Get ready to explore the next big thing in space exploration - the world of Very Low Earth Orbit (VLEO) satellites is about to take center stage!
With over 15,000 satellites already orbiting our planet, most of them residing in Low Earth Orbit (LEO), it's no surprise that this region is getting a bit crowded. But fear not, because there's another orbit even closer to Earth that promises to alleviate this congestion.
VLEO, as it's known, sits just 60 to 250 miles above the Earth's surface, offering a range of advantages over higher-altitude satellites. As an engineer and professor developing technologies for space exploration, I'm excited to share these benefits with you.
VLEO satellites provide sharper, higher-resolution images, faster communication, and better atmospheric science data. Imagine being able to see the Earth's surface in incredible detail, almost as if you were standing right there! This technology has applications in agriculture, climate science, disaster response, and military surveillance.
But here's where it gets controversial...
The main challenge with VLEO is atmospheric drag. Space may be thought of as a vacuum, but the Earth's atmosphere extends far beyond what we typically consider 'space'. In fact, the von Kármán line, at around 62 miles up, is often considered the starting point of space. However, there's no clear boundary; the atmosphere simply thins out as you move away from Earth.
Satellites in VLEO experience significant atmospheric drag, which causes them to deorbit quickly, sometimes in a matter of weeks or days. To counteract this, satellites must constantly propel themselves forward, much like a cyclist pedaling into the wind.
Our team at Penn State, in collaboration with Georgia Tech and funded by the U.S. Department of Defense, is developing an innovative propulsion system to tackle this issue. We've designed a new thruster that collects the atmosphere using a scoop and then heats it with high-power microwaves. The heated gas is expelled through a nozzle, propelling the satellite forward. We've successfully demonstrated a prototype in a vacuum chamber simulating conditions at 50 miles above the Earth.
This technology has the potential to revolutionize VLEO operations, especially at lower altitudes where the atmosphere is thicker.
And this is the part most people miss...
VLEO satellites also face other challenges, such as exposure to high levels of atomic oxygen, a highly reactive form of oxygen that can corrode materials, and extremely high temperatures caused by friction as they move through the atmosphere.
Despite these challenges, the potential of VLEO satellites is driving significant research and investment. Juniper Research estimates that $220 billion will be invested in this field over the next three years alone.
So, what do you think? Are VLEO satellites the future of space exploration and communication? I'd love to hear your thoughts and opinions in the comments below!
