An Aging Space Telescope Restarts Its Science Work After a Failed Rescue Mission
A famous space telescope is back to work studying the mysteries of the universe. This comes after spending months in a special energy-saving mode while waiting for a rescue mission that unfortunately did not succeed. Mission controllers recently turned two of the telescope's main cameras back on, allowing it to take pictures of deep space once again.
The space observatory has spent more than twenty years exploring the cosmos. However, it is slowly falling toward Earth. Scientists had hoped a robotic helper spacecraft would save it, but those plans had to be abandoned after the helper experienced major technical problems in orbit.
A Robotic Rescue Plan Goes Wrong
Because the aging telescope does not have its own engines to push itself higher, it relies on staying in a stable orbit. To help the telescope stay in space longer, scientists planned an ambitious rescue. A private aerospace company launched a small robotic servicing satellite during the summer. The goal of this helper satellite was to fly up to the telescope, grab onto it, and push it into a higher, safer orbit.
Unfortunately, the rescue mission ran into serious trouble shortly after launch. The robotic helper began to spin out of control, which made it very difficult for controllers on Earth to talk to it. Engineers discovered that several key parts of the rescue satellite had stopped working:
- Reaction wheels: Two of the three wheels used to steer and stabilize the satellite broke down.
- Thrusters: The gas thruster system used for movement lost some of its power.
Even though engineers on Earth managed to stop the satellite from spinning and regained control, the damage was already done. The robotic helper was no longer capable of safely grabbing and moving the heavy space telescope. Instead of a rescue, the helper satellite will now only practice flying close to the telescope to test technology for future missions.
The Invisible Pull of Earth's Atmosphere
Without the planned boost, the space telescope faces a certain end. The spacecraft flies in what is called low Earth orbit. Even though this is considered space, there are still a tiny number of air molecules present. Over time, these molecules rub against the spacecraft, creating atmospheric drag that slows it down and pulls it closer to Earth.
Recently, this drag has become much worse. High solar activity from the sun has heated up the outermost layers of Earth's atmosphere. When the air heats up, it expands outward into space. This means the telescope is hitting more air particles than usual, causing it to fall much faster than scientists originally predicted.
To prepare for the rescue, controllers had previously shut down the telescope's instruments and angled its solar panels. This was done to make the spacecraft as sleek as possible, reducing drag and helping it stay in orbit a little bit longer.
Instruments Return to Action
Now that the rescue mission is no longer happening, scientists have decided to make the most of the telescope's remaining time. They have restarted two of its three primary tools to gather as much data as possible before the spacecraft falls. Here is the current status of the telescope's instruments:
- The X-ray Telescope: This instrument is back online and actively observing high-energy light from distant cosmic events.
- The Ultraviolet and Optical Telescope: This camera is also working again, capturing both visible light and ultraviolet light from space.
- The Burst Detection Instrument: This third tool remains turned off for now to save power, but controllers hope to turn it back on in the coming weeks.
The Final Days of a Space Pioneer
When the observatory was first launched more than two decades ago, it was only expected to work for two years. Its main job was to search for gamma-ray bursts, which are the most powerful and violent explosions in the universe. The telescope succeeded far beyond anyone's expectations, spending twenty years spotting fleeting space events and quickly alerting other telescopes around the world so they could look at them too.
Now, the clock is ticking. Without a boost to its orbit, the telescope is expected to drop below a critical altitude of about 185 miles within the next month or two. At this low height, the air resistance becomes too strong for the telescope to function properly, and its descent will speed up rapidly.
The telescope is expected to fall back to Earth later this year. As it plunges through the thick air of the atmosphere, most of the spacecraft will burn up harmlessly. Until that happens, the veteran explorer will keep its cameras pointed at the stars, collecting valuable information until its very last moment.