Celestial Code
How rockets are coded to conquer the universe !
The night sky has always captivated the minds of all those who have gazed upon it for centuries. For many a century, we have gazed at the millions of pinpricks of light that dot the dark tapestry and marvelled at the celestial dances they follow as they trace their perfect ellipses across the night sky. Space unites us as a species, as it brings the same unfiltered desire and yearning in all of us to explore its vastness and majesty.
Particularly close to our home planet, though, is our very own Moon. Since time immemorial, there have been legends and stories about the shadowy craters that dot the barren, monochrome desert. From Greek great chariots of war freckling the moon’s surface and the tapestry of an Asian rabbit cooking rice cakes to giants like the Apollo 11 mission, we as a species have always been fascinated with the lunar surface and how it came to be.
In the endeavour of exploring our crescent neighbour, space programmes have been at the forefront. With them, we explore the vast expanse of the cosmos, pushing the boundaries of human knowledge and expanding our understanding of the universe. Through a combination of scientific curiosity, technological innovation, and human ingenuity, space programmes have embarked on incredible journeys of discovery, unveiling the wonders of space. There are many famous Space programme like America’s NASA, India’s ISRO, and even private programmes like Musk’s SpaceX.
Recently, in the realm of space exploration, the remarkable Chandrayaan 3 mission has taken centre stage. Representing India’s ambitious foray into lunar exploration, Chandrayaan 3 stands as a testament to the nation’s unwavering commitment to scientific advancement and cutting-edge technology. Building upon the achievements of its predecessors, Chandrayaan 1 and Chandrayaan 2, this mission aims to unlock the mysteries of the moon’s unexplored terrain. Equipped with advanced instruments and state-of-the-art technology, Chandrayaan 3 seeks to delve deeper into the moon’s geology, mineralogy, and the presence of water ice deposits. Chandrayaan 3 represents the remarkable culmination of scientific expertise, engineering excellence, and technological innovation. It exemplifies India’s determination to explore the lunar frontier, broaden our understanding of the moon’s mysteries.
Anyone who even has the remotest interest in space programmes knows how challenging they are. Each mission is nothing short of a miraculous orchestra, a perfect balance of the sciences that propels metal tubes containing our hopes and dreams into the great beyond. With a little thought, one would realise that the amount of human interference on most missions past the pre-launch stage is practically zero.
One must wonder, though, how such magnificent machines perform such complex operations in outer space, where human interference is not possible? Most probes are sent out so far that it takes a few minutes and sometimes hours for the signals to eventually reach them due to the sheer distance! How do they manage to stay functional without us telling them what to do?
The answer to this intriguing question lies within the realm of computer science. It is through the ingenuity of computer scientists and the advanced technologies they develop that these magnificent machines can perform complex operations in the vastness of outer space, where human interference is not possible. At the heart of these space-faring machines are sophisticated computer systems specifically designed for the harsh conditions of space. These systems are meticulously engineered to withstand the rigours of the cosmic environment and ensure reliable operation over vast distances.
At this point, we wonder how exactly code would be used in such space programmes. Here are some of the primary areas where code is employed:
1. Mission Planning and System Design:
- Trajectory Calculations and Orbital Mechanics: Optimising Spacecraft Paths.
- Structural Design and Optimisation): Simulating Spacecraft Integrity.
2. Launch Operations and Countdown Sequencing:
- Launch Vehicle Control Systems: Real-time Control for Precision Liftoff.
- Telemetry and Tracking: Handling Data for Mission Monitoring.
3. Onboard Software and Guidance Systems:
- Command and Data Handling: Managing Spacecraft Tasks.
- Attitude Determination and Control: Ensuring Spacecraft Stability.
- Autonomous Operations: Real-time Decision-Making.
4. Ground Control and Mission Monitoring:
- Ground Station Software: Controlling the Spacecraft.
- Mission Planning and Analysis: Predicting Mission Outcomes.
- Anomaly Detection: Rapidly Identifying Issues.
5. Data Analysis and Scientific Exploration:
- Data Processing and Visualisation: Extracting Insights from Data.
