .67% of Earth ("less than 1%"): sqrt(2*7500*.39/(.0000159*1.05*3.1416*26^2)) = 480.6184193229 ft/s (328 mph) => 406.1963147613 ft/s (277 mph) @ 1% of Earth: sqrt(2*7500*.39/(.0000237*1.05*3.1416*26^2)) = 393.6629039055 ft/s (268 mph) => 332.7057930503 ft/s (227 mph) @ NAM model: sqrt(2*7500*.39/(.000029*1.05*3.1416*26^2)) = 355.8766635654 ft/s (243 mph) => 300.7707078120 ft/s (205 mph) This is highly unlikely for a parachute with a hole in it - consider this: NASA wants the herd to think that their parachute has the same drag as a Cube or Disk with the flat side facing into the airstream ... OK - we all smoke crack, so we will believe it. It's just gets too crazy to work on this problem. I am being forced to utilize CRAZY-FACTS in calculations. I am being tossed into the realm of "Make Believe Land", and nothing I do is of any real consequence, all my calculations will be a joke if I use NASA's data. And remember, I am assuming a free-fall from REST, I am not even taking into account the fact that this thing is starting many many many times faster than a bullet out of a high-power long-range sniper rifle. WHAT PROOF OF THEIR BS DO YOU WANT? I wish I could work intelligently on this, with REAL data, not bogus "models". |
Engineer User ID: 694654 United States 08/13/2012 11:43 AM Report Abusive Post Report Copyright Violation | So, what if I am making an error because this is not in free-fall, and it is still decelerating, and therefore the speed is faster than free-fall? No, this is the opposite of things. Using NAM model at 1.1 miles altitude: sqrt(2*7500*.39/(.000025*.75*3.1416*26^2)) 383.2908968626 (261 mph) sqrt(2*7500*.39/(.000025*1.05*3.1416*26^2)) 323.9399322821 ft/s (221 mph) There would have to be even MORE drag to allow for a faster-than-free-fall velocity while maintaining all other parameters, and it's a little difficult to get more drag than a flat solid plate. Circular cylinder, side-on => Cd = .75 Circular cylinder, end-on => Cd = 1.0 For example, if the unit is decending at 220 mph at 1.1 miles in altitude BECAUSE OF it's intial high velocity, but would be going much slower in a free-fall from rest, then the velocity result in the equations would have to be even slower than 220 mph, which means either density or Cd would have to be even greater. And NASA is already exaggerating those figures into Make-Believe-Land. Beam me up Mr. Rogers ... |
Engineer User ID: 694654 United States 08/13/2012 12:14 PM Report Abusive Post Report Copyright Violation | sqrt(2*7500*.39/(.000025*.75*3.1416*26^2)) 383.2908968626 (261 mph) sqrt(2*7500*.39/(.000025*1.05*3.1416*26^2)) 323.9399322821 ft/s (221 mph) sqrt(2*7500*.39/(.000025*1.4*3.1416*26^2)) 280.5402106565 (191 mph) sqrt(2*7500*.39/(.000025*1.5*3.1416*26^2)) 271.0275923386 (185 mph) So then the extra 35mph (220 - 185) is due to the high initial velocity. Well, I don't have parachute specs either. hmmm. Maybe I am just frustrated with the lack of specifications and data - and maybe in the future it will be released. The problem with a parachute with a 1.5 Cd is that it doesn't sound like the right choice for a parachute rated for Mach 2.2. Although, I must admit, things start to make some sense if the NAM and 1.5 Cd for the parachute is correct. |
Engineer User ID: 694654 United States 08/13/2012 12:46 PM Report Abusive Post Report Copyright Violation | "When the entry phase was complete and the capsule slowed to Mach 1.7 or 578 m/s (1,900 ft/s) and at about 10 km (6.2 mi), the supersonic parachute deployed, as was done by previous landers such as Viking, Mars Pathfinder and the Mars Exploration Rovers. The parachute has 80 suspension lines, is over 50 m (160 ft) long, and is about 16 m (52 ft) in diameter. Capable of being deployed at Mach 2.2, the parachute can generate up to 289 kN (65,000 lbf) of drag force in the Martian atmosphere." Hmmm. I am wondering why this made me so upset, and maybe it is because I am not comfortable being spoon-fed beyond-imaginable figures that I am forced to believe without evidence, and that NASA doesn't put critical information out to make it easy for people to believe them. After looking at some images of the parachute, it is clearly bowl shaped, and looks like a 1.5 Cd parachute. The hole seems very small. It's difficult to imagine these things. 