Speed of Gravity

[rynner2]

A recent example would be the discussion on the neutral point Earth/Moon where rynner spent several days posting about the Lagrange points that had nothing whatsoever to do with the neutral point.

I very carefully distinguished between the Lagrange points and your pseudo-neutral point. But you seem to be too mathematically challenged to understand the concepts, let alone accept my results, which is why I'm wasting no more time answering your pointless questions. (But I might jump in to point out any further errors or misunderstandings you reveal! )

 

[Ghostisfort]

Is there any chance that we could have an uninterrupted discussion on the topic without subject changes, conspiracies or cut and pasted diversions about unrelated subjects?

It's not as if we haven't been through all of this?

Your math's had nothing to do with the neutral point and therefore nothing to do with the subject discussed. (Repeats the same thing over and over, but no response) The old and tired "you don't understand" is of no use because it's used so often to get those such as yourself out of awkward situations. Try something new.

My understanding of atomic clocks can be examined by all and sundry @ http://www.n-atlantis.com/atomicclock.htm
I welcome any comments on mistakes or misunderstandings by you or kamalktk. I don't think I can do more?

Quote kamalktk:
12 pages later and no response to the experiments that were going to prove aether existed, that all disproved it.

I see this sort of thing regularly on other forums. Poster makes claim, proceeds to have to back down in face of evidence otherwise and posits backup claim, repeat until poster is able to make backup claim that circles around to original claim. Poster claims victory despite losing every point of debate.

I'm afraid you're going to have to put this archaeology into context. I don't recognise it. http://www.forteantimes.com/forum/viewt ... &start=570

This was the 20-11-2011, getting on for a month ago I complained that you had missed the point and Lagrange had nothing to do with it. Now I find that you are still crowing about your math' that also had nothing to do with the topic?
The truth as I see it is that you didn't know what the neutral point was, confusing it with a Lagrange point. When you found you had been mistaken you decided to call it pseudo.
Can I take it that this paticular manoeuvre was taught to you during your scientific education?

PS I'm quite prepared to continue with the aether thread.

 

[wembley9]

Just as with the early Moon missions, the problems with Mars missions are due to gravity and a failure to land on the planet because the lander doesn't know where the planet is.

?? Can you give any examples where this has actually happened??

There are lots of hard landings on Earth, is that due to gravitational anomalies too?

 

[Ghostisfort]

Just as with the early Moon missions, the problems with Mars missions are due to gravity and a failure to land on the planet because the lander doesn't know where the planet is.

?? Can you give any examples where this has actually happened??

There are lots of hard landings on Earth, is that due to gravitational anomalies too?

If you look at the unmanned Moon landers you will find that it is landing that causes the majority of the problems.
Armstrong was forced to make a manual landing with Apollo 11 due to "computer failure". The same excuse is used several times even on Mars landings.

As someone who has used various computers and computer applications in engineering since the eighties, I've found them to be very reliable if treated with the respect due to any machine. I am aware that the state of the art was sufficiently developed to land a spacecraft at the time of Apollo and well before. (I'm told that the Russians did it with much more simple equipment.)

I'm afraid that one has to look else ware for an INPUT to the computer that would cause failure. The obvious culprit is the gravity formulas. As an engineer and not being a scientist, I would look at such things and not consider them as being sacred.

I mentioned in passing, on another thread, that Newton was not happy with his gravity conclusions and never got around to correcting them.

You see, science knows about as much about gravity as it knows about time (zilch) and yet both are crucial in modern physics.
GARBAGE IN GARBAGE OUT..??????????????? computer failure.

On Apollo 11, each time a 1201 or 1202 alarm appeared, the computer rebooted, restarted the important stuff, like steering the descent engine and running the DSKY to let the crew know what was going on, but did not restart all the erroneously-scheduled rendezvous radar jobs. The NASA guys in the MOCR knew - because MIT had extensively tested the restart capability - that the mission could go forward. http://www.hq.nasa.gov/alsj/a11/a11.1201-pa.html

The rendezvous radar was giving the computer data that did not agree with the altitude given by other means and so the computer gave an error and rebooted.
The hight above the Lunar surface was less than it should have been at this point in the mission.

