NORAD, which tracks tens of thousands of pieces of debris in Earth's orbit every day, can be accessed through API requests. However, the resulting dataset is far too massive to analyze each piece of debris and the probability of deorbit. Each OSCaR satellite only has the capability to deorbit up to 3 pieces of debris, thus the data must be efficiently sifted to provide a short list of viable candidates. The variable of interest when sorting through this data is the amount of fuel (∆V) required to intercept a piece of space debris given some initial orbit an OSCaR satellite may be in. ∆V is calculated using a set of equations derived from a two-burn node-to-node non-Hohmann orbital transfer (seen in the image above). Our team developed a method capable of reducing a list of over 10,000 pieces of debris and their ephemeris data to less than 100 possible targets in under 3 seconds on an ordinary laptop. The resulting list can then be assessed using more expensive optimization algorithms to determine the final 3 candidates for deorbit. Our work was published in the 2020 Small Satellite Conference and can be found on this link.

In 1958, the United States’ Vanguard I satellite became the first man made object to enter orbit around earth and not reenter into the atmosphere. Since then, over 5,000 rockets have been launched with the intention of putting satellites in orbit, but they have no plans to deorbit even after the satellites lose function. Current estimates from the ESA provide that there are nearly 130 million pieces of space debris circling earth at every moment due to detritus from rockets, satellites, and other space endeavors. 34,000 of these objects are 10cm or larger, 900,000 are 1cm to 10cm large, and 128 million are less than 1cm in size. While debris may in theory seem harmless, debris orbiting earth travel at up to 7.8 kilometers per second. Objects traveling at this level of hypersonic speed can cause incredulous damage and put craters in objects that are exponentially larger than the projectile itself.

OSCaR is a 3-Unit CubeSat satellite designed to deorbit multiple pieces of space debris through the use of weighted nets. The debris and weighted net will then be put out of orbit vie electromagnetic tethers, which will slowly drag the debris back into Earth's atmosphere where it will burn up upon re-entry. One of the greatest challenges the OSCaR project has to solve is determining how to intercept debris, and when to intercept it.

A diagram of a two-burn node-to-node non-Hohmann orbital transfer

A CAD drawing of OSCaR