80 cables - 65,000lbs of drag - hmmm ... 812lbs per cable - not too bad, but the shocks of it snapping open and other shocks due to turbulence - where the cables attach to the chute - well, I guess it is possible - it doesn't sound beyond the realm of possibilities any more than a bullet-proof vest. I guess I stop today thinking maybe it is possible, but I am still interested to see if the upper Martian atmosphere is dense enough to slow down the Curiosity assembly from 13,000 mph to 1,300 mph (when the parachute was deployed). |
nomuse (not logged in) User ID: 2380183 United States 08/13/2012 01:51 PM Report Abusive Post Report Copyright Violation | IF NASA WON'T RELEASE VALID DATA OF MARS' ATMOSPHERIC DENSITY AT VARIOUS ALTITUDES - F-EM! THEY ARE JUST SCAMMERS! THAT'S THE BOTTOM LINE! I lean toward "they won't release it" Quoting: Engineer 694654 because: 1) if they do release it, and it is true data, it will be shown that Curiosity is a SCAM, a VIDEO GAME for "SCIENTISTS". 2) if they do release it, and it is false, a 3rd party will uncover their fraud someday when they send probes to Mars. PROVE ME WRONG - FIND THIS DATA!!! Yes, I am pissed! Always the same old story! I wasted many hours on this garbage, hoping I would find some amazing truth, but no ... JUST MORE BS/NONSENSE FROM US, INC. IT'S OUR MONEY, IT'S OUR DATA! WE PAID FOR IT ALL! Try "The Structure of the Upper Atmosphere of Mars: In Situ Accelerometer Measurements from Mars Global Surveyor" -- G. M. Keating et al, Science 13 March 1998 Free to read online, describes measured profiles of upper atmosphere taken during multiple passes of the spacecraft. Or "Structure of the Atmosphere of Mars in Summer at Mid-Latitudes" -- Seiff and Kirk, JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 82, NO. 28. This one gives atmosphere temperature and pressure as experienced by the two Viking landers from 120 km to ground. Or "Structure of the Mars upper atmosphere - MGS aerobraking data and model interpretation" Bougher, S W | Keating, G M The Fifth International Conference on Mars, Pasadena, CA And tell me if you find a free copy of this one! |
nomuse (not logged in) User ID: 2380183 United States 08/13/2012 01:54 PM Report Abusive Post Report Copyright Violation | So, what if I am making an error because this is not in free-fall, and it is still decelerating, and therefore the speed is faster than free-fall? Quoting: Engineer 694654 No, this is the opposite of things. Using NAM model at 1.1 miles altitude: sqrt(2*7500*.39/(.000025*.75*3.1416*26^2)) 383.2908968626 (261 mph) sqrt(2*7500*.39/(.000025*1.05*3.1416*26^2)) 323.9399322821 ft/s (221 mph) There would have to be even MORE drag to allow for a faster-than-free-fall velocity while maintaining all other parameters, and it's a little difficult to get more drag than a flat solid plate. Circular cylinder, side-on => Cd = .75 Circular cylinder, end-on => Cd = 1.0 For example, if the unit is decending at 220 mph at 1.1 miles in altitude BECAUSE OF it's intial high velocity, but would be going much slower in a free-fall from rest, then the velocity result in the equations would have to be even slower than 220 mph, which means either density or Cd would have to be even greater. And NASA is already exaggerating those figures into Make-Believe-Land. Beam me up Mr. Rogers ... It enters from ORBIT, not from rest. The angle of entry is whatever they chose. It isn't constrained to be a vertical entry. PLUS, the spacecraft is aerodynamic -- it can dynamically change the angle of attack using the lifting body of the aeroshell itself. All of this is described in any introductory article about the landing. |
bvndy User ID: 20644442 United States 08/13/2012 02:05 PM Report Abusive Post Report Copyright Violation | NASA has one misson, to provide cover for the Airforce's massive space program, including MOL'S (manned orbiting labs-weapons platforms), advanced space shuttles, etc You can ignore the consequences of your actions, but you cannot ignore the RESULTS of the consequences of your actions Ayn Rand |
