The 2011 Space Elevator Conference

It is that time of the year again.  Over the course of this weekend (Aug 12 - 14), space elevator enthusiasts will gather in Redmond, Washington to present new research on what may well be the most exciting engineering project of the 21st century.  Those with little or no knowledge about the space elevator may wish to check out my space elevator page (link above) before reading on.

The space elevator topic is the focus of three annual conferences; the two other conferences are held in Japan and Europe, respectively, while this weekend's event is the North American edition.  I had the opportunity to attend and speak at the 2009 Space Elevator Conference, and have kept in contact with the small but growing space elevator community in North America.

Although I will not be attending the conference this year, I am on the judging panel for the Pearson and Artsutanov prizes, which are awarded to the best papers.  This year, the theme for these papers is research that will lead towards a material suitable for the construction of the space elevator ribbon.  The material challenge remains the most daunting technological one for the overall project.  In a way, this is a very good thing, because it is not an isolated challenge - stronger and lighter materials are being developed continuously for non-space related use as well.

The entity that organizes the Space Elevator Conference in North America is called ISEC (International Space Elevator Consortium).  ISEC seeks to aid in making the space elevator a reality sooner than later, and has taken a bold step this year by creating the journal, Climb: it is the first scientific journal specific to the space elevator topic.  The journal will help to centralize the state of the art for the space elevator project, and will be particularly important for space elevator academics that cannot attend the conferences.  Those interested in the space elevator project should consider joining ISEC, as the very reasonable membership fee includes a copy of Climb.

For those attending the conference this year, I hope that you enjoy it.  The space elevator project needs a community, and the conference helps to grow and strengthen it.  For more information regarding this weekend's conference, please click on this link.

The Space Elevator

There are two main reasons why, for the past sixty years, man has launched rockets from the surface of the Earth. 

The first reason is to place satellites into an orbit around our planet.  The moon is a Celestial body that orbits the Earth in an elliptical fashion at an average of about 380,000 km away from the Earth.  Other than this large body and other small space debris that orbit the Earth, all other bodies that do so were placed in their respective orbits by man to serve some purpose.  One can think of an orbit as a path that a falling object takes continuously around a larger body.  Much in the way that a baseball’s path curves to fall towards the Earth once it is thrown, an orbit is in a perpetual state of falling.  The difference is that the orbiting body is moving much faster than the baseball (think kilometres per second), and the baseball faces the resistance of air, whereas the drag forces in space are negligible. 

It boggles the mind, but we (and when I say we, I mean America and Russia) have transported thousands of satellites into space.  Most satellites are used for communication, be it internet, phone, or television, while some are used for Earth observation leading to weather prediction, the tracking of oil spills, and the marvel that is Google Earth.  Most satellites are located hundreds of kilometres above the surface of the Earth (note that an airplane’s altitude rarely exceeds 12 km) in an area known as LEO (Low Earth Orbit).  

Another popular zone is at the GEO (Geosynchronous) altitude of about 35,800 km altitude; this is a special altitude for which the orbital period of a satellite is the same as that of the Earth.  If one were to stand on the equator and stare up at an equatorial GEO satellite, one would observe no motion at all.  It would be as though the satellite were attached to the Earth by an invisible cord.  The typical operational life of a satellite is fifteen years.  As such, the majority of satellites currently in orbit are decommissioned and commonly referred to as space junk.

The other reason for which man sends payloads to space via rockets is for interplanetary travel.  Such ventures are done in the name of research, observation, exploration, and discovery.  Sometimes these payloads contain astronauts, as in some trips to the moon, but often these are unmanned missions, or probes, investigating, for example, Mars or Saturn’s moons.  The missions are very exciting, sometimes providing answers to important scientific questions, other times demonstrating what we can achieve when we put our minds to it; the 1969 moon landing was perhaps the defining moment, technologically speaking, of the twentieth century. 

An even more formidable task would be sending man on a return trip to Mars.  The greater distance to Mars as well as the greater Martian escape velocity means that the payload leaving the Earth would be much more massive than that for Apollo 11.  Also, the trip length (years instead of days) would make the challenge for the astronauts far greater.  However, it is the issue of the large mass which makes the Mars mission unrealistic today.  Transporting mass away from the Earth using rockets is prohibitively expensive.  The cost for satellite placement in GEO is in the area of $10,000 US per kilogram of payload; it is substantially greater for interplanetary travel. 

In today’s space industry, every gram is questioned.  In order for a payload to achieve the escape velocity required for interplanetary travel, over 90% of the mass leaving the Earth must consist of fuel; this is a chemical constraint associated with rocket travel.  For this reason and others, the rocket will probably not be the principal mode of travel used to escape the Earth’s gravity fifty years from now.  

The most promising upgrade from the conventional rocket appears to be the space elevator, which could reduce the cost to GEO to as low as one hundred or even ten dollars per kg (reducing satellite placement costs by at least a factor of one hundred).  An operational space elevator, which would carry no fuel, would open up space to mankind; it would bridge the gap between us and the vastness we see when we stare up at night, both figuratively and literally.