Mission launched to save falling Swift space telescope

In a low-cost, high-risk gamble, a small company in partnership with NASA and Northrop Grumman launched an experimental space tug Friday to hunt down and grab a falling space telescope that otherwise would plunge back to Earth and burn up by year’s end.

Using small robot arms to lock onto the $250 million Neil Gehrels Swift Observatory, the tug will attempt to boost the satellite back up to a safe altitude, giving it a new lease on life spotting the most violent explosions in the universe and continuing its role as a “first responder” for follow-on observatories.

If the gamble pays off, that is.

Katalyst Space designed, built and tested the LINK satellite in just eight months under a $30 million contract with NASA that included the cost of its air-launched Northrop Grumman Pegasus XL booster and carrier jet — a bargain-basement price for such an ambitious mission.

Running three days late because of bad weather and a software snag, the LINK and its booster were released from Northrop Grumman’s L-1011 jet at 4:36 a.m. ET, dropping like a bomb from an altitude of 40,000 feet above the Marshall Islands in the South Pacific Ocean.

NASA confirmed the booster’s three solid-fuel stages fired as planned to put the satellite in orbit, saying flight controllers will begin detailed checkout operations after confirming LINK’s solar arrays deployed as expected.

Assuming no problems, controllers will spend several weeks checking out the spacecraft’s systems before kicking off the actual rendezvous with Swift. If all goes well, the LINK spacecraft will use three robotic arms to lock onto a flange that was used before launch to secure LINK for ground transport.

Low-power, but efficient, ion thrusters then will start firing to begin boosting the telescope up to an altitude of around 370 miles, extending its mission another 10 years or so. The entire reboost mission is expected to take 10 to 12 weeks to complete.

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

Why the accelerated timeline?

“If we don’t do something, [Swift] will come out of orbit by the end of this calendar year,” Shawn Domagal-Goldman, director of astrophysics at NASA Headquarters, told CBS News. “The clock is ticking.”

And why go to all this trouble to extend the life of a satellite that has already lasted two decades longer than originally planned?

Launched in 2004, Swift was built to scan deep space, on the lookout for the high-energy radiation emitted by gamma ray bursts, the most powerful explosions since the big bang birth of the universe more than 14 billion years ago.

Gamma ray bursts are thought to be triggered by the collapsing cores of massive stars in supernova explosions, possibly creating black holes in the process, or when two high-density neutron stars collide, generating energies high enough to forge the heavy elements that even the big bang could not produce.

“Swift was designed to study gamma ray bursts, short-lived flashes of high-energy light that release more energy in just a few seconds than the sun will in its entire lifetime,” said Brad Cenko, Swift’s principal investigator.

“Since launching in 2004, it’s been extremely successful in this regard, detecting over two thousand of these sources all the way out to the edge of the visible universe, and helping confirm that most of the heaviest elements in the periodic table, including the gold and platinum in our jewelry, are forged in these systems.”

Designed for a two-year mission, Swift has been slowly falling to lower and lower altitudes over the past two decades because of interactions with traces of the extreme upper atmosphere that extend out into the realm of low-Earth orbit.

Solar storms can heat up the atmosphere, periodically causing it to swell, increasing the “drag” on the spacecraft, and Swift is not equipped with thrusters to counteract that downward pull.

The observatory currently is falling about five miles per month, a descent that will slowly but surely pick up speed as it drops lower and lower into thicker regions of the upper atmosphere. The satellite is predicted to reach an altitude of 186 miles in October.

“At the moment, we think we have several months where Swift will be at a sufficiently high altitude to give the Katalyst folks a great chance to capture and boost us,” Cenko said.

Katalyst Space was already working on robotic satellite rescue and servicing systems and NASA saw the Swift reboost mission as an ideal way to test the technology while at the same time possibly restoring a valuable science satellite to service.

The result was LINK, a 940-pound spacecraft with three xenon-fueled ion engines, solar panels that can generate 4 kilowatts of power, three robot arms, 16 orientation control thrusters and a complex suite of sensors and other systems focused on rendezvous and the “proximity operations” required for capturing Swift.

“No one thought it was going to be possible,” said Domagal-Goldman. “No one thought we would get as far as we’ve already gotten today, and I have to be honest, there are still risks ahead of us. But I’m both deeply thankful and as optimistic as I can be that we’ll meet those challenges.”

The Swift space telescope is equipped with three instruments that work together to observe GRBs, capturing gamma rays, X-rays and ultraviolet emissions.

The spacecraft was originally named “Swift” because it can spot and rapidly re-orient itself to lock onto a GRB, radioing precise location data to other observatories for coordinated observations before the objects fade from view.

“The Hubble Space Telescope is much more sensitive than Swift, and it takes much crisper pictures,” Cenko said. “But Hubble takes at least one to two days to repoint to a target of interest in the best case scenario where Swift can routinely conduct follow up of things that go bump in the night within minutes.

“It really is NASA’s ‘first responder,’ and by working together in this complementary manner, the NASA astrophysics portfolio can tackle questions that would be impossible for any single facility to answer.”

Katalyst Space has high hopes for the Swift reboost mission. The company plans a variety of robotic spacecraft that one day could be used to not only reboost aging satellites, but also refuel and even repair high-value civilian and military spacecraft that otherwise could be disabled or lost.

The same technology, at a much larger scale, could perhaps be used at some point to boost the slowly falling Hubble back up to a safe altitude. The world’s most famous space telescope, now 36 years into its historic mission, is expected to re-enter the atmosphere in the 2030s if nothing is done.

“Katalyst is here really to kind of mark the end of that throwaway model and the start of a new model,” said Robert Lamontagne, Katalyst vice president of strategic partnerships. “You should be able to refuel, reposition, repurpose, repair and even upgrade satellites, even if they were never prepared for it.”