Four Attributes of a Space Transportation System With Radical Improvements in Cost

On Tuesday, 9/27/2016, Elon Musk addressed an audience of about two thousand people to outline his “Mars Colonial Transportation System” which had been in the works for years.  But more importantly, he made a compelling argument about the attributes required by any system that seeks to make a radical improvement in cost of space transportation:  Full Reusability, Refilling in Orbit, Propellant Production On Mars, and Right Propellant.

Full reusablity is a must in any system that has high capital costs.  Everything from bicycles to air travel would be cost prohibitive without re-usability.  Can you imagine if every time you rode your $100 bike some place you had to build a new one?  How many bike trips could you take?  Air travel is even a better example.  When you ride a Boeing 737 some place, you are riding a $90M piece of equipment.  It holds about 180 people, which means that the cost would be $500,000 per person if it was not re-usable.  But right now you can use that plane from LA to Las Vegas for only $43 per person.  That is because the fuel only costs $10 per person.  And the plane can be use with very little maintenance on trip after trip after trip.  Full reusability is key to reducing the costs of space travel..

Refilling in orbit means that the space craft that goes to Mars can be launched with nearly empty tanks and then multiple filling trips can be made to fill the tanks.  This reduces the size of the system and allows for the materials required to go to Mars to be split across multiple launches.

Being able to produce propellant on Mars (or at other destinations) is key to reducing the cost.  It takes fuel to carry the fuel to return.  Being able to produce fuel at Mars, and use that fuel to get the space craft back to earth will be key.

In order to produce fuel on Mars, you need to make sure that you are using the right propellant.  The F9 rocket uses kerosene which is produced from oil.  And as best we know, there is no oil on Mars.  But methane is another choice.  Methane can be produced with CO2 and H2.  And since the atmosphere of Mars is 97% carbon dioxide and there is significant amounts of water ice, which can be broken into H2 and O2 using electrolysis, it would be possible to produce methane on Mars.  SpaceX has also developed and recently tested the Raptor engine which is a methane burning rocket.

With the four characteristics of Full Reusability, Refilling in Orbit, Propellant Production On Mars, and Right Propellant, it would be possible to reduce the cost of space travel to a level that would open up the solar system to more exploration and colonization.

Art of Effective Delegation

Last week I attended a company workshop which had one hour dedicated to time management and effective delegation.  There are many directions to delegate: Up, Down, and Sideways.  Delegate UP when you need more support.  Delegate sideways when others provide a service that is dependable and more efficient than doing it on your own.  Or when people in your team have availability and can help you to complete the job quicker.  Delegate down when you have direct reports and you can set their priorities and focus.

There are many risks with delegation.  There is an overhead to delegation.  The efficiency provided by delegation needs to be greater than this overhead.  Otherwise there is a near term increase in the total effort required.  (There is the potential that by delegating now with an eye to delegating in the future that this overhead will be reduced.)  There is also a risk about commitment.  Unless the person that you are delegating too is a direct report, it may be difficult to hold them to their commitments.  There is also a risk that they will be given work from their reporting chain that preempts the work that you had delegated to them.  Also there is an implicit assumption that they will be able to delegate back to you.  Will you be able to reciprocate?

What is included in the overhead with the delegation?  And how can this overhead be reduced?  In any situation, there is information required to perform a task.  This information may be “tribal knowledge” and is assumed as known to all that work on a project and is not documented in a way to bring others up to speed.  There are situations where the knowledge is documented, but it would require a significant amount of time to review the requisite documentation to be able to perform the task.  This overhead can be reduced by ensuring that knowledge is capture in consistent way in the organization that optimizes the location of the critical pieces needed to perform a given task.  Also, finding task units and activities that are common through out the organization can help to reduce the overhead of delegating a task.

How is efficiency achieved to offset the overhead of the delegation?  In the situation where everyone is similarly skilled, it only makes sense to delegate tasks based upon the availability of the people involved where the overhead is extremely low.  However, in most cases, the group will be made up of people with different skills, experiences, and inclinations.  It is quite possible that a given task could be performed more than twice as fast by someone else because they have a more efficient way of approaching the problem.  In this case, the ability to delegate can reduce the over all work in a group.  But it is necessary to have some mechanism to identify who is better skilled in a particular area and who has a desire to do a particular type of task.

Delegation can allow a group to get more done only if approached correctly.  Otherwise it might increase the risk and the effort required to perform the same amount of work.

New Ultralearning Project: Can You Learn to Draw Realistic Portraits in One Month?

New Ultralearning Project: Can You Learn to Draw Realistic Portraits in One Month?




