Hodoyoshi 4

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Hodoyoshi-4
Mission type Earth observation
Operator NESTRA
COSPAR ID 2014-033B
SATCAT no. 40011
Mission duration 1254 days (ongoing)
Spacecraft properties
Manufacturer University of Tokyo
Launch mass 66 kg (146 lb)
Start of mission
Launch date 19:11, June 19, 2014 (2014-06-19T19:11)
Rocket Dnepr
Launch site Dombarovsky
Orbital parameters
Reference system Geocentric
Eccentricity 0
Perigee 620 km (390 mi)
Apogee 620 km (390 mi)
Inclination 97.9°

Hodoyoshi-4 is a Japanese micro-satellite launched in 2014. The satellite is built in 0.5x0.6x0.7m box-shape bus, optimized for piggy-back launch. All instruments are powered by solar cells mounted on the spacecraft body and two stub wings, with estimated electrical power of 50W.[1] For orbit-keeping, a "miniature" (5 kg dry weight) ion thruster with specific impulse 1100s and operating power 20W is integrated into the body.[2] The satellite was developed under the Funding Program for World-Leading Innovation R&D on Science and Technology.[3]

Launch[edit]

Hodoyoshi-4 was launched from Dombarovsky (air base) site 13, Russia, on 19 June 2014 by a Dnepr rocket. Two-side communication with Earth was successfully achieved at 2nd pass over ground station.

Mission[edit]

The satellite is intended primarily for technology verification in space, main test piece being Earth observation telescope with nominal 6.7m GSD at 650 km altitude.

Hiroshima Japan, taken by Hodoyoshi-4 Satellite
Albert France taken by Hodoyoshi-4 Satellite
Space Message Display System: Electronic Message Display & Observation Window
Hosted Payload Box installed on Hodoyoshi-3 & Hodooyshi-4 satellites

[4]

Specification of Hodooyshi-4 Earth observation telescope
Item Value
GSD 5-7m @ 600-650 km
Type Pushbroom scan
Diameter 150mm
Focal Length 1,000mm
Swath 24 km
Format Raw, 12bit
Band Blue: 0.45 um-0.52 um, Green: 0.52 um-0.60 um, Red: 0.63 um-0.69 um, NIR: 0.73 um-0.90 um

Secondary mission is measurements of water level in rivers to monitor floods by using Store&Forward System.[5] Third mission is Hosted Payload. Hosted Payload mission consisted of 10 cm-cubic boxes on which users could install their own apparatuses for their own applications. Project members asked users in private partnership in order to explore new market of satellite utilization. One of the apparatuses was space message display system. Electronic message display was installed which operators could change characters on the display by sending commands from the ground station. Users can take photos of their messages with the view of the earth from the window.

See also[edit]

References[edit]

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