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This topic is created for our new member, HG Muller.
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Hi everyone!
Let me introduce myself:
I am a retired Dutch physicist, and have been interested in space travel since I was in highschool. I even applied for a job as astronaut once (and was swiftly rejected...), because I fitted the profile for flying as a mission scientist in the shuttle spacelab. (But that was before I learned these things could explode!) I worked until 2008 as a researcher in the government-funded laboratory for Atomic and Molecular Physics, studying interaction of atoms with super-intense and ultra-fast light pulses, after which I took an early retirement to spend more time on my (other) hobbies. Since then I spent most of my time developing software for playing various forms of chess, and genealogical research.
I noticed that youtube is recently flooded by AI slop claiming that return trips to Mars would be impossible, largely based on flawed arguments, in particular w.r.t. required velocities. This annoyed me, so I was looking for more serious discussions on the subject. An inetrnet search on the terms "mars forum" then brought me to this place. I have some ideas for lowering the effort required for space exploration, and would like to share those with knowledgeable persons, hence I applied for registeration here.
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Welcome to the forums, HG Muller!
I think you have encountered Tahanson43206, and there are a few others of us on these forums. I am an old retired defense industry development engineer, and a retired teacher. I got started in the slide rule days, and was interested in spaceflight long bore anybody went up there. Never actually worked for NASA, though. When I was young, the X-15 replaced the X-1 and the D-558-2, just about the same time as NASA was founded from the old NACA. I well remember the hoopla when Sputnik first went up.
Most of my industrial work was in air-launched missiles and the countermeasures that defeat them. But you might remember the LTV "Scout" satellite launcher. It was a 4-stage solid that could put small (by today's standards) satellites into orbit. I got to work on advanced configurations for it at LTV one summer as a graduate student. About that same time, I learned the old Allen & Eggers simplified by-hand analysis for entry dynamics and heating. Did my MS in a hypersonic wind tunnel working on Shuttle nose shapes before that design "gelled". What we grad students found, about the AOA limits on shuttle entry, was later verified at the AEDC facility in Tennessee.
Anyhow, welcome!
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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For HG Muller re post in Engineering tools forum ....
Thank you for your many interesting and helpful posts!
In general, the members of this forum ignore the topic and write whatever they feel like.
The Tools forum was created in a Category that is hidden from public view.
GW Johnson created a topic about a specific set of tools. You have the opportunity to open the tool box and see if you can understand how to use the set. No one else appears to have the time, or perhaps the interest, or perhaps even the ability to use the tools GW Johnson has created.
Your post is more or less a free form essay on the general theme of orbits and interaction with an atmosphere.
Please go back and see if you can understand the tool set, and perhaps even use it effectively.
I am confident GW Johnson would respond favorably to feedback you might be able to provide on the accuracy of the tool set or the ease of use for persons with varying backgrounds.
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I posted it in the tools topic because GW's announcement of the posting there mentioned that his tools did not calculate the flight path through the atmosphere, but expected it as an input that the user would have to supply (in the form of an angle). So it would be of interest to potential users of the tool to know how to calculate that angle, and what a typical value would be.
I will have a look at the tools. We have Excell only on my wife's computer, though, and my only remaining laptop that could run Linux (in a virtual machine) has a broken keyboard. Things degrade fast when you have no time to remedy them... :-(
Last edited by HG Muller (2026-10-20 11:16:16)
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For HG Muller ... there is a way to post equations in this forum...
We offer an image server that can hold images up to 256 kb. Here are a couple of many examples:
It helps to explain mathematical thinking if the correct display format is available.
This post shows an image created by GW Johnson:
https://newmars.com/forums/viewtopic.ph … 51#p240051
and this post shows an image created by ChatGPT under my direction.
https://newmars.com/forums/viewtopic.ph … 74#p240674
There are many image servers and you may well have your own preferred service.
If you would like to use ours I'd be happy to create an account for you.
Images need to be entered as Left Bracket img Right Bracket (URL of image) Left Bracket /img Right Bracket]
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For HG Muller ...
GMAT is a software sponsored by NASA and available to the public.
I investigated it and learned that it depends upon MATLAB.
I hesitated to pay for a license for MATLAB because at time there was no one in the forum able and willing to help me figure out how to use it.
