The University of Colorado Boulder and Lunar Resources Inc. has just received NASA funding to investigate the possibility of building a radio telescope on the other side of the Moon. The project, called FarView, would harvest building material from the lunar surface itself and use robot controversy to build a massive, intricate network of wires and antennas over 400 square kilometers. When completed, FarView would allow radio astronomers to observe the sky at low frequency radio wavelengths with unprecedented brightness.
Radio telescopes work best in isolation. If radio telescope operators want to ‘hear’ the earth without interference, they will have to establish huge exclusion zones around the telescope on earth where cell phones, wi-fi and even the spark plugs of petrol cars are banned. FarView proposes to place a telescope in the quietest place we can think of, away from the earthlings and our noisy equipment. With this Lunar Observatory, astronomers would be able to listen to the universe more clearly than ever before, allowing them to go deeper into time and space, perhaps even to the cosmic dark ages when the first stars formed.
It may just work, although the plan is still in its early stages. FarView is funded by NASA’s Innovative Advanced Concepts (NIAC) program, which works with entrepreneurs to fund ideas that are innovative and technically sound, but largely untested and still in their infancy. NIAC projects are a look at the possibilities of space exploration in a decade or more in the future. It will still be a long way to go to create the proposed lunar-based observatory.
Dr. Alex Ignatiev, chief technology officer of Lunar Resources, is confident that they can pull it off, and do so without breaking their bank. “We can build FarView at about 10% of the James Webb telescope cost and work for more than 50 years,” he said. This is an impressive goal.
Build with lunar soil
The key to cost reduction is to build FarView using materials already available on the moon, also known as in situ resource utilization (ISRU). ISRU has become a buzzword in recent years regarding the exploration of the moon and the march, as it will be necessary to maintain human activities on the moon and in the long run. In this case, ISRU will allow FarView to reduce the costly cost of escaping Earth’s troublesome gravity well by building the telescope from the lunar recovery.
The exact manufacturing process for FarView is based on two techniques. The first is molten regolith electrolysis (melting lunar soil to separate the metals from the oxygen), and the second is vacuum deposition (the deposition of thin film-like material films). Lunar Resources has experience in both techniques on a small scale; they will have to be raised to create the enormous FarView observatory.
During a future presentation in space (FISO) in December last year, Ignatiev explained that the regolith over the moon is a mixture of metal oxides, with more iron in the mares and more aluminum in the Highlands, and elements such as silicon and magnesium available throughout. ‘Our challenge in terms of producing raw materials on the moon,’ he said, ‘is to break the regolith-oxygen bond … and obtain the raw elements from the regolith’ using electric currents.
A small robot processing plant would extract these metals from the ground and deposit them in a rover. FarView chief investigator Ronald Polidan told FISO that when the rover collided, it “melted the regolith surface into a glass, and then laid the metal antennas on it, with connecting wires and all the other necessary infrastructure.” Using this method, it will take 26 months to manufacture the 100,000 ten meter long dipoles needed for the telescope. The wanderer will only be able to work during the Mondays (about two Earth weeks) and have to sleep during the nights.
Challenges and opportunities
Building a lunar telescope sounds complicated, but its principles are fairly simple once the material is extracted. Laying strips of metal foil over the lunar surface should not be too hard, and no large-scale load-bearing construction is required to work. The best part is that, in theory, the metal dipoles are serviceable and repairable, giving FarView a long life.
However, to start working, a different infrastructure will probably be needed first. The team also plans to build solar panels and batteries from regolith, which will provide power sources for the telescope. They hope that ISRU techniques will be tested and proven in the coming years in collaboration with the Artemis program.
Finally, for FarView to succeed, consideration must be given to communication. When China landed their Chang’e 4 lander on the other side of the Moon in 2019, they first had to place a communications satellite (Queqiao) at the Earth Moon L2 Lagrange point to allow the lander to talk to Earth. . NASA does not yet have such a satellite available – and cooperation with China in space has been politically difficult in recent years. An observatory on the other side of the Lunar will require a bit of renewal: engineering or diplomacy.
Are Lunar Observatories the Future of Astronomy?
As new mega-constellations like Starlink become available online in the next few decades, astronomy on earth is becoming increasingly challenging. These low-flying satellite swarms create bright streaks of light that pollute the telescope images. Moon observatories may seem like a promising alternative to circumvent this problem. But the fact is that for most types of telescopes, you can not exceed the cost and ease of its construction on Earth, even if Starlink sometimes gets in the way. As such, it seems likely that Lunar observatories such as FarView will only supplement Earth observatories, not replace them, at least not soon. Not even with ISRU.
FarView is not exciting because it solves the Starlink problem (which mostly affects optical telescopes), but rather because FarView offers a unique opportunity for low-frequency radio astronomy, something that is not viable on Earth due to all the radio noise that we create. With FarView, we can learn things about the cosmic dark ages that are simply not possible with Earth-based infrastructure. Its scientific value is great. Just do not assume that it serves as a substitute for mega-constellation regulations or stripe-reducing brightness techniques. We’re still going to need those to ensure that Earth astronomy can coexist with mega-constellations, because none of them are going anywhere anytime soon.
New telescopes on the ground like the Vera Rubin Observatory and the extremely large telescope are going to do amazing things in the next decade. If and when FarView joins them, it might just usher in a new golden age of astronomy, with Earth, space and moon telescopes working together to understand our place in the universe. It’s worth pursuing, and with a little cooperation and ingenuity, it might come sooner than we think.
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