In the previous article we learned about two topics: Space Situational Awareness (SSA) and Space Traffic Management (STM). Let’s learn what are technologies and systems used for achieving both of these.
The complete program of SSA comprises of 4 parts —
Space Weather
This caters to monitoring the impact of the Sun, its solar wind and the disturbances in the Earth’s magnetosphere, ionosphere and thermosphere. This is achieved by Space Weather Service Network. This network works by using two set of instruments to gather data:
- Instruments from ground: These ground-based instruments are usually less expensive and easier to maintain and upgrade. Many European and international observatories and instrument networks are part of this system. These monitor solar radiation levels, radio waves, and other space events.Kanzelhöhe Solar Observatory, Austria (Credits: ESA)
- Instruments from space: These monitor particles and fields within the magnetosphere (that is, inside Earth’s magnetic field) and Auroral images from instruments in orbit. Many SmallSats and CubeSats are planned to complement these instruments.
Planetary Defence
We, of course, don’t want to end up like dinosaurs in the event of an asteroid strike. Data of various asteroids and comets are collected from telescopes all around the world. The data is used to plot the trajectories of these celestial objects and the impact risk is calculated.
International Asteroid Warning Network (IAWN) and the Space Mission Planning Advisory Group (SMPAG) are two groups that help in coordinating different data sources and results across the world. Further, missions such as NASA’s DART and the upcoming ESA’s Hera mission are also planned to develop sufficient technology in case an asteroid poses enough threat to our planet and escapes the monitoring system.
Space Debris
By now movies like Gravity and various articles on this topic must have got you aware of the seriousness of the space debris. It is estimated that there are 34,000 objects of size larger than 10 cm; 900,000 objects between 1 cm to 10 cm and 128 million objects from 1 mm to 10 cm.
Currently, a manual collision avoidance system is in place. In this operators in highly-trafficked orbits spend time protecting their spacecraft from potentially catastrophic collisions with space junk, by performing ‘collision avoidance maneuvers’ – basically sending the commands to their spacecraft to get out of the way.
A system known as Automated Collision Avoidance is also being developed using machine learning to protect satellites from the very real and growing danger of space debris.
Clean Space
With the rising concern of space debris, a new approach to the design of satellites is being increasingly adopted. In this, the “end-of-life” stage and beyond are being considered to ensure that no debris is left out in space after the mission gets completed.
An ESA Space Debris Removal mission ClearSpace-1 has also been planned, which will be the first mission to remove a piece of space debris from orbit. Technologies to service the satellites in orbit are also being developed.
All in all, it is reassuring to understand that worldwide various space organizations have recognized this issue and are actively working to get this in control.
In next article we will continue on another interesting topic.
