Race against time: This spacecraft went to rescue the Swift telescope

An unprecedented high-risk mission

The rescue mission, launched on Friday, had never been attempted before and was described as “high risk” by space scientist Dr. Simeon Barber. The successful launch was carried out using the Pegasus XL rocket, which took off from a modified aircraft over the Marshall Islands. This pioneering venture, worth 30 million dollars, represents the first American attempt at robotic satellite rescue.

​- But NASA clearly thinks it’s worth a try. And the scientific community hopes for success because it is an important telescope that enables us to study super-high-energy phenomena for which we have no other methods of study – said Barber, senior research associate at the Open University.

Why is Swift in danger at all?

The Swift Observatory is falling because increased solar activity has expanded Earth’s atmosphere to the point where it touches Swift. This creates drag on the observatory and slows it down as it orbits the Earth, lowering its altitude. When it was first launched in 2004, it was in orbit at 600 kilometers (373 miles), and has now descended to about 360 kilometers (220 miles), with most of that descent occurring in the past two years. Without intervention, the telescope was predicted to enter the atmosphere and burn up by October 2026.

Satellites constantly fall to Earth and burn up on re-entry. But Swift is scientifically special, a favorite among researchers who use it to peer into the very dawn of the cosmos. The observatory, the size of a large car, has three telescopes for studying the most powerful explosions in the universe. They are caused by the final, violent deaths of giant stars and the collisions of the debris they leave behind. In just a few seconds, they release the same energy that the Sun will emit during its entire lifetime of ten billion years. Since these precious cataclysmic moments are so short, the craft must be fast and agile – hence its name. In short, there is nothing like Swift, and NASA has judged it to be a craft worth saving.

The race against time of the startup company

The task of rescuing the observatory was entrusted to the engineers of the young company Katalyst Space Technologies from Flagstaff, Arizona. They had less than a year to launch their mission before Swift fell below an altitude of 300 kilometers (186 miles), where rescue becomes impossible.

“What the Katalyst team has accomplished in just eight months is remarkable. The team has designed, built, tested and integrated a robotic spacecraft capable of performing one of the most ambitious commercial servicing missions ever attempted,” company CEO Ghonhee Lee said in a press release.

What will the rescue operation look like?

The LINK spacecraft, designed by Lee’s team, is a refrigerator-sized robot with three arms, equipped with cameras and guidance systems and powered by small thrusters. After launch, the spacecraft will spend the next few weeks gradually activating its systems: power, navigation, cameras and sensors it will rely on, checking to see if each of them survived the journey.

Although the Pegasus XL rocket brought LINK close to Swift’s orbit, the three-armed robot still has a lot of work to do to get close to the target, whose altitude changes from week to week. The rescue craft, which is moving itself, must approach the moving target. It is expected to be finally aligned with the telescope approximately three to four weeks after launch.

Using its cameras and sensors, LINK will approach and circle the telescope, photographing it from every angle. Engineers speculated where they might catch it, but Swift must have changed after twenty years in orbit. If all goes according to plan, LINK will capture Swift and gradually, over several months, raise its orbit back to a safe altitude of about 600 kilometers.

​- The Swift telescope was never designed to be captured in space and re-orbited. Therefore, the spacecraft that saved him approached very slowly and attached itself to him – explained Barber.