NASA hits big milestone in new spacecraft propulsion that uses the Sun

It's currently extremely expensive to get anything with significant weight into space, let alone travel from one space bearing to another.

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For these reasons and many others, NASA is throwing money into the research and development of alternative ways of spacecraft propulsion, and the space agency just hit a critical milestone in the development of one of those alternative methods - solar sails. NASA has successfully rolled back or deployed one of the four quadrants of a massive solar sail currently being constructed at Redwire Space facility in Longmont, Colorado.

The idea behind the solar sail is similar to a sail on a boat, but instead of wind pushing the spacecraft, the solar sail absorbs and reflects sunlight, giving it energy and, therefore, propulsion. More specifically, when light from the Sun hits the solar sail, the momentum of the photons transfers a portion of their momentum onto it. This is a small transfer of momentum with a single photon, but since the Sun and the solar system are abundant with them, the solar sail, at least in theory, could travel much faster than the chemical rockets we see today.

"In the future, we might place big lasers in space that shine their beams on the sails as they depart the solar system, accelerating them to higher and higher speeds, until eventually they are going fast enough to reach another star in a reasonable amount of time," said NASA technologist Les Johnson

As you have probably already worked out, solar sails don't require any fuel and are extremely light, making them attractive uses of propulsion for low-mass missions into orbit. This specific sail, when fully unfurled, will measure 17,780 square feet when fully deployed.