Our deepest view of the universe is powered by PV. NASA was one of the first to adopt solar technology, and today it remains an important feature of spacecraft.
July 15, 2022 Ryan Kennedy
From the magazine pv USA
American engineers at Bell Laboratories introduced the first photovoltaic solar cell in 1954. Four years later, the National Aeronautics and Space Administration (NASA) launched solar panels into space.
Today, solar panels power the James Webb Space Telescope, which gave the world the most detailed view of the most remote confines of the universe to date.
The James Webb Space Telescope. Image: NASA
NASA launched the Webb Space Telescope on Christmas Day 2021. The telescope uses less energy than one might think. In fact, only one kilowatt, equivalent to the power used to cook lunch with the microwave, is needed to power the device. NASA said Webb will maintain energy efficiency more than 1 million miles from Earth, reliably powered by photovoltaic energy.
A 20-foot deployable solar array is connected to the boat’s main observatory. It will act as the telescope’s “power plant”, supplying energy to all its scientific instruments, communications and propulsion systems. The system has a size of 2 kW to take into account the degradation that will occur over time due to the harsh conditions of the space.
The matrix consists of five panels connected by hinges to fold them into the launch vehicle, the Ariane 5 rocket. The battery on board the telescope was designed to last only a few hours, so that the deployment and activation of the matrix were considered one of the most critical first steps in the telescope’s journey. Below is a video of the deployment of the drop-down array.
Solar in space
The James Webb telescope is not the only NASA project that relies on photovoltaics to power its systems. Last June, NASA astronauts Shane Kimbrough and European Space Agency (ESA) Thomas Pesquet completed their space upgrade of the International Space Station, installing the iROSA deployable solar arrays.
The installation of the six matrices cost about $ 100 million. The arrays are expected to add more than 120 kW of capacity, which will increase the station’s power generation by between 20% and 30%. The solar panels that were replaced were designed for a useful life of 15 years, but had been in continuous operation since December 2000. Although they worked well, the older arrays showed signs of degradation, as expected.
The DART spacecraft is designed to crash into asteroids to defend the Earth from impacts. Image: NASA
Last December, NASA announced that it was testing solar-powered electric propulsion systems for asteroid defense. The Double Asteroid Redirection Test (DART) mission will use deployable solar arrays and a 6.9 kW grid ionic electric propulsion system to redirect terrestrial asteroids by crushing the small spacecraft against the asteroid.
The boat is designed to propel at about 250 miles per hour, guided by an onboard camera and standalone navigation software, directly in the path of the asteroid. The DART test will come into contact with the moon of the Didymos system that will be launched into orbit in September 2022.
NASA is also using two large cross-shaped photovoltaic arrays to drive its Psyche mission, which will take a spacecraft 1.5 billion miles away from Earth to the asteroid Psyche. The mission is to explore a large metal-rich asteroid with the vessel operated remotely.
The Psyche solar array is 37.1 feet long and 24 feet wide on each side when fully deployed. The two cross-shaped matrices are deployed from the spacecraft and represent the largest solar matrix deployed by the Jet Propulsion Laboratory, NASA said. So large, in fact, that the entire vessel could not be deployed during the test in the Arizona State University laboratory in Tempe. ASU has partnered with NASA on this mission, which will observe the unusually high amount of metals in the thickest band of the asteroid.
Psyche’s photovoltaic array is the largest to date for NASA’s Jet Propulsion Laboratory. Image: NASA
On Earth, the solar matrix can generate about 21 kW of electricity, but far from the sun next to Psyche, they will only produce 2 kW, roughly the same energy demand as a hair dryer. Despite this low amount of energy, it will be enough to drive the planned three-and-a-half-year journey to the asteroid and the two-year orbit and observation of the body.
“Even at the beginning, when we were designing the mission for the first time in 2012, we were talking about solar electric propulsion as part of the plan. Without her, we would not have the Psyche mission, “said Lindy Elkins-Tanton of Arizona State University, who, as principal investigator, leads the mission.” And it has become part of the character of the mission. “Specialized equipment is needed to calculate trajectories and orbits using solar electric propulsion.”
The launch is scheduled for this August, and the Psyche spacecraft may have its first contact with the asteroid Psyche in 2026.
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