You are certainly capable. However, your time may well be limited.
You also may have to update your computer hardware, and that may be low priority as you work on your "new" home.
Never-the-less, the offer is "out there"
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I never used MATLAB. When I want to calculate something I just write a program in a simple programming language, usually C. In the past years I also got some experience with JavaScript, for web applications.
I am usually not to keen on using software written by others anyway; it often takes me more time to learn how to use it than it would have taken me to write something myself that does the one thing I want to do. And very often it doesn't do exactly what you want to do anyway. And I hate to use software that I cannot change.
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Welcome to the forum Dr Muller. You clearly have a lot of technical knowledge and you have brought a lot of discussions back to life. I look forward to working with you.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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For HG Muller!
It appears that your idea of replacing MATLAB with Python was actually done by volunteers supporting the open source GMAT package.
I learned today that the MATLAB structure has been duplicated in an open source equivalent called "Octave" but (more importantly) someone has apparently duplicated all the MATLAB functions in Python.
If you are curious, here is a post that summarizes the news!
https://newmars.com/forums/viewtopic.ph … 86#p242286
So! Congratulations on having anticipated how things would go!
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I haven't had time to look into this yet, so I am not sure what orbital calculations this software does. But it gave me an idea:
Wouldn't it be great if there were on-line tools associated with this forum that people could use directly by just going to a web page and putting some numbers into a form? Solving Newton's equation of motion for a several-body problem numerically isn't a very taxing task with modern computer technology. A typical smartphone is now more powerful than the world's largest supercomputer I could use for my calculatons at the start of this century, and finite-element methods can use such small time steps that even very simplistic numerical methods can produce converged results.
I have made web applets using the JavaScript programming language (which runs on the computer of the people visiting those web pages) in connection with calculation-intensive chess questions. E.g. for demonstrating how one should win an end-game with almost arbitrary unorthodox chess pieces ( https://www.chessvariants.com/page/MScheckmating-applet ), or to allow people to play chess variants of their own design against an AI ( https://www.chessvariants.com/page/MSpl … s-variants ).
I am sure I could make something in the same spirit for calculations on orbital mechanics or the rocket equation. If I did that, would it be technically possible to host these pages on the website, in a way that makes them easily accessible from the forum?
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For HG Muller...
The forum does not support the kind of service you described in Post #11, but you can link from here to any web site.
Almost everything you can imagine has been programmed and is available online. Just ask Google and chances are good that it can find multiple sites that do what you might want to do.
GMAT is in a different category. You run that on your personal Linux box, and it allows you to calculate entire missions.
There are YouTube videos that explain how to use the system.
I learned today that in the years since I first looked at the system, volunteers have added alternatives to MATLAB including Python code.
Everything is downloadable and open source, so you can study every component.
I'm hoping we can create an environment here where serious students or actual practitioners (space mission designers) might be willing to bring some of the rest of us along.
I posted the File Tree of the unpacked system You you can see all the files and if you want to look at the code you can download the system and unpack it.
The room required is on the order of 400 Mb.
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Well, even standard forum software can often be made to do more that you would expect, through plugin modules. Look for instance at https://talkchess.com/viewtopic.php?t=46462&start=1 , where postings can contain images of chess positions that are generated on-the-fly from a text line, or game records where you can step through the game interactively using buttons. And you wrote me that you guys 'owned' the forum software, so what the forum can and cannot do is basically up to you.
But I was not thinking about integrating something into the forum; what I had in mind was hosting some web pages with interactive content on the server. I don't know what dgital infrastructure you are running on (e.g. VPS, shared web space, ...), but the welcome page on newmars.com does look like a page that lives outside the forum database.
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For HG Muller re Post #13
Thank you for bringing your experience and perspective to the forum!
It may be time to review a bit of history, and to (at least try) to explain how the human side of the system works right now.
I don't know ** all ** the history.
Senior Moderator RobertDyck has been here longer than anyone else.
Senior Administrator SpaceNut hjas been here almost as long.
This forum was created independently of the Mars Society, but then picked up (ie, paid for) by the Mars Society
That happened on the order of 25 years ago. The forum has been upgraded and converted multiple times.
