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

[dwight]

Hey everybody. STOP PRESS! A few pages ago I announced that our resident quasi-engineer had scarped. Several pages later he actually did. Does that mean I posses super human abilities to predict the future???

[raven]

Even a fool can see a storm on the horizon.
EDIT: Sorry if that sounds meaner than intended. It sounded more clever in my head.

[Sus_pilot]

My work here is done.

So, exactly as expected, your sole aim is to get banned so you can brag about it at some other forum, as if you were banned because we couldn't deal with your arguments. It is painfully obvious to all and sundry that your reason for being banned, should a ban in fact be given, is simply your resorting to insults and absurdities rather than actually answering any questions sensibly.

You know, just once it would be nice to meet an HB who was actually capable of a discussion that didn't degenerate rapidly into lies, insults and pathetic behaviour.

The most disheartening thing of all about dealing with people like you, alex, is that I always used to think people grew out of such immaturity once they left school. I've seen people aged between 12 and 16 doing this sort of trolling just to wind people up. I thought grown ups didn't behave so idiotically. It is sad to see some do. Sad as much for you that you have so little else to do in your life than stir up trouble on so many messageboards.

Well, I can't brag about it on cluesforum.  I got banned for saying the ISS was real.  Where were you people then? 

THIS IS MY FINAL TRANSMISSION.

Buzzing sound.  Did anyone else hear a buzzing sound?

[Sus_pilot]

Can you see stars during the day on Earth? Why or why not?

Can you see stars at night on Earth? Why or why not?

Actually, you first statement illustrates just how wrong alexsanchez is, because while you cannot normally see stars during the day with the unaided eye, you can with a telescope....

http://sky.velp.info/daystars.php

NOTE:  I say normally because you can actually see Sirius in broad daylight with the unaided eye (I have done so myself) if you know exactly where to look.

When Northwestern University still had an observatory, I saw Venus through the telescope at about noon on a hazy day.  Admittedly that's a planet, but a -1 magnitude object is a -1 magnitude object...

[ka9q]

Clearly you have never looked through a telescope.

Yes I have.  Next question.

Then you are deliberately lying.

He could well be telling the truth if he doesn't know he's supposed to take the lens cap off the telescope.

Or if he's blind.

[raven]

Or it was a really small telescope.

[ka9q]

"...the LM had an Alignment Optical Telescope, and could only determine the craft's orientation."
(Not without seeing stars.  And that still doesn't give you your position.  How do you calculate a trajectory???  You can't.)

The LM's AOT is only one part of its guidance and navigation system. Its primary purpose is to align with respect to the stars a gyroscopically stabilized platform able to read the Euler angles of the LM's orientation in inertial space. The system also includes three orthogonal accelerometers, a computer with a gravity model, and a ground radio tracking network.

The gyro platform allows the computer to resolve the accelerometer data into inertial coordinates. The computer then numerically integrates the accelerometer data to update the vehicle state vector, its estimate of its position and velocity. It did this every two seconds, regardless of whatever else it might also be doing.

That's how you calculate a trajectory, and this is how any inertial guidance system operates, including those on civil aircraft.

Every inertial guidance system requires initialization to a known state. The primary method of doing this on Apollo was radio tracking from earth, which could measure to extreme accuracy the range (straight line distance) and range-rate (rate of change in straight line distance) between ground and spacecraft antennas. The earth antenna positions were known very accurately, and so were the trajectories of the spacecraft. The ground periodically loaded the new state vectors directly into the onboard computers; you often hear the Capcoms ask the astronauts to give them "P00 and accept" to allow this to be done. (POO, pronounced "pooh", refers to executing program #0, the idle program. The block/accept switch allowed the computer to accept the uplink data.)

As a backup in case communications were lost, the command module astronauts could use their optical instruments to determine their absolute position in the earth-moon system. So the assertion that telescopes were good only for orientation is simply false. This was done by sighting stars against the limb of the earth or moon. Jim Lovell practiced this intensively during Apollo 8, and his results were just as good as those from ground radio tracking.

[Echnaton]

"NASA must have had a less massive version.

Also, I think NASA must have dropped some navigation aids on the lunar surface before they attempted any manned landings."

Alex, what do you think of people who just parrot anonymous third party speculation?

Buzz Armstrong said they "couldn't see stars on the moon."  Therefore, you can't get a bearing from a star for navigation.  Therefore, you are all stuck on the moon.  The optics were just a telescope.  If you can't see a star with your eyes, you can't see it with a telescope.  Nobody went anywhere.  End of story.  Sorry.

http://www.hq.nasa.gov/alsj/aot.htm

Yawn.  Do you really find trolling to be fun and a good use of your time?

[Echnaton]

Or it was a really small telescope.

Perhaps he just looked into the big end.

[dwight]

Or perhaps he just looked at the telescope.

[Noldi400]

Yanno, it's probably just as well Conrad and Bean couldn't find their camera timer on AS-12. The HBs would have had no end of fun with that.

[smartcooky]

The primary method of doing this on Apollo was radio tracking from earth, which could measure to extreme accuracy the range (straight line distance) and range-rate (rate of change in straight line distance) between ground and spacecraft antennas. The earth antenna positions were known very accurately, and so were the trajectories of the spacecraft.

And as I posted earlier, Jodrell Bank was so accurate that they were able to tell that Eagle had stopped descending when Armstrong took manual control prior to landing and started flying sideways to find a landing spot that wasn't strewn with big boulders.

[gillianren]

Or it was a really small telescope.

Ooo, I think I had a plastic one as a child that was literally just a toy--no magnification at all.

[smartcooky]

I have a question about orbits that may have something to do with TLI and how it is accomplished.

I have difficulty in understanding how Apollo 11 could have made an near equatorial orbital insertion at the moon

Firstly, the moon's orbit is inclined to the earth's equator by about 5.1°, and the moon's equator is inclined to its own orbit by 1.5°. This means that, depending upon where the moon is in its orbit, the actual inclination of the moon's equator could be anywhere between 6.6° (5.1° + 1.5°) and 3.6° (5.1° - 1.5°). It is  beautifully illustrated in this gif.



Secondly, AIUI, Apollo 11 launched from Cape Canaveral into an earth orbit of about 32° inclination. This seems high (was it due to the Cape's latitude of 28½° N?).

It remained in that orbit for only 1½ revolutions before TLI.

It seems to me that a TLI burn at an earth orbital inclination of 32° is not going to send the spacecraft anywhere near the moon . I know there are mid course corrections, but correcting a deviation of at least 26° seems a bit extreme. To insert the spacecraft into a near-Lunar equatorial orbit would mean that it would have to approach the moon near the plane of its equator, and I imagine that would need to be set up a considerable distance and time advance.

I feel I am missing something really simply, but what?

[nomuse]

I dunno...I have a 6" Newtonian that is just good enough to reveal a disk on Jupiter.  That is to say...its a Gakken Mook scale model of the telescope Newton presented to the Royal Society, and the total model is less than 6" long.  Means the objective is about 1 3/8"!