The era of solar sails will arrive sooner than expected

NASA has launched its latest effort to test solar sail propulsion technology.

The Advanced Composite Solar Sail System (ACS3), which consists of a Microwave-sized CubeSat and a solar sail, took off aboard a Rocket Lab Electron rocket from Launch Complex I on New Zealand's Mahia Peninsula. After reaching 600 miles above Earth, ACS3 deployed its sails.

The ACS3's solar sail is made of reflective polymer and held by a boom made of carbon fiber composite material. Previous solar sail tests have used metal booms, which tend to bend due to the extreme temperatures of space. The sail area is 680 square feet.

ACS3's goal is modest: use solar sails to raise and lower spacecraft orbits. But the technology could lead to celestial sailing ships that use the pressure of sunlight to fly around the solar system and visit other star systems.

Spacecraft using solar sails have both advantages and disadvantages compared to rocket-powered spacecraft.

Spacecraft propelled by solar sails have three main advantages. First, the mass of the engine and rocket fuel is saved. Second, if the solar sail is intact and undamaged, it could theoretically fly forever. Finally, such a spacecraft accelerates very slowly, but with constant acceleration. The more time passes, the more incredible speed will be created.

Disadvantages of solar sails include that they become less effective the further they are from the sun, tend to be large and difficult to manage, and are susceptible to damage from natural or even man-made space debris.

Still, if the solar sail system works, it opens up a variety of possibilities for inexpensive planetary missions.

A recent study published in Phys.org suggests that a spacecraft propelled by a solar sail could reach Mars in just 26 days. In contrast, exploration using conventional rockets takes seven to nine months. A combination of aerobrakes and conventional rockets will be used to put the spacecraft into orbit around Mars.

The University of California, Berkeley has proposed sending a solar sail fleet to visit asteroids and comets near Earth. Berkeley's Low-Cost Interplanetary Solar Sail (BLISS) project envisions swarms of these small vessels sailing towards these celestial bodies and capturing high-resolution images of them.

Near-Earth objects are interesting for two reasons.

First, asteroids and comets that intersect Earth's orbit could provide valuable resources to fuel the space industry. A solar sail probe of the kind envisioned by BLISS would be able to discover where these objects are and their orbits.

Secondly, these objects can be dangerous to the Earth and all living things living on it. More than 60 million years ago, an asteroid crashed into Earth, ending the age of dinosaurs. A similar object could do the same to humans. Detecting objects approaching Earth, measuring their trajectories, and determining the likelihood that they will collide with Earth could give us time to prepare to change the course of objects heading toward the destruction of humanity. maybe.

What about using sails of light to send probes beyond the solar system, to, say, the Alpha Centauri star system? Space.com recently discussed two of his studies on just such missions.

Breakthrough Starshot envisions using lasers on Earth to accelerate a microchip-sized spacecraft to 20% of the speed of light. The spacecraft is expected to reach Alpha Centauri within just 20 years. The two studies discuss the types of materials that would make up a solar sail and the shape of the sail that could survive long enough to accelerate the spacecraft and traverse interstellar distances within a human lifetime.

The idea of ​​solar sails has been the subject of science fiction and speculation for decades. With the exception of test flights such as ACS3, this technology has not yet been fully utilized.

If solar sail spacecraft ever set out to interstellar destinations, space travel would carry the romance of the golden age of navigating Earth's oceans. These will be like the clippers and galleons that once transported cargo and people around the world before the advent of coal, diesel, and nuclear power.

Mark R. Whittington, who writes frequently about space policy, writes,Why is it difficult to return to the moon?” Similarly “To the moon, Mars and beyond”, and more recently”Why will America return to the moon?” He blogs at: Karma John's Corner.