Rocket Lab’s disco ball satellite has plunged back to Earth — and some aren’t sad to see it go

The Humanity Star sparked a contentious debate

In January, US spaceflight startup Rocket Lab stealthily launched a small “disco ball” satelliteinto orbit as part of a cosmic art project aimed at inspiring people to come together and look up at the sky. But after just two months in space, the satellite — called the Humanity Star — has fallen back to Earth and burned up in the planet’s atmosphere. It brings a premature end to the probe’s life, which turned out to be more controversial than the company had hoped.

No satellite in lower Earth orbit lasts forever. Though objects in this region are technically in space, there’s still a very thin atmosphere as high as 300 miles up. So satellites in low orbits are constantly bombarded by small atmospheric particles that slowly nudge vehicles closer to Earth, until gravity snags them back to the planet. Satellites equipped with thrusters can correct for this effect as long as they have fuel. But eventually, they all must come down to burn up in the atmosphere.

NO SATELLITE IN LOWER EARTH ORBIT LASTS FOREVER

The Humanity Star didn’t have thrusters, but its plunge wasn’t expected until nine months after launch, according to Rocket Lab. A couple days ago, satellite-tracking websites and even Rocket Lab’s own website showed that Humanity’s altitude was dropping fast, according to The Atlantic. So what gives? The company blames the premature end of the project on the satellite’s shape and weight. The Humanity Star is (or was) a three-foot-wide sphere comprised of 76 triangular panels, and it weighed just 18 pounds. That means it’s a small and lightweight satellite, with a large surface area. It’s a bit like a hollow ball, making it more susceptible to the atmosphere’s bombardment than a clunkier, heavier satellite.

A sphere is also a rare shape for a satellite, and that made it hard to predict its future, according to the company. “There’s not a whole lot of data out there about geodesic spheres and how long they’re supposed to [stay up] and what time frame they’re supposed to re-enter on their own,” Peter Beck, Rocket Lab’s CEO, tells The Verge. “So it’s always been tough to calculate.” Beck added that nine months was meant to be the maximum amount of time the Humanity Star could remain in orbit.

Now that the satellite is gone, some are breathing a sigh of relief, as many in the space community were not happy when the satellite launched. One point of frustration was the secrecy behind it. The Humanity Star rode into space on January 21st on the second test flight of Rocket Lab’s Electron rocket, along with three other small satellites. The company, which launches out of New Zealand, kept silent on its existence until after the flight was over. Rocket Lab then revealed the Humanity Star was in orbit by unveiling a website that allowed users across the world to track the probe.

“THE WHOLE POINT OF THE PROJECT WAS TO GET PEOPLE TO LOOK UP.”

The company claimed that the sphere’s reflective panels made the satellite the brightest thing in the night sky, and people could go outside whenever the disco ball passed overhead to see it twinkle. Beck says the goal was to give people a similar experience to one he had as a kid when his dad took him outside to show him the stars, and he wondered if we were the only ones out there in the Universe. “The whole point of the project was to get people to look up, not just at the Humanity Star, but to look past the Humanity Star and have that moment I did,” he says.

But some astronomers saw the Humanity Star as something more sinister akin to light pollution or “space graffiti” — a bright object that served no purpose other than to mess up astronomy observations. During the night, astronomers try to capture very precise images of the night sky with large ground-based telescopes. Satellites travel super fast in orbit, so any time a probe goes through a telescope’s field of view, it can leave a long, bright streak through an image.

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source:https://www.theverge.com/2018/3/22/17144208/rocket-lab-humanity-star-satellite-new-zealand-astronomy