Generally, most people know salt is only limited to cooking spices and complementary flavors of a dish. However, the results of the research shown by the The Indonesia National Institute of Aeronautics and Space (LAPAN) research team were able to reveal another benefit of salt, namely as fuel for rockets.
Indonesia itself is the second country in Asia that has succeeded in making and developing rockets after Japan. Mastery of rocket technology has started more than 50 years ago.
The development of rocket technology continues, but one of the crucial problems in the development of national rockets is the difficulty of obtaining raw materials for rocket fuel (propellant).
Indonesia has enormous potential to be able to make its own propellant raw materials from salt. Indonesia has an area of ​​almost 5.5 million km2 and more than 3.5 million km2 or 2/3 of its territory is ocean, so it has great potential as a salt-producing country.
Based on the results of their research (LAPAN), ammonium perchlorate (AP) can be made from an easily available raw material, namely sodium chloride (NaCl), which contains 70-80% of the total weight of the propellant. According to Anita Pinalia, a researcher at the LAPAN Rocket Technology Center, it is quite difficult to bring in these raw materials from abroad.

One of the biggest components in the propellant is the oxidizing agent (providing oxygen for the combustion reaction) which greatly affects the performance of the rocket. A rocket can travel a certain distance, one of which can be determined by the oxidizer. The most widely used oxidizing agent in solid rocket propellants is AP.

The AP produced by the LAPAN research team has the advantage that the particle size range is narrower than imported products. The particle size range greatly affects the quality of the propellant. The wider the range of particle sizes, the more diverse the particle sizes, so it will be difficult to determine the standard particle size distribution used to have a propellant with the desired characteristic quality.
Another advantage of AP made from salt is that the particles that have been coated with a coating agent on the surface can make AP particles not easily absorb water, so that the quality is maintained. In addition, it is not easy to agglomerate within a certain storage time.
Although the efficiency is still relatively low, which is around 40-60%, where in every one kg of propellant containing 700-800 g of AP it takes about 3-4 kg of NaCl salt. However, the quality is not inferior to imported products. The purity of the AP produced is also quite high, reaching 99.9%.
The technical NaCl salt production process generally goes through three stages. First, the conversion of chloride to perchlorate using the electrolysis method to sodium perchlorate. Second, the conversion of sodium perchlorate into other perchlorate derivatives or derivatives as needed, one of which is ammonium perchlorate. Third, purification of perchlorate salt using recrystallization and drying methods.

The Indonesia National Institute of Aeronautics and Space (LAPAN) itself has launched an experimental rocket named RX-450 in December 2020. The rocket which has a diameter of 450 mm is designed to reach a distance of 100 km. It is hoped that by 2025 this two-stage rocket can be flown for atmospheric research.
Reference:
- Pinalia, A et al ., 2021. How Local Salt Can Be a Solution in National Rocket Development. Accessed on January 22, 2022. https://theconversation.com/how-garam-lokal-bisa-men-solution-dalam-pengembangan-roket-nasional-167790
- Research-Pro. 2021. Local Salt for National Rocket Fuel Mixture. Accessed on January 22, 2022. https://risetpro.brin.go.id/web/2021/10/28/garam-lokal-untuk- Campuran-bahan-bakar-roket-nasional/
- Santoso, W., B. 2021. Original Indonesian Salt Will Be The Most Important Part in the Rocket Industry. Retrieved January 22, 2022.