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The small satellite market has grown significantly in the last few years as more and more companies send all sorts of various spacecraft into calculated orbits. One of the reasons why smallsats are in such demand is that they allow reducing the costs of space exploration and manufacturing time. However, smallsats can also be challenging to produce because they don’t have sufficient power for payload storage and little room for propulsion and orbit orientation systems on their platforms. Fortunately, advances in small satellite platform development are already addressing these challenges. But what are satellite platforms, and how do they help smallsats keep to their calculated orbits? Read on to find out.
What are the methods to make satellites that are present in an orbit stable?
To make satellites that we can send into a stable orbit, space engineers design advanced orbit determination platforms, aka buses hosting smallsat equipment. Most of these platforms are expensive to build and require consistent research funding to keep the technology evolving. An orbit determination system relies on thrusters and propulsion components to make sure satellites remain in their right places. Minor platform adjustments could be necessary over the spacecraft timespan, including avoiding collisions with space debris.
What are the two methods used for attitude and orbit control systems?
It’s very challenging to mount attitude determination and orbit control systems on satellite platforms. A small satellite platform works with an inertial navigation system. These satellites’ attitude and orientation, as well as orbit control systems, consisting of software, actuators, and sensors. One method used for attitude and orbit control systems is providing an Earth-positioning attitude control during mission modes. Another method is using a Star Tracker Assembly based on a GPS receiver. This second option also employs a fluxgate magnetometer, magnetic torques, inertial measurement units, and cold gas systems for propulsion. Now let’s see what GPS receivers do for satellite orbit determination platforms.
How do GPS receivers for orbit determination systems work?
GPS receivers installed onto satellite platforms work as references for determining precise locations of satellites in orbit. These receivers measure distance changes of GPS satellite constellations that circle our planet. Every satellite platform that has GPS receivers features at least three transmitters. One collects navigation data, another one responds to atmospheric data, while one more works for backup. GPS receivers work to provide digital signal processes that go into a Microwave Instrument. If we want to have an advanced space program, we can’t use orbit determination systems that don’t have GPS receivers. GPS didn’t seem the most advanced technology until recently, but now it’s often installed on orbit determination satellite platforms.
How does the Star Tracker Assembly work?
Star Tracker Assembly determines satellites’ orbit control relying on data it collects on the spot. The satellite’s orientation platform determines the star reference. Spacecraft control and dynamics researchers are interested in developing understandable and accurate satellite models. There are simulations that verify motion principles and test control designs for both orbit control and attitude. Within this package array, there are all sorts of specialized applications that appeal to different spacecraft modelling aspects, such as attitude, communications, or power. Star Tracker Assembly consists of the following mechanisms:
- Star image processing
- Star Tracker control
- Star pattern identification
- Attitude estimation
How does the measurement correction system for the orbit determination system work?
Orbit determination system conversion blocks and measurement corrections depend on specific sensor typologies installed on satellite platforms. These sensors’ on-board calibration system is an operation that estimates the unknown quantity of an orbit determination performance and attitude. Then, the orbit determination system measures how correctly a given satellite is placed. There are sensor typologies that require raw sensor signals to convert. Such sensors work for photodiodes, thermopiles, and Earth sensors, while some other basic instrument typologies are common for small spacecraft platforms.
What’s the technological design of an orbit determination system for satellite platforms?
The classification of tracking devices and star sensing systems of a satellite platform’s determination system is:
- Star scanners, which work for spacecraft rotation to provide a sensing function and searching
- Head star trackers that are fixed on a platform and have electronic tracking and searching capabilities for limited view fields
- Star trackers that are gimballed and acquire information from the stars through mechanical action
It’s very important for this 3-class system to be in an angular position. If we want to reach the stars and be space travelers, we should focus on what’s important as far as technological developments go for small satellite platforms as well.
Most orbit determination systems on small satellite platforms work according to what star sensing systems and tracking devices indicate so that tracking and scanning are more accurate and can help us become a multi-planetary species one day.
