Merging Ground Network Systems in Japan
M. Ohta · Space OPS 2004 Conference · 2004
Japanese space activities were conducted by three different space agencies, ISAS (Institute of Space and Astronautical Science), NASDA (National Space Agency of Japan), NAL (National Aerospace Laboratory). On October 1, 2003, these three organizations were consolidated into a single entity, Japan Aerospace Exploration Agency (JAXA), which can promote a broad range of space and aerospace activities systematically and consistently. Bringing together space and aeronautic technologies and resources developed by the original three organizations, JAXA will improve efficiency and advance Japan's space development further. In terms of satellite tracking and operations, ISAS facilities, such as a 64m antenna at Usuda and a 34m antenna at Uchinoura in Japan, have the capability for deep space missions. In contrast, NASDA has the global TT&C ground network system. By consolidating such two complementary agencies, we create a ground network system which can handle the various satellite missions (from Low-Earth-Orbit to Deep Space) by its own. In this paper, we show an overview of the ground network system of JAXA, advantage from this consolidation, and some projects already decided. INTRODUCTION FORMER-ISAS GROUND NETWORK ISAS has two tracking stations (USC and UDSC) and one spacecraft operation center (SSOC). USC (Uchinoura Space Center) is located on the southeast coast of Kyushu (a southwestern major island of Japan). UDSC (Usuda Deep Space Center) is located in a mountainous region in the center of Honshu (the main island of Japan). SSOC (Sagamihara Space Operations Center) is in the main campus of ISAS, which is located in Sagamihara about 40 km west of the center of Tokyo. USC has three antennas (10m, 20m and 34m) for spacecraft tracking mostly in earth orbit, which SpaceOps 2004 Conference Montreal, Canada – May 17 – 21 2004 2 of 7 can be remotely controlled and monitored from SSOC. USC also has a launch site for science spacecrafts. A spacecraft launched from USC is controlled from KSC (Kagoshima Space Center) during prelaunch, launch and early orbit phases. UDSC has a 64m antenna and a 10m antenna. The 64m antenna is used for deep space communications and VLBI observations of radio stars (quasars) with MUSES-B (HALCA). No. Antenna Dia. Rx, Tx band Remarks 1 Usuda(64m) 64m Tx X/S, Rx X/S For Deep space 2 Uchinoura(34m ) 34m Tx X/S, Rx X/S Az 5deg/sec 3 Uchinoura(20m ) 20m Tx S , Rx X/S Table. 1-1 Former-ISAS antenna list Former-ISAS 3 stations for science spacecraft related TT&C and mission operations (see table: 1-1) have also the capability for early deep space mission operations, and function of multi-band(S/Xband) operating. However, at the ISAS stations, visibility of a spacecraft is limited to the period during which the spacecraft passes over Japan, therefore, former-ISAS needed launch-TT&C and other critical mission operations support from foreign space tracking networks. FORMER-NASDA GROUND NETWORK NASDA has three tracking stations (KTCS, MTCS and OTCS) in Japan, four remote sites in overseas, and two different ground network systems: the Old GN (Ground Network System) and the New GN, which are operated at TACC (Tracking and Control Center) in JAXA Tsukuba Space Center (TKSC). Table 1-2 shows the antennas and service capabilities of former-NASDA TT&C antennas. MTCS (Masuda Tracking and Communication Station) is located in the center of Tanegashima Island, 115 kilometers south of Kyushu. KTCS (Katsuura Tracking and Communication Station) is located on the southeast coast of Honshu(the main island of Japan). OTCS (Okinawa Tracking and Communication Station) is located on the Okinawa island (the southern island of Japan), the site of NASDA's southernmost tracking and Communication station. There are two antennas of the Old GN(USB(Unified S-Band) (F)-1,USB(F)-2), and one antenna of the New GN (Masuda Remote Station(MSD), Katsuura Remote Station(KTU), and Okinawa Remote Station(OKN) ) in each communication stations in Japan. And the New GN antennas in overseas are located in Santiago, Maspalomas, Perth, and Kiruna. Each antennas are called Santiago Remote SpaceOps 2004 Conference Montreal, Canada – May 17 – 21 2004 3 of 7 Station(SNT), Maspalomas Remote Station(MSP), Perth Remote Station(PRT), and Kiruna Remote Station(KRN). The new GN system has been established on the basic concept below (see [1] for additional information), and is now fully operational. 1. Reduced operation cost. 2. Remote monitoring and controlling of each remote site from Tsukuba Ground Network Control Center (GNCC). 