nomuse (not logged in) User ID: 2380183 United States 08/13/2012 02:08 PM Report Abusive Post Report Copyright Violation | Using NAM model at 1.1 miles altitude: Quoting: Engineer 694654 sqrt(2*7500*.39/(.000025*.75*3.1416*26^2)) 383.2908968626 (261 mph) sqrt(2*7500*.39/(.000025*1.05*3.1416*26^2)) 323.9399322821 ft/s (221 mph) PLEASE start labeling your variables. You'd flunk out of class with these, and for the same reason I am asking; to be able to check your assumptions without staring at a page of magic numbers. As far as I can tell without reverse-solving each of your unlabeled variables, you are ignoring a full third of what your Aeronautics prof taught you about parachutes; aka you are plugging in the wrong diameter for the actual Curiosity chute. |
nomuse (not logged in) User ID: 2380183 United States 08/13/2012 03:37 PM Report Abusive Post Report Copyright Violation | I don't have time to get into all the details of the stupid Gemini and other "re-entry" missions you mentioned. They were nonsense examples of high-altitude rockets utilizing retro-rockets or other techniques to come back down on a planet with a thick atmosphere, and had nothing to do with high-speed re-entries from outer space. Quoting: Engineer 694654 The only thing I may grant you along those lines are the missions to Venus, where the Soviets dropped something down that lasted for a few minutes, and that only worked: a) because it was tiny and very light, and b) because Venus has a very very dense atmosphere. Actually, Venera 7 (the first one to survive soft landing) looked like a tank. Venera 9 (the first one to return a photograph) weighed over 2,000 kg. The vehicles in the series from 7-12 weighed as much as 5 TONS each. |
Engineer User ID: 694654 United States 08/13/2012 09:45 PM Report Abusive Post Report Copyright Violation | See: [link to www.braeunig.us] to understand Cd and how it relates to super/sub sonic speeds for various shapes. For a round nose projectile, such as the it looks like the range is about: Subsonic: Cd = 0.2 Supersonic: Cd = 0.6 (maybe .65 @ Mach 1.5 or so) The Curiosity protective shell looks more flat than a round nose projectile and probably has a Cd MUCH higher as supersonic speeds, dropping very quickly at subsonic speeds, more similar to the cylinder and sphere than a round nose projectile. But we don't have that data to my knowledge. Unfortunately, my communication with Earth is about the same speed as Curiosity, 32kbps, so I am not so informed with graphical data as most, and no video data at all. I see many physics types trying to calculate everything with math and energy formulas, but :) That's not really possible. Physicists create formulas like computer programs that model relationships we see in nature, so we can put numbers into them, and get other numbers out of them. But especially in Aeronautics, physics has it's limits - there are some things in this world that become too mind-bogglingly complex with fluids - fluids have too many variables, they change too quickly, in all directions, with a different set of physics for every change and direction. Playing with air/water isn't exactly like playing with billiard balls and beams of iron. NASA would not be able to do much at all without extensive real-world testing and real-world measurements, refining things in the real-world to get the results they are looking for. That is why we use wind-tunnels to find coefficients of drag, it's just too complex for physics. Anyway, I will try to think of some way to approach a sanity check for high-altitude deceleration due to friction. It would be helpful if anyone has data on the "shell" or "pod" that is carrying the Curiosity assembly, also the height when it was released, it's velocity, etc. Gotta go for now, maybe a few days. |
