A European satellite will make spaceflight history today (July 28), if all goes in response to plan.
The European Space Agency’s (ESA) Aeolus spacecraft is scheduled to reenter Earth’s atmosphere this evening, capping a four-day orbit-lowering campaign that might blaze a brand new trail for satellite operators.
“This is kind of unique, what we’re doing. You do not find really examples of this within the history of spaceflight,” Holger Krag, head of ESA’s Space Debris Office, said during a press briefing on July 19. “That is the primary time to our knowledge [that] we’ve got done an assisted reentry like this.”
Related: When and where will Europe’s Aeolus wind satellite fall to Earth this week?
Aeolus was a pioneer in life as well. The three,000-pound (1,360 kilograms) satellite launched in August 2018 to watch Earth’s winds, something that had never been done intimately from orbit.
The spacecraft’s data have helped researchers improve their climate models and weather forecasts, ESA officials have said. And there may be more of this data than the mission team expected: Aeolus operated for nearly 4.5 years, about 18 months longer than its planned scientific lifetime.
However the spacecraft eventually began running low on fuel. Fairly than let Earth’s atmosphere drag Aeolus down in a chaotic fashion, as is the norm for orbiting satellites, mission team members decided to take a more energetic role within the spacecraft’s demise. They orchestrated the de-orbit campaign, which goals to make sure that Aeolus burns up over an empty stretch of the Atlantic Ocean, posing no threat to people and buildings on the bottom.
That threat, though small, is real each time a satellite falls uncontrolled to Earth: Usually, about 20% of a spacecraft’s mass survives the fiery trip through the atmosphere and hits terra firma (or, more commonly, ocean waters). And there is lots of stuff up there just waiting to return down.
“Today, we’ve got 10,000 spacecraft in space, of which 2,000 aren’t functional. When it comes to mass, we’re speaking about 11,000 tons,” Krag said on the July 19 press conference.
About 100 tons of human-made space junk fall to Earth annually, and huge objects reenter our atmosphere about once per week on average, he added.
Guided reentries, that are commonly performed by rocket stages after orbital launches, could help make a dent on this space-junk problem. And the Aeolus team hopes to paved the way on this respect.
Aeolus’ reentry campaign “sets a brand new precedent for protected spacecraft operations and sustainable spaceflight, for each future missions and people already in orbit,” ESA’s Rosa Jesse wrote in a blog post last month.
Aeolus studied Earth’s winds from an altitude of about 200 miles (320 kilometers). The spacecraft began falling from this orbit on June 19, and the mission team began accelerating the method five weeks later.
On Monday (July 24), Aeolus performed two engine burns that lasted a complete of 37.5 minutes and lowered its altitude by about 19 miles (30 km), to 155 miles (250 km). The campaign picked up again Thursday (July 27), with 4 planned orbit-lowering maneuvers.
One final maneuver is planned for today, with reentry expected about five hours after its conclusion, ESA officials have said. In the meanwhile, nonetheless, it’s too soon to predict when and where Aeolus will come down, and which parts of Earth might have the ability to see the satellite’s blazing death dive. We’ll just must keep our eyes peeled for updates from ESA and the Aeolus team.
It is also possible that the assisted reentry won’t go entirely in response to plan, and that Aeolus’ reentry will find yourself being a minimum of partially uncontrolled. But, even in that case, the present campaign would still have been well worth the effort, ESA officials said.
“Successful or not, the attempt paves the way in which for the protected return of energetic satellites that were never designed for controlled reentry,” the agency’s Peter Bickerton wrote in a July 19 blog post.