posted
Nope. If NASA wants in, it just means that the DC politicians wanna make China's moon program as snafued as they have made the US and European space programs, and are trying to fubar the Russian.
Posts: 8501 | Registered: Jul 2001
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Blayne Bradley
unregistered
posted
that makes no sense, your saying that NASA a usa agency intentionally torpeedoed its own efforts at space travel/research and are doing likewise to the other countries space programs?
Either you are joking and haha good joke or your being serious and if your being serious then i still dont believe you because its ludicruse, both the USA and China intent to go to the moon around the same time and the russians want to g to mars 24 years from now thats not exactly fubared imo, so nasa i think is failure at trying to sink its own boat.
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posted
Well, Blayne, for a change you have the right of it. It's early in the morning; aspectre needs conspiracy theories like the rest of us need coffee. He'll be more rational after lunch.
Posts: 10645 | Registered: Jul 2004
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posted
I certainly wouldn't mind the Chinese funding, but I'd rather have first dibs on all the good sites for potential moon beaches. Oh well. The things we do for diplomacy.
Posts: 21898 | Registered: Nov 2004
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posted
Yep, I am saying that NASA has been and is VASTLY more interested in promoting "TheWhiteStuff", subsidizing military/intelligence hardware, and stamp-collecting than in running a real Man-in-Space program.
Give a moment of thought to the physics of building the InternationalSpaceStation, King of Men, then compare to whatcha'd do if ya wanted to engineer a success.
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quote:Originally posted by King of Men: Well, Blayne, for a change you have the right of it. It's early in the morning; aspectre needs conspiracy theories like the rest of us need coffee. He'll be more rational after lunch.
Your statistically more likely to be murdered by a paranoid schizo after lunch. Higher blood sugar levels = higher blood loss levels. FYI.
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quote:Originally posted by aspectre: Yep, I am saying that NASA has been and is VASTLY more interested in promoting "TheWhiteStuff", subsidizing military/intelligence hardware, and stamp-collecting than in running a real Man-in-Space program.
There is I believe, a specific reason why NASA is NOT part of the military complex. Not that the government cares or acts any other way, but for the record they are suppossedly a research based organization.
Otherwise I agree. Not that I think they wouldn't like to actually do something adventurous, I just think the current political and socio-economic climate naturally encourages them to be unproductive and toady-like. We spend 100 billion dollars on a station that looks good and does nothing, and we let the greatest optical telescope ever constructed fall out of the sky for it. Pathetic .
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posted
I've yet to see the military put a railgun on a tank or ship or aircraft. Your point?
Got another easy easy easy one for ya, KoM. What's wrong with the reporting in Noeman's Billiards in Spaaaaaaace? Hint: I gave a wys ars answer three posts down.
posted
i'm saying I dont see any effort on the part of NASA to weaponize space and I see them every year or so doing stuff, Martian rovers, laucnhing sats, relaunching the shuttles again after the columbia fiasco. trust me i dont see anyone in NASA saying "I dont think we should go into space anymore so lets me as inefficient as possible"
China was invited to look into it China dispite oh i dont know 2 decades of being barred from purchasing technology that can be used for booster rockets has progressed rapidly in space technologies give or take a few purchases of systems from Russia. If China gets invited in it will build trust between the too nations and maybe speed up scientific advancement.
Posts: 1567 | Registered: Oct 2004
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posted
isnt the ISS a cooperative effort by a dozen countries to imprpove relations and increase multilateral participation into its construction? Whats inefficient about its design?
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quote:Originally posted by Blayne Bradley: isnt the ISS a cooperative effort by a dozen countries to imprpove relations and increase multilateral participation into its construction? Whats inefficient about its design?
Its an expensive excercise if that's what it does. And besides the cost got to be so great that alot of the investments dried up and the "international" effort will end up getting funded by US. When its finished, it won't be good for very much.
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We take China with us to the moon. When we get there, we beat them up and leave them behind. When we get back to the earth, we go over to China and take all their oil!
posted
aspectre, as an aerospace engineer who works with NASA, I would pretty much agree with pH here, it is remarkably inefficient, but not militant.
There IS some connection between NASA efforts and military efforts, but only in the fact that both largely use the same set of launch vehicles. However, as almost all these vehicles were developed as offshoots of ballistic missile programs it's more an issue of the military being more research oriented.
