# An Overview of CubeSat Missions and Applications
## 3 CubeSats as Earth Observation and Earth Science Platforms
### The Role of CubeSats in Earth Observation Missions
The main mission of FOREST-1 was to demonstrate the capability of wildfire detection and monitoring using its payload. Furthermore, using its payload, FOREST-1 was also capable of monitoring ground, sea surface, and urban area temperature distributions. The success of the FOREST-1 mission led to the development of FOREST-2, another 6U CubeSat by Spire, now equipped with OroraTech's more capable SAFIRE Gen-2 TIR sensory instrument, which comprises two TIR cameras and an RGB camera. Compared to SAFIRE Gen-1, it features an improved detector offering three times more pixels and is capable of providing 200 m GSD and a 160 km swath; furthermore, it provides data in one MWIR and two separate LWIR bands [65; 66; 67; 68]. An example of an upcoming Earth observation mission is the Field Imaging Nanosatellite for Crop residue Hyperspectral mapping (FINCH). FINCH is a 3U SWIR imaging CubeSat under development by the University of Toronto, which is going to undertake the mission of measuring CH\({}_{4}\) column concentrations over landfills by using the atmospheric absorption features present between 1600 nm and 1680 nm wavelengths. For this mission, FINCH is going to be equipped with a custom-made hyperspectral spectrometer operating in the SWIR spectrum, called the FINCH Eye, as its main payload. The data collected by FINCH could help in the improvement of crop residue retention practices and the reduction in greenhouse gas emissions from the crop soil, thus aiding in precision agriculture operations [69]. Another example of an upcoming Earth observation mission is VULCAIN, a mission that will consist of two 12U CubeSats developed under the supervision of ESA by Politecnico di Milano and five more Italian space science and engineering entities. Their mission will primarily revolve around the performance of IR observations in volcanic areas to detect surface temperature changes due to volcanic activity and the Measurement of SO\({}_{2}\) and ash emissions from active volcanoes in an effort to detect anomalies that could indicate changes in activity such as upcoming volcanic eruptions. For this mission, the two VULCAIN CubeSats will be equipped with a custom designed and built TIR imaging instrument developed by LEONARDO S.p.A. (Rome, Italy) and a COTS VNIR camera developed by Dragonfly Aerospace (Stellenbosch, South Africa). The two CubeSats are expected to orbit the Earth at a 400 km Sun-synchronous orbit, maintaining an along-track formation with a separation distance of 300 km using low-thrust electric propulsion [70; 71]. So far, that present work has been limited in discussing examples of CubeSat missions comprising of single platforms or CubeSat constellation examples that are so far comprise only a few satellites. However, it must be noted that due to their low cost and their ability to manufacture, integrate, and launch fast and in large numbers, CubeSats represent excellent platforms for the formation of large Earth observation constellations that ensure short revisit times and continuous data flow. Such constellations are extremely useful for both civilian and military applications by providing institutions and other potential customers with continuous image data from the surface of the Earth, enabling near-real time monitoring of the planet's surface and/or its weather conditions. This way, organizations, industries, governments, and militaries around the world can make timely, well-informed decisions. Perhaps the most prominent and well-known example among existing and proposed commercial optical-imaging Earth observation CubeSat constellations is the Flock constellation, which comprises SuperDove CubeSats that are developed and operated by Planet Labs PBC (San Francisco, CA, USA). The 3U SuperDove CubeSats orbit the Earth at altitudes between 400 km and 550 km and are equipped with an eight-spectral-band VNIR imaging sensor each, providing optical imagery with resolutions between 3 m and 5 m, depending on the satellite's orbital altitude.