As the Eagle, the Lunar Exploration Module piloted by
Neil Armstrong and Buzz Aldrin, approached the Moon,
the onboard computer "panicked," repeatedly stating
that it could not handle the data. The astronauts took
over the landing procedure.

"One small step for a man; one giant leap for mankind."

...one unexpected screw-up for a machine.

Painius wrote...

"One small step for a man; one giant leap for mankind."

...one unexpected screw-up for a machine.

Didn't Armstrong screw-up by forgetting to say the word "a" in the above quote?
("man" instead of "a man")

Pilgrims and the Mayflower Compact
http://members.aol.com/RichClark7/pilgrims.htm

Jesus' Birth (and related issues)
http://members.aol.com/RichClark7/read/birth_JC.htm

Personally, i think the boys did it on
purpose to be able to land the
Eagle themselves. Trust in computers
was not at a high level in those days.
What do you think?

You posted:

As the Eagle, the Lunar Exploration Module piloted by
Neil Armstrong and Buzz Aldrin, approached the Moon,
the onboard computer "panicked," repeatedly stating
that it could not handle the data. The astronauts took
over the landing procedure.

It did not "panic" (see the section on Apollo 11 in the Apollo Lunar Surface
Journal at http://www.hq.nasa.gov/alsj/frame.html ). It was overloaded by
incoming false data due to Armstrong switching the rendezvous radar to the
"Slew" mode. The data "overflow" consists of an unexpected flow of data
concerning radar pointing. This overloaded the computer (false warnings that
the radar's Command/Service Module tracking angle has changed) and generated
the alarms. It was not necessarily a mistake (and the machine didn't "screw
up"), but was something which in retrospect should have been looked at a
little more carefully. Clear skies to you.
--
David W. Knisely KA0CZC@navix.net
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 11th Annual NEBRASKA STAR PARTY *
* July 18-23, 2004, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************

"Richard Clark" <richclark7@aol.comedy> wrote in message...
news:20031214032205.07934.00000888@mb-m16.aol.com...

Painius wrote...

"One small step for a man; one giant leap for mankind."

...one unexpected screw-up for a machine.

Didn't Armstrong screw-up by forgetting to say the word "a" in the above
quote?
("man" instead of "a man")

That *is* the way it sounded; however, according to
Armstrong he *did* say the article, "a." It was dropped
out due to a communications problem with Earth while
he made the historic statement.

Painius wrote,

Personally, i think the boys did it on
purpose to be able to land the
Eagle themselves. Trust in computers
was not at a high level in those days.
What do you think?

Actually, there was later found to be a stowaway on board the lander, a
Señor Manuel Kontrol.<G> oc

"Painius" <starswirler@aol.com> wrote in message
news:ITWCb.453341$0v4.20944461@bgtnsc04-news.ops.worldnet.att.net...

"Richard Clark" <richclark7@aol.comedy> wrote in message...
news:20031214032205.07934.00000888@mb-m16.aol.com...

Painius wrote...

"One small step for a man; one giant leap for mankind."

...one unexpected screw-up for a machine.

Didn't Armstrong screw-up by forgetting to say the word "a" in the above
quote? ("man" instead of "a man")

That *is* the way it sounded; however, according to
Armstrong he *did* say the article, "a." It was dropped
out due to a communications problem with Earth while
he made the historic statement.

Try doing a poor impersonation of John Wayne doing it.
"for a" becomes "fora" or "fore-man"

"Painius" <starswirler@aol.com> wrote in message
news:FOTCb.452463$0v4.20930010@bgtnsc04-news.ops.worldnet.att.net...
|
| As the Eagle, the Lunar Exploration Module piloted by
| Neil Armstrong and Buzz Aldrin, approached the Moon,
| the onboard computer "panicked," repeatedly stating
| that it could not handle the data. The astronauts took
| over the landing procedure.

"Panicked" is too strong a term. A program alarm per se is not a fatal
error, although it can be. A program alarm simply alerts the crew to an
unexpected condition withing the software programs.

