The Ministry of Science and ICT recently said that the Korea Aerospace Research Institute (KARI) and the National Aeronautics and Space Administration (NASA) are discussing various measures to address the impact of a change in orbit and NASA will continue to work with South Korea in the latter's lunar orbiter project in that it is very important for the former's lunar exploration program. The two organizations held their first and second technical meetings regarding the issue last month and this month, respectively.
The issue emerged with regard to the target weight set during lunar orbiter design. A weight of 550 kilograms was set in the design process, but a post-development conclusion was reached that the weight must be at least 678 kilograms. This means the target mission cannot be fulfilled due to fuel shortage without a change in design.
The ministry decided to maintain the design and change the flight path instead. In addition, it postponed the launch by 19 months to July 2022. This orbit change was announced in September this year. NASA raised an objection the next month, claiming that its shadow camera on the lunar orbiter may malfunction on the new path. NASA proposed an alternative orbit for fuel saving and intended shadow cam operation, but KARI is yet to look into the option.
If NASA’s proposal is accepted, the launch, which has been postponed three times so far, will be put off yet again. The ministry explained that the orbit issue is not going to cancel the project itself.