Space Elevators Are Less Sci-Fi Than You Think

I think space elevators will be a reality in the next two or three decades. The idea of a cable stretching from Earth to space is something I keep coming back to. New ways to tinker with designs and answer questions about how space elevators work have been found by me and other researchers.

There are a lot of reasons to build an elevator. It is obvious that the major energy and cost savings are the ones that matter the most. accessibility is one of the reasons that is overlooked. As trips to space become routine and mostly independent of weather conditions, the word'space mission' would be replaced by 'transit'. Current practices require astronauts to accept a nonnegligible risk to their lives with each launch in order to be safe. The entire solar system is bridged by a space elevator. If you want to go around Earth but not the sun, you need to release a payload in the lower portion.

I enjoy studying the mechanics of space elevators, even though I may come across as an advocate. I can imagine a scenario where we have become responsible custodians on this planet if I were to dream of such a project.

In 2004, when I was a master's degree student, I sat in the office of Professor Misra, hoping he would help me finish my thesis. I was a little intimidated by the fact that Misra was the leading space expert at the university. The conversation was similar to this.

What kind of research would you like to do?

Do you know of a space elevator?

I don't think so. Which is it?

Imagine a 100,000-kilometer-long cable that goes up from the equator and ends at a satellite. The system moves along with the earth. Climbers can scale the cable and release their cargo. You could study the dynamics of this system.

That sounds very difficult.

Misra: Your work will not be hard. Building an actual space elevator here on Earth….
That will be hard.

It's a few years ago. The Dynamics of a Space Elevator is a thesis I wrote for my master's degree. I work in satellite design. Colin and I were introduced to one another as the space elevator guy. My wife didn't like what she saw. Colin was told how a space elevator works.

If you stood on the equator and stared up at a satellite, it would appear fixed in space because of its speed. The satellite drops a cable to Earth and uses fuel to go up. The system still rotates along with the Earth even though the cable is fastened on the Earth end. The cable becomes the track for mechanical climbers to scale and deliver cargo to space.

Colin wondered what kept the cable taut.

The effects of gravity and scuplture compete with one another and vary along the length of the cable The effects of gravity are beyond the reach of the earth's magnetic field. The result is tension and a maximum amount at the same time.

Colin said it was Friday night. Don't use a lot of words.

We need a material that's 50 times stronger than steel. While we wait, I and a few other people in the world are pretending that this problem will be solved and that we will be able to use space elevators again.

Colin: Well, I'm not sure.

We crossed paths with Colin again. He wanted to know how the space elevator was going. My wife said, "please, no."

Colin doesn't understand why the whole cable isn't pulled down when a climber is on it.

The tension profile along the cable can change if a climber is located below the earth. The real problem is that the portion of cable between the climber and the Earth experiences a drop in tension. The structure would lose its stability if the tension dropped to zero. A climber with a maximum mass of 1 percent of the total cable mass is a good one. The cable is expected to be hundreds of tons.

Colin is wondering how the cable material is coming together.

My thing is not that.

Colin said to get on it.

It's now 22 years away. A few weeks ago, I presented a summary of my work on space elevators in a seminar at Vanier College. The Q&A portion starts after the talk is over.

The student wants to know when the material will be ready.

The synthesis of potentially suitable materials has progressed in recent years, but we are still at least 10 years away from a material solution that can be manufactured quickly at a reasonable cost. It is not unusual for new technologies to be waiting for better material science.

Student 2: I think it's cool. Why should it be built?

When you think about it, rockets are ridiculous. Up to 90 percent of the total mass on the launchpad is fuel for a space mission. It is similar to being in a car with no motor, just a pressurized 100,000 liter fuel tank. This method of escaping Earth's gravity is inefficient and needs to be replaced with a better alternative.

Humans will go to Mars before the year 2040. For this to be a sustainable endeavor, we will need an infrastructure like a space elevator, and better sooner than later.

Student asked when one would be built.

The author of The Fountains of Paradise was asked this question in the 1990s. He said it would take about 50 years for everyone to stop laughing. When Musk takes credit for it, we will know we are close.

I feel like I did as I sat nervously in his office, I now call him that, and it will always be strange. It fills me with hope because it captures my imagination.

The views expressed by the author or authors are not necessarily those ofScientific American.