Hodoyoshi 4

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]

Hodoyoshi-4
Mission typeEarth observation
OperatorNESTRA
COSPAR ID2014-033B
SATCAT no.40011
Mission duration9 years, 3 months, 22 days (ongoing)
Spacecraft properties
ManufacturerUniversity of Tokyo
Launch mass66 kg (146 lb)
Start of mission
Launch date19:11, June 19, 2014 (UTC) (2014-06-19T19:11Z)
RocketDnepr
Launch siteDombarovsky
Orbital parameters
Reference systemGeocentric
Eccentricity0
Perigee altitude620 km (390 mi)
Apogee altitude620 km (390 mi)
Inclination97.9°
 

Launch

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

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
ItemValue
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

References
  1. "Archived copy" (PDF). Archived from the original (PDF) on 2016-10-11. Retrieved 2014-06-24.{{cite web}}: CS1 maint: archived copy as title (link)
  2. Koizumi, Hiroyuki; Komurasaki, Kimya; Arakawa, Yoshihiro (2012). "Development of the Miniature Ion Propulsion System for 50 kg Small Spacecraft". 48th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit. doi:10.2514/6.2012-3949. ISBN 978-1-60086-935-8.
  3. "Funding Program for World-Leading Innovative R&D on Science and Technology(FIRST Program) | Japan Society for the Promotion of Science". Archived from the original on 2016-03-04. Retrieved 2014-11-25.
  4. "Hodoyoshi 4".
  5. "Satellites to track Fukushima, Chernobyl effects". Business Standard India. 2014-06-19.


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