After malfunctions, silences and other unexpected twists, a small experimental spacecraft testing the possibility of harnessing sunlight for propulsion finally did what it was designed to do on Sunday: It unfurled a large, shiny sheet of Mylar.
“It worked,” said William Sanford Nye, chief executive of the Planetary Society, a nonprofit organization promoting space exploration that is operating and financing the project.
Nye — who is better known as the host of the TV show Bill Nye the Science Guy — acknowledged that success did not come easy, calling it an “emotional roller coaster.”
Twice since it was launched last month, LightSail fell into an unexpected silence, but the team of engineers working on the project managed to revive it.
On Sunday, just after 2pm, a command was sent to the spacecraft to deploy the sail.
Nothing happened.
For reasons not understood, LightSail ignored the command.
On the next orbit, about two hours later — the last chance for the day — the team sent the command again. The electric motor that was to extend four booms 4m to pull out almost 32m2 of Mylar started turning.
When the spacecraft passed out of radio range, the tiny motor had turned 67,000 times, halfway to the 134,200 needed to fully deploy the sail.
“There was no reason to expect it wouldn’t keep going,” Nye said.
On Monday, the spacecraft was due to send down photographs to confirm that the sail is spread out.
The technology, using sunlight to traverse the solar system in the same way mariners once crossed oceans in sailing ships, is not a new idea, but it has not been widely used. While particles of light impart only a tiny amount of momentum, the force is continuous and provides propulsion without fuel.
LightSail, packed into a box about the size of a loaf of bread, was one of 10 payloads that last month hitchhiked on a rocket that took an uncrewed US Air Force space plane into orbit. LightSail was successfully deployed and worked for two days before its computer crashed because of a software flaw.
Eight days of silence followed until, as engineers expected, a high-speed charged particle zipping through space fortuitously scrambled part of the computer’s memory and caused the computer to restart.
On Saturday afternoon, the team again made contact with LightSail, and moved quickly to execute the deployment of the sail before anything else could go wrong. The mission should now come to a quick conclusion.
Solar sailing has been a dream for Planetary Society leaders for four decades. One of the organization’s founders, Carl Sagan, talked about the idea with Johnny Carson on The Tonight Show in 1976.
Nearly half of China’s major cities are suffering “moderate to severe” levels of subsidence, putting millions of people at risk of flooding, especially as sea levels rise, according to a study of nationwide satellite data released yesterday. The authors of the paper, published by the journal Science, found that 45 percent of China’s urban land was sinking faster than 3mm per year, with 16 percent at more than 10mm per year, driven not only by declining water tables, but also the sheer weight of the built environment. With China’s urban population already in excess of 900 million people, “even a small portion
UNSETTLING IMAGES: The scene took place in front of TV crews covering the Trump trial, with a CNN anchor calling it an ‘emotional and unbelievably disturbing moment’ A man who doused himself in an accelerant and set himself on fire outside the courthouse where former US president Donald Trump is on trial has died, police said yesterday. The New York City Police Department (NYPD) said the man was declared dead by staff at an area hospital. The man was in Collect Pond Park at about 1:30pm on Friday when he took out pamphlets espousing conspiracy theories, tossed them around, then doused himself in an accelerant and set himself on fire, officials and witnesses said. A large number of police officers were nearby when it happened. Some officers and bystanders rushed
HYPOCRISY? The Chinese Ministry of Foreign Affairs yesterday asked whether Biden was talking about China or the US when he used the word ‘xenophobic’ US President Joe Biden on Wednesday called for a hike in steel tariffs on China, accusing Beijing of cheating as he spoke at a campaign event in Pennsylvania. Biden accused China of xenophobia, too, in a speech to union members in Pittsburgh. “They’re not competing, they’re cheating. They’re cheating and we’ve seen the damage here in America,” Biden said. Chinese steel companies “don’t need to worry about making a profit because the Chinese government is subsidizing them so heavily,” he said. Biden said he had called for the US Trade Representative to triple the tariff rates for Chinese steel and aluminum if Beijing was
Beijing is continuing to commit genocide and crimes against humanity against Uyghurs and other Muslim minorities in its western Xinjiang province, U.S. Secretary of State Antony Blinken said in a report published on Monday, ahead of his planned visit to China this week. The State Department’s annual human rights report, which documents abuses recorded all over the world during the previous calendar year, repeated language from previous years on the treatment of Muslims in Xinjiang, but the publication raises the issue ahead of delicate talks, including on the war in Ukraine and global trade, between the top U.S. diplomat and Chinese