For many years, the gent who is now the Executive Director of the Mars Society was our Webmaster.
After Mr. Burk took on the Executive Director role he turned over the keys to kbd512, and kbd512 supervised an upgrade of our software from 2012 to 2024 standards.
This web site has been subject to hacker/spammer attacks all along, but the tempo increased to a ridiculous level after I arrived.
SpaceNut made the decision to block automated registration, and I spent a couple of years cleaning up the mess. All the spammer accounts were converted to usable accounts.
Recently, a spammer gained access to the WordPress front end, and Mr. Burk replaced the front end with the html you see now.
He also changed passwords, and that included NOT telling kbd512 what the new passwords are, so kbd512 is no longer able to serve as webmaster.
Meanwhile, the Mars Society has been preparing for the annual Convention that is currently underway. You can see news about the Convention at the Mars Society web site marssociety.org. What this means in practical terms is that Mr. Burk is not available. We are pretty far down the totem pole right now.
We have an image server configured in phpBB3 that sits on the server next to newmars.com, but Mr. Burk did not provide that system with the password it needs to access the MySQL database so we do not have that system available right now.
We have a phpBB3 lifeboat system that runs on Azure, which is available for members in case the main site goes down. I presume every legitimate web site is under constant attack by hackers and spammers, and the Mars Society sites have taken their share of abuse. Our lifeboat is behind Cloudflare protection, so very few spammers gain access. You can see the daily count of spammer activity if you look at the Index at the bottom. You will see a count of "guests". Those are almost entirely spammers. We have seen counts over 1000 unique IP addresses pounding at our system.
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For HG Muller re Internal Server errors...
SpaceNut thinks this issue may have to do with fragmentation of the data base.
We have no chance of anyone working on anything until after the Convention.
I just used the code parameter to solve an Internal Server error...
I enclosed the offending text inside Left Bracket code Right Bracket and the corresponding closing.sequence.
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I understand the forum is in dire straits. But just for my understanding: the forum software used is a phpBB version? I run a phpBB3 forum on talkchess.com (which currently seems to suffer from DDoS attack, but I had no time to look into that yet). I think that 3 passwords are involved in this: for the MySQL database, for the forum administrator, and to log in as a Linux user on the server.
Are all these passwords lost? Did you ever have the password for the server? If the Mars Society hosts it, I can imagine they use their own server where they also have activity not concerning us. And that they likely have their own webmaster for that stuff. Who then must have a password of his own, and perhaps even super-user access to the server. Or is the Mars Society as poorly off as we are?
What happened to Mr. Burk? Did he die or disappear? Should he be considered an adversary?
Last edited by HG Muller (Yesterday 11:55:47)
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For HG Muller re Post #16
James Burke is the Executive Director of the Mars Society. I put that information in my post but you missed it somehow.
Mr. Burke pays our bills.
Please consider using respectful language.
We were attacked and Mr. Burke took charge since were were unable to solve the problem.
In taking charge, Mr. Burke made the decision to remove us from control of the forum.
SpaceNut is the Senior Administrator.
It would be up to SpaceNut to persuade Mr. Burk to trust us with the keys to the forum again.
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Sure, I got that, and no disrespect meant. I just wondered how a situation could arise where access was lost. But I gather that we are under probation.
But in that case there is no reason why we couldn't work out some solution with Mr. Burk for doing some necessary maintenance and other improvements to the forum in some way.
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For RG Muller re #18
Thank you for recognizing the sensitivity of our situation. Mr. Burk is fully engaged in supervising the 2026 Mars Society Convention. We are in the same category as chapters right now, far from the focus of attention.
We are hoping that after the Convention and after the heavy work of post-convention activity is over, we might be able to win a few minutes of Mr. Burk's time.
We have a PHP file that SpaceNut designed and which I tweaked that will report (recapitulate) the daily posts. You can see what this looks like if you call up the Daily Recap topic. I am particularly interested in seeing that service in operation now that we have reached 80+ posts each day. Our Webmaster could easily have installed that, but due to the hacker attack, we are (as you put it) "on probation".
You are welcome to continue adding suggestions in Housekeeping.
SpaceNut doesn't necessarily respond to everything there but I read everything there and will respond if appropriate.
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