On August 25, 2017, FORMOSAT-5 launched from Vandenberg Air Force Base in California, USA. Now celebrating the fifth anniversary of its launch, the still-operating satellite has already had great success in fulfilling its mission objectives. NSTC Minister Wu Tsung-Tsong stated that FORMOSAT-5, the first remote sensing satellite developed solely by Taiwan, not only establishes Taiwan's capability to independently develop satellite bodies and optical payloads, but also shows mastery in the design and manufacture of core components. In its mission, FORMOSAT-5 has provided great assistance in the understanding and monitoring of global disasters. For example, Minister Wu illustrated, Taiwan recently assisted diplomatic allies in Central America with establishing a large-area monitoring system for Panama disease using satellite images to identify the damage of the disease to banana leaves. This can help prevent and control Panama disease more smoothly, thus preserving the development of the banana industry. Our diplomatic allies have expressed deep gratitude for this assistance.
FORMOSAT-5 is Taiwan's first independently-developed optical remote sensing satellite. Since its launch in 2017, it has accumulated more than 60,000 sets of black and white and color images, with a 94.87% success rate in image reception. It has also captured images of 19 domestic and 101 foreign disaster events. Images taken by FORMOSAT-5 have a wide range of applications; they can be used to survey disasters, as well as to assist the government, industry, and academia in territorial monitoring and the research of vegetation and hydrology. These images are helpful not just for Taiwan, but for the whole world.
One of FORMOSAT-5's most notable contributions has been to assist our Central American diplomatic allies in preventing the spread of Panama disease. Panama disease, which affects banana plants, has recently struck Central America. Bananas are an important industry for our allies Guatemala, Honduras, and Belize, who requested help from Taiwan on the issue. The Ministry of Foreign Affairs then worked with the National Science and Technology Council (NSTC), which instructed NARLabs' National Space Organization (NSPO) to take systematic photographs using FORMOSAT-5 and design a program to automatically identify areas affected by Panama disease. This way, our allies' governments can carry out effective isolation in time to prevent the expansion of the disease and preserve the development of the banana industry.
FORMOSAT-5 can also provide concrete assistance to combat increasingly frequent global climate disasters. For example, during the 2019 Ridgecrest earthquakes in Southern California, the Kaohsiung floods on August 6, 2021, and the 2022 volcanic eruption in Tonga, FORMOSAT-5 provided real-time satellite images to international disaster prevention organizations such as Sentinel ASIA to help governments ascertain the situation. The images can also serve as a basis for reconstruction and territorial planning. NSPO explained that although photos taken by aerial vehicles can be used to survey disasters and are advantaged in terms of mobility, wind and weather that affect flight must also be taken into consideration. If airstreams are unstable, the functions of aerial vehicles will also be limited.
The FORMOSAT-5 was designed to have a lifespan of five years, and after five years in operation, it has reached TRL 9¹, the highest level of technical maturity recognized by NASA and the European Space Agency, setting a milestone for Taiwan in space technology. This also means that FORMOSAT-5 subcontractors have successfully obtained a five-year flight record at TRL 9, which will help them gain a firm foothold in the international manufacturing supply chain for satellite components.
Taiwan's first optical remote sensing satellite was FORMOSAT-2, which was launched in 2004. French company EADS Astrium was commissioned to manufacture the body and optical remote sensing payload for the satellite. Minister Wu emphasized the pioneering achievement Taiwan made in independently developing the satellite body and optical payload for FORMOSAT-5. Meanwhile, the computer and power control system of the TRITON satellite, which is expected to be launched in 2023, are improved from those of FORMOSAT-5. The FORMOSAT-8 remote sensing satellite system, which is currently being designed and manufactured, is inheriting both its optical remote sensing payload and body subsystem design from FORMOSAT-5.
Although FORMOSAT-5 has reached its fifth anniversary of service as well as its expected lifespan, NSPO stated that it is still in good condition and will not immediately be taken out of service. FORMOSAT-5 will continue to guard Taiwan and watch over the world. In the future, more experimental projects for FORMOSAT-5 will be carried out, including taking images outside its original mission range (60 degrees north to 40 degrees south), performing larger angles of rotation, and conducting subsystem component tests to obtain more data for use in future satellite design and manufacturing.
¹ TRL (Technology Readiness Level): a measure of the maturity of technological development (including materials, components, equipment, etc.), divided into nine levels. NASA and the European Space Agency define TRL 9 as "actual system 'flight proven' through successful mission operations" and "actual system proven in operational environment," respectively.
【FORMOSAT-5 - Fast Facts】
The 450-kg FORMOSAT-5 was lifted off by a SpaceX Falcon 9 rocket on August 25, 2017 at Vandenberg Air Force Base in California, USA. It orbits in a sun-synchronous circular orbit at 720 km with an angle of inclination of 98.28°. Its main optical component is its remote sensing payload, which can provide black and white images with a 2-m resolution and color images with a 4-m resolution.
In addition to its mission payload, FORMOSAT-5 also carries an Advanced Ionospheric Probe, which is a multifunctional plasma measurement instrument that can measure plasma composition and density, movement speed, temperature, and other physical quantities in the ionospheric region it passes through and study possible abnormalities in the ionosphere before an earthquake.
FORMOSAT-5 takes about 99 minutes to orbit the Earth, making 14 orbits per day, and can cover the whole globe. It revisits a location once every two days. FORMOSAT-5 makes two passes over the vicinity of Taiwan each day, with about eight minutes for image acquisition around 11:00 a.m. and data downlink around 11:00 p.m.
