## 4 Supply and Demand  
### Upstream, Midstream and Downstream  
The space economy encompasses all activities and resource uses that generate value and benefits for humanity through the exploration, study, management, and utilization of space [1]. Although this definition is widely used, there are differing interpretations of which activities to include in the space economy [53]. Of the many options available in the literature, the most convincing is the approach offered by [PERSON] [2]. He proposed to look at the space economy through the lens of the basic economic category, namely supply and demand. Thus, the space economy can be divided into three key segments: supply (the space infrastructure industry), demand (namely buyers and operators of space infrastructure), and induced markets (products and services induced by space infrastructure). From the value chain perspective, these segments could also be named as upstream, midstream, and downstream, respectively (c.f. Figure 1).  
The upstream segment (supply) focuses on the design, construction, and sale of space systems that play the role of space infrastructure. In the same fashion as the on-Earth equivalents (e.g., transport or telecommunications), it requires substantial investment, has long production cycles, and is costly to maintain and operate. The upstream segment value could be estimated at 88 billion dollars. It comprises the following:  
* Launch systems (\(\sim\) USD 12 billion): rockets used to deploy spacecraft into orbit;
* Spacecraft systems (\(\sim\) USD 64 billion): mainly satellites, transport modules, etc.;
* Ground systems (\(\sim\) USD 12 billion): including production support systems, ground launch support systems, and ground support systems for spacecraft [2] (pp. 2-3, 7).  
The space infrastructure, driven by demand for space systems (midstream estimated at USD 125 billion), is fueled by the following:* Political requirements for space services (\(\sim\) USD 110 billion): the acquisition and utilization of space systems (infrastructure) to fulfill the needs of public space programs, including military, scientific, and other civil applications;
* Commercial demand for space systems (\(\sim\) USD 15 billion): increasing number of private companies, which exploit space assets [2] (pp. 3-4, 7).  
The third and last segment of the space economy is the downstream, which encompasses areas of economic activity that directly result from space-based services provided by midstream operators. These areas could be called space-enabled products and services or induced markets, including the following:  
* User terminals (\(\sim\) USD 83 billion): hardware enabling consumers and industries to access satellite services (e.g., GNSS chipsets for phones and cars, satellite antennas).
* Value-added services (\(\sim\) USD 84 billion): data processing, analytics, and enhancement of raw satellite data for various applications [2] (pp. 4-7).  
Thus, according to Lionnet's estimations, the total space economy has a consolidated value of USD 292 billion (USD 125 billion + USD 83 billion + USD 84 billion). The value of the upstream (USD 88 billion) is already included in the value of the midstream. Therefore, it should not be counted twice [2] (p. 7).