Engineer User ID: 694654 United States 08/13/2012 10:15 PM Report Abusive Post Report Copyright Violation | > Actually, Venera 7 (the first one to survive soft landing) looked like a tank. Venera 9 (the first one to return a photograph) weighed over 2,000 kg. The vehicles in the series from 7-12 weighed as much as 5 TONS each. Why? Stupid Russians :) They build everything like a tank :) Let me check that :) I am reading about them now - that always interested me more than Mars :) We can pretty much see all of the Mars desert from a satellite, but Venus - that's a real mystery. Lots of energy there too! Lots of chemistry! I think we'd be better off learning how to live underground in Venus :) I do enjoy your interest in this topic, I don't know anyone else with an interest in aeronautics/physics/space. I pretty much lost interest in it a long time ago. I am pessimistic about the future of humanity :) |
Engineer User ID: 694654 United States 08/13/2012 10:22 PM Report Abusive Post Report Copyright Violation | "They included a transfer and relay bus that had engines to brake into Venus orbit (Venera 9 and 10, 15 and 16) ..." Anyway, as I said, Venus has a very dense atmopshere. It's almost like landing in an ocean (of sulfuric acid to the best of my memory :) But there is a place in the atmosphere where people could live quite comfortably, if they had the energy to remain aloft. I don't remember the details, but there is a "sweet spot" where the air is 60degF and lots of oxygen - I think - don't quote me on that - just very old vague memories. |
Engineer User ID: 694654 United States 08/13/2012 10:25 PM Report Abusive Post Report Copyright Violation | The Venera 9 lander operated for at least 53 minutes and took pictures with one of two cameras; the other lens cap did not release. The Venera 10 lander operated for at least 65 minutes and took pictures with one of two cameras; the other lens cap did not release. The Venera 11 lander operated for at least 95 minutes but neither camera's lens cap released. The Venera 12 lander operated for at least 110 minutes but neither camera's lens cap released. |
Engineer User ID: 694654 United States 08/13/2012 10:29 PM Report Abusive Post Report Copyright Violation | |
Engineer User ID: 694654 United States 08/13/2012 10:33 PM Report Abusive Post Report Copyright Violation | Venera 1 and Venera 2 were intended as fly-by probes to fly past Venus *without entering orbit*. Telemetry on the probe failed seven days after launch. It is believed to have passed within 100,000 km of Venus and *entered heliocentric orbit*. Venera 2 launched on November 12, 1965, but also suffered a telemetry failure after leaving Earth orbit. THIS IS SO FUNNY - typical of the "commies" :) |
Engineer User ID: 694654 United States 08/13/2012 10:39 PM Report Abusive Post Report Copyright Violation | TOO FUNNY TO BE TRUE! The first Soviet attempt at a flyby probe to Venus was launched on 4 February 1961, but failed to leave Earth orbit. In keeping with the (then) Soviet policy of not announcing details on failed missions, the launch was announced under the name "Heavy Satellite". The Venera 7 probe was the first one designed to survive Venus surface conditions and to make a soft landing. Massively overbuilt to ensure survival, it had few experiments on board ... Venera 7's parachute failed shortly before landing, fortunately very close to the surface. It impacted at 17 metres per second (56 ft/s) and toppled over, but survived. Due to the resultant antenna misalignment, the radio signal was very weak, but was detected (with temperature telemetry) for 23 more minutes before its batteries expired ... |
nomuse (not logged in) User ID: 2380183 United States 08/13/2012 10:41 PM Report Abusive Post Report Copyright Violation | See: [link to www.braeunig.us] Quoting: Engineer 694654 to understand Cd and how it relates to super/sub sonic speeds for various shapes. For a round nose projectile, such as the it looks like the range is about: Subsonic: Cd = 0.2 Supersonic: Cd = 0.6 (maybe .65 @ Mach 1.5 or so) The Curiosity protective shell looks more flat than a round nose projectile and probably has a Cd MUCH higher as supersonic speeds, dropping very quickly at subsonic speeds, more similar to the cylinder and sphere than a round nose