In 2004, President Bush kicked off a space race at NASA when he announced that the U.S. was going back to the Moon by 2020. With the funds to design multiple new technologies, hundreds of scientists and engineers set to work.
To test their inventions, however, they needed one elusive material – Moon dust – and lots of it. They required upwards of 450 tonnes, yet the space agency’s 383 kilograms of authentic lunar rock is carefully rationed out to only the most developed and essential projects. So NASA encouraged Sudbury mining technology developer NORCAT to improve and mass produce a top-of-the-line mechanical lunar soil simulant called CHENOBI, which it had created to test drills it built for the space agency.
An unusual substance
Even though it looks like a fine grey powder in photographs, lunar regolith is granular, extremely abrasive and cohesive. Without air or water on the Moon, there is little to smooth the rock particles with time. “The behaviour of this material is not what you’d expect,” says Rob Mueller, a lunar destination co-lead at NASA’s Kennedy Space Center. “Lunar regolith doesn’t act like sand or anything that occurs naturally here on Earth.”
During the Apollo 11 mission, lunar soil ground into the joints of the astronauts’ space suits, clogging their gear and lodging in their lungs after they tracked it into the lander. And efforts to test mining equipment in regolith simulant show that the dust can easily disable equipment prototypes.
A chief reason for the rugged quality of lunar soil is particles called agglutinates that speckle the lunar landscape. When frequent micrometeorite bombardments hit the Moon, agglutinates form after an impact superheats the dust particles into molten glass and ejects the globules into the surrounding regolith. Rolling with unheated moon dust, this globule creates a jagged, dirty glass that is nearly unheard of here on Earth. Yet agglutinates are a big part of what NASA calls “high-fidelity” simulants.
“To produce agglutinates on a large scale is very difficult and expensive,” says Jim Richard, president of Electric Vehicle Controllers Ltd., which partnered with NORCAT on the development of the mock Moon dust. “So our approach in creating CHENOBI has been to add more abrasive glass to our recipe to replace the agglutinates.” If test machines work with a higher content of glass, he reasons, they should work with the real thing.
In the end, NORCAT used anorthosite that had been subjected to a plasma arc process and then crushed and mixed with the original material of OB-1, an older simulant, to create CHENOBI. “They changed their source of glass and got a simulant that was much better,” says Doug Rickman, project scientist, NASA’s simulant development program.
Last year, President Bush’s Moon mission was quashed just as NORCAT’s lunar simulant was about to become commercially available. Nevertheless, demand for simulants shows signs of re-emerging as the commercial space industry and nations such as China begin stepping up their own lunar missions.
“Right now, everyone is sitting and wondering where we go from here,” says Richard. “We’re in a really good position to get out of the gate when things come back around, since there’s a shortage of high-quality simulants. The momentum just needs to build back up to a point where the people who control the money want to get back to doing these things.”
That time may come sooner than expected: by the end of July – with $30 million in prize money in their sights – 29 teams signed up for a shot at the Google Lunar X Prize, a competition to become the first private venture to land on the Moon by 2015. One of these teams, Moon Express, says it will spend $70 million to $100 million in its effort to win, but could recoup the costs by selling sponsorships for its rocket.
The bulk of the prize money will go to the first team to land a craft on the Moon and explore 500 metres of its surface. To do this, the teams will need to rigorously test their rovers and rockets to withstand the rugged lunar environment.
A tonne of CHENOBI costs $44,000, and even higher grade simulants can reach $1,000 to $5,000 per kilogram. But it is worth it, says Rickman. “For the commercial space industry, the more demanding what they try to do on the surface is, the more they will need to test their equipment in the best regolith simulant they can find,” he explains.
If companies find that a part breaks because they have not tested their equipment in accurate conditions, it is a long way back to Earth. Richard says that some researchers who used NORCAT’s simulants to test wheel designs, flow dynamics in zero gravity and other properties were surprised to find that the high-fidelity simulant gave them different results. “This caused them to drop back and look at the other simulants they were using,” he adds.
Still, the nascent commercial aerospace industry may find high-quality simulants in short supply. “The availability of high-fidelity simulants is an issue,” says NASA’s Rob Mueller, “since they’re commercially available from only two companies: Orbitec and NORCAT.”
With the downward trend in the market, neither company has stored large quantities of their products. “I’m enough of a businessman that I’m not going to stockpile this material,” says Richard. “Researchers have inquired about our simulants, but I don’t have any orders in-hand at the moment.”
With the market’s current inconsistency, it is possible these manufacturers may have to sit on their product for a while before they can sell it. “There will, however, be a time when we need lots of simulants again,” says Rickman.
But long-term, the market appears to have powerful potential. Right now, Japan, China and South Korea are all working on projects that require lunar simulants, and Google’s Lunar X Prize is rallying commercial players to the industry’s growing opportunities.
“We’ve pioneered a lot of this work and we’re hopeful that there’s a path forward,” says Richard. “At NORCAT, we proved things with those simulants that we wouldn’t have been able to using a lesser substance.”