Example of Standardization
As an example of standardization, I will introduce our ground system used to test and operate satellites at JAXA’s Institute of Space and Astronautical Science (ISAS).
The ISAS ground system provides the following two standard tools. The first is the Space Data Transfer Protocol (SDTP), a standard system for exchanging data between ground instruments and its execution software. The second is the Spacecraft Information Base (SIB), a database that defines the format of data exchanged between satellites and the ground. The SDPT can be used for all ISAS satellites and ground processing equipment. The SIB varies slightly depending on each satellite, but the same SIB is applicable to all processing equipment for one satellite.
When developing a system to process data sent from satellites, even if a new, proper data processing program is required, we can incorporate and utilize the standard SDTP and SIB in the system (Fig. 1). Thus, we have only to develop an exclusive program for the system.
The example is a system used on the ground. Standardization is also possible for satellites. In collaboration with researchers in the U.S.A, I am now working on the design of a standard method to exchange information between onboard satellite systems.
I have discussed standardization, but it is a limited approach to FBC because, as mentioned above, every satellite has its own specific requirements. For scientific satellites in particular, new satellites are required for new observation missions, and standard resources are not always applicable. Does this mean that FBC can never be achieved in such cases?
No, it doesn’t. Things are not that hopeless, and there is a way to realize FCB even with the development of different satellites. It is digitization, the second subject of this article. More specifically, it is an approach to control the satellite’s profile information (i.e., information on satellite itself) as data, on the assumption that every satellite is unique. In other words, it means that we build databases of each satellite’s specifications and manual.
You may think that “this is too easy”, but it is not so. The database we intend to develop is one that can store all the data for every satellite as shown in Fig. 2. Also, it can be accessed and utilized by every program. It is easy to build a database that can store data for a specific satellite or can be utilized by a specific program. The development of the database shown in Fig. 2, however, is not easy because we have to standardize “how to express the satellite’s profile information as data.” To advance digitization, standardization is also essential.
Before discussing the “standard method to express the satellite’s profile information as data,” I will first explain how the database will contribute to FBC. Its versatile effects are as follows:
(1) Previously paper-based works can be digitized
(2) There is no need to design a database for each satellite
(3) Using the satellite’s profile information stored in the database, programs applicable to any satellite can be developed.
The third effect is the most important. The current SIB is not capable of storing a satellite’s profile information, because, as mentioned before, a standard method to express satellite information as data has not yet been established. Under these circumstances, even if we use the SIB as in Fig. 1, a data-processing program must be created for each satellite, based on knowledge of the satellite. If we use the database in question, however, the program will be able to customize itself for unknown satellites, because we can input information on individual satellites as data. The problem of the limits of standardization remains. It may be difficult to convert all (100%) of the information on any satellite into data by the standard method. Nevertheless, even if only 80% of the information can be digitized, it will contribute to FBC.