The Indo-Pacific is a dynamic and competitive geopolitical region. Besides its core maritime nature, there is also outer space politics. There are three important spacefaring states in the region, namely India, Japan, and China, as well as dozens of emerging space countries. Entering the New Space era, however, tense space competition among them is increasing. While space technologies are becoming a significant part of the pursue of their cooperative developmental agenda, so is the use of it for their own national security interests. The problem that arises is whether space diplomacy increases or decreases the stability of the competitive Indo-Pacific region. This paper aims to explore the opportunities and challenges of how space diplomacy can be a means to keep a stable Indo-Pacific by using qualitative approaches and concepts of space diplomacy.