Drawing on the Right Side of the Brain



Cristina Gatti

Cristina Gatti is a singer with Post Modern Jukebox.   Here are links to some of her songs.

Continue reading

1-Day Project: Arduino and nRF24L01+ Data Transceiver


MRF24J40 connection to Arduino



Pin mapping:

MRF Arduino
INTR 4 2 Interrupt 0
SCK 6 13 SCK
CS 8 7
VIN 10 3V3

Dad Joke Survivors

Nickelodeon Australia put together a public service announcement (PSA) in honor of father’s day.  The premise is that dads all over the world are telling poor, barely humorous jokes to their children.  It is having an effect.  It is no laughing matter.  Definitely worth watching.

CodeForces gives you programming problems and contests.  You can choose to solve them in many different languages including Python.

Once you get an account, go to problem sets and sort by solved from “highest to lowest”.  This will give you the easiest problems first.

I have made just a little progress.  But I am hoping to do this on a daily basis.  You can see my progress:

If you sign up for an account, leave your user name in a comment.

CodingBat, CloudCoder,, CodeMirror, and


CodingBat is a free site of live coding problems to build coding skill in Java, and now in Python (example problem), created by Nick Parlante who is computer science lecturer at Stanford. The coding problems give immediate feedback, so it’s an opportunity to practice and solidify understanding of the concepts. The problems could be used as homework, or for self-study practice, or in a lab, or as live lecture examples. The problems, all listed off theCodingBat home, have low overhead: short problem statements (like an exam) and immediate feedback in the browser. The idea for CodingBat came from my experience teaching CS at Stanford combined with seeing how student’s used unit-tests in more advanced courses, and crystalized when I saw an Owen Astrachan demo of a unit-testing thing he uses with his Duke students.

It is idea.  There are a few drawbacks.  The coding editor does not capture “tab” characters which is a real killer in Python where indention is nearly as common as “;” is in Java or C#.  The problems are great to get started.  Each problem essentially tells you to write a subroutine (def) and then it runs a set of unit tests on it.  It does allow for you to create your own problems.  But the editor to do this does not look to inviting.



CloudCoder is an open source web-based programming exercise system (inspired by CodingBat). It is designed to make it easy for instructors of introductory programming courses to assign short exercises to students for skills development and assessment. Currently, exercises in C/C++, Java, Python, and Ruby are supported.

Because CloudCoder is web-based, it is easy for students to use. The only software students need to work on exercises is a web browser.

It is opensource and written in Java, and it is hosted on GitHub:

PythonTutor Visualization

Online Python Tutor is a free educational tool created by Philip Guo that helps people overcome a fundamental barrier to learning programming: understanding what happens as the computer executes each line of a program’s source code.

Using this tool, you can write Python, Java, JavaScript, TypeScript, and Ruby programs in your Web browser and visualize what the computer is doing step-by-step as it executes those programs.

Their visualization component can be embedded in a website using an iFrame and the code is passed in URLEncoded to the source.    This allows for the student to step through the code line by line.  They see what is in memory, the input and the output.  It can be a great way for students to explore their code.  And it seems like a natural extension to the CloudCoder and CodeBat sites.


Trinket lets you run and write code in any browser, on any device.

Trinkets work instantly, with no need to log in, download plugins, or install software.

Easily share or embed the code with your changes when you’re done.


Skulpt is an entirely in-browser implementation of Python.

No preprocessing, plugins, or server-side support required, just write Python and reload.


CodeMirror is a versatile text editor implemented in JavaScript for the browser. It is specialized for editing code, and comes with a number of language modes and addonsthat implement more advanced editing functionality.

A rich programming API and a CSS theming system are available for customizing CodeMirror to fit your application, and extending it with new functionality.

The Idea

A few of my friends and their children meet up on Sundays to review MathCounts and now we have added a program/electronics/robotics section which we have started out by doing Python.  These are middle school kids.  Their ability to control their attention span is limited.  Don’t misunderstand me.  They have long and focused attention spans.  But only for things that capture their interest (like Brawl on the Nintendo or Type Racer or some other game).  Our Python training on the first day did not fall into that category.  So after a few hours of math in the morning, the Python training essentially put them to sleep.

But they love Type Racer.  Which has me on the quest to bring the same focus, interest, and experience to our Python classes.  More on that later..

LilyPond = LaTex for Music!!

LaTeX is used to format math and science papers.  It is a markup language (similar to what HTML is for the web).

LilyPond ( is a markup language for writing musical scores.




Fescobaldi ( a Python program that makes it easy to write the LilyPond code and see the resulting script.