Miniature spaceships the size of cellphones could fly across the solar system using sails propelled by lasers, which would allow them to reach much faster speeds than conventionally powered rockets, according to a new study.
NASA's New Horizons probe took nearly 10 years to reach the dwarf planet.
Conventional rockets would take thousands of years to complete a voyage. The nearest star system to Earth is Alpha Centauri, which is more than 276,000 times the distance from Earth to the sun. It would take about 75,000 years for NASA's Voyager 1 to reach Alpha Centauri even if it were headed in the right direction.
Is it possible to travel through space?
The propellant they carry with them has mass, which is a problem with rocket thrusters. It takes a lot of propellant to make a long trip heavy, which in turn requires more propellant, making them heavier.
Light sailing may be one of the only technically feasible ways to get a spaceship to another star within a human lifetime. Scientists have long believed that light could have a major effect if it applied little pressure. Many experiments have shown that solar sails can rely on sunlight for power if the craft is light enough and has a large sail.
The $100 million Breakthrough Starshot initiative plans to launch swarms of microchip-size spaceships to Alpha Centauri, each of them sporting incredibly thin, incredibly reflective sails propelled by the most powerful lasers ever built. The plan is for them to reach Alpha Centauri in 20 years.
Starshot faces a major challenge in building the lasers. It calls for a ground-based laser array that is as powerful as 100 gigawatts, which would be the most powerful laser ever made on Earth.
In the new study, the researchers suggest that a ground-based laser array of 100 kilowatts to 10 kilowatts in power could still be useful.
Artur Davoyan, a materials scientist at the University of California, Los Angeles, told Space.com that such lasers can be built with a relatively small investment.
voyaging within the solar system can be done on a reasonable timescale. Starshot wants to send probes to another star within a human lifetime, so they are designed to be lightweight, so they can fly as fast as possible.
Laser sails do not have to be as heavy. The scientists envision a mass comparable to that of a cell phone in the range of 3.5 ounces (100 g) or so.
Starshot faces mass constraints that make it challenging to fit all the needed systems and instruments into a single platform, and a 3.5-ounce probe can easily be equipped with all the needed components.
A fleet of tiny probes, each with different equipment, could be sent to a destination if a laser array could launch more than one probe.
Because interplanetary voyages do not require the kind of powerful lasers needed with Starshot, they also do not require large sails with the kind of extraordinary material properties needed to survive the many demands of interstellar flight. The researchers suggested that the sails of the solar system should be about 10 centimeters wide.
There is a guide to things around the sun.
Davoyan said that their work is a first step to fast and low-cost interplanetary and deep space missions.
The U.S. Navy received a 150-kilo watt laser in 2020 for its littoral combat ship. The cost of high-power lasers is going down every year because of the need for optical telecommunications, with 1-kilo watt lasers available for less than $10,000.
Estimates show that a 1-megawatt laser beamer can be built for less than $100 million, which is less than most of NASA's missions. Once built, the laser beamer serves as a launchpad. The cost of the mission includes the production of probes, which can be on the order of $100, and the launch of probes for less than $100 per probe, and then operating the mission during its useful lifetime. The laser-driven approach offers a low cost for space exploration.
The scientists estimated that a 0.035-ounce laser sail with a 4-inch sail could reach Mars in 20 days, compared with 200 days for NASA's Perseverance rover.
The fact that we can change the way space is being explored with a minimal investment is very exciting. It would be great to see an undergrad send their own science probe to Jupiter.
The scientists hope to test and prototype their ideas.
The scientists wrote about their findings in the journal.
It was originally published on Space.com.
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