The national defense system is a unified system designed to protect state sovereignty, maintain territorial integrity, and protect the safety of the nation from threats both from within and outside the country (Kemhan, 2016). This system includes military and non-military aspects that are synergistically integrated in facing various forms of strategic, tactical, and operational threats (Harsono et al., 2018). The success of this system relies heavily on the integration of technical aspectssuch as the development of reliable defense equipment technologies, including propellants and oxidizers and strategic elements that support the independence of the defense industry (Dirloman et al., 2020). Moreover, addressing environmental impacts is a crucial component in building a sustainable defense system, where green technology innovations contribute to reducing pollution risks while enhancing national resilience by decreasing reliance on imports (Chen et al., 2023; Bohn, 2002).

Composite propellants are solid fuels composed of several main components such as oxidizers, fuel, and binders. The oxidizer serves as the oxygen provider for the combustion reaction, especially in oxygen-deficient environments such as outer space (Ardianingsih & Kumoro, 2019). Ammonium Perchlorate (AP) is the most widely used oxidizer in composite propellants due to its stability and high specific impulse value (Lysien, 2021). However, AP combustion produces chlorine gas emissions that are corrosive and harmful to the environment (EPA, 2014). Therefore, the demand for environmentally friendly oxidizers has emerged as a major challenge in the future development of propellants.

Explanation of theory here green oxidizers are oxidizing agents that do not produce harmful emissions such as chlorine and have the potential to improve combustion efficiency (Bohn, 2002). ADN and HNF, as examples of green oxidizers, demonstrate high specific impulse values as well as cleaner gas emission compositions compared to AP. However, these green oxidizers have drawbacks such as high hygroscopicity and low thermal stability, which present significant barriers to their use in the defense industry (Chen et al., 2023).

The development of green oxidizers also has strategic implications, namely reducing dependence on imported raw materials such as AP, strengthening the independence of the national defense industry, and increasing national logistics and security resilience (Dirloman et al., 2020; Harsono et al., 2018). Collaboration between the defense industry and research institutions is key to accelerating the adoption of this technology.

This conceptual framework is designed to illustrate the relationship between the main variables in this study—technical, environmental, and strategic factors that influence the implementation of green oxidizers in composite propellants. The conceptual framework can be explained as follows based on the previous description:

As one of the primary components accounting for more than 50% of the total mass of a propellant, oxidizers are compounds with high oxygen content that release a significant amount of energy (Abdillah, 2018). Consequently, oxidizers play a crucial role in determining combustion performance, storage stability, and environmental impact. To date, Ammonium Perchlorate (AP) has been the most commonly used oxidizer due to its stability and high specific impulse. However, as previously mentioned, AP poses environmental concerns, particularly related to chlorine emissions and groundwater contamination.

In the search for more environmentally friendly alternatives to AP, several compounds such as Ammonium Dinitramide (ADN), Hydrazinium Nitroformate (HNF), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) have emerged as potential oxidizers. These four compounds are known for their high energy potential and produce significantly lower chlorine emissions during combustion. Table 1 presents a comparison of key characteristics of these oxidizers based on findings from the literature.

Source : Team Author, 2025 based on Bohn (2002); Cican & Mitrache (2017); Louwers (1997); Sutton & Biblarz (2017); Zhang et al. (2021).

Table 1 presents a comparison of the characteristics of several oxidizers that may serve as environmentally friendly alternatives to Ammonium Perchlorate (AP) in solid propellants. The oxidizers reviewed include Ammonium Dinitramide (ADN), Hydrazinium Nitroformate (HNF), and high- energy compounds such as RDX and HMX. Based on thermodynamic characteristics, it can be observed that ADN and HNF demonstrate superior performance compared to AP, particularly in terms of specific impulse (Isp) and oxygen balance. A higher Isp indicates a greater ability to generate thrust per unit mass of propellant (Frem, 2018). ADN and HNF exhibit Isp values exceeding 265 seconds, highlighting their potential as alternative oxidizers. Additionally, their positive oxygen balance suggests more complete combustion, which contributes to improved overall propulsion system efficiency (Bohn, 2002).