As for the inefficiency it is largely due to some combination of: Domestic Politics Bureaucratic Management International Politics
As a scientific organization NASA is definately crippled by its very nature as a highly public governmental organization. The government has long been known to be a terrible guide of research efforts, and when it's as public as NASA there is too much face saving to really make much progress.
All that being said, while international cooperation is great and all, I can't see a teaming of China and NASA working at all for either side. China's space program is run so absolutely vastly differently from NASA that there would be huge disconnects as to acceptable risks etc concerning human spaceflight. Additionally, I can see it being another gigantic financial sinc as the Russian portions of the ISS were (i.e. the US payed for the vast majority of the Russian "contributions" to the ISS due to Russia's weak economy)
Posts: 1038 | Registered: Feb 2006
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posted
China may have a larger economy (not entirely sure of the numbers) but even if the situation is somewhat changed, someone is going to have to spend a LOT of money to get its space program anywhere near the capabilities/redundancies/reliabilities of US or Russian technology.
A good example was a few years back when there were a few long-march explosions and there was a HUGE uproar about US technological aid being given even with very simple pointers on this kind of thing.
A large part of why NASA is so expensive to do anything is because of the massive safety precautions taken with regards to human safety at all points in the industry. China on the other hand is not exactly known for its respect for human life in high-risk/high-visibility ventures like this.
On top of all this is the issue of exchanging technology with other nations, especially nations that we aren't on 100% good terms with. I realize this would be a governmental program, and thus regulations would be backed off a great deal, but when I can't tell a foreign customer to look up a basic physics equation on google, how are we supposed to work with a country whos space program is arguably decades behind our own?
Posts: 1038 | Registered: Feb 2006
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posted
"I'm one of those geek types that doesn't find physically impossible jokes funny."
And I'm one of the geek types who find physically impossible jokes such as NASA's "billiards in space" to be hilarious. Which is why I bumped this up to have our resident physicist KoM explain the joke.
I agree with pH and TheGrimace. On the main, NASA employees are not militant. And for highest portion of the most valuable of them, perhaps the opposite of militant is the best description.
But I was refering to the DC politicians who fund and give orders to NASA, and the why. Which I'll return to when KoM deigns to show how most "secret"s cannot hide from even the simplest of scientific scrutiny. Or I get tired of waiting...
quote:NASA’s DART spacecraft...was intended to manoeuvre to within five metres of an experimental military communications satellite, MUBLCOM...[but]...may have accidentally hit the satellite...[and]...the contact boosted MUBLCOM to a higher orbit - between 5.5 and 9.25 kilometres higher.
So let's turn to physics: the Newtonian "What goes up must come down." ie In order to travel upward, the object must have excess KineticEnergy (represented by initial speed upward) that converts into the PotentialEnergy difference between the highest point of the object's travel and it's initial starting point. eg In a vacuum, if ya throw a rock straight upward at 100kilometresperhour, it slowly loses speed (due to gravity pulling downward) until at the top of it's climb the rock's upward speed becomes zero, at which point the rock's gravitational PE reaches maximum. Then that potential energy is converted back into KE (and thus speed) as gravity pulls the rock downward, until the rock reaches a final speed of 100kph when ya catch it again. 100kph up means 100kph down.
Next, a calculation* of the gravity at MUBLCOM's initial orbital height of 775to780kilometres above the Earth's surface. Then a few more to approximate how much speed that MUBLCOM would have had to gain to travel 5.5kilometres upward and the speed gain to travel 9.25kilometres upward for that new orbit "between 5.5 and 9.25 kilometres higher" than the original orbit.
* Using the simplest equations because a "more precise" calculation inregard to gravitational force change with height change won't affect the answers much: ie the answer's will still be within the margin of error of the numbers that are provided by the articles.
posted
So your saying you can tell where that satellite was based on the data that is public knowledge?
Posts: 9912 | Registered: Nov 2005
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posted
The MUBLCOM link is a NASA website. Not that it really matters, a substantial number of amateur astronomers are into satellite tracking. And a lot of professionals keep track for a view clear of satellites flashing through their photographs. So NASA/etc might as well make nearly all of the satellite orbits public.
As to airmanfour's question, there's a LOT more to be gleaned inre ELINT and other "secret" capabilities through NASA's/USAF's disinformation within the NewScientist article. And what those astronomers and others could have seen has bearing on the why of those misrepresentations, and on how to interpret them.
