Launching deep space probes is great, but to really explore space and unlock its secrets, it sure would be helpful if getting there were as easy as pressing a button. That's the vision of Liftport, which Gizmag first reported on back in 2012. Now, more than two years after Liftport raised over US$100,000 on Kickstarter, the team is sharing its progress towards creating an elevator from Earth to space, a journey that – interestingly enough – begins on the Moon.
Building an Earth-to-orbit elevator is beyond tricky at the moment due to the relative abundance of gravity, weather and water around our planet. We've yet to perfect the material that could create a ribbon long enough to support an elevator that won't collapse under its own weight or run into problems with ice in the upper atmosphere.
But those challenges are significantly lessened when you attempt to do the same thing from the Moon rather than Earth. Much less gravity and a lack of a wet atmosphere make the Moon the ideal testing ground for constructing a space elevator. Which is why Liftport is currently focusing all its energy on building a lunar elevator by the end of this decade.
The plan for the lunar lift revolves around a space station called the PicoGravity Lab that will be positioned at the lunar LaGrange point – the spot in space that is exactly between the gravitational fields of the Moon and Earth. From that point, a Kevlar ribbon will be anchored to the Moon's surface via a docking port as shown in the video at the end of this post. This isn't your average ribbon, though. It will stretch 250,000 km (155,350 mi) towards Earth, where a counterweight within our planet's gravity well will help keep it taut.
Once that's all in place, an electrically-powered lifter will be able to transport samples, equipment and, eventually, perhaps people. The lifter moves up and down the ribbon between the Moon and the PicoGravity Lab, which Liftport sees as complementary to the International Space Station.
The video below put together by DSEA, Glasgow Caledonian University and shared by Liftport this week provides an overview of the infrastructure for the lunar elevator. It also provides a look at a few concept rovers that could help install and maintain the Liftport station. It also hints at another potential benefit of the lunar elevator – exploring for resources that could be studied at the attached lab and perhaps, eventually, be mined.
Source: Liftport
I don't care how light the material is, 250,000 km of anything isn't going to be a featherweight and making it in one piece with no weak points would be an engineering nightmare. I see it is expected to end in Earth's gravity well, but what about in our atmosphere? If it could extend low enough for aircraft (maybe dirigibles of some sort?) to reach, we wouldn't need an elevator on this end.
It's too bad we don't know if the moon has the materials we need to make the cable. It seems if the materials could be obtained on the moon, it would be far easier and less expensive to simply put a "factory" up there to make the cable there. Much easier to get it off of the moon's surface than the earth's. Still, I'm glad someone is actively working on this. I'd love to see this happen in my lifetime, and at 48, I'm running out of time to see such an ambitious project come to fruition.
They don't save energy costs, just spread them out, they will always be a single-point failure risk, and the cost of them and the costs of catastrophic failure in large gravity wells is far more than many other far simpler and better-tested systems, like rail-guns or laser light vaporizing propellant from the ground.
Sure they do; a rocket uses several orders of magnitude more energy to lift the same mass. It has to lift all of its fuel off the ground, 3/4th of its fuel 1/4th of the way up, half of its fuel half-way up, etc. That fuel weighs on the order of fifty times what the payload weighs. Space elevator climbers won't carry any fuel, will be powered by light.
"they will always be a single-point failure risk"
Not so, any more than a suspension bridge has a single point of failure. The elevator will consist of many interconnected strands spread out over several meters. Google hoytether.
"the cost of them and the costs of catastrophic failure in large gravity wells is far more than many other far simpler and better-tested systems"
You may be assuming the science fiction version of a space elevator, a massive construct as big around as a sequoia. In fact it will resemble a 3-foot wide sheet of saran wrap. If it breaks, that part that falls toward the Earth will either burn up in the atmosphere or flutter down like a falling sheet of newspaper.