Japan's superlow altitude satellite Tsubame has been registered by Guinness World Records as having achieved the "lowest altitude by an Earth observation satellite in orbit," the nation's space agency has announced.
The satellite flew at an orbital altitude of 167.4 kilometers from Sept. 23 to 30 as part of its test mission from Dec. 23, 2017, to Oct. 1, 2019, compared with the 600 to 800 km zone where most Earth observation satellites operate.
Tsubame maintained the record-low altitude for a period of seven days by using its ion engine system — developed by the Japan Aerospace Exploration Agency or JAXA — and gas-jet thrusters, successfully capturing high resolution images despite atmospheric drag and the density of atomic-oxygen present in superlow altitudes.