After a short break from observing space, NASA's Hubble Space Telescope officially returned and is working, and the observatory has captured a stunning new view of a distant star-forming galaxy.
On October 5, the Hubble telescope switched to the protective “safe mode” when one of its orientation-supporting gyros failed. After about three weeks, the mission team was able to fix the erratic gyroscope and return Hubble online. Soon after, the telescope was on a field of star-forming galaxies, located approximately 11 billion light-years from Earth, in the constellation Pegasus.
According to a new NASA statement, a new image taken on October 27 using a broadband camera 3 telescope was the first image taken with a telescope. However, the return of Hubble online was not an easy feat; It involved a whole team of engineers and experts who worked tirelessly to find a fix, officials said in a statement. [The Hubble Space Telescope’s Greatest Discoveries]
“It was an incredible saga based on the heroic efforts of the Hubble team,” said Jennifer Wiseman, senior researcher at Hubble at the Goddard NASA Space Flight Center in Greenbelt, Maryland. “Through this work, the Hubble Space Telescope has returned to a full scientific ability that will benefit the astronomical community and the public for many years.”
As soon as the Hubble Task Force members were notified that the telescope had stopped taking scientific observations, they quickly tried to revive the failed gyroscope, but were unsuccessful.
Instead, the team was able to activate the backup gyroscope on the spacecraft. However, this gyroscope soon reported an incredibly high rotation speed of 450 degrees per hour, when the Hubble actually turned at a speed of less than 1 degree per hour. According to the statement, the team has never seen rates that would be high on any other gyros.
The Hubble telescope has a total of six gyros, but usually it uses only three at a time to collect data on the orientation of the telescope. Since two of the six gyroscopes of the telescope had not previously been performed, this was the last gyroscope. This meant that the operating group had to figure out how to make it work or resort to a possible “single gyro mode”, which would significantly limit Hubble’s observations.
In 2011, the Hubble control center switched to automated operations, that is, people no longer followed the telescope 24 hours a day. However, during Hubble’s short stay offline, team members continuously monitored the telescope’s health and safety.
“The team came together for staff around the clock, which we haven’t done for years,” said Dave Haskins, Goddard’s mission manager for Hubble, in a statement. "For me it was unhindered, it demonstrates the versatility of the team."
NASA also brought in an additional team of experts to figure out how to fix the unusual behavior of the backup gyro. After several weeks of creative thinking, continuous tests and small failures, the team came to the conclusion that there could be some kind of blockage. They tried to solve this problem by switching the gyroscope between different modes of operation and the rotating spacecraft. As a result, the gyro gradually changed its rotation to more normal speeds, according to the statement.
After this success, the team loaded new software into a telescope and conducted a series of practical maneuvers to simulate real scientific observations. This ensured the telescope's readiness for action with three working gyroscopes.
Meanwhile, other team members focused on preparing Hubble to use only one gyroscope. Despite the fact that these drugs are not needed now, NASA officials said that at some point the telescope would inevitably switch to a single gyro mode, and now the teams will be ready for this.
“Many team members made personal sacrifices for long shifts and shifts to ensure the health and safety of the observatory, while defining a path that would be safe and effective,” said Hubble’s project manager, Pat Krause, in a statement.
“The restoration of the gyroscope is not only vital for the life expectancy of the observatory, but also the Hubble is most productive in three-dimensional mode, and the extension of this historical period of productivity is the main objective of the mission,” he said. "Hubble will continue to make amazing discoveries when the time comes to work in a single gyro mode, but because of the tremendous effort and determination of the mission team, this is not the time."