A privately operated spacecraft that was intended to rescue NASA’s aging Swift Observatory succeeded in approaching the troubled telescope and photographing it, even though the rescue mission had been abandoned two weeks earlier.
However, the robotic spacecraft, equipped with three mechanical arms, was forced to retreat because it was running low on fuel, according to Katalyst Space Technologies, the company behind the attempted rescue.
“We got so close, but so far,” Katalyst CEO Ghonhee Lee told The Associated Press this week.
Katalyst’s Link spacecraft came within about 15 kilometers (9 miles) of Swift on Tuesday. During the approach, its instruments collected valuable information about the aging observatory for NASA. Although the rescue attempt had been officially canceled in August because of problems with Link, Katalyst decided to continue the approach as a training exercise for future satellite-maintenance missions.
Shortly after being launched toward Swift in July, Link began spinning uncontrollably. Mission controllers eventually managed to reduce the spacecraft’s rotation and regain control, but doing so consumed a significant amount of its limited fuel. As a result, Link no longer had enough fuel to move Swift into a higher and more stable orbit that would have allowed the telescope to continue its scientific work.
Lee attributed Link’s difficulties partly to the speed with which the mission had to be developed. The spacecraft was prepared in only nine months, forcing engineers to use available components rather than wait for their preferred equipment.
NASA spent $30 million on the rescue attempt, which was designed from the beginning as a fast-paced experimental mission. Both NASA and Katalyst regarded it as an opportunity to test new technology, although they were concerned that a collision could create dangerous clouds of space debris.
NASA Administrator Jared Isaacman said after Sunday's launch of the Roman Space Telescope that the unsuccessful result was disappointing but still provided valuable experience. He argued that NASA should continue pursuing challenging missions because lessons learned from failures can improve future efforts.
Isaacman also said extending the operational life of expensive spacecraft is worthwhile when doing so costs less than building replacements. The Roman Space Telescope, for example, was designed to be refueled despite being intended to operate roughly 1 million miles (1.6 million kilometers) from Earth.
Lee said Link probably does not have enough fuel for another attempt to approach Swift closely. Nevertheless, the spacecraft can continue testing its three approximately 3-foot (1-meter) robotic arms and gathering useful information before it eventually falls back into Earth's atmosphere and burns up within the coming weeks.
Swift was launched in 2004 and still has some time left in orbit, although its remaining lifetime depends partly on solar activity. Strong solar storms in recent years have caused its orbit to decay much faster than anticipated. By Friday, Swift was orbiting about 208 miles (335 kilometers) above Earth, less than half the altitude at which it began studying some of the universe's most powerful explosions.
NASA expects Swift to reenter the atmosphere sometime between October and the end of the year. The agency restarted observations with the telescope last week after suspending them earlier this year to preserve its limited power supply.
Solar activity has also caused the orbit of the Hubble Space Telescope to gradually decline. Katalyst is working on a newer spacecraft that could eventually raise Hubble into a higher and more durable orbit.
Lee noted that Hubble is still expected to remain operational for several more years, meaning that any potential servicing mission is not an immediate necessity.
According to Lee, repairing and maintaining aging telescopes and other satellites was once considered a highly specialized idea. He believes, however, that such missions will become increasingly common as space agencies and companies look for ways to extend the useful lives of valuable spacecraft.
The report was later corrected to clarify that Link's close approach to Swift occurred on Tuesday rather than the previous weekend, following updated information provided by Katalyst Space Technologies.