Heavy landings on Earth are not caused by gravity because the formulas have been patched-up for earthly use. This is why they don't work on other worlds.
And...I think if you look at the number of landings on Earth and compare with the number of landings on other worlds, the safety of landings on Earth is outstanding. [/quote]

 

[Monstrosa]

From the same article you quoted from

So what was happening during Apollo 11, as I recall, was that repeated jobs to process rendezvous radar data (that of course were not really there) were scheduled because a misconfiguration of the radar switches.. Thus, the core sets got filled up and a 1202 alarm was generated. The 1201 that came later in the landing was because the scheduling request that caused the actual overflow was one that had requested a VAC area

No mention of gravity.

 

[Jerry_B]

Heavy landings on Earth are not caused by gravity because the formulas have been patched-up for earthly use.

Evidence please.

 

[kamalktk]

From the same article you quoted from

So what was happening during Apollo 11, as I recall, was that repeated jobs to process rendezvous radar data (that of course were not really there) were scheduled because a misconfiguration of the radar switches.. Thus, the core sets got filled up and a 1202 alarm was generated. The 1201 that came later in the landing was because the scheduling request that caused the actual overflow was one that had requested a VAC area

No mention of gravity.

Part of the conspiracy of "academic scientists" to cover things up.

 

[Ghostisfort]

Heavy landings on Earth are not caused by gravity because the formulas have been patched-up for earthly use.

Evidence please.

Here we go again:
You really don't follow these posts do you?
Not long ago I gave a link to rynner, to an Ebook by a Harvard scholar that tells the history of Newton's gravity formulas.
I even linked him to the pages concerned.
How the astronomers of Newton's day failed to plot the Moons position by their use.
He never did put them right and they have been patched-up to suit Earth gravity.
I'm certainly not looking for this again.

 

[rynner2]

You see, Jerry, it's all my fault that you keep asking for information that the omniscient Gif has already supplied! :shock:

I apologise.

 

[Ghostisfort]

From the same article you quoted from

So what was happening during Apollo 11, as I recall, was that repeated jobs to process rendezvous radar data (that of course were not really there) were scheduled because a misconfiguration of the radar switches.. Thus, the core sets got filled up and a 1202 alarm was generated. The 1201 that came later in the landing was because the scheduling request that caused the actual overflow was one that had requested a VAC area

No mention of gravity.

Part of the conspiracy of "academic scientists" to cover things up.

What academic is going to admit to a problem with gravity theory?

If you read the account of the landing, you will see that the lander was completely lost, both as regards its position on the Moon and to its height above the Moon.
The rendezvous radar was probably the only instrument that knew where it was because it was in direct contact with the command module. The rendezvous radar must have been functioning correctly or the astronauts would not have been able to dock and return to Earth.

Never A Straight Answer is not applied to NASA for no reason. They would never admit to a gravity problem because gravity is science and science can never be seen to be wrong.

Think back to missions past, good and bad. If they succeed they are a triumph for science. If they fail, they fail because of "engineering problems" never science.

 

[Ghostisfort]

You see, Jerry, it's all my fault that you keep asking for information that the omniscient Gif has already supplied! :shock:

I apologise.

I always had the feeling that the jerry chimera was two people. My only mistake (or is it a mistake?) is that I feel that one member is/was female.

 

[feen5]

Never A Straight Answer is not applied to NASA for no reason. They would never admit to a gravity problem because gravity is science and science can never be seen to be wrong.

Can you answer something for me please. If this problem with gravity exists how come they can get most missions right and in some cases spectacularly so. How come the Voyager probes didn't fly off into the void instead of preforming perfectly and rendezvousing with all of their targets.

If the same gravity equations buggered up the moon landing (as you claim) how come the Cassini Huygens probe was able to land on Titan. And the Cassini probe itself is able to position itself and move around Saturn without bumping into anything.

 

[rynner2]

Can you answer something for me please. If this problem with gravity exists how come they can get most missions right and in some cases spectacularly so. How come the Voyager probes didn't fly off into the void instead of preforming perfectly and rendezvousing with all of their targets.

Don't ask questions!

It'll be all my fault again, just you wait and see...

 

[Ghostisfort]

Self pity is so unbecoming for a king and doubly so for a chimera...

feen5 I am so honoured by your presence.

The Voyagers were not required to land on anything. An earlier poster remarked that the calculation for a Moon landing was only one percent adrift. One percent is fine for Voyager but disastrous for a lander.
Even in that case the error was around 5,000 miles or km, I can't recall. Extrapolated to the outer solar system this becomes a large figure.

