The Problem of Low-Earth Orbit Satellites
Low-earth orbit satellites, located about 160 to 2,000 kilometers above the Earth, are particularly valuable for providing rapid communications services. Their relative proximity to the planet allows for lower latency and higher data transmission speeds compared to geostationary satellites, which are much further away.
Companies like SpaceX, with its Starlink network, have already exploited these advantages to provide high-speed Internet services in underserved regions. Amazon, with its Project Kuiper, is another example. We also know that mega-constellations are planned in China.
The problem with these structures is that managing communications for many users via a limited number of satellites remains a major challenge.
Currently, each satellite in low orbit can only handle one user at a time per antenna array. This means that as demand for communications services increases, companies are forced to launch either large constellations of satellites or individual machines equipped with multiple antenna arrays.
These solutions, while effective in the short term, pose long-term challenges in terms of cost and management.
SpaceX's approach, for example, is to launch thousands of satellites into low orbit to create a global network. Starlink already has more than 6,000 structures in orbit and plans to launch several thousand more. This “constellation” model offers extensive coverage, but it also presents technical and economic challenges. Not only are the launch and management costs of these constellations high, but the proliferation of satellites in space also increases the risk of collisions.
An innovative solution: managing multiple users per satellite
In order to address these challenges, researchers from Princeton and Yang Ming Chiao Tung University propose a method for splitting a beam of radio waves into several sub-beams. This could essentially allow a single antenna array to simultaneously manage multiple users, eliminating the need for multiple antenna arrays or launching additional satellites.
This new approach relies on optimizing antenna positioning to precisely direct the beams where they are needed, without interference between the different signals. The researchers liken the technique to using a single flashlight that can project multiple beams of light simultaneously, instead of needing multiple lamps to illuminate different areas.
By applying this principle to satellite communications, it becomes possible to significantly reduce the amount of hardware needed for each satellite.
Credits: NicoElNino/istock
Reducing costs and space debris
This advance could transform the low-orbit satellite industry. By allowing a single satellite to handle multiple users simultaneously, companies could significantly reduce the number of structures needed to provide global coverage.
For example, according to the researchers, a traditional network of low-orbit satellites would require about 70 to 80 machines to cover a country the size of the United States. With this new technology, this number could be reduced to just 16 satellites.
This reduction in the number of satellites would have several positive impacts. First, it would reduce the costs associated with launching and maintaining constellations. Each launch costs millions of dollars. The savings from reducing the number of satellites could be reinvested in improving services or researching new technologies.
Second, this approach would help limit space congestion. With the rapid increase in the number of satellites in low orbit, the probability of collisions and the generation of space debris are becoming major concerns. This debris can remain in orbit for decades and pose a threat to other satellites, as well as to manned space missions.
By reducing the number of satellites needed, this new technology could help reduce these risks in the long term.
A realistic and promising implementation
At a time when many players are planning to launch their own constellations to offer Internet services, this new technology is therefore timely.
Although this advance is mainly theoretical for now, the first results are promising. The researchers tested their method on terrestrial antennas and confirmed that their calculations work in real conditions. The next step is to integrate this technology into satellites and test it in space.
One of the advantages of this approach is that it does not require major modifications to existing satellites. This means that satellite companies could integrate this technology into satellites already built or under construction, making the transition to this new method smoother and less expensive.
Source: IEEE Transactions on Signal Processing
With an unwavering passion for local news, Christopher leads our editorial team with integrity and dedication. With over 20 years’ experience, he is the backbone of Wouldsayso, ensuring that we stay true to our mission to inform.
