there’s been little progress toward creating the unfathomably long carbon fiber tether
When space elevators were first discussed, there were no materials that could possibly be used. Now we have carbon nanotubes that may be strong enough. That’s huge progress.
But yeah, the political issues will prevail. If we can’t even agree enough to build California high speed rail, think of the impossibility of a major infrastructure project several orders of magnitude bigger and more complex, several orders of magnitude more costly, and where a failure is essentially a weapon of mass destruction affecting hundreds of millions of people.
In 2003 Liftport forecast they would build the first space elevator by 2018. Since then, nobody has been able to solve the problem of catalysts gradually degrading, and other issues that limit the length of carbon nanotubes to about half a meter. So research has mostly given up on trying to make really long nanotubes tubes and is focused on weaving shorter ones together into a “yarn”. But the yarn has only 1 or 2% of the tensile strength of individual nanotubes - too weak to be a tether material.
So it’s not like there’s a steady stream of progress. The field seems to be waiting for a new revolutionary nanotube making process that avoids the original problems. Recent forecasts I’ve seen don’t expect the tech to get here until near the end of this century. With climate change becoming a more pressing issue (finally) my bet is more like well into the next century. That’s what makes me think better, cheaper rocket propulsion will come along sooner.
I liked the idea that any space elevator might be built elsewhere, such as mars. The lower gravity makes it less impossible, the lower population reduces the impact of catastrophe, and you are more likely to have space based trading and supply once you’re outside earths gravity
Very interesting idea! I never thought about a space elevator on a moon, like say Titan.
The length of the tether depends on the planet or moon’s gravity and how fast it rotates. Lower gravity and faster rotation make for a shorter tether. A Mars one would only have to be about 3/4 as long as on Earth. Unfortunately, a space elevator tether on any planet or major moon in the solar system would be tens of thousands of kilometers long - all on the same scale of difficulty in terms of materials science.
One of my assumptions is getting off earth will always be the most expensive part of any space activity. Implications are
getting bulk materials from other than earth will be critical to make it sustainable
some degree of local manufacturing and farming is vital
mining in space will never be worth returning to earth
Therefore even relatively small permanent presences in space might quickly turn to “trade”. If we can refine mineral X on the moon it may be cheaper to ship to a Europa base than for Europa to find it locally, and both be far cheaper than bringing it up from earth
When space elevators were first discussed, there were no materials that could possibly be used. Now we have carbon nanotubes that may be strong enough. That’s huge progress.
But yeah, the political issues will prevail. If we can’t even agree enough to build California high speed rail, think of the impossibility of a major infrastructure project several orders of magnitude bigger and more complex, several orders of magnitude more costly, and where a failure is essentially a weapon of mass destruction affecting hundreds of millions of people.
In 2003 Liftport forecast they would build the first space elevator by 2018. Since then, nobody has been able to solve the problem of catalysts gradually degrading, and other issues that limit the length of carbon nanotubes to about half a meter. So research has mostly given up on trying to make really long nanotubes tubes and is focused on weaving shorter ones together into a “yarn”. But the yarn has only 1 or 2% of the tensile strength of individual nanotubes - too weak to be a tether material.
So it’s not like there’s a steady stream of progress. The field seems to be waiting for a new revolutionary nanotube making process that avoids the original problems. Recent forecasts I’ve seen don’t expect the tech to get here until near the end of this century. With climate change becoming a more pressing issue (finally) my bet is more like well into the next century. That’s what makes me think better, cheaper rocket propulsion will come along sooner.
I liked the idea that any space elevator might be built elsewhere, such as mars. The lower gravity makes it less impossible, the lower population reduces the impact of catastrophe, and you are more likely to have space based trading and supply once you’re outside earths gravity
Very interesting idea! I never thought about a space elevator on a moon, like say Titan.
The length of the tether depends on the planet or moon’s gravity and how fast it rotates. Lower gravity and faster rotation make for a shorter tether. A Mars one would only have to be about 3/4 as long as on Earth. Unfortunately, a space elevator tether on any planet or major moon in the solar system would be tens of thousands of kilometers long - all on the same scale of difficulty in terms of materials science.
One of my assumptions is getting off earth will always be the most expensive part of any space activity. Implications are
Therefore even relatively small permanent presences in space might quickly turn to “trade”. If we can refine mineral X on the moon it may be cheaper to ship to a Europa base than for Europa to find it locally, and both be far cheaper than bringing it up from earth