However, I don't think Voyager needed such gravity calculations, just pointing them at the next target. As I understand it, spacecraft use star/s to navigate (optical navigation).

 

[Timble2]

There isn't a problem with gravity, at least not the way Ghostisfort thinks. Ghostisfort's problem with gravity is that no-one accepts Tesla's contribution to the field and it has been suppressed by THEM!

http://peswiki.com/index.php/PowerPedia ... of_Gravity

 

[rynner2]

However, I don't think Voyager needed such gravity calculations, just pointing them at the next target.

Wrong again, as usual.

The Voyagers were powered enough to reach Jupiter, and from then on they used the slingshot effect of Jupiter's gravity (a gravity assist) to reach Saturn, and then a similar process to reach Uranus and Neptune, and then on out forever, having achieved solar escape velocity. So gravity calculations were a crucial part of the mission. (At that time, the gas giants were arranged suitably for this to be attempted, so two probes were sent to take maximum advantage of the situation.)

Your comment about 'pointing them at the next target' suggests you think the probes were under power all the time. Not so - that's why they had to use gravity assists, as the probes could never have carried enough fuel for such a journey.

 

[wembley9]

As someone who has used various computers and computer applications in engineering since the eighties, I've found them to be very reliable if treated with the respect due to any machine. I am aware that the state of the art was sufficiently developed to land a spacecraft at the time of Apollo and well before. (I'm told that the Russians did it with much more simple equipment.)

People have been landing without computers at all for quite a while.
But you haven't given any reason why you think the problem is with gravity?

And, having also been using computers since the 90's, I disagree with your comment about reliability, especially if they suffer the sort of abuse that the Apollo machines did...

 

[wembley9]

What academic is going to admit to a problem with gravity theory?

I don't know what you mean by 'gravity theory' here, but I assume you're aware of how much discussion there is in physics over theories of gravity?

It's not an area where there is one theory that explains everything.

However, from an engineering point of view, they seem to have it nailed down pretty thoroughly, which is why they can do clever things like mapping subsurface features of Mars from its gravitational anomalies -
http://www.spacedaily.com/news/mars-surveyor-00d.html

 

[Monstrosa]

I have read the transcript of the Apollo 11 landing. Theree were several problems, Armstrong did not change the Rate Scale from 5 degrees per second to 25 degrees per second. There was a problem with the fuel sloshing in the tank There is the problem with the Rendezvous Radar overloading the computer. There were unforseen inputs from venting events, manouvering. When it was realised that Armstrong had failed to change the Rate Scale this reduced the time available to make corrections. Armstrong took control near the end of the landing because they were going to land in a boulder field and the decision was taken to overfly it.

 

[Anome]

What's more, Aldrin did all the calculations for deceleration burns without even an electronic calculator.

That's right, Buzz Aldrin played Lunar Lander, for real even, on a slide rule.

There really wasn't much computing power in the Apollo 11 capsule.

 

[petrosio]

Why are people responding to this ghostifort person? he is clearly winding you all up with his ridiculous theories.

 

[Ghostisfort]

102:33:03 Aldrin: Altitude light's on.

[In his excellent book, How Apollo Flew To The Moon, David Woods tells us that, when Neil arms the descent engine, two indicator lights on the DSKY come on indicating that the landing radar is not providing adequate data to calculate the LM altitude and rate of descent. Later in the descent, when they get close enough to the surface that the radar is getting good data, those lights will go out.]
102:35:28 Armstrong (onboard): Okay, what do you want? (Garbled) Let's get...Want to get rid of this radar?

102:35:37 Aldrin (onboard): Yeah.

[Fjeld - "Neil is referring to the Rendezvous Radar mode dial, which is in Auto Track and has been since he and Buzz did a post-DOI ranging test - another 'confidence builder'."]

102:35:38 Armstrong (onboard): You're Slew? Okay. (Pause)
[Fjeld - "Here, Neil puts the Rendezvous Radar mode switch in Slew - an action that leads to the Program Alarms and accompanying excitement in the landing. Because the dial is not set at LGC (computer control), once they start getting radar data, the computer will be continuously interrupted with useless (and false) 'warnings' that the radar's CSM tracking angle has changed. The computer will get overloaded five times during the descent and, later, this leads Neil to decide not use the computer for re-targeting the landing site. There was post-flight controversy about the possibility that Neil had made a mistake here, but I think the Crew Procedures Division, misunderstanding or using bad information from MIT, trained the crew that way."]

