Scientists Figure Out How to Continuously Watch the Entire Planet With Just 4 Satellites

For decades, scientists have been trying to figure out the minimum number of satellites that would be able to see every point on Earth. This question is motivated in part by the growing problem of space debris, but also by considerations of cost and efficiency. By the mid-1980s, researcher John E. Draim proposed a solution to this problem in a series of studies, claiming that a four-satellite constellation was all that was needed.

Unfortunately, his solution simply wasn’t practical at the time since a tremendous amount of propellant would be needed to keep the satellites in orbit. But thanks to a recent collaborative study, a team of researchers has found the right combination of factors to make a four-satellite constellation possible. Their findings could drive advances in telecommunication, navigation, and remote sensing while also reducing costs.

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LightSail 2 is Still Solar Sailing, But it’s Getting Lower and Lower with Each Orbit

LightSail 2 deployed it solar sail five months ago, and it’s still orbiting Earth. It’s a successful demonstration of the potential of solar sail spacecraft. Now the LightSail 2 team at The Planetary Society has released a paper outlining their findings from the mission so far.

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Now that Many Countries Have the Ability to Destroy Satellites, the US is Figuring Out Ways to Make Them More Armored

As long as human beings have been sending satellites into space, they have been contemplating ways to destroy them. In recent years, the technology behind anti-satellite (ASAT) weapons has progressed considerably. What’s more, the ability to launch and destroy them extends beyond the two traditional superpowers (the US and Russia) to include newcomers like India, China, and others.

For this reason, Sandia National Laboratories – a federal research center headquartered in New Mexico – has launched a seven-year campaign to develop autonomous satellite protection systems. Known as the Science and Technology Advancing Resilience for Contested Space (STARCS), this campaign will fund the creation of hardware and software that will allow satellites to defend themselves.

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Move Over SpaceX. Amazon Wants To Launch Thousands of Internet Satellites Too

NASA has released new composite images of the Earth at night, the first ones since 2012. NASA Earth Observatory images by Joshua Stevens, using Suomi NPP VIIRS data from Miguel Román, NASA's Goddard Space Flight Center

Back in April 2019 Amazon signaled its intention to get into the internet satellite business. Following in the footsteps of SpaceX and their Starlink satellite system, Amazon intends to launch thousands of internet satellites in the coming years. Now that they’ve filed their application with the FCC, we have more details of their plan.

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Virgin Orbit Tests its Satellite-Delivery Rocket for the First Time

Since 2015, Virgin Orbit has been developing a launch system that will send satellites into space using a rocket launched from a modified 747. This is part of Sir Richard Branson’s plan to crack the burgeoning market of cost-effective satellite deployment. This market is especially lucrative considering how many satellites are expected to be launched into orbit in the coming years.

This week, the Virgin Orbit team achieved a major milestone by flying the LauncherOne rocket into the air and releasing it over the Mojave desert for the first time. This drop-test not only validated the design of the modified 747 (named Cosmic Girl) that serves as its flying launchpad, it also demonstrated the effectiveness of the launch system – which can rely on regular airstrips instead of launch pads to send satellites into space.

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Satellites Equipped With a Tether Would be Able to De-Orbit Themselves at the end of Their Life

There’s no denying it, we are facing an orbital debris problem! As of January 2019, the ESA’s Space Debris Office estimates that there are at least 34,000 pieces of large debris in Low Earth Orbit (LEO) – a combination of dead satellites, spent rocket stages, and other assorted bits of space junk. And with thousands of satellites scheduled to be launched in the next decade, that problem is only going to get worse.

This is a situation that cries out for solutions, especially when you consider the plans to commercialize LEO and start sending crewed missions to deep space in the coming years. A team of scientists from the Universidad Carlos III de Madrid (UC3M) has come up with a simple but elegant idea: equip future satellites with a tether system so they can de-orbit themselves at the end of their lives.

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Before We Ruin the Universe, We Should Follow Some Space Sustainability Guidelines

There are over 20,000 objects in orbit around Earth that are larger than 10 cm. Image Credit: European Space Agency.

There are 20,000 objects orbiting Earth at this moment that are larger than 10 cm. Out of that number, only about 2,000 are operational satellites. The other 18,000 objects are pieces of junk of varying sizes. But it’s not just junk: it’s dangerous junk.

If that doesn’t sound like a problem, keep this in mind: Thanks to SpaceX and others, we’re living in the age of cheap access to space, and we’re seeing more and more satellites boosted into orbit. The problem won’t go away on its own.

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