why was the usa the only one to go to the moon?

[Bob B.]

The DRA Table of Space Vehicles gives inclinations, period and eccentricity.  The inclinations for Apollo are:
8 - 168   10 - 174.4   11 - 178.75   12 - 164.7   14 - 165.6   15 - 151.28   16 - 169.3   17 - 159.9

Thanks to you too.

The reason I'm asking is because I'm thinking about doing a complete beginning to end simulation of the Apollo 11 mission, and the more information I have, the better I can confirm my results.  As many of you know, I've already done a series of simulations, but they don't really fit together nicely into a presentation.  I want to redo it into a complete presentation of a single mission that confirms every maneuver step by step.  I also want to strip away most of the math so its more easily understood.  I still want to make the math available, but you'll have to click some sort of "more information" button to see it.  I envision perhaps several tiers of details - (1) a general overview, (2) a more detailed description, and (3) all the underlying calculations.  It's likely to be months before I can get around to it, however.

[Chew]

smartcooky, here is an excellent essay on launch windows which covers most of your question: http://history.nasa.gov/afj/launchwindow/lw1.html

Concerning plane changing at LOI, the velocities for Apollo 11 before and after LOI are here: http://history.nasa.gov/SP-4029/Apollo_11g_Lunar_Orbit_Phase.htm

It lists the space fixed velocities as 8250 and 5479 ft/sec which is a difference of 2771 ft/sec. "velocity change" is listed as 2917.5 ft/sec. Is this discrepancy because the spacecraft continued to accelerate as it approached perilune? Or was was it used for a plane change? The LOI burn ground track shows Apollo 11 was at about a 4° inclination during LOI: (5.9 mb size png) http://history.nasa.gov/afj/launchwindow/figs/Fig%2020.png

The circularization orbit performed 4 hours after LOI also has a velocity discrepancy; the excess might have gone into a plane change.

Were any mid-course corrections used to adjust the inclination the spacecraft would have once it arrived at the Moon?

[Bob B.]

It lists the space fixed velocities as 8250 and 5479 ft/sec which is a difference of 2771 ft/sec. "velocity change" is listed as 2917.5 ft/sec. Is this discrepancy because the spacecraft continued to accelerate as it approached perilune?

Yes, the spacecraft was still speeding up as it appraoched perilune.  You can see that the altitude at LOI ignition was 86.7 n.mi. and at cutoff was 60.1 n.mi.  The spacecraft was losing potential energy and gaining kinectic energy from its decreasing altitude at the same time the engine was slowing it down.  Therefore, the engine had to do more work than it appears when you just look at the initial and final velocities.  It's like putting on the brake while the accelerator is still on.

[smartcooky]

Thank you to everyone for all your replies, especially these links from Chew....

http://history.nasa.gov/afj/launchwindow/lw1.html

http://www.braeunig.us/apollo/apollo11-TLI.htm

I can see that these issues are going to be more difficult should the manned missions to Mars ever eventuate, with long intervals between launch windows.

How difficult must the calculations have been to launch Voyager 2 on the "Grand Tour" in 1977, in a window that was not going to open again for another 175 years; lining up all those apogees and orbital inclinations to execute three gravitational slingshots at intervals measured in years to hit targets measured in billions of kilometres?

It boggles the mind!

[Bob B.]

It lists the space fixed velocities as 8250 and 5479 ft/sec which is a difference of 2771 ft/sec. "velocity change" is listed as 2917.5 ft/sec. Is this discrepancy because the spacecraft continued to accelerate as it approached perilune? Or was was it used for a plane change? The LOI burn ground track shows Apollo 11 was at about a 4° inclination during LOI: (5.9 mb size png) http://history.nasa.gov/afj/launchwindow/figs/Fig%2020.png

I've been running some numbers on this and it looks like there's more to it then what I previously posted.  I figure that if the LOI burn were not performed and the spacecraft continued on its trajectory from 86.7 n.mi. altitude to 60.1 n.mi. altitude, it would have picked up only about 27.2 m/s.  This alone can't account for the apparent ΔV discrepancy.

According to the data posted by gwiz, Apollo 11's lunar orbit had an inclination of 178.75°.  You say that the ground track during LOI shows an inclination of 4°, but since the orbit was retrograde, this would actually be 176°.  If correct, this implies that Apollo 11 made a 2.75° plane change during LOI.  If we add the plane change and the extra 27.2 m/s into the maneuver, I calculate a total ΔV of 877.4 m/s, or 2,879 ft/s.  This is still less than the 2917.5 ft/s shown in the referenced document, but we're getting closer.

It looks like there is still something else going on here, but since I don't know all the parameters of the before and after orbits, it's impossible to determine.  Perhaps I'll figure it all out if I ever get around to doing a complete mission simulation.

[Noldi400]

It looks like there is still something else going on here, but since I don't know all the parameters of the before and after orbits, it's impossible to determine.  Perhaps I'll figure it all out if I ever get around to doing a complete mission simulation.

