While NASA says solar sails could enable low-cost missions to the Moon and Mars, some scientists believe they could send a probe to another star system.

NASA’s solar sail demonstration mission

If all goes to plan on April 24, Rocket Lab’s Electron vehicle will deploy NASA’s CubeSat approximately 600 miles (965 km) above Earth’s surface.

The ACS3 mission will fly at more than double the altitude of the International Space Station (ISS). At that altitude, NASA says the force of sunlight on the sail will be enough to overcome atmospheric drag and increase its altitude. 

All it needs is the “equivalent to the weight of a paperclip resting on your palm”, NASA explained in a statement.

After launch, there will be a two-month initial flight phase, where NASA’s ground team will check the CubeSat’s subsystems are working as intended. Once that is complete, the CubeSat will deploy its reflective solar sail.

For the following weeks, it will then perform several pointing maneuvers to demonstrate orbit raising and lowering.

LightSail missions to Proxima Centauri

In 2019, the Planetary Society’s LightSail 2 mission demonstrated for the first time that a LightSail could be used to elevate a small satellite’s orbit around Earth. 

The LightSail used an incredibly lightweight mylar material. Spread out, it captured enough photons from the Sun to propel itself upward.

According to NASA’s statement, the ACS3 mission “sets out to prove its ability to sail across space, increasing access and enabling low-cost missions to the Moon, Mars, and beyond.”

In fact, some of the most ambitious space mission concepts to date are working on taking LightSails to the next level. 

Breakthrough Starshot, for example, aims to train a million lasers on a LightSail probe so it can reach our nearest star system, Proxima Centauri, in our lifetimes.

The mission was proposed in 2016 by Breakthrough Initiatives, a science program founded by Israeli billionaires Yuri and Julia Milner, with backing from Mark Zuckerberg and Stephen Hawking.

Space Initiatives Inc. and the Initiative for Interstellar Studies (i4is), meanwhile, recently proposed a similar mission to Proxima Centauri. Instead of sending one probe, however, it would send a whole swarm of LightSails to uncover the mysteries of the nearest solar system to Earth.