102:36:11 Armstrong (onboard): Okay, we went by the three-minute point early. We're (going to land) long.

102:36:13 Aldrin: Rate of descent looking real good. Altitude's right about on.

102:36:18 Armstrong: (To Houston) Our position checks down range show us to be a little long.

102:36:21 Duke: Roger. Copy. (Heavy Static)


...There were several interrelated navigation problems, i.e. known deficiencies in the R2 lunar (gravitational) potential model, down-track (along the flight path toward the landing site) and cross-track (left or right, perpendicular to the flight path) propagation errors (errors that start out small but become larger as the flight proceeds), and errors induced by maneuvering of the spacecraft. The principal error induced by maneuvering of the spacecraft was, however, the incomplete vent of the tunnel propagated over one orbit after separation.

[And, finally, Hamish LIndsay, author of Tracking Apollo to the Moon notes that imperfect knowledge of the effects of mascons (mass concentrations) may have also contributed. In 2006, Hamish consulted with Jerry Bostick, who served as Flight Dynamics Officer on Gene Kranz's White Team. Bostick tells us, "It's one of those things that is hard to definitely prove one way or the other, but my opinion is that it was a combination of the tunnel pressure and us not completely understanding - being able to accurately model - the mass concentrations."]

[Armstrong - "We ended up three miles long."]

...However, the downrange position marks after ignition indicated that we were long. Each one that was made indicated that we were 2 or 3 seconds long in range. (That is, they were reaching landmarks 2 or 3 seconds early. One second corresponds to about a mile of miss distance.) The fact that throttle down essentially came on time, rather than being delayed, indicated that the computer was a little bit confused at what our downrange position was. Had it known where it was, it would have throttled down later (to kill a little velocity). Landmark visibility was very good. We had no difficulty determining our position throughout all the face-down phase of powered descent. Correlating with known positions, based on the Apollo 10 pictures, was very easy and very useful."]

However, this delayed it somewhat and, consequently, we were in a slightly lower altitude at the completion of the yaw around than we had expected to be, so we were probably down to about 39,000 or 40,000 feet (altitude) at the time we had radar lockup - as opposed to about 41,500 that we expected to be."]

102:38:25 Duke: That's affirmative.

[They have switched to a data readout which shows Houston the difference between their altitude as determined by the radar and the inertial estimate provided by the PGNS.]
102:38:26 Armstrong: (With the slightest touch of urgency) Program Alarm.

[Armstrong - "I clearly must have said this, and it strikes me as that it's probably right. At least, it was true for me and I think it was for Buzz. We had gone that far and we wanted to land. We didn't want to practice aborts. So I'm sure that we were focusing our attention on doing what was required in order to complete the landing."]
http://next.nasa.gov/alsj/a11/a11.landing.html

Armstrong did eventually change the Rate Scale.
It is admitted above that the landing problem was due to gravity although they call it mascons.
The propellant slosh problem is something that must have been known about from other missions or training flights in the LM and I find it hard to believe it was a surprise. This again can be put down to underestimating the Lunar gravity. (see posts on neutral point)
As can be seen, they were navigating by landmarks with constant alarms from the computer and incorrect data from all the other instruments.

 

[Ghostisfort]

Why are people responding to this ghostifort person? he is clearly winding you all up with his ridiculous theories.

You are perfectly at liberty to believe everything NASA tells you, but it's not recommended in the mental health manual.
They have been denying UFO sightings by pilots, military and police for many years.

 

[Jerry_B]

Here we go again:
You really don't follow these posts do you?
Not long ago I gave a link to rynner, to an Ebook by a Harvard scholar that tells the history of Newton's gravity formulas.
I even linked him to the pages concerned.
How the astronomers of Newton's day failed to plot the Moons position by their use.
He never did put them right and they have been patched-up to suit Earth gravity.
I'm certainly not looking for this again.

Of course I follow them - you tend not to, which is why you consistently fail to answer questions aimed at you, especially those that rely on proof.
Your statement doesn't prove your assertion that 'Heavy landings on Earth are not caused by gravity because the formulas have been patched-up for earthly use'.

Again you are saying that your opinions are proof, rather than giving us actual proof based on reality and not your own biases.

