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Re: APOD: Apollo 17 at Shorty Crater (2012 Jun 24)
Posted: Mon Jun 25, 2012 3:36 am
by Flase
If the Moon landings were a hoax, they were much better than I would expect from the American military. Even
2001 A Space Odyssey from the same year (1969) was less realistic.
The only thing that doesn't look right to me is how small the Lunar lander was. With a little puff of flame, it was able to reach the Moon's escape velocity, whereas craft that takeoff from Earth require huge whopping booster rockets...
http://news.nationalgeographic.com/news ... 44445.html
If it's a hoax, I'm willing to admit I'm a sucker for it because it's such a good one.
Re: APOD: Apollo 17 at Shorty Crater (2012 Jun 24)
Posted: Mon Jun 25, 2012 4:31 am
by Chris Peterson
Flase wrote:The only thing that doesn't look right to me is how small the Lunar lander was. With a little puff of flame, it was able to reach the Moon's escape velocity, whereas craft that takeoff from Earth require huge whopping booster rockets...
Actually, none of the Apollo spacecraft reached escape velocity with respect to either the Earth or the Moon. They never left orbit from the Earth-Moon system, and were only boosted to a slightly faster velocity than the orbital velocities they were initially lifted into.
That said, the thrust of the lander motor was higher than it appears in images. Rockets don't normally produce much visible output, unless they are in the atmosphere. So the Saturn boosters appear more powerful than they actually are, and the lander boosters appear less so. (Not that the Saturn motors weren't vastly more powerful... after all, the fuel laden Saturn with its payload massed nearly 3 million kg, compared with the lunar module ascent stage mass of less than 5000 kg, and the latter with no atmospheric drag and 1/6 the surface gravity.)
Re: APOD: Apollo 17 at Shorty Crater (2012 Jun 24)
Posted: Mon Jun 25, 2012 6:17 am
by Flase
Yeah nah I'm willing to believe that it's deceptive.
Re: APOD: Apollo 17 at Shorty Crater (2012 Jun 24)
Posted: Mon Jun 25, 2012 6:35 am
by Ann
One of the best arguments that I've ever heard against the claim that the Moon landings were a hoax is that this happened during the height of the Cold War. After all, the Moon landings were just as much about the United States beating the Soviet Union as it was about exploring the Moon.
Remember that the Soviet Union had made it into space themselves, and they had various equipment to help them monitor what the Apollo spacecraft were doing. You can be sure that they could see that the Apollo craft really did lift off and really did proceed towards the Moon. They could also make sure that the voice of Neil Armstrong (and other astronauts later on) really did come from the Moon and not from a studio in the Nevada desert.
In other words, the Soviet Union leaders, who would have loved to expose the Apollo landings as a fake, never questioned the authenticity of the landings.
Which makes me wonder: What is it about people in the West these days who want to prove, decades later, that "their own" Moon landings never happened?
Can't resist telling you about a weird Swedish conspiracy. In 1958, the Football (=soccer) World Championship was held in Sweden, and the Swedish team did so well that they reached the final, where they were soundly beaten by Brazil. However, nowadays some Swedes are saying that Sweden can't possibly have played so well and made it so far, and some of them claim that the entire Football World Championships in Sweden in 1958 must be a fake!!
What is it with some people nowadays?
Ann
Re: APOD: Apollo 17 at Shorty Crater (2012 Jun 24)
Posted: Mon Jun 25, 2012 7:17 am
by Flase
Of course under fascist regimes particularly, the propaganda of football results was taken very seriously and ... influenced. Particularly famous is the history between Real Madrid and Barcelona under Franco...
Also in sport there can be match-fixing from betting syndicates. The cricket world has recently been rocked by a few such scandals and I wouldn't be surprised if it happens in American sport.
Re: APOD: Apollo 17 at Shorty Crater (2012 Jun 24)
Posted: Mon Jun 25, 2012 7:34 am
by bystander
Re: APOD: Apollo 17 at Shorty Crater (2012 Jun 24)
Posted: Mon Jun 25, 2012 12:21 pm
by neufer
Chris Peterson wrote:
That said, the thrust of the lander motor was higher than it appears in images. Rockets don't normally produce much visible output, unless they are in the atmosphere. So the Saturn boosters appear more powerful than they actually are, and the lander boosters appear less so. (Not that the Saturn motors weren't vastly more powerful... after all, the fuel laden Saturn with its payload massed nearly 3 million kg, compared with the lunar module ascent stage mass of less than 5000 kg, and the latter with no atmospheric drag and 1/6 the surface gravity.)
Also import is the fact that at just ¼ the orbital diameter
½ the velocity will give the same orbital centrifugal force.
.....................................................................
Earth Orbital velocity ~ 2 X rocket exhaust gas velocity Ve
Lunar Orbital velocity ~ ½ X rocket exhaust gas velocity Ve
Code: Select all
7.91 km/s : Earth Orbital velocity
1.68 km/s : Lunar Orbital velocity
................................................
