This is good news for the US space agency, which has spent the past few weeks trying to fix issues with its current window to the universe, the Hubble Space Telescope.
The legendary telescope that has revolutionized our understanding of the cosmos for more than three decades has a technical problem. According to NASA, the Hubble Space Telescope payload computer, which powers the spacecraft’s scientific instruments, suddenly broke down on June 13.
As a result, the on-board instruments for taking photos and collecting data are not currently functioning. The agency’s best and brightest have worked diligently to bring the aging telescope back online and run a barrage of tests, but still can’t seem to figure out what went wrong.
“It’s just the difficulty of trying to fix something in orbit 400 miles away [653 million kilometres] above your head rather than in your lab, ”NASA director of astrophysics Paul Hertz told Al Jazeera.
“If this computer was in the lab, it would be very quick to diagnose it,” he explained. “All we can do is send a command, see what data is coming out of the computer, then send that data and try to analyze it. “
When Hubble launched on April 24, 1990, scientists were excited to scan the vast expanse of space with a new pair of “eyes,” but they had no idea how much a telescope would change our understanding of space. ‘universe.
The telescope explored the far reaches of space, spying on the most distant galaxy on record, the one that formed just 400 million years after the Big Bang.
Hubble has also produced some great galactic snapshots like the Hubble Ultra Deep Field.
Capture in a single photograph the hundreds of thousands of ancient galaxies that formed long before Earth even existed – each galaxy is a vast flourishing star center, where hundreds of billions of stars have been born, have lived their lives and died.
Light from these galaxies took billions of years to reach Hubble’s sensors, making it a sort of time machine – one that takes us on a journey through time to see them as they were. billions of years ago.
Hubble also spied on our cosmic neighbors, discovering some of the moons around Pluto.
His observations have shown us that almost every galaxy has a supermassive backhole at its center, and Hubble has also helped scientists create a vast three-dimensional map of an elusive and invisible form of matter that makes up most of the matter in it. ‘universe.
Called dark matter, the enigmatic substance is not visible. Scientists only know it exists by measuring its effects on ordinary matter. Using Hubble’s suite of science instruments, scientists were able to create a 3D map of dark matter.
What went wrong
Scientists have been planning Hubble’s inevitable demise for some time. Over the past 31 years, the telescope has seen its fair share of turmoil.
Shortly after launch, NASA discovered that something was wrong: Hubble’s main mirror was faulty. The telescope is the only one in NASA history that was designed to be maintained by astronauts.
During its lifetime (and during the agency’s shuttle program), groups of NASA astronauts repaired and upgraded Hubble and its instruments five times.
When the Space Shuttle retired in 2011, that meant Hubble would be on its own. If the telescope was in trouble, ground controllers would have to perform remote troubleshooting.
So far, this has proven to be effective. That is to say until June 13.
Just after 4:00 p.m. EDT (8:00 p.m. GMT), an issue with the observatory payload computer appeared, putting the telescope and its science instruments in safe mode.
Hubble has two payload computers on board – the main computer and a backup for redundancy. These computers, called NASA Standard Spacecraft Computer-1 (or NSSC-1), were installed during one of the telescope’s maintenance missions in 2009; however, they were built in the 1980s.
They are part of the Science Instrument Command and Data Handling (SI C&DH) unit, a module of the Hubble Space Telescope that communicates with the telescope’s scientific instruments and formats the data for transmission to the ground. It also contains four memory modules (one primary and three backup).
The current unit is a replacement that was installed by astronauts during the STS-125 shuttle mission in May 2009 after the original unit failed in 2008.
When the main computer crashed in June, NASA tried to activate its backup, but both computers are experiencing the same problem, suggesting that the real problem is in another part of the telescope.
Currently, the team is examining the different components of the SI C&DH, including the power regulator and the data formatting unit. If any of these parts are the problem, engineers may need to run a more complicated series of commands to move on to backups for those parts.
NASA says it will take some time to sort out the issue and move on to backup systems if necessary. That’s because activating these saves is a riskier maneuver than anything the team has tried so far.
The operations team will need several days to see how the backup computer is performing before they can resume normal operations. The backup has not been used since it was installed in 2009, but according to NASA it has been “thoroughly tested on the ground before being installed on the spacecraft.”
Part of the problem with Hubble is that the observatory was designed to be serviced directly. Without a space shuttle, there is simply no way to do it.
“The biggest difference between past problems and this one is that there is no way to replace parts now,” John Grunsfeld, a former NASA astronaut, told Al Jazeera.
But, he added, “The team working on Hubble are masters of engineering. I am convinced that they will be successful.
To look forward
The James Webb Space Telescope, scheduled to launch in November, is expected to extend Hubble’s legacy. The enormous telescope, essentially a giant piece of space origami, will unfold its shining golden mirrors and look even further into the universe than Hubble ever could. Its infrared sensors will allow scientists to study star nurseries, the heart of galaxies and much more.
#Webb takes a big step towards the launch !!! 🚀🛰️🔭
Webb has just successfully passed his “Final Mission Analysis Review”, bringing him closer to seeing further!
– Télescope ESA Webb (@ESA_Webb) July 1, 2021
Hubble has shown us that almost all galaxies have supermassive black holes at their centers, the brightest of which are called quasars. These incredibly bright objects can tell us a lot about the evolution of galaxies, as the jets and wind produced by a quasar help shape its host galaxy.
Previous observations have shown that there is a correlation between the masses of supermassive black holes and the masses of their galaxies, meaning that quasars could help regulate star formation in their host galaxy.
“We see black holes at a time when the universe was only 800 million years old and are almost as massive as the bigger ones we see today, so they evolved very early,” said Chris Willott. from the Canadian Space Agency to Al Jazeera.
“By studying their galaxies, we can see what impact these extreme black holes have on the early star formation in these galaxies. “
Through the eyes of Hubble, scientists cannot detect individual stars in galaxies with these ultra-bright quasars, but with Webb, scientists hope to be able to see not only individual stars, but also the gas from which those stars. are formed.
This means that the Webb Telescope has the potential to truly revolutionize our understanding of the formation and evolution of galaxies, in the same way that Hubble has done with our knowledge of the universe over the past three decades.