- Scientific Instrumentation: Controlling Scientific Instruments.
An interesting factor to consider in such a mission is the harsh environment that space is. In the depths of space, unyielding background radiation poses a constant threat to the integrity of electronic systems. Cosmic rays are energetic particles that zip through space. They can penetrate sensitive electronic components and induce what is known as a “bit flip.” Essentially, a bit flip occurs when a single bit of data within a computer memory or storage unit is altered from its original state, potentially leading to incorrect calculations or erratic behaviour. The engineers tasked with the Apollo missions also had to face this problem. In this regard, the engineers came up with a brilliant idea.
Recognising the peril, the engineers behind the Apollo missions understood the need to fortify their systems against such cosmic interferences. They employed a strategic approach: redundancy. Rather than relying on a solitary computer, they integrated four computers. Yes! four computers, into the Apollo Guidance Computer (AGC) system, which played a vital role in navigation, guidance, and control.
This redundancy of four computers served as an ingenious solution to counter the effects of bit flips and other cosmic radiation. The computers operated in parallel, constantly cross-checking and verifying their calculations. By comparing the outputs, the computers could detect any discrepancies caused by bit flips or other radiation-induced errors. If a disagreement occurred, the system could correct itself, ensuring accurate data and reliable decision-making.
We must now talk about the interesting considerations that make modern computers successful. One key aspect is the autonomy built into these systems. Given the communication delays between Earth and the distant probes, it is crucial for spacecraft to make decisions independently. Computer scientists develop intelligent algorithms and decision-making frameworks that allow these machines to adapt to changing circumstances and respond to unexpected events.
Another vital element is fault tolerance. Spacecraft computers are designed to be resilient in the face of potential failures. Redundancy, where multiple systems work in parallel, is incorporated to ensure that if one component malfunctions, others can seamlessly take over.
Furthermore, the software running on these computers is meticulously crafted to be robust and efficient. Computer scientists optimise the code to minimise resource usage and ensure efficient execution of tasks. They conduct extensive testing and simulations to identify and eliminate potential software bugs that could jeopardise the mission’s success.
Additionally, the planning and scheduling of operations are carefully managed by computer scientists. They develop sophisticated algorithms that optimise the utilisation of limited resources such as power, data storage, and communication bandwidth. These algorithms allow the spacecraft to prioritise and execute tasks effectively.
Another interesting thing we must consider is the environment our code is being deployed to. When it comes to writing code to be deployed into space, there are a bunch of wacky rules that the developers must follow.
1. Strict Compliance: Space software development follows strict compliance with industry standards and guidelines. These standards provide a framework for designing, coding, testing, and verifying software to meet the highest levels of safety and reliability.
2. Minimalism: The code is kept minimalistic, with a focus on simplicity and clarity. Unnecessary complexity is avoided to minimise the chances of bugs, making it easier to analyse and verify the code’s correctness.
3. Robust Error Handling: Space software is designed to handle errors effectively. Developers employ robust error handling mechanisms to detect, report, and recover from errors, ensuring that the software can gracefully handle unexpected situations.
4. Defensive Programming: Defensive programming techniques are applied to anticipate and prevent potential failures. This includes input validation, boundary checking, and error checking at critical points in the code to prevent software failures caused by unexpected data or conditions.
5. Static Analysis and Formal Methods: Static analysis tools and formal methods are employed to analyse the code for potential issues, such as memory leaks, race conditions, and undefined behaviour. These tools help identify potential bugs and security vulnerabilities, enabling developers to address them early in the development process.
This article is just a brief foray into the wild world of space-proof code. Actual engineers use a variety of languages like C, Python, Fortran, Ada, MATLAB, Java, and Assembly for various purposes.
Coding is the backbone of launching space programmes, driving the success and efficiency of space exploration missions. From the initial stages of mission planning and system design to launch operations, onboard guidance systems, ground control, and data analysis, coding enables precise calculations, automation, and effective decision-making. As technology continues to advance, the role of coding in space programmes will become increasingly vital, empowering us to unlock the mysteries of the cosmos and push the boundaries of human exploration.