Exhaust gas velocity Ve for rocket engines:
2.9 to 4.5 km/s : liquid bipropellants
2.1 to 3.2 km/s : solid propellants
1.7 to 2.9 km/s : liquid monopropellants
NASA Saturn V thrust:
34,000,000 Newtons (~
2100 LEMs)
Black Brant III thrust:
49,000 Newtons (~
3 LEMs)
NASA LEM thrust:
16,000 Newtons (~
530 ESTESs 
)
ESTES Saturn V thrust: ~
30 Newtons ~(1/100 scale)
3
Re: APOD: Apollo 17 at Shorty Crater (2012 Jun 24)
Posted: Mon Jun 25, 2012 3:59 pm
by Chris Peterson
Ann wrote:One of the best arguments that I've ever heard against the claim that the Moon landings were a hoax is that this happened during the height of the Cold War. After all, the Moon landings were just as much about the United States beating the Soviet Union as it was about exploring the Moon...
I've always thought that was a good argument, as well, although hoaxers make a (very weak) case for mutual support of fake space programs.
There's a
really good technical demonstration that the landings were real- one which is completely devastating to any suggestion that the imagery was faked. We can see in the movies that the astronauts are operating in a vacuum. How can we tell? By the way the dust flies when they walk, or when the rovers move. Dust in even thin air is very non-ballistic in its motion. With its very low mass, its behavior is dominated by aerodynamic effects, not gravity. Toss a little dust in the air, and you get a cloud that floats off. But the Apollo films show something very different (I love using them in the classroom, because everybody instantly recognizes that something looks "wrong", but it can take a while before anybody figures out what that is)- the dust moves in beautiful little parabolic arcs, purely ballistic. Certainly, no CGI capability existed back then to fake that, so it could only be done in a vacuum. The suggestion that everything was filmed in massive vacuum chambers just adds to the absurdity of hoaxers claims (especially since the same people often suggest the flags are blowing in the wind).
Re: APOD: Apollo 17 at Shorty Crater (2012 Jun 24)
Posted: Mon Jun 25, 2012 8:57 pm
by eltodesukane
Re: APOD: Apollo 17 at Shorty Crater (2012 Jun 24)
Posted: Mon Jun 25, 2012 9:10 pm
by eltodesukane
Chris Peterson wrote:Ann wrote:One of the best arguments that I've ever heard against the claim that the Moon landings were a hoax is that this happened during the height of the Cold War. After all, the Moon landings were just as much about the United States beating the Soviet Union as it was about exploring the Moon...
I've always thought that was a good argument, as well, although hoaxers make a (very weak) case for mutual support of fake space programs.
There's a
really good technical demonstration that the landings were real- one which is completely devastating to any suggestion that the imagery was faked. We can see in the movies that the astronauts are operating in a vacuum. How can we tell? By the way the dust flies when they walk, or when the rovers move. Dust in even thin air is very non-ballistic in its motion. With its very low mass, its behavior is dominated by aerodynamic effects, not gravity. Toss a little dust in the air, and you get a cloud that floats off. But the Apollo films show something very different (I love using them in the classroom, because everybody instantly recognizes that something looks "wrong", but it can take a while before anybody figures out what that is)- the dust moves in beautiful little parabolic arcs, purely ballistic. Certainly, no CGI capability existed back then to fake that, so it could only be done in a vacuum. The suggestion that everything was filmed in massive vacuum chambers just adds to the absurdity of hoaxers claims (especially since the same people often suggest the flags are blowing in the wind).
The best argument is this:
Between "going to the Moon" and "faking going to the Moon", they choose the easiest way by far: going to the Moon.
Re: APOD: Apollo 17 at Shorty Crater (2012 Jun 24)
Posted: Tue Jun 26, 2012 4:30 am
by Dreadmon
Odd that you don't see the rover's tracks in the picture.
Re: APOD: Apollo 17 at Shorty Crater (2012 Jun 24)
Posted: Tue Jun 26, 2012 12:41 pm
by rstevenson
Dreadmon wrote:Odd that you don't see the rover's tracks in the picture.
It's easier to see some soil disturbance, which I assume indicates the tracks of the rover, on the full panorama picture (linked above.) The disturbed soil is whitish, as you can see around the front of the rover where the astronaut has been walking.
Rob
Re: APOD: Apollo 17 at Shorty Crater (2012 Jun 24)
Posted: Wed Jun 27, 2012 7:03 am
by Mactavish
Mactavish wrote:The full panorama is even more spectacular!
My apology for not including the link to the full panorama. It was APOD Dec 14, 2007.
http://apod.nasa.gov/apod/ap071214.html
Re: APOD: Apollo 17 at Shorty Crater (2012 Jun 24)
Posted: Sat Jun 30, 2012 7:07 am
by SFCass
Ann: Thank you for the thorough and fascinating explanation for the missing stars!
