NASA Solar Sail Satellite Ejects from Mothership in Space

A small NASA satellite carrying a folded-up solar sail ejected from its mothership in low-Earth orbit Monday (Dec. 6), marking a key success in NASA's efforts to develop and deploy solar-sail technology.

NanoSail-D, which is about the size of a loaf of bread, ejected from NASA's washing-machine-sized FASTSAT satellite at 1:31 a.m. EST (0631 GMT) Monday.

NanoSail-D's 100-square-foot sail is still folded up tight for now. It should unfurl in about two days,  demonstrating a technology that NASA hopes will help bring decommissioned satellites down from Earth's orbit without using up valuable propellant. The idea is to use radiation from the sun as a sort of wind pushing against a thin sail to propel the lightweight craft through space. [Picture of NanoSail-D satellite.]

"This is a great step for our solar sail team with the successful ejection of the NanoSail-D satellite from FASTSAT," Dean Alhorn, NanoSail-D principal investigator and aerospace engineer at NASA's Marshall Space Flight Center in Huntsville, Ala., said in a statement.

Doing things differently

Nanosatellites, also known as cubesats, are typically launched and deployed from a mechanism that mounts directly on a launch vehicle. This is the first time NASA has mounted this mechanism on a microsatellite to eject a cubesat, agency officials said.

FASTSAT ? short for Fast, Affordable, Science and Technology Satellite ? launched Nov. 19 from Kodiak Island, Alaska, bearing six different science and technology demonstration payloads, including NanoSail-D.

"The successful ejection of NanoSail-D demonstrates the operational capability of FASTSAT as a cost-effective independent means of placing cubesat payloads into orbit safely," said Mark Boudreaux, FASTSAT project manager at Marshall Space Flight Center. "With this first step behind us, we have demonstrated we can launch a number of different types of payloads using this common deployment system from an autonomous microsatellite like FASTSAT."

Sailing through space

Upon ejection, NanoSail-D initiated a three-day countdown to sail deployment, which should therefore take place in the early morning hours of Dec. 9. 

At that time, four booms will pop out, deploying the nanosatellite's sail in about five seconds if all goes according to plan. The sail, made of a polymer material thinner than a human hair, catches photons from the sun much as ships' sails catch the wind. [How Do Solar Sails Work?]

With its sail out, NanoSail-D should stay in low-Earth orbit from 70 to 120 days, according to NASA officials. Over time, the satellite will use the sail to de-orbit, spiraling lower and lower without using costly propellants like traditional satellites do.

The NanoSail-D flight results will help to mature this technology, perhaps enabling it to be used on future missions. Solar sails could help de-orbit larger craft, thus helping free Earth orbit of dangerous, cluttering space junk, NASA officials said.

NanoSail-D is not the first spacecraft to demonstrate solar-sail technology. In June, Japan's Ikaros probe deployed its solar sail, becoming the first craft to cruise through space propelled only by sunlight.

• How Do Solar Sails Work?
• Tiny Satellites Can Do Big Science
• World's First Solar Sail Photographed in Deep Space