Back later today with the arithmetic and explanations.
How many trips do you think it's going to take until all of China is on the moon? I wonder if we can start taking their oil while the last group is on the way up, or should we wait until the rocket leaves them behind before we start drilling?
Posts: 3950 | Registered: Mar 2006
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Ge = Gravity on the Earth's surface Gh = Gravity at a height above the Earth's surface Re = Radius of the Earth Rh = Radius of the Earth plus the height above Earth's surface ~ = approximately / = divided by X = multiplied by ^ = raised to the power of eg y^2 equals y multiplied by y ..... y^3 equals y multiplied by y multiplied by y ..... etc
(Newton's) Hooke's inverse square law of gravitation: Gh = Ge divided by ([Rh divided by Re] multiplied by [RH divided by Re]) Gh = Ge / (Rh/Re)^2 Gh = Ge X (Re/Rh)^2
Re = 6378.137kilometres Rh = 6378.137km + 780km = 7158.137 Chose 780km cuz the result should minimalize the speed that MUBLCOM must gain to achieve its new orbital height.
Gh = Ge X (6378.137km/7158.137km)^2 = Ge X ~0.891033^2 = ~0.79394 X Ge Ge = gee = g = ie The gravitational acceleration on the Earth's surface is commonly known as 'one gee' or '1 g' g = 9.08665meters per second per second = 9.80665m/s^2 Gh = 0.79394g = 0.79394 X 9.80665m/s^2 = ~7.78589m/s^2
Since "what goes up must come down", the question of "How much speed did MUBLCOM gain to be boosted upward into an orbit 5.5km to 9.25km above its old orbit?" is equivalent to "How much speed would an object gain from falling downward at 0.79394g for 5.5km and for 9.25km?" - - - - - - - - - - - - - - - - - - - - - - - - -
Sorry for the delays. I don't believe in "trust me" while pulling a rabbit out of a hat. So I try to explain things so that everyone who reads my posts can understand&check what is written. When a decent explanation is so much easier to do in the real life with sketches/etc, it takes a while to work up the will to type one up for the internet world. But like MacArthur said: I shall return.
posted
Once the last rocket leaves, and you're sure that they're not really looking back, then you start drilling. Becasue, if they see you drilling, they might just turn the ship around, and then--boy, are you going to look stoopit!
Posts: 1862 | Registered: Mar 2000
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posted
aspectre, I've been trying to figure out where you're going with this for a few days and I can't see it... also, assuming you're trying to determine something about the military satellite from this whole thing, you're missing a lot of data and a lot of important physics since these are orbiting bodies, not hanging/falling bodies.
Posts: 1038 | Registered: Feb 2006
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posted
booth, alternately you can host an elaborate "going away party" and just have the drilling equipment under a big tent where you claim the food is being prepared. Then you can get a jumpstart on the whole thing and get drilling that much earlier =p
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And not to forget that DART probably 1) didn't dump all its KE into MUBLCOM, and 2) Probably weighs a lot less than MUBLCOM, so it's initial velocity at impact was higher than the delta-V of MUBLCOM.
In other words...*BANG* Or, in the vacuum of space...*[]*
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posted
An orbiting body is a falling body, TheGrimace, with a trajectory that causes it to miss the ground.
Posts: 8501 | Registered: Jul 2001
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posted
yes, but dropping a ball involves much less complicated equations and relations than throwing a ball parallel to the ground. And even better yet, throwing two balls both parallel to the ground, each with different velocities and masses and figureing out what effect this has on each.
In any case, what is your point? what are you trying to prove, find out etc?
Posts: 1038 | Registered: Feb 2006
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posted
When I worked at Grumman, a friend of mine calculated the accurate orbits of a number of sensitive military satellites. He sort of had to, since his project involved accessing them with a new piece of equipment he was developing.
When he presented his overall project to the client (military), they were shocked to learn he had this info. They took his information away from him, since he wasn't cleared to know it. He had developed all this data based on publically available documents. The MIL guys asked him, politely, "not to do it again."
Posts: 1862 | Registered: Mar 2000
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posted
Oh, sorry aspectre, I lost interest in the thread and didn't see you wanted me to explain something. Anyway, seems you did a pretty good job yourself.