In terms of thermal stability, AP remains superior; however, ADN offers a more optimal balance between stability and performance. While HNF also achieves a high Isp, it presents storage stability challenges. Its melting point, approximately 124°C, makes it more sensitive to temperature fluctuations compared to AP (230°C) and HMX (275°C). This increases the risk of premature degradation or unintended reactions under suboptimal storage conditions.

From the standpoint of combustion temperature (Tc), AP excels with a value of 3371 K. However, ADN and HNF record values of 3075 K and 3080 K, respectively still within an efficient range for solid propellant combustion. This demonstrates that although AP is thermally robust, green oxidizers such as ADN and HNF can still deliver competitive performance, provided they are properly integrated with a suitable binder system in rocket.

The environmental aspect is a critical factor in evaluating oxidizer selection. To assess whether an oxidizer is environmentally friendly, it is essential to examine its combustion reaction. Table 2 presents the general combustion reactions of each oxidizer.

Source : Team Author, 2025

Based on Table 2, it is evident that only Ammonium Perchlorate (AP) produces chlorine-containing compounds (HCl) during combustion, which pose serious risks to human health and the environment (EPA, 2014). In contrast, the other four oxidizers ADN, HNF, RDX, and HMX do not contain chlorine atoms in their chemical structures, making them significantly safer for the environment.

Overall, the preceding analysis indicates that ADN and HNF demonstrate strong potential as replacements for AP in solid propellants. The use of green oxidizers contributes not only to reducing environmental impact but also to enhancing the endurance of defense systems and optimizing propulsion performance. These findings align with previous studies by Bohn (2002) and Louwers (1997), which suggest that the development of alternative oxidizers can strengthen the long-term sustainability and self-reliance of a nation’s defense capabilities.

Growing awareness of the importance of sustainable defense technologies has driven efforts to replace Ammonium Perchlorate (AP) with more environmentally friendly oxidizers. Compounds such as Ammonium Dinitramide (ADN), Hydrazinium Nitroformate (HNF), hexahydro-1,3,5- trinitro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) have been widely explored in the literature as primary alternatives, due to their high specific impulse and cleaner combustion products.

However, transitioning from laboratory-scale research to full-scale industrial production presents significant challenges. Key obstacles include thermal stability, high production costs, complex synthesis processes, and the need for supporting infrastructure. These factors currently hinder the widespread implementation of green oxidizers in the defense industry.

Green oxidizers such as Ammonium Dinitramide (ADN) and Hydrazinium Nitroformate (HNF) are next-generation oxidizing compounds currently being developed as more environmentally friendly alternatives to Ammonium Perchlorate (AP). ADN and HNF produce cleaner combustion products as they do not release corrosive and toxic chlorine-containing compounds. This advantage makes them highly promising for application in rocket propulsion systems, particularly in efforts to reduce the environmental footprint of the defense industry.

Despite these benefits, both compounds have critical drawbacks, notably their strong hygroscopic nature and sensitivity to temperature and humidity. ADN, in particular, readily absorbs moisture from the air. This absorption process occurs in three stages: starting with the interaction between water vapor and the surface of solid ADN, followed by the formation of a thin water layer, and ultimately leading to deliquescence a phase in which the absorbed moisture forms a liquid interface with the ADN, resulting in its partial dissolution (Chen et al., 2023).

The use of Ammonium Perchlorate (AP)-based oxidizers remains heavily reliant on imported supply chains. Innovations in alternative materials such as Ammonium Dinitramide (ADN), Hydroxylammonium Nitrate (HAN), RDX, and HMX create opportunities to reduce this dependence and promote national self-reliance in raw material production. The development of eco-friendly oxidizers like ADN contributes not only to lowering reliance on foreign suppliers but also to strengthening domestic defense capabilities (Dirloman et al., 2020).

The development of green oxidizers as part of composite propellant technology must be examined not only from the perspective of technical performance and environmental impact, but also in terms of how their application can be aligned with the current state of Indonesia’s defense industry. Accordingly, the following discussion presents a case study of implementation, national data on raw material dependency of this technology.

