The idea of flying satellites in "very" low Earth orbit is not new. Back at the dawn of the space age, in the late 1950s, the first American spy satellites under the Corona program orbited at an altitude of 120-160 kilometers above the Earth.
This low vantage point allowed the Kodak cameras aboard the Corona satellites to take the highest resolution images of Earth during the height of the Cold War. However, flying so close to the planet presents a number of challenges, most notably atmospheric drag.
So for most of the space age, satellites flew in much higher orbits. Today, most satellites fly at altitudes between 400 and 800 kilometers, which is high enough to avoid most atmospheric effects but still close enough to provide good communications and a clear view of the planet.
In recent years, new space companies have announced plans to develop small and medium satellites designed to operate in very low Earth orbit (VLEO) and take advantage of a close vantage point.
The first of these companies to actually reach the launchpad was a Denver-based startup called Albedo.
Launching a startup
Albedo was founded about four years ago by two engineers from Lockheed Martin, Topher Haddad and AJ Lasater, and a software engineer from Facebook, Winston Tree. Since 2021, the trio has raised more than $100 million to develop satellites capable of transmitting visual images with a resolution of 10 centimeters.
"The vision was to commercialize VLEO as a means of acquiring imagery at a resolution that today can only be obtained from aircraft or drones, either commercially or by billion-dollar national systems in the national security domain," says Haddad. This resolution is significantly higher than all currently available commercial satellite imagery and rivals the resolution of some of the best spy satellites currently operated by the U.S. and other major space powers."
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Today, helicopters or drones are sometimes the only real solution to obtaining high-resolution imagery, Haddad said. But there are many places on the planet where flights are limited, and the cost of regular airplane flights is rising rapidly.
Clarity-1 is on site
Albedo's first major test could come as early as next week, when the Transporter 13 mission launches on SpaceX's Falcon 9 rocket. The company's first satellite, Clarity-1, weighing 530 kilograms, will sit atop a stack of spacecraft designed to travel together. The mission could launch as early as next weekend from Space Force Base Vandenberg in California.
The Clarity-1 satellite will be launched into an orbit between 500 and 600 kilometers high and then attempt to transfer itself into an operational orbit 274 kilometers above the planet.
The spacecraft is larger than a full-sized refrigerator, looks like a phone booth and is designed to last about five years, depending on the solar cycle.
Clarity-1's launch falls at the peak of the 11-year solar cycle, so this could shorten its active lifetime.
Albedo was recently awarded a contract from the U.S. Air Force Research Laboratory for up to $12 million to share VLEO-specific orbital data and analysis to support the development of new missions and payloads beyond its own optical sensors.
Serving a variety of customers
Among the advantages of such a platform are superior image quality, less congested orbits, and natural cleanup of
trash as idle satellites descend into Earth's atmosphere and burn up. But what about the downsides?
In orbits closer to Earth, the main problem is atomic oxygen, which is highly reactive and energetic. In addition, there are plasma vortices and other phenomena that interfere with the satellites and destroy their materials. This makes VLEO much more dangerous than satellites at high altitude.
It's also more difficult to get accurate images. "The hardest part is pointing and position control," says Haddad. "Because it's already challenging at LEO when you have a big telescope and you're trying to get high resolution. Then you put it on VLEO, where the Earth's rotation is faster, and that just compounds the problem."
Haddad said Albedo will likely have 24 satellites in the next few years, but that number will depend on customer demand. Albedo has already announced half a dozen commercial customers who will use Clarity-1 for a variety of purposes, such as monitoring power supplies and pipelines or maintaining solar farms.
But first, the company must demonstrate its technology.