3. Expansion of the S-band tracking coverage by four overseas remote sites. 4. Compliance with the Consultative Committee for Space Data System (CCSDS). 5. Improved efficiency with regard to the satellite compatibility test by establishing Tsukuba Compatibility Test Site (TCTS), which is equipped with the same functions as the ground station. 6. Reduction of the development/maintenance cost through utilization of COTS. No. Antenna Dia. Rx, Tx band Remarks 1 Katsuura USB(F)-1 18m Tx S, Rx S 2 Katsuura USB(F)-2 13m Tx S, Rx S 3 Masuda USB(F)-1 18m Tx S, Rx S 4 Masuda USB(F)-2 13m Tx S, Rx S 5 Okinawa USB(F)-1 18m Tx S, Rx S 6 Okinawa USB(F)-2 30m Tx S, Rx S S-band effective Are. 18m 7 Katsuura(KTU) (new GN) 10m Tx S, Rx S 8 Masuda(MSD) (new GN) 10m Tx S, Rx S 9 Okinawa(OKN) (new GN) 10m Tx S, Rx S 10 Santiago(SNT) (new GN) 10m Tx S, Rx S 11 Maspalomas(MSP) (new GN) 10m Tx S, Rx S 12 Perth(PRT) (new GN) 10m Tx S, Rx S 13 Kiruna(KRN) (new GN) 10m Tx S, Rx S Table. 1-2 Former-NASDA antenna list The network of the Former-NASDA stations had a worldwide coverage and were cost-effective. However, it did not have the capability to support Deep Space Missions and X-band TT&C function. Former-NASDA has also DRTS (Data Relay Test Satellite) [2], which was launched by H-II A rocket from the Tanegashima Space Center (TNSC) in September 2002, serves as a data relay station. The DRTS Space Network Control system (SN) is a part of DRTS verification experiment ground system, and which is fully operational. SpaceOps 2004 Conference Montreal, Canada – May 17 – 21 2004 4 of 7 NEW ORGANIZATION AND SYSTEM INTEGRATION PROGRAM From 1st Oct 2003, all TT&C stations of former-NASDA and former-ISAS have been maintained by the Consolidated Space Tracking and Data Acquisition Department (CSTD) of JAXA (see Fig. 2-1). Under consolidate of satellite tracking operation and management body by efficient and effective manner to streamline the management and its operation, CSTD was formed to integrate former-ISAS and formerNASDA Ground Networks. Fig. 2-1 Organization of JAXA CSTD Figure 2-1 shows the vision of JAXA satellite operation system after 2007. To construct that JAXA Network system, we need 2 procedures. 1. Integrating former-ISAS GN system and former-NASDA GN system, and expand contingency satellite tracking capability for both former-ISAS and former-NASDA GN. 2. Integrating former-NASDA GN systems (the Old GN and the New GN). SpaceOps 2004 Conference Montreal, Canada – May 17 – 21 2004 5 of 7 For the first step, Former-ISAS and former-NASDA networks will be consolidated with SLE gateways, which are essential to consolidate the operations of these two networks. SLE gateways will be operational from 2006, the launch of SOLAR-B as a target satellite of both ISAS-NASDA cross-support. And after that time, every (former-ISAS and former-NASDA) satellites are operated within former-ISAS and former-NASDA Operation Center and it supports to each other according to need. For the second step, two antennas (Katsuura USB(F)-2 and Okinawa USB(F)-1 ) will be refurbished as the New GN antennas. We also doing feasibility study of X-band telemetry receiving function to Katsuura USB(F)-2 as a pathfinder X-band station in the New GN. And then, We will terminate the rest of Old GN operation in 2007, because of their aging and the end of hardware and software warranty. Fig. 2-1 JAXA Tracking Network Overview (Low Earth Orbit to Deep Space) SpaceOps 2004 Conference Montreal, Canada – May 17 – 21 2004 6 of 7 After these developments, the new network system will be global and be able to support various space missions, from low-earth orbit to deep space missions, and also it’s ready to be an useful system for the other foreign space agencies. Fig.2-2 Mission schedule CONCLUSION We have been promoting the consolidation of former-ISAS and former-NASDA ground network systems, from October 1, 2003, to achieve the following key objects: 1. To establish an efficient and stable satellite tracking system. 2. To provide various types of satellite tracking services which can respond to any potential users. 3. To implement a satellite tracking system development to meet future user missions. SpaceOps 2004 Conference Montreal, Canada – May 17 – 21 2004 7 of 7 REFERENCE [1] D. Asoh et al, “FEASIBILITY STUDY ON LOW COST AUTONOMOUSGROUND TERMINALS AND TRACKING NETWORK”, SpaceOps 2000. paper-ID 1a003. [2] H. Nakata, “AUTONOMOUS OPERATING CAPABILITIES OF NASDA SPACE NETWORK EXPERIMNTS SYSTEM”, SpaceOps 2002. P-T-3-46.