PT Dahana, a state-owned enterprise (BUMN) specializing in explosives, has taken a leading role in the development of solid propellant technology for military applications. In its 2022 Annual Report, PT Dahana affirmed its commitment to supporting research on more environmentally friendly rocket fuels through collaborations with various national institutions, including BRIN and LAPAN (PT Dahana, 2022). Although domestic production still relies heavily on Ammonium Perchlorate (AP), internal experimental studies have begun to explore the substitution potential of Ammonium Dinitramide (ADN), a green oxidizer that does not emit chlorine-based compounds during combustion.

In addition, PT Dahana has also begun developing variants of smokeless composite-based propellants for ammunition and tactical rocket applications, aimed at reducing visual signatures during launch and enhancing stealth characteristics in combat. These smokeless composite propellants are designed to minimize the formation of white smoke resulting from the combustion of aluminum or carbon-based materials and can be combined with green oxidizers to produce a cleaner and more efficient propulsion system (PT Dahana, 2023). The smokeless composite propellants are engineered to reduce the white smoke generated by the combustion of aluminum or carbon materials and can be

formulated with green oxidizers such as ADN (Ammonium Dinitramide) or HAN (Hydroxylammonium Nitrate) to produce a cleaner propulsion system. The implementation of green oxidizers offers several advantages, such as:

In addition to PT Dahana, PT Pindad is also actively strengthening its expertise in energetic materials technology. In 2023, PT Pindad established a partnership with the Bandung Institute of Technology (ITB) to conduct research and development on propellants and explosive detection devices (PT Pindad Persero, 2022). The focus of this collaboration includes improving the performance and efficiency of rocket fuels as well as enhancing safety in the handling of explosive materials. Such collaboration reflects a crucial synergy between industry and academia, which plays a key role in accelerating national technological readiness.

Furthermore, the collaboration between the defense industry and research institutions reflects a new direction in the transformation of national explosive materials technology. In addition to reducing dependence on imports, this initiative also aims to establish a sustainable domestic production base. The implementation of green oxidizer technology, such as ADN, in the national propellant systems is not only intended for rocket applications but can also be expanded to include weapon systems and small-caliber ammunition. Such initiatives also open opportunities for technology transfer from basic research to ready-to-use products that can support the operational readiness of the Indonesian Armed Forces (TNI).

An example of early implementation could be directed toward the LAPAN RX-450 or RS-122B rocket systems as test platforms for integrating ADN as an alternative oxidizer to AP. Additionally, the initial phase can be carried out through a staged technology readiness level (TRL) scheme coordinated by the Ministry of Defense and the Defense Industry Policy Committee (KKIP), ensuring that the development of green oxidizers progresses beyond the laboratory stage toward industrialization and operational deployment.

The performance of propellants produced by LAPAN has not yet reached optimal standards, which is believed to be influenced by the relatively low quality of domestically produced Ammonium Perchlorate (AP). One strategy to improve the characteristics of local AP is to conduct comparative analyses with imported materials, particularly those sourced from China and South Korea. This approach aims to bridge the quality gap in oxidizers and

enhance the thrust performance of Indonesian-made propellants to meet international standards (Hutauruk, et al, 2020).

Meanwhile, Indonesia remains highly dependent on imported propellant raw materials, especially AP from China and Russia. The demand for composite propellants is expected to continue increasing in line with the development of rockets and missiles. This is further supported by official data from Statistics Indonesia (Badan Pusat Statistik/BPS), which shows a consistent trend in the import of propellant raw materials specifically those classified under HS code 36010000 (Propellant Powders) over the past four year.

The data indicates a consistent and significant reliance on imports. The highest import volume occurred in 2021, reaching over 5.2 million kilograms. Although there was a decline in subsequent years, the import volume remained high, averaging more than 3 million kilograms per year. These fluctuations may be influenced by variables such as changes in defense budget allocations, the dynamics of national defense equipment (alutsista) projects, or external factors like global prices and supply availability.

This situation highlights that domestic production is still unable to meet propellant demands independently, both in terms of quality and quantity. Dependence on imported materials creates strategic vulnerabilities, including risks of supply chain disruptions due to embargoes, geopolitical conflicts, or international logistical barriers. To better understand the scale of Indonesia’s propellant needs, the annual demand composition by propellant type is illustrated in Figure 6 below.