Formosat-5

Formosat-5 (Formosa Satellite 5; Chinese: 福爾摩沙衛星五號) is the first Earth observation satellite manufactured and operated solely by the National Space Organization, the national civilian space agency of Taiwan. The satellite was launched from a Falcon 9 rocket on 24 August 2017, and placed into a Sun-synchronous orbit at an altitude of about 720 km. Formosat-5 can capture color and more detailed monochrome images, along with measuring the ionosphere plasma's properties.

Formosat-5

Artist's concept of Formosat-5
Mission type	Earth observation
Operator	NSPO
COSPAR ID	2017-049A
SATCAT no.	42920
Website	Formosat-5
Mission duration	Planned: 5 years Elapsed: 7 years, 8 months, 14 days
Spacecraft properties
Manufacturer	NSPO
Launch mass	475 kg (1,047 lb)[1]
Dimensions	1.6 × 2.8 m (5.2 × 9.2 ft)[1]
Start of mission
Launch date	24 August 2017, 18:51 (2017-08-24UTC18:51) UTC[2]
Rocket	Falcon 9 FT
Launch site	Vandenberg SLC-4E
Contractor	SpaceX
Orbital parameters
Reference system	Geocentric
Regime	Sun-synchronous
Semi-major axis	7,101.4 km (4,412.6 mi)
Eccentricity	0.0009348
Perigee altitude	716.6 km (445.3 mi)
Apogee altitude	729.9 km (453.5 mi)
Inclination	98.2892°
Period	99.25 minutes
Epoch	25 August 2017, 12:30:14 UTC[3]
FORMOSAT programme ← FORMOSAT-3 FORMOSAT-7 →

Spacecraft design

Formosat-5 primary goal is to demonstrate Taiwan's satellite manufacturing capabilities and produce data for various academic research. The satellite is 2.8 m tall, 1.6 m wide octagonal prism body, and weighs about 450 kg. Formosat-5 contains the Optical Telemetry Payload (Chinese: 光學遙測酬載) capturing color and monochrome images, and the Advanced Ionospheric Sounder (Chinese: 先進電離層探測儀) measuring the ionosphere.^[4]

The Optical Telemetry Payload is the primary instrument aboard the spacecraft, composed of a telescope and an electrical unit. The telescope uses a CMOS chip designed to see four light wavelengths: blue, green, red, and near infrared. The chip also has a dedicated monochrome sensor with 12-bit color depth. The Optical Telemetry Payload has a 10GB storage device, which can store panoramas that take 8 minutes to capture.^[4] Formosat-5 can capture images with a 2-meter resolution in black and white and 4 meters in color.^[5]

Formosat-5 also contains a scientific payload, called Advanced Ionospheric Probe, that studies plasma physics and properties in the ionosphere.^[6] This instrument can measure plasma composition, density, temperature, and flow rate. The Advanced Ionospheric Probe is expected to be sensitive enough to capture anomalies of the ionosphere before earthquakes.^[4]

Other components of Formosat-5 include a power control and distribution unit, heaters, batteries, and foldable solar panels. The power control and distribution unit can output a voltage of 5.2V with a maximum wattage of 50W. Formosat-5's MIPS computer can process 20 million instructions per second, with high-speed data channels.^[4]

Operation

Artist's concept of Formosat-5 in orbit

Formosat-5 is the National Space Organization's first indigenously developed observation satellite, directed by Chang Ho-pen (張和本).^[7][8][9][5]

The satellite was flown from Taiwan to Los Angeles International Airport in the United States on 19 July 2017 via a China Airlines transport aircraft, and arrived at Vandenberg Air Force Base on 26 July.^[10][11] Launch took place on 24 August 2017 at 18:51 UTC from Vandenberg Space Launch Complex 4 aboard a Falcon 9 rocket.^[2]

In September 2017, Formosat-5 transmitted its first images, which were blurry. A subsequent rescue mission fixed the satellite; however, it is limited to capturing images during good weather.^[5]