An experimental spacecraft testing solar sails as a way of cost-effective space propulsion that might energy future missions to distant locations remains to be using the sunbeams in Earth’s orbit greater than two and a half years after its launch.
The spacecraft, referred to as LightSail 2, is a cubesat concerning the dimension of a loaf of bread however fitted with a solar sail the scale of a boxing ring: It covers about 433 sq. toes (32 sq. meters). This sail captures incoming photons from the sun, simply as a wind sail catches the transferring air, to propel the spacecraft.
MildSail 2 is a personal challenge of the Planetary Society, a U.S.-headquartered space training and outreach nonprofit group. But the outcomes of the experiment have already knowledgeable the design of upcoming NASA missions resembling NEA Scout, Solar Cruiser and ASC3 that may too depend on solar sails, Planetary Society mentioned in a statement Monday (Nov. 15). NEA Scout, one of many “passengers” on NASA’s upcoming moon-bound Artemis 1 mission, will use the solar propulsion expertise to go away the moon’s orbit and go to a near-Earth asteroid.
MildSail 2 shouldn’t be utilizing the solar sail to go to distant locations however to easily maintain itself in orbit above Earth. The spacecraft is at the moment orbiting on the altitude of 426 miles (687 kilometers) the place the planet’s residual environment causes friction. This friction would below regular circumstances sluggish the satellite down and pull it again to Earth, however the sail’s energy makes up for that. The spacecraft initially managed to lift its orbit utilizing simply the solar sail. Now, it’s slowly dropping its battle with the environment, however this course of is going on way more slowly than it could with out the sail.
“Thanks to optimized sail pointing over time, altitude decay rates during recent months have been the best of the entire mission,” the Planetary Society mentioned within the assertion. “Thrust even occasionally overcame atmospheric drag, slightly raising the spacecraft’s orbit.”
The $7 million mission, crowdfunded by donors and launched in 2019, benefitted from a quiet interval within the 11-year solar cycle, which has, nevertheless, just lately ended. In the previous few months, extra sunspots have been forming on the sun’s floor and highly effective eruptions have been launching big quantities of charged particles into the encompassing space. These particles, within the type of solar wind, attain Earth the place they work together with the planet’s environment, making it thicker.
“Below-average sun activity has kept Earth’s upper atmosphere thin for much of the mission, creating less drag on the sail,” the Planetary Society mentioned within the assertion. “That has recently changed, with the sun becoming more active and emitting significant solar flares. The LightSail 2 team believes that this activity is likely now causing higher orbital decay rates than those seen earlier in the mission.”
During its mission, MildSail 2 captured some amazing images of its dwelling planet utilizing its two fisheye cameras, together with snapshots of tropical storm Mirinae, which approached the coast of Japan throughout the Tokyo Olympics in August this yr.
The objective of those fish-eye cameras is to primarily monitor the state of the solar sail. Experts have already observed some indicators that the sail could also be affected by some put on and tear. The Society’s calculations predict the spacecraft ought to keep afloat for a minimum of one other yr.