projectile. But we don't have that data to my knowledge. Unfortunately, my communication with Earth is about the same speed as Curiosity, 32kbps, so I am not so informed with graphical data as most, and no video data at all. I see many physics types trying to calculate everything with math and energy formulas, but :) That's not really possible. Physicists create formulas like computer programs that model relationships we see in nature, so we can put numbers into them, and get other numbers out of them. But especially in Aeronautics, physics has it's limits - there are some things in this world that become too mind-bogglingly complex with fluids - fluids have too many variables, they change too quickly, in all directions, with a different set of physics for every change and direction. Playing with air/water isn't exactly like playing with billiard balls and beams of iron. NASA would not be able to do much at all without extensive real-world testing and real-world measurements, refining things in the real-world to get the results they are looking for. That is why we use wind-tunnels to find coefficients of drag, it's just too complex for physics. Anyway, I will try to think of some way to approach a sanity check for high-altitude deceleration due to friction. It would be helpful if anyone has data on the "shell" or "pod" that is carrying the Curiosity assembly, also the height when it was released, it's velocity, etc. Gotta go for now, maybe a few days. Yup. Sanity check is all that's really appropriate here; formula may not be completely applicable in the specific domain, modeling is complex (and can also be incomplete), and if you are assuming malfeasance you have already determined not to accept empiricism (at least, not from the usual suspects). One simplification that may help; according to NASA the parachute deploys at supersonic speed. So it is a pretty good assumption that the entire performance of the heat shield is in the supersonic regime. |
nomuse (not logged in) User ID: 2380183 United States 08/13/2012 10:44 PM Report Abusive Post Report Copyright Violation | ROTFLMAO!!! Quoting: Engineer 694654 Venera 13 and 14 were the only landers on which all cameras worked properly; although unfortunately, the titanium lens cap on Venera 14 landed precisely on the area which was targeted by the soil compression probe. I suspect clear titanium (c.f. your earlier comment) may not have been available at the time. I'm guessing here about the constraints, but I wonder if industrial diamond would work? |
Engineer User ID: 694654 United States 08/13/2012 10:52 PM Report Abusive Post Report Copyright Violation | Venus would be the PERFECT planet to terraform. It is loaded with CO2 (96.5%), super-dense atmosphere (equal to 1000m below the ocean) and could be turned into an oxygen rich atmosphere. We need to send some GM algae there and maybe some GM cactus and coconut trees, and get that planet turned into a new world ASAP :) |
nomuse (not logged in) User ID: 2380183 United States 08/13/2012 11:06 PM Report Abusive Post Report Copyright Violation | Venus would be the PERFECT planet to terraform. It is loaded with CO2 (96.5%), super-dense atmosphere (equal to 1000m below the ocean) and could be turned into an oxygen rich atmosphere. We need to send some GM algae there and maybe some GM cactus and coconut trees, and get that planet turned into a new world ASAP :) Quoting: Engineer 694654 Hrm. According to Oberg et al, the biggest difficulty is the heat. Planets don't cool fast. If all you did was make the atmosphere transparent, passive radiation would take thousands of years. More active measures are still on the order of several hundreds of years. |
Engineer User ID: 694654 United States 08/13/2012 11:26 PM Report Abusive Post Report Copyright Violation | |