One thing that may be playing a little hell with the precise numbers are the lunar mascons.  The moon's gravity isn't evenly distributed, so orbits can be perturbed in strange ways.

AS-16 released a satellite (PFS-2) into a 55 x 76 mile orbit, where it was expected to stay indefinitely. Instead it crashed just over a month later after being pulled into a lower and lower orbit.

http://science.nasa.gov/science-news/science-at-nasa/2006/06nov_loworbit/

[Chew]

I've been running some numbers on this and it looks like there's more to it then what I previously posted.  I figure that if the LOI burn were not performed and the spacecraft continued on its trajectory from 86.7 n.mi. altitude to 60.1 n.mi. altitude, it would have picked up only about 27.2 m/s.

That's what I got, too. I suspect the extra velocity might come from adjusting the flight path angle (i.e. pointing up or down relative to the local vertical).

[ProfessorAlfB]

im a firm believer that usa landed on the moon. but i wonder why no one has been there ?so there was a race to the moon with russia , but they never continued their program. and no one since

What makes you think there even was a race to the Moon with Russia? 
There is documented evidence to the contrary...On November 12th 1963 President Kennedy issued a Top Secret National Security Action Memorandum No. 271 with the subject header:"Cooperation with the USSR on Outer Space Matters:".  It was sent to the then NASA administator, James Webb, (as well as the US Secretary of State, the US Secretary of Defense, the Director of the CIA, the President’s Science Advisor, and three other agency directors) instructing Webb to develop a program with the Soviet Union in Joint space and lunar explorations...In other words, it is evidence that US and the Soviets could well have been working together on the Apollo project.
You may think that President Kennedy’s assassination, two days later, quickly led to the abandonment of his plan to cooperate with the USSR on Space exploration, but his death didn't stop the Apollo missions he santioned going ahead, so this is unlikely.
In fact there is actual photographic evidence that it went ahead...At least one of the official Apollo mission photos where a US Astronaut was supposed to be in Space, was clearly taken in a Russian Soyuz spacecraft!
In the likelyhood that it has now been deleted by NASA, for obvious reasons, the photo can still be found in the book: "Apollo, Dark Moon And The Whistle Blowers".
And before you ask, no, I am not the author or connected financially with the publication in any way.  I have read the latter book though and seen the photo for myself.  The book was freely available to borrow from my local public library.

[Andromeda]

I am confused, ProfessorAlfB.

One the one hand you seem to be saying that the Apollo missions "went ahead" with USSR cooperation, but you also believe that Apollo was faked and are a fan of Jarrah White (going by your posts elsewhere).

Which is it?

Or should I just say, "Hi, Patrick"?

[gwiz]

In fact there is actual photographic evidence that it went ahead...At least one of the official Apollo mission photos where a US Astronaut was supposed to be in Space, was clearly taken in a Russian Soyuz spacecraft!
In the likelyhood that it has now been deleted by NASA, for obvious reasons, the photo can still be found in the book: "Apollo, Dark Moon And The Whistle Blowers".
And before you ask, no, I am not the author or connected financially with the publication in any way.  I have read the latter book though and seen the photo for myself.  The book was freely available to borrow from my local public library.

To save us all a trip to your local library, perhaps you could scan the photo in question and post it here.

[raven]

What page is it on? I have a substantial access to this work.
Also, have you heard of the Apollo Soyuz Test Project?

[Bob B.]

On November 12th 1963 President Kennedy ... You may think that President Kennedy’s assassination, two days later

That's ten days later.  Kennedy was killed on November 22.

[Bob B.]

For the record, American leaders made several attempts to try to cooperate with the Soviet Union in space initiatives.  This started with a series of letters written by President Eisenhower to the Soviet leadership back in 1957-58.  As soon as Kennedy came to office he also tried to engage the Soviets and encourage cooperation.  In fact, in Kennedy's inaugural address he said, "Let both sides seek to invoke the wonders of science instead of its terrors. Together let us explore the stars."  All these overtures were rejected by the Soviets, as they believed at the time that they were winning the space race.

Why do you think the outcome was any different in 1963 after all previous attempt failed?

[Bob B.]

...At least one of the official Apollo mission photos where a US Astronaut was supposed to be in Space, was clearly taken in a Russian Soyuz spacecraft!

In fact, there are several such photos.  After the moon missions, the US and USSR finally started to work together in space.  They flew a joint mission in 1975 in which an Apollo and a Soyuz spacecraft joined up in space.  Astronauts/cosmonauts transferred from one spacecraft to the other.  Look up Apollo-Soyuz Test Project.

[ProfessorAlfB]

I am confused, ProfessorAlfB.

One the one hand you seem to be saying that the Apollo missions "went ahead" with USSR cooperation, but you also believe that Apollo was faked and are a fan of Jarrah White (going by your posts elsewhere).

Which is it?

Neither, I try to keep an open mind on the matter.

Or should I just say, "Hi, Patrick"?