Sunday, October 13, 2013

Which way to the Moon?

Some have said we never went to the Moon. Back when computations were done with paper and pencil, slide rule and graphs, one might have believed such stories, even if made into some sort of documentary.

Do you fall back to Earth like a ball thrown into the sky or can you reach a point where the Moon will pull you in?  You know the answer.  What about your young students?
The following problem is solved: On the way to the Moon the Apollo astronauts reached a point where the Moon's gravitational pull became stronger than the Earth's. a) Determine the distance of this point from the center of the Earth. b) What is the acceleration of Earth's due to Earth's gravitation at this point?

A look at some of what ESA has done.


rbulletin 103 — august 2000
Ways to the Moon?
R. Biesbroek
JAQAR Space Engineering, Den Haag, The Netherlands
G. Janin
Mission Analysis Section, ESA Directorate of Technical and Operational Support,
ESOC, Darmstadt, Germany

ESA has conducted several studies on missions to the Moon in recent years. The lunar trajectories for most of these missions differ substantially from those of the lunar missions flown in the 1960s and 70s. In particular, the use of shared Ariane-5 launches to reduce cost puts the spacecraft into a transfer orbit from which novel transfers and trajectories are needed to inimise the propellant required to reach lunar orbit. This has led to intensive studies of Weak Stability Boundary (WSB) transfers, which exploit the presence of low-gravity fields in which small manoeuvres can have large effects on the spacecraft’s motion. The long travel times incurred with this approach are compensated by the large reduction in propellant mass.


And since we have already mentioned AGI's STK check out this study that was done when we were planing on setting up camp on the Moon.

Mike Loucks1
, John Carrico2
, Timothy Carrico2
, Chuck Deiterich3
Space Exploration Engineering Co.687 Chinook Way, Friday Harbor WA 98250 360-378-7168 
2Analytical Graphics Inc. 220 Valley Creek Blvd. Exton, PA 19341 
3Applied Technology and Engineering. P.O. Box 476, Bertram, TX 87605 

The authors present several lunar landing trajectory strategies, including those used on the Apollo, Ranger and Surveyor programs; some planned for a commercial lunar mission; and some new techniques based on artificial intelligence. The paper describes the complete strategies for trajectory design from Earth-launch to Lunar landing. This includes a comparison between using Earth and Lunar orbit strategies versus direct ascent and direct descent methods. Closed-loop landing controls for the descent to the Lunar surface are also discussed. Each of these cases is modeled with a high-precision numerical integrator using full force models. The authors document and compare the maneuvers, fuel use, and other parameters affecting the transfer and landing trajectories. In addition, the authors discuss methods to expand the launch window. The fully integrated end-to-end trajectory ephemerides are available from the authors in electronic ASCII text by request. 

The work presented in this paper originally started in support of developing a software framework in response to the NASA Space Exploration Initiative1. In developing the software framework, it became apparent that there was not a lot of recent literature on the methods of Lunar landing. This current work is the result of investigating how Lunar landings were achieved on previous missions, and modeling these techniques with modern software. The results of modeling previous techniques with high-precision numerical integration are presented. In addition, some work has been done to use new methods, and a subset of that work is also presented. 

Earth-to-Moon Transfers 
Earth-to-Moon transfer trajectories can be described in three major phases: Leaving the Earth, transferring from the Earth to the proximity of the Moon, and approaching the Moon.

1.  NASA Space Exploration Initiative, announced at NASA Headquarters, Washington D.C., U.S. President Bush, 14 
January, 2004

Thanks for looking up with me.  
- LRK -
Why the Moon Landings Could Have Never EVER Been Faked: The Definitive Proof

This video is so good, so incredibly brilliant, solid and simple, that you will want to paste it all over your Facebooks and Twitters just to piss off all the IMBECILES who still claim that the Moon landings were faked.* The reason is simple: the technology to fake it didn't exist.