NASA recently announced that they will be pursing two new unmanned missions. The missions, Lucy and Psyche, are both “Discovery Class”—the name of their low-tier missions. Previous Discovery missions have included the Mars Pathfinder, recently brought back to center-stage by its role in the book The Martian; and Stardust, the first probe to return samples of a comet’s tail to Earth. These are narrowly-focused missions that are designed to answer specific questions about planetary bodies. This is in contrast with the Flagship missions like Cassini, which are designed to do detailed and wide-ranging research; and mid-range New Frontiers missions like New Horizons and Juno that fall somewhere in between.
There were five missions in the running for funding from the Discovery program this year. Two Venusian missions and an Earth-observation mission completed with Lucy and Psyche, which are both directed at asteroid observation. As noted by the Planetary Society, there has been a drought in missions to Venus in the previous decades. NASA Planetary Science head, Jim Green, was reported saying that each mission was assessed on its own merits; the Venus missions, unfortunately, came up short.
Lucy, the first mission to launch, will be heading out as far as Jupiter. Specifically, it will be heading to the Trojans and Greeks, two groups of asteroids that are in orbits associated with Jupiter. The two groups are so referred because the objects within each group are named after characters from the Greek myth of the Trojan War. The Greek bodies orbit the Sun at a location known as Jupiter’s Lagrange Point 4 (L4). This is a point 60º ahead of where Jupiter is in its orbit around the Sun. Objects in this location are in stable orbits, forced to remain there by the gravitational interactions of Jupiter and the Sun. The Trojans are similarly located at L5, 60º behind Jupiter.
Psyche, which will launch in 2023, will be heading to an asteroid of the same name. It is one of the largest asteroids in the solar system, and the largest of the M-type metallic asteroids—asteroids that are made almost entirely from metal. This mission has gotten more of the hype that Lucy has, perhaps with good reason. While Lucy will undoubtedly make many terrific findings during its tour of the Jovian trojans, Psyche is exploring a never-before-visited type of asteroid. It also helps that there was an attention-grabbing headline for Psyche that Lucy couldn’t match: NASA to Visit 10 Pentillion Dollar Asteroid (although, curiously, most articles seemed to say 10 000 Quadrillion dollars instead). The assertion is true but, unsurprisingly, misleading. Psyche is made primarily of nickle and iron, just like the Earth’s core; it is speculated that Psyche is the remains of a protoplanet that formed in the asteroid belt, but had all of its rocky exterior pounded away by impacts. If one could get all of that metal back to Earth, along with the smaller amounts of rare metals like gold and platinum that are assumed to be present, it would sell for the aforementioned sum. However, it would cost an enormous amount of money to retrieve any of that material. It will probably not be worth it for a long time, with iron being an abundant metal on Earth.
While the $1×10^19 price tag on this asteroid is ridiculous, the concept of mining asteroids may not be. Several companies have formed with the purpose of starting commercial ventures centered around the prospect. One is Planetary Resources. They are currently working on designing and testing cheap (relatively speaking) prospecting probes that they could send to observe and land on potentially-mineable asteroids. Their current plan, as lain out on their website, is first target the numerous water-bearing asteroids—some of which Lucy will fly by. After retrieving the water, they can turn it into rocket fuel in the form of liquid oxygen and hydrogen. This fuel could be sold to other companies, many of whom will be clamoring at the chance to escape the tyranny of the rocket equation by refilling their spacecraft in space. It could also be used to fuel Planetary Resources’ own fleet of metal-mining ships. These mining drones could then harvest precious metals and return them to Earth, or could harvest the non-precious metals and use or sell them in space, once again avoiding the high costs of lifting material out of Earth’s gravity well.
This discussion of metal asteroids raises some interesting political and legal questions specifically tied to the 1967 Outer Space Treaty (OST). This treaty, signed at the height of the Cold War and in the context of the race to put humans on the Moon, forms the basis for international space law. Among other things, it prevents nations from laying claim to any objects in space, except those that it launches from Earth. This has caused some concern to would-be asteroid miners, who are worried about their ability to stake out an asteroid for mining and their ability to enforce any claims they make.
To inspire more development in outer space commercialization, ex-US President Barrack Obama signed the U.S. Commercial Space Launch Competitiveness Act in 2015. This act recognizes the right of US citizens to own resources they obtain from asteroids. This act is controversial because it may be in conflict with the OST, especially depending on how it is implemented. To comply with the OST, the US would have to assert its citizen’s right to a contested asteroid without asserting that the US owns the asteroid.
Two new missions are, as always, exciting. These missions will mean more research and more discoveries. Lucy is embarking on an odyssey that will take it from one side of Jupiter’s orbit to the other. Psyche’s mission is to visit a type of body that, at some point in the future, will have enormous political, economic, and legal importance. It is, as always, an exciting time in space exploration.
Leave a Reply