A new NASA spacecraft is spinning through space uncontrollably as engineers on the ground work to fix a problem that caused the $20 million ship to lose control.
The agency’s Advanced Solar Composite Sail System (ACS3), a vessel with four reflective ‘sails’ designed to test a new type of propulsion system, ran into a problem when it deployed the sails.
Engineers noticed a slight curvature in one of the ‘boots’ or structural beams that support the sails, affecting their ability to stay on course.
NASA has kept ACS3’s attitude control system, which controls a spacecraft’s orientation, turned off while engineers assess this damage.
As a result, the microwave-sized spacecraft is currently moving through space.
This mission is a test of new spaceflight technology that It uses the pressure of sunlight for propulsion, similar to how a sailboat is propelled by the wind.
One day, it could reduce the extremely high cost of deep space missions. But first, NASA will have to get their runaway ship under control.
The Advanced Solar Composite Sail System (ACS3) is a microwave-sized spacecraft equipped with four reflective ‘sails’ designed to test a new type of propulsion system
ACS3 launched from New Zealand aboard Rocket Lab’s Electron rocket on April 23.
Just months after launch, the spacecraft’s sail jammed when an onboard power monitor detected higher-than-expected engine currents and halted the deployment process.
In late August, NASA successfully deployed the sails in a second attempt.
But before doing so, engineers disabled the spacecraft’s attitude control system to accommodate dynamic changes as the sails deployed. It has been off since then.
Now, the discovery of this curve in one of the barriers has further delayed the reactivation of the attitude control system, while engineers work to assess the damage.
“This likely occurred when the booms and sails were tightened to the spacecraft during deployment,” NASA’s update states.
“The analysis indicates that the curve may have partially straightened over the weeks since the boom’s deployment, as the spacecraft slowly circled.”
Engineers are currently working to reposition the spacecraft, keeping it in “low power mode” until its sails are facing direct sunlight.
This system uses sails powered by the pressure of sunlight for propulsion, similar to the way a sailboat is propelled by wind.
Once the team reaches the desired position, they will be able to reactivate the attitude control system and stop the spacecraft’s constant fall.
At that point, the refocused spacecraft will be able to point its radio antenna toward mission control on Earth and communicate with NASA engineers on the ground.
This will allow engineers to collect even more data, calibrate the precise shape of the sail, and prepare to begin their navigation maneuvers, according to NASA.
Navigation maneuvers will be the true test of this new propulsion system.
Engineers will tilt the sails to change the spacecraft’s orbit, which is critical to their ability to maneuver ACS3.
It currently sits about 600 miles above the Earth’s surface, twice as high as the International Space Station.
Once the spacecraft entered sun-synchronous orbit, which allows a satellite to remain synchronized with the sun as it orbits Earth, NASA engineers disconnected the attitude control system and deployed the sails.
The ACS3 mission was designed to test solar propulsion as a way to reduce the cost of deep space missions, such as flights to Mars.
The spacecraft’s four sails unfold to form a 30-foot-wide silver square supported by two diagonal arms.
When light particles (or photons) from the sun hit these sails, small bursts of momentum are created that propel the spacecraft forward, like a sailboat.
The force exerted by sunlight is roughly equivalent to the weight of a paper clip resting on the palm of your hand, according to NASA, enough to allow the spacecraft to overcome atmospheric drag and gain altitude.
NASA is not the first to test a solar sail propulsion system in space.
The Planetary Society’s LightSail 2 launched in 2019 and gained two miles of altitude two weeks after deploying its 300-square-foot sail.
But the mission ended in disaster when the spacecraft began to lose altitude and eventually burned up in Earth’s atmosphere.
LightSail 2 inspired the ACS3 mission. If NASA can prove that this technology works, could significantly reduce the amount of fuel needed for deep space missions, saving the agency a lot of money.
“The data collected in this flight test has already proven to be very valuable, and the demonstration will continue to produce critical information to enable future solar sail missions,” the agency wrote in a recent update.