 

[Jerry_B]

I always had the feeling that the jerry chimera was two people. My only mistake (or is it a mistake?) is that I feel that one member is/was female.

That sort of speculation will get you banned from the FTMB.

 

[kamalktk]

102:36:21 Duke: Roger. Copy. (Heavy Static)


...There were several interrelated navigation problems, i.e. known deficiencies in the R2 lunar (gravitational) potential model, down-track (along the flight path toward the landing site) and cross-track (left or right, perpendicular to the flight path) propagation errors (errors that start out small but become larger as the flight proceeds), and errors induced by maneuvering of the spacecraft. The principal error induced by maneuvering of the spacecraft was, however, the incomplete vent of the tunnel propagated over one orbit after separation.

....

[Armstrong - "We ended up three miles long."]

http://next.nasa.gov/alsj/a11/a11.landing.html

Armstrong did eventually change the Rate Scale.
It is admitted above that the landing problem was due to gravity although they call it mascons.
The propellant slosh problem is something that must have been known about from other missions or training flights in the LM and I find it hard to believe it was a surprise. This again can be put down to underestimating the Lunar gravity. (see posts on neutral point)
As can be seen, they were navigating by landmarks with constant alarms from the computer and incorrect data from all the other instruments.

What's not at all surprising is you incompletely quote things.

For instance, you left out the entirety of the bit about how they were three miles downrange because of something other than incorrectly calculated gravity. Here's the full quote:
http://next.nasa.gov/alsj/a11/a11.landing.html
----------------
102:36:21 Duke: Roger. Copy. (Heavy Static)

[In a post-mission analysis, Apollo Descent and Ascent Trajectories, Floyd Bennett notes that, at PDI, Eagle was about 3 miles farther downrange than planned, due to "small delta-V inputs to the spacecraft state in coasting flight. These inputs were from uncoupled RCS attitude maneuvers and cooling system venting not accounted for by the propagation of the predicted navigates state at PDI."]

-----------------

And here is your edit to make it seem that Armstrong was alarmed by the altitude discrepancy and blaming it on the radar

102:38:25 Duke: That's affirmative.

[They have switched to a data readout which shows Houston the difference between their altitude as determined by the radar and the inertial estimate provided by the PGNS.]
102:38:26 Armstrong: (With the slightest touch of urgency) Program Alarm.

[Armstrong - "I clearly must have said this, and it strikes me as that it's probably right. At least, it was true for me and I think it was for Buzz. We had gone that far and we wanted to land. We didn't want to practice aborts. So I'm sure that we were focusing our attention on doing what was required in order to complete the landing."]

As can be seen, they were navigating by landmarks with constant alarms from the computer and incorrect data from all the other instruments.

Versus the actual transcript where the commentary from Armstrong shows that he was incorporating the radar data. Data you say they were ignoring.
-------------------
102:38:26 Armstrong: (With the slightest touch of urgency) Program Alarm.

102:38:28 Duke: It's looking good to us. Over.

102:38:30 Armstrong: (To Houston) It's a 1202.

102:38:32 Aldrin: 1202. (Pause)

[Altitude 33,500 feet. In the 16mm film record, the lunar surface can be seen in the very bottom of Buzz's window. As indicated in Figure 5-5 in the Mission Report, the LM is pitched back about 77 degrees at this time but will start coming noticeably more upright between now and P64.]

102:38:42 Armstrong (onboard): (To Buzz) What is it? Let's incorporate (the landing radar data). (To Houston) Give us a reading on the 1202 Program Alarm.

[The 1202 program alarm is being produced by data overflow in the computer. It is not an alarm that they had seen during simulations but, as Neil explained during a post-flight press conference "In simulations we have a large number of failures and we are usually spring-loaded to the abort position. And in this case in the real flight, we are spring-loaded to the land position."]

[David Woods has provided scans of pages 15 ( 1.0Mb ) and 16 ( 1.0Mb ) from the Apollo 15 Lunar Module Cue Cards, which cover various abort scenarios. On page 16, for a return to orbit using either the descent engine (lefthand column) or the ascent engine (righthand collumn), Then Neil would check the position of the Guidance Switch and then push either the Abort button or Abort Stage button, respectively.]

[Armstrong - "I clearly must have said this, and it strikes me as that it's probably right. At least, it was true for me and I think it was for Buzz. We had gone that far and we wanted to land. We didn't want to practice aborts. So I'm sure that we were focusing our attention on doing what was required in order to complete the landing."]
--------------------------

You follow up with a post about ufo's, a further attempt at misdirection, one so out of left field it would only be suitable when one knows they've been caught out, as you have been, again.

