NASA plans radio telescope across the moon

The University of Colorado Boulder and Lunar Resources Inc. have just obtained funding from NASA to study the possibility of building a radio telescope on the other side of the moon. The project, called FarView, would harvest building materials from the lunar surface itself and use robotic robots to build a massive and complex array of wires and antennas spanning 400 square kilometers. When complete, FarView would allow radio astronomers to observe the sky in low-frequency radio wavelengths with unprecedented clarity.

Radio telescopes work best in isolation. On Earth, if radio telescope operators want to “ hear ” the sky without interference, they must establish huge exclusion zones around the telescope where cell phones, Wi-Fi, and even car spark plugs gasoline are prohibited. FarView suggests placing a telescope in the quietest place you can think of, away from Earthlings and our noisy gadgets. With this lunar observatory, astronomers would be able to listen to the Universe more clearly than ever before, allowing them to go further in time and space, perhaps even to the dark cosmic ages when the first stars were forming.

It might work well, even though 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 innovative and technically sound ideas that are largely untested and still in their infancy. CANI projects are a glimpse of the possibilities for space exploration a decade or more into the future. The creation of the Moon-based observatory project will take a long time to come.

Dr Alex Ignatiev, chief technology officer at Lunar Resources, believes they can do it without breaking the bank. “We could build FarView at about 10% of the cost of the James Webb Telescope and operate for over 50 years,” he said. It is an impressive goal.

Building with lunar soil

The key to reducing costs is to build FarView using materials already available on the Moon, also known as In Situ Resource Use (ISRU). ISRU has become a buzzword in recent years when it comes to lunar and Martian exploration, as it will be necessary to maintain long-term human activity on the Moon and Mars. In this case, ISRU will allow FarView to cut the costly costs to properly escape the pesky gravity of Earth by building the telescope out of lunar regolith.

The exact manufacturing process of FarView relies on two techniques. The first is the electrolysis of molten regolith (melting the lunar soil to separate metals from oxygen) and the second is vacuum deposition (laying thin films of sheet-like material). Lunar Resources has experience in both small-scale techniques; they will have to be strengthened to create the enormous FarView observatory.

During a future operations in space (FISO) teleconference last December, Ignatiev explained that the regolith across the moon is a mixture of metallic oxides, with more iron in the Ponds and more aluminum. in the Highlands, and elements like silicon and magnesium available. all along. “Our challenge in terms of manufacturing on the moon with raw materials,” he said, “is to break that regolith-oxygen bond… and get the raw elements of that regolith” using electric currents.

A small robotic processing plant extracts these metals from the ground and deposits them in a rover. FarView principal researcher Ronald Polidan told FISO that when the rover rolls, it “melts the surface of the regolith into a glass, then puts the metal antennas on it, along with connecting wires and all the other necessary infrastructure.” . Using this method, it would take 26 months to fabricate the 100,000 ten-meter-long dipoles needed by the telescope. The rover could only work during lunar days (about two Earth weeks) and would have to hibernate during the nights.

Challenges and opportunities

Building a lunar telescope sounds complicated, but its principles are pretty straightforward once the materials are mined. Laying metal foil strips over the Moon’s surface shouldn’t be too hard, and no large-scale load-bearing construction is needed for this to work. The best part is that, in theory, metal dipoles are usable and repairable, which gives FarView a long lifespan.

To begin operations, however, other infrastructure will likely be required first. The team also plans to build solar panels and batteries from regolith, providing power sources for the telescope. They hope that ISRU techniques like these will be tested and proven in conjunction with the Artemis program in the years to come.

Finally, for FarView to be successful, some consideration will need to be given to communications. When China landed its Chang’e 4 lander on the other side of the Moon in 2019, it first had to put a communications satellite (Queqiao) at the Earth-Moon L2 Lagrange point, to allow the lander to talk to Earth. NASA does not yet have a satellite available – and cooperation with China in space has been politically difficult in recent years. A distant lunar observatory will require some innovation: either in engineering or in diplomacy.

Are lunar observatories the future of astronomy?

With new mega-constellations like Starlink coming online over the next several decades, Earth-based astronomy is becoming more and more difficult. These low-flying satellite swarms create trails of light that pollute the telescope’s images. Lunar observatories may seem like a promising alternative to get around this problem. But the point is, for most types of telescopes, you just can’t beat the cost and convenience of building them on Earth, even if Starlink gets in their way from time to time. As such, it seems likely that lunar observatories like FarView will only complement Earth-based observatories, not replace them, at least not anytime soon. Not even with ISRU.

FarView is exciting not because it fixes the Starlink problem (which primarily affects optical telescopes anyway), but rather because FarView offers a unique opportunity for low-frequency radio astronomy, something that is not viable on Earth. because of all the radio noise that we create. With FarView, we could learn things about the cosmic dark ages that are simply not possible with Earth-based infrastructure. Its scientific value is enormous. Don’t count on it to replace mega constellation regulations or dimming techniques that reduce streaking. We’re still going to need them to make sure that Earth-based astronomy can coexist with the mega-constellations, because neither of them is going anywhere soon.

New ground-based telescopes like the Vera Rubin Observatory and the Extremely Large Telescope are going to do incredible things over the next decade. If and when FarView joins them, it might ring in a new golden age of astronomy, with telescopes from Earth, space, and the Moon working together to understand our place in the Universe. It’s a goal worth pursuing, and with a little cooperation and ingenuity, it could come sooner than we think.

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