The AGC operating system maintained two lists of active programs. One list
contained the high-level "brainy" programs. The other was the list of
short, real-time tasks such as obtaining information from external sensors
and updating the associated variables within the computer's memory. In
order to be "real-time" (i.e., to keep up with what was happening) this list
had to be kept as short as possible and each item on the list had to be done
relatively quickly. The entire list of programs had to run in a fraction of
a second.

The side effect of the radar having been set to the wrong mode was that
data-collection programs for the radar were added to the real-time list, and
the computer wasn't able to execute the entire list in the required time.
If this situation were allowed to continue unchecked, the computer would
have fallen farther and farther behind. Fortunately the programmers had
anticipated just such an error. Every real-time program had been assigned a
priority, and the programs on the list were always run in priority order.
So when the list "overflowed", the lowest-priority tasks were skipped so
that the computer could continue to service the high-priority real-time
tasks in an appropriate manner.

The program alarm in this case was to inform the crew that the computer was
omitting some tasks. Neither Armstrong nor Aldrin knew exactly what the
error meant. Some program alarms indicated a condition that would have
required an abort, but others were merely notices. But the controllers on
the ground knew, having incorrectly called an abort when these exact program
alarms had come up in simulation. And so the controller was able to
correctly and confidently report to the crew that the 1201 and 1202 program
alarms were not a source for concern unless they were constant (indicating
that some computer task was being consistently omitted).

The crew did in fact take over manual control of the spacecraft. "Manual"
control in this case still required the use of the computer, since the hand
controller's inputs were simply signals to the low-level computer software
that a certain type of manuever was desired. The computer was responsible
for signalling the RCS control hardware to fire the correct jets and that
portion of the computer was operating perfectly. But the high-level
computer program that would have essentially landed the craft automatically
was disabled.

This was not done because of the program alarms that arose from an improper
switch setting. This was done because the landing program had relied upon
inexact data and for this and other reasons was about to dump Eagle into a
field strewn with boulders. The computer-selected landing site was
unsuitable and so it fell to the crew to select a new one.

--
|
The universe is not required to conform | Jay Windley
to the expectations of the ignorant. | webmaster @ clavius.org

This week of all weeks, the person I
think of is Orville Wright. What can
_that_ have felt like? No computers,
flying a machine you have built yourself
and as much part of it as a bird's brain
inside its body. That was the giant leap
for mankind.

"Jay Windley" <webmaster@clavius.org> wrote...
in message news:brkrlh$q7s$1@terabinaries.xmission.com...

|
The universe is not required to conform | Jay Windley
to the expectations of the ignorant. | webmaster @ clavius.org

That's some great detail, Jay! It's fortunate that they go
over the procedures over and over again, refining them
as they need to. Can you imagine how they must have
felt as the LEM steadily approached the surface of the
Moon? Man, i get goose-pimples when i think of it!

Trouble is, when you practice something over and over again, how much

In message
XMZEb.498415$0v4.21657028@bgtnsc04-news.ops.worldnet.att.net>, Painius
starswirler@aol.com> writes

That's some great detail, Jay! It's fortunate that they go
over the procedures over and over again, refining them
as they need to. Can you imagine how they must have
felt as the LEM steadily approached the surface of the
Moon? Man, i get goose-pimples when i think of it!

Trouble is, when you practice something over and over again, how much
emotion is left when you actually do it?
This week of all weeks, the person I think of is Orville Wright. What
can _that_ have felt like? No computers, flying a machine you have built
yourself and as much part of it as a bird's brain inside its body.
That was the giant leap for mankind.
--
Rabbit arithmetic - 1 plus 1 equals 10
Remove spam and invalid from address to reply.

"Richard Clark" <richclark7@aol.comedy> wrote in message...
news:20031214032205.07934.00000888@mb-m16.aol.com...
"One small step for a man; one giant leap for mankind."
...one unexpected screw-up for a machine.

[RC7] Didn't Armstrong screw-up by forgetting to say the word
"a" in the above quote?
("man" instead of "a man")

That *is* the way it sounded; however, according to
Armstrong he *did* say the article, "a." It was dropped
out due to a communications problem with Earth while
he made the historic statement.
As Neil put it, "When you think about it, it doesn't make
any sense without the 'a,' does it?"

Try doing a poor impersonation of John Wayne doing it.
"for a" becomes "fora" or "fore-man"