 

[rynner2]

Gif:

It is admitted above that the landing problem was due to gravity although they call it mascons.

What was actually written has a different emphasis:

Hamish LIndsay, author of Tracking Apollo to the Moon notes that imperfect knowledge of the effects of mascons (mass concentrations) may have also contributed.

Indeed, this was a problem NASA was already working on.

At that time, one of NASA's highest priority "tiger team" projects was to explain why the Lunar Orbiter spacecraft being used to test the accuracy of Project Apollo navigation were experiencing errors in predicted position of ten times the mission specification (2 kilometers instead of 200 meters). This meant that the predicted landing areas were 100 times as large as those being carefully defined for reasons of safety.

Lunar orbital effects principally resulting from the strong gravitational perturbations of the MASCONS were ultimately revealed as the cause. William Wollenhaupt and Emil Schiesser of the NASA Manned Spacecraft Center in Houston then worked out the "fix" that was first applied to Apollo 12 and permitted its landing within 163 meters of the target, the previously-landed Surveyor 3 spacecraft.

http://en.wikipedia.org/wiki/Mass_conce ... (astronomy)

We can be sure that this "fix" simply meant understanding and compensating for mascons better, using standard gravitational theory.

There is nothing wrong with gravitational theory, but mascons introduce complexities that weren't fully understood at the time of Apollo 11.

Gif would do well to heed these wise words:
"And don't criticize
What you can't understand"

(No prizes for guessing whose words!)

 

[Anome]

GiF always seems to be selectively quoting things, and interpreting them to his own benefit, when they frequently show quite the opposite.

I wouldn't go so far as to attribute this to deliberate misrepresentation of the facts, I think he just doesn't actually understand what he reads, and leaves out the bits that confuse him.

 

[kamalktk]

For having such a "wrong' understanding of gravity, it seems highly lumpy objects that have uneven gravity, like asteroid Eros, no longer cause problems since we land on them. http://impact.arc.nasa.gov/news_detail.cfm?ID=101

Eros, shaped rather like a potato.

 

[Ghostisfort]

There are far too many posts on this subject to answer individually and so I'll touch on as many as I can in reverse order.

Asteroid Eros is approximately 34.4×11.2×11.2 km in size and gravity is not likely to have been an issue on something so small and certainly would not be responsible for a heavy landing like the ones on Mars or the Moon.
Landings without a need for gravity calculations work fine. GiF's law.

I would also like point out that the size and mass of Venus is very close to that of Earth and so landing is relatively simple using earth parameters. This is in line with my theory that gravity has been patched for Earth and does not work on other bodies.

Anome_: This post is boringly, about my not understanding something or other.

rynner2: seems to think that mascons were new to the Moon when they have been acknowledged on Earth for ages. However, they don't cause crash landings on Earth and so they need some kind of explanation. Unfortunately no one knows what they are. What I do know is that they have been used as a get-out-of-jail card by NASA ever since the disastrous unmanned missions.

We read that "William Wollenhaupt and Emil Schiesser of the NASA Manned Spacecraft Center in Houston then worked out the "fix"." But we are not told what the fix was. I'm tempted to speculate that it was a method that did away with reliance on gravity calculations.
I'll continue looking at this one.
Again the "you don't understand ad nauseum".

Jerry_B: wants proof and seems not to realise that all of science is opinion.
He's also hoping I will be banned for exposing his secret identity.
Way to go Batman!

petrosio: thinks I'm winding everyone up. The purpose is to make you think petrosio, something exorcised like an evil spirit by your science based education.

Anome: "Aldrin did all the calculations for deceleration burns without even an electronic calculator." Well that's amazing, but it's what everyone did before calculators.

Monstrosa: I think I've answered all of his points in my last post?

wembley9: seems unaware that the gravimeter measures a downward pull of gravity and it's variations. This has little or nothing to do with Newton's original formulas being incomplete and basically not working.

He asks a good question though, something not often encountered on these pages. Why I think gravity is a problem for landers.
Apollo 11 and the transcript is not the best example or the one I would choose to show that gravity downs spacecraft. I intend to rectify this by looking at the early Moon landers (crashers) on these pages, if I get the opportunity.