Thursday, October 2, 2014

IAC 2014 - Day 4: My Presentation

Today, I give my presentation about the static deformation of the space elevator tether due to the presence of a climber.  I have decided to open the talk with a picture of the CN tower.  You see, its been a foggy week of weather in Toronto, and I have taken some time to stare up at the tower from its base.  The top of the tower disappears into the fog - no end in sight.  The sight appeals to me for obvious reasons, so I have to mention it to the other space elevator aficionados in attendance.  Imagine a time, decades from now, when there will be no end in sight to such a structure, even on the clearest day.

I present a summary of my most recent research.  One of the most surprising things is that this fundamental mechanical analysis had not been documented yet.  You station a climber at some location on the tether, and what will the new equilibrium state of the tether be?  Will it stretch more or less and in what locations?  What are the changes in stress and tension throughout the tether?

The results are as follows:

  • If a climber is stationed below GEO, the tension in the tether below it is reduced, and there is a decrease in extension - if the climber is above GEO, the tension below the climber is increased, and there is an increase in extension.  In either case, the portion of tether beyond the climber displaces up or down as a unit, by tens of kilometers.
  • A decrease in tension is a concern because if it disappears altogether, there can be no equilibrium; the tether is no longer taught.  This places a limit on the climber's mass.
  • An increase in tension means an increase in stress, which must be accounted for when sizing the tether and climber.
My talk is well-received, as are the seven others involving space elevators.  The fifty or so in attendance are interested.  I actually met a student from Montreal who has recently completed a Masters Degree at the International Space University in France.  He is now returning home to find work, as well as dabble in space elevator research.

The day is filled with meetings within the space elevator arena.  First, the kick-off meeting for a new study group entitled: "Road to the Space Elevator Era".  The group consists of about twenty experts in the field.  I am a member of the tether systems and dynamics subgroup.  An ambitious research plan for the coming three years is outlined.

Later, there is a research meeting where various possible topics are thrown around.  I have recently begun working with a couple of students from Vanier College, and I intend to run some of these ideas by them.

When my talk and meetings are through, I get on a shuttle to a nearby airport and fly home.  It is the closest to being a "Rock Star" that someone in my line of work gets.

No comments: