Researchers are reporting a significant breakthrough in developing a material that could make the construction of a space elevator a reality. The International Space Elevator Consortium (ISEC) is set to announce next month that polycrystalline graphene is their most promising candidate yet for the ultra-strong, lightweight tether required for such a structure.
A space elevator is envisioned as an electrified cable stretching from Earth's equator into space, beyond geostationary orbit, with a counterweight to keep it taut. Vessels would travel along the cable, powered by electricity, to deliver cargo and potentially humans into orbit. Proponents argue this method would be significantly more efficient, cleaner, and cheaper than current rocket technology.
"We're really pushing for permanent infrastructure, like a bridge replacing ferries to cross a river," said Pete Swan, president of ISEC. "The beauty is that, raising it with electricity saves our atmosphere from pollution, it doesn't leave any debris along the way and it will be routine, daily, inexpensive, safe. It's gonna be a bridge to space."
The primary challenge for space elevators has always been the tether material. It needs to be exceptionally strong—reportedly 100 times stronger than steel—lightweight, and capable of being spooled efficiently for deployment. Graphene, a material derived from carbon atoms arranged in a crystal lattice, has long been considered an ideal candidate due to its inherent strength.
The development of polycrystalline graphene, which involves a patching process to make the material more scalable, appears to be the crucial step. Researchers noted that this material is already used in consumer electronics and is known for its exceptional strength, with some applications involving bulletproof vests. Engineers in South Korea have reportedly manufactured a 1,000-meter long polycrystalline graphene molecule and are producing it at a rate of about two meters per minute.
This advancement brings the long-held concept, popularized by science fiction writer Arthur C. Clarke in his 1979 novel "The Fountains of Paradise," closer to potential realization. Clarke's vision described these structures as "orbital towers."
Each strand of the proposed tether would be a single molecule, one atom thick, one meter wide, and approximately 62,000 miles long. The ISEC envisions 20,000 stacked sheets of this molecule forming the colossal cable, which would be nearly invisible but reflective. The structure would extend from an "Earthport" on the equator to an "apex anchor" spaceport beyond geostationary orbit, about 22,000 miles above Earth.
The journey for cargo vessels, known as climbers, to reach geostationary orbit would take approximately two weeks. After reaching this gravitational sweet spot, centrifugal force would propel the climbers the remaining 40,000 miles into space at high speeds. This could drastically reduce travel times for missions, with cargo potentially reaching the Moon in 14 hours and trips to Mars taking between 61 and 120 days, compared to current transit times of three days to the Moon and seven months to Mars.
Despite the material breakthrough, challenges remain. Space debris in low Earth orbit is a significant concern, prompting proposals for multiple tethers and designated no-fly zones for satellites. Furthermore, securing the necessary investment for such an ambitious project is a hurdle. The ISEC estimates a cost of $15 billion for the first robotic space elevator, a figure considered potentially economical compared to the long-term costs of the Artemis program, which is projected to exceed $200 billion by 2030.
Space economics professor Armen Papazian cautioned that while the concept is exciting, a functional space elevator is still a long way off. He noted that investors require a demonstrable return, which could take decades to materialize. The ISEC suggests that the initial 10 to 15 years would focus on logistics, moving cargo, with human transport potentially beginning after that period. The organization claims a space elevator could deliver 30,000 metric tons of cargo annually, a volume far exceeding all objects ever sent into space since 1957.