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View Full Version : Moon Pans - cool, but...



Madalone
2005-Sep-06, 05:36 AM
After some time, I have been revisiting the Bad Astronomy site - boy, it is getting better every year, kudos! Especially the blog rocks.

Just been catching up on the blog and reading the entry of August 15th, "Moon Pans (http://www.badastronomy.com/bablog/?p=73)". Hans Nybergs panoramas are cool for sure, but directly underneath the Apollo 17 panorama (http://www.panoramas.dk/fullscreen3/f29.html) he links to www.moonmovie.com and www.thefinaltheory.com.

Outch!

Nevertheless, keep up the good work!

Madalone
2005-Sep-06, 07:04 AM
OK, meanwhile I realized that the links haven't been placed there by Hans Nyberg himself - it's "Ads by Google", but the contrast is startling nonetheless...

KingNor
2005-Sep-24, 03:39 PM
just kind of felt like commenting on that first video.

the girl states that we didn't go to the moon because of the calculations made to flight "strait" there.

i'm not terribly knowlegeable about this stuff, but to me, it seems pretty obvious that a rocket punching strait up, and then straight to the moon would have to be MUCH bigger than say.. a rocket that launches into orbit, then uses gravity and such to slingshot its speed up to escape velocity.

wasn't that what the S5 designer was talking about? you can't fly straight there, so you fly in a round about way.

Jeff Root
2005-Sep-24, 11:44 PM
i'm not terribly knowlegeable about this stuff, but to me, it
seems pretty obvious that a rocket punching strait up, and then
straight to the moon would have to be MUCH bigger than say.. a
rocket that launches into orbit, then uses gravity and such to
slingshot its speed up to escape velocity.

wasn't that what the S5 designer was talking about? you can't
fly straight there, so you fly in a round about way.
No, there's no reason a rocket can't launch directly
to the Moon, and there's no saving in going into orbit first.
The Apollo spacecraft went into orbit to be sure everything
was working okay before committing to a minimum 3-1/2 days
away from Earth. And perhaps to make the exact time of launch
less critical. The time for translunar injection from Earth
orbit could be determined much more precisely, because it
didn't involve as many uncertain factors as launch from the
ground through the atmosphere.

I think that three spacecraft have used gravitational tricks
to reach the Moon, two of which were powered by ion engines.
They slowly spiralled away from Earth, were captured by the
Moon's gravity, then slowly spiralled into lower, circular
orbits. Another was a spacecraft which wasn't originally
intended to go to the Moon, but which used the Sun's gravity
to help get it from high Earth orbit to lunar orbit.

-- Jeff, in Minneapolis

Maksutov
2005-Sep-27, 05:39 AM
just kind of felt like commenting on that first video.

the girl states that we didn't go to the moon because of the calculations made to flight "strait" there.

i'm not terribly knowlegeable about this stuff, but to me, it seems pretty obvious that a rocket punching strait up, and then straight to the moon would have to be MUCH bigger than say.. a rocket that launches into orbit, then uses gravity and such to slingshot its speed up to escape velocity.

wasn't that what the S5 designer was talking about? you can't fly straight there, so you fly in a round about way.Direct ascent and landing was one of the scenarios that Von Braun and team considered. It was going to be accomplished by a huge rocket called the Nova. Here's an article about the various designs that constituted the Nova family of launchers. (http://www.astronautix.com/lvfam/nova.htm) None of these designs was ever built.

Jeff Root
2005-Sep-27, 06:41 AM
I wrote:
> The Apollo spacecraft went into orbit to be sure everything
> was working okay before committing to a minimum 3-1/2 days
> away from Earth.

Correction: minimum six days away from Earth, pretty nearly.

-- Jeff, in Minneapolis

spaceman
2005-Sep-29, 10:30 PM
Couple of points about Sibrels intro video: 1. Back in the early 50's the efficiency of the rocket engines was no where near the awesome F1s used more than a decade later. Lower efficiency/thrust means enormous extra fuel payload. 2. The staging process is there to reduce weight overhead to increase efficiency. Taking a whole empty rocket to the moon would be a huge waste of energy and again increase the fuel payload. 3. Originally the direct ascent launch mode was considered the only feasible method, and would require *several* Saturns to build a lunar vehicle to get to the moon and back, so at least they should have acknowledged that. (Thats why the VAB is as big as it is, they were gearing up for several launches a month - imagine the cost projected before lunar orbit rendevous was agreed!!)

Overall, IMHO, the comparison is useless, and the claimed 280x inacuracies are groundless and demostrate plainly the HB unscientific approach.

+Tim+
PS: Got to see this outrageous lie, via the google ads from this sight - so its not just moonpans affected (or is that infected?)

jkmccrann
2005-Oct-26, 01:51 PM
Direct ascent and landing was one of the scenarios that Von Braun and team considered. It was going to be accomplished by a huge rocket called the Nova. Here's an article about the various designs that constituted the Nova family of launchers. (http://www.astronautix.com/lvfam/nova.htm) None of these designs was ever built.


Looking through those designs it is intriguing to note that the Saturn V, which most of us consider to be the reigning behemouth of US launch rockets, was in fact slightly dwarfed by some of these Nova designs that never in fact made it much off the drawing board. The tallest design being over 150m tall, excedding the height of the Saturn V by a good 40m.

Impressive, and slightly sad that they never came to pass really, although the cost must have been astronomical and they were never really needed I guess.

Grand_Lunar
2005-Nov-22, 08:04 PM
No, there's no reason a rocket can't launch directly
to the Moon...

I think there IS a reason.
You don't go DIRECTLY to your destination in space, but where it WILL be when you get there.
So, in Apollo, they didn't aim for the moon, but rather where it would be in 3 1/2 days.
Or am I in error here?

LurchGS
2005-Nov-24, 04:43 AM
I think he was meaning there was no thruster/acceleration reason for the Apollo missions to circle the earth a number of times for boosting to moon orbit. In this, he is correct - today. At the time, they wanted to double check all systems after launch, and re-crunch the numbers.

Today, if we had the launch vehicle, we *could* lift 'straight' to the moon.