Posts: 10645 | Registered: Jul 2004
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posted
oh sure... As if physics weren't the lazy man's way to get out of heavy lifting
From last time: gravitational acceleration at MUBLCOM's height above the Earth's surface is ~0.79394g, or in this particular case, acceleration will be equal to ~7.78589m/s^2 And some more definitions: d = distance a = acceleration t = [amount of] time [of the fall/acceleration] v = velocity (distance) equals (one half of the acceleration) multiplied by (time) multiplied by (time) d = (1/2 X a) X t^2 With distance and acceleration of the fall already known, solve for time by using t^2 = (2 X d) / a (velocity) = (acceleration) multiplied by (time) v = a X t
MUBLCOM's new orbit is between 5.5km and 9.25km above its old orbit, so t^2 = (2 X 5.5km) / (7.78589m/s^2) = 11,000m / 7.78589m X s^2 = ~1412.8118693s^2 time = square root of t^2 = (1412.8118693s^2)^(1/2) = ~37.587389seconds Now that we know the time it takes to fall 5.5kilometres at MUBLCOM's height, the minimum speed that MUBLCOM must fall can be calculated from knowing that v = a X t = 7.78589m/s^2 X 37.587389s = 7.78589 X 37.587389 (m/s2 X s) = ~292.65134m/s Since an hour is equal to 3600seconds 292.65134m/s X 3600 = ~1,053,544m/h = ~1053km/h = ~654miles per hour
And**
For a 9.25kilometer boost in orbital height t^2 = (2 X d) / a = (2 X 9.25km) / 7.78589m/s^2 = 18,500m / 7.78589m/s^2 = ~2376s^2 time = ~48.745seconds v = a X t = 7.78589m/s^2 X 48.745s = ~379.5246945m/s = ~1,366k/h = ~848 miles per hour
Using Noeman's billiards analogy: NASA/USAF representatives are claiming that DART "accidentally hit" MUBLCOM pret-ty darn hard. Or as Boothby171 put it, "...*BANG* Or, in the vacuum of space...*[]*
* Do not try this on your physics professor: velocity is actually speed plus direction. In this case, v actually represents speed rather than velocity. The problem was that I had already used s for seconds, so using that letter for speed would have needlessly confused things.
Same thing for my method of "approximation", which I didn't actually do between intermediate results: too much trouble repunching the numbers into the calculator. Since NewScientist/NASA/USAF implied 3 decimal places of accuracy for 5.5kilometres by using 9.25kilometers for their second number, only the first three decimals places can be used for a real approximation.
Plus, using the international standard g for acceleration is misleading when calculating Earth orbits. It does not affect the main point of the "bump" calculations, but I might explain the why as the last thing I post on this thread.
** Which will become relevant in the next discussion via Newton'sCannon and the HohmanTransferOrbit.
posted
so I'm still somewhat unclear on your point here... though I THINK it may be that you're trying to say that the collision was intentional based on the speeds involved in the collision. however, it's times like this that I can actually make use of the fact that I'm a rocket scientist in order to poke holes (very large holes... rather gaping actually) in your "proof".
all of these calculations are based on MUBLCOM sitting stationary with no tangential velocity, and DART hitting it with only axial velocity as if fired straight up into MUBLCOM. This bears absolutley no resemblance to what would have actually happened.
In fact MUBLCOM would have been at it's given altitude orbiting the earth at the appropriate velocity to keep it stable at that altitude. Then the DART would have come along, most likely in the same orbit and hit it tangentially (to the orbit) increasing MUBLCOM's orbital velocity. this in turn would gradually increase the altitude of the orbit until it settled into it's new higher orbit.
so the key paramater you're looking at here is the DV (change in velocity) of MUBLCOM which is imparted by a transfer of kinetic energy from DART. this means that if DART was significantly more massive than MUBLCOM it may have only needed to be slightly faster in order to impart the needed DV, or if it was much less massive then it would have to be going significantly faster according to Ke=(1/2) m*v^2. Of course all that is assuming an elastic collision which is also not going to be what happened, but it would get you closer to the ballpark.
even assuming mDart << mMUBLCOM, which may or may not be valid, a seemingly large difference in velocities is not necessarily out of the question. we don't know if DART was supposed to do a flyby or a 5m docking operation, and either way the kind of velocities we're talking about here are literally and figuratively astronomical. velocities of many kilometers/s are completely within reason in these cases.
my basic word of wisdom: don't try to go into complicated mathematical proofs when you don't know what you're talking about. just as I don't attempt brain surgery because I don't have any medical training.
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