Engineer User ID: 694654 United States 08/14/2012 01:10 PM Report Abusive Post Report Copyright Violation | I learned how they did it - not how they landed on Mars, but I learned how they created atmospheric density models to fool everyone :) NASA is LIAR CHEATER FRAUD HOAXER - 99%. I am almost 100% certain now that Curiosity is a new video game for the myopic geeks at NASA to play with. It will take time for me to present things in a way that may be understood, but basically, this is what learned this morning, and it's supported by actual data: It seems that the near-ground-level air is much colder than the general temperature gradient of the rest of the atmosphere. And this makes sense. Mars cycles in a 24 hour day like Earth, and as we all know, the air heats up faster than the ground in the morning. Since Mars has no real atmosphere (it is the smallest planet with the lowest gravity), it's easy to imagine how frigid it gets at night without the Sun, without any atmosphere to hold in any heat on the night side. Basically, the surface of Mars comes into the day colder than a SOB! And that frigid temperature probably goes well below the surface, much the same as Permafrost. So, the surface stays much much colder than the lower atmosphere during the day. This has the effect of keeping near-ground-level air MUCH colder than the rest of the air, which means MUCH MORE DENSE, and this is what NASA uses for "atmospheric density" - they don't want to show the public what the temperature/density gradient/profile of the atmosphere is, because then everyone would see what a bunch of LIARS CHEATERS FRAUDS & HOAXERS they are. If you search REAL HARD, you will find that they give out ***1 number***, for ground (datum) air density only - but this is a GROSS MISCHARACTERIZATION of the general atmospheric density. I only spent a hour this morning finding and verifying this "theory", but after running some numbers, I am in awe of this fraud - JUST ASK YOURSELF WHY NASA IS NOT PROVIDING THIS DATA AFTER 3+ PROBES WERE SENT DOWN THE ATMOSPHERE TO MEASURE IT!!! KEEP ASKING YOURSELF THAT!!! Because there is a VERY GOOD REASON! And this is why we have statements like this: [link to www.nasa.gov] NES Chat With NASA Scientist Dr. Joel S. Levine 01.21.11 Joel Levine and ARES model in NASA Langley wind tunnel Joel S. Levine, Research Scientist NASA Explorer Schools invites you to join a live chat on Jan. 21 from 2 - 3 p.m. EST to ask Dr. Joel S. Levine, Chief Scientist of the ARES Mars Airplane Mission questions about the the development of a robotic, rocket-powered airplane that will fly through the atmosphere of Mars to search for evidence of life by looking for trace gases of biogenic origin. Levine has a bachelor's degree in physics, Brooklyn College, City University of New York; master's in meteorology, New York University; master's in aeronomy and planetary atmospheres, University of Michigan; and doctorate in atmospheric science, University of Michigan. His hometown is Brooklyn, N.Y., and hobbies include photography and foreign travel. Peterson_Warren(Q) What is the atmospheric density of Mars compared to Earth? Joel_Levine(A) On the surface of Mars, the atmospheric density is less than 1 percent of the density of Earth's atmosphere. Why is this EXPERT on the atmosphere answering "less than 1%" ??? Why isn't he stating a solid number? "Less than 1%" could mean .1% or .5% or .9% or anything! THINK PEOPLE, THINK! Why is this person saying things like: [link to forum.nasaspaceflight.com] Quote from: jpaulb1 on 08/06/2012 08:59 AM C) What is the atmospheric density profile through altitude? general rule of thumb for me is that Mars atmosphere is about 1000 times less dense than on Earth. So a 200 km/h wind is about a 1000 times less strong, so feels like a 0.2 km/h wind. However, 200 km/h dust particles can still be very abrasive. pressure is greater at the bottom of a crater (up to 4 times greater I believe, depending on crater depth), so winds would be 250 times less strong than on Earth, at most. REMEMBER, AS I PRESENTED, NASA's MARS ATMOSPHERIC MODEL gives us figures for atmospheric density FAR ABOVE "1% OF EARTH'S ATMOSPHERIC DENSITY" - CONTRADICTING THEIR OWN EXPERT ON ATMOSPHERES! It may take a few days, because I am very busy with other work! If I don't return, either I died, got arrested, or GLP is giving me the crazy notice & IP block and won't let me return. STAY TUNED! |