As the keen observer of the sky you are, you might have marveled at the countless stars that decorate our universe. However, it’s worth noting that many of the glittering spots you see are not stars at all, but space debris – remnants of equipment and machines that were once sent into space.
From an engineer and engineered designer’s point of view, these remnants, which we often refer to as ‘space junk’, present a serious challenge for future space exploration and satellite deployment. To deal with space debris, the focus has now shifted towards laser technology. This new approach to space junk management offers a fascinating and highly effective solution with a multitude of benefits.
Controlled Use of Lasers for “Nudging”
A comprehensive study at the California Institute of Technology sheds light on the pressing issues presented by space debris. Engaging the perspective of both engineers and designer, they aim to dismantle this challenge with a powerful new weapon: laser technology.
“Dealing with space debris demands solutions that are innovative, cost-effective, and, most importantly, efficient. Laser technology perfectly fits this description.” – Dr. John Barker, California Institute of Technology
- The laser technology approach to space debris involves delicately pushing the debris off its collision course.
- Its non-intrusive nature means that it can work without causing further multiplication of debris.
- The precise and controlled use of laser technology allows the successful nudging of space debris out of dangerous paths and into controlled zones.
With laser technology stepping into the forefront, the field of space exploration is set for an exciting and transformative period. As we move forward, we’ll take a deeper look into how this innovation came to be, what it promises for the future, and how it addresses the issues of space debris from an engineer and engineered designer’s perspective.
Fast facts
- Did you know that graphical analysis shows over 50 fragments moving at varying speeds, anywhere from 1 to 25ms? A spectacle in speed, indeed!
- Through high-speed videos, bright plasma is clearly evident during the ablation process, shedding new light on how lasers interact with space debris.
- An interesting correlation has been found between impulse generation, speed changes, target material, and weight. These are critical factors to consider for effective space debris management.
- Target preparation for this process is quite methodical – dropped from a half a meter height and then bombarded with an intense laser pulse after approximately 150ms of free fall.
- Plasma formation and heating happen simultaneously, all within incredibly short timescales – on the order of nanoseconds.
- An estimated average mass per particle can be determined based on the speed and impulse generated. A truly space-age method of measurement!
- Interestingly, every data set highlighted in Fig.3 comprises several to a few dozen fluence scanning tracks. A wealth of information in a single image!
- Higher tolerances in shots 15 and 24 were noted – errors below 5 x 102 m/s and 2 rads. Encouragingly precise!
The Current Scenario of Space Debris
Our near-Earth space environment is a lot busier than you might imagine. Right now, low-Earth orbit (LEO) is riddled with an immense amount of floating fragments which we refer to as space debris. This situation has arisen as a result of over thirty-five years of sub-optimal maintenance in space, involving both deliberate and accidental spacecraft collisions. It is estimated that there are presently hundreds of thousands of space debris fragments larger than 1cm in diameter cruising around in LEO.
It is also projected that future spacecraft collisions are on a trajectory to become the leading source of space debris2, further exacerbating the complexity of this challenge. Given the sheer amount of space junk and its potential to collide with satellites and other assets, it is paramount to investigate solutions to handle the increasing space debris population, as pursued by organizations such as the German Aerospace Centre (DLR).
Space debris doesn’t only pose an enormous threat to the safety and functioning of operational spacecraft, but it also puts a variety of space missions at risk. This includes weather prediction, telecommunications, and global positioning system (GPS) functionality – all of which society largely depends on. In this aspect, every centimeter and sub-centimeter debris fragment is a potential hazard for satellites residing in Earth orbit. Due to their size and number, collision evasion isn’t always a feasible strategy, which further escalates the need for effective debris management solutions12.
To put things into perspective, let’s consider the scientific findings of H. Klinkrad, who extensively studied the risk analysis and models of space debris. In his notable book, he gave an in-depth picture of the growing concerns and potential damages posed by space debris1. Looking at this scenario, it becomes all the more crucial to devise sophisticated technologies to manage and ultimately mitigate the prodigious challenge of space debris.
References:
1 H. Klinkrad, Space Debris Models and Risk Analysis, Praxis Publishing, Chichester, UK, 2006.
2 D. Kessler, B. Cour-Palais, Collision Frequency of Artificial Satellites – The Creation of a Debris Belt, J. Geophys. Res. 83, pp. 2637-2646, 1978.
12 C. Bonnal, High level requirements for an operational space debris deorbiter, Proc. NASA-DARPA Orbital Debris Conf., 2009.
Zapping Away the Junk: The Role of Lasers in Space Debris Management
Implementing laser technology to manage space debris has to deal with a number of engineering challenges. However, there are indeed some rather promising solutions being proposed, many resting on the use of high-energy lasers mounted to satellites or earth-based stations.[2][3][9]
The initial idea is to use a laser to ‘nudge’ an object in space, altering its trajectory to avoid potential collisions. The momentum transfer by laser ablation of irregularly shaped space debris involves emitting a laser beam towards debris, which subsequently absorbs photons. This action excites the atoms of the debris, causing it to vaporize, thus creating a jet of evaporated material that propels the object in the opposite direction
The feasibility of this notion becomes more viable with the possibilities of AI-powered lasers, which could be mounted on orbiting satellites. These lasers would be capable of monitoring and adjusting the trajectories of space debris objects continuously.
However, the current practices predominately rely on ground-based laser systems. These practices come with their own set of drawbacks, such as inefficient power transmission and various atmospheric disruptions leading to a weakened and distorted laser beam.[3]
Researchers are therefore proposing and investigating the idea of placing a laser system in space directly. Such a system would encounter fewer obstacles to the laser beam, leading to a more efficient cleanup operation.
Still, all these measures need to consider the inclination of debris, relative movement between the laser and debris, and laser repetition frequency, among other factors, to assume a successful elimination of space debris.
As we can see, this strategy is neither quick nor simple – yet, with the right engineering and constant technological advancements, it has the potential to be a feasible and sustainable solution to our space debris management problem.
Space Debris Management: The Essential Role of International Cooperation
The process begins with identifying and tracking the thousands of debris pieces revolving around our planet using radar and other detection systems. But how do we engineer a solution to get rid of this space junk? This is where lasers come into the picture.
The Need for Global Cooperation
A global cooperation system could contribute significantly to space debris management. Its successful implementation and operation necessitate collaborative work between countries and their respective space organizations. This demands pooling resources, sharing technology, and collaborating on collecting data and research for the system’s effective application.
The nature of space debris is such that it is not confined to the territory of one country alone. It is a global issue that calls for cooperative global management. Therefore, in the technical engineering aspect, the solutions developed must be universally adaptable and regulatory compliant.
Collaborative efforts have been initiated, with the European CLEANSPACE project being one example, where they are studying a global architecture of debris tracking and removal laser stations. Platforms such as these ensure the engaged collaboration between countries and advance holistic solutions to tackle the issue of space debris management.
