Mission typeTechnology
COSPAR ID2012-025C
SATCAT no.38339
Spacecraft properties
Spacecraft typeSDS
Launch mass50 kilograms (110 lb)[1]
Start of mission
Launch date17 May 2012, 16:39 (2012-05-17UTC16:39Z) UTC[2]
RocketH-IIA 202
Launch siteTanegashima Yoshinobu 1
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
Perigee altitude666 kilometres (414 mi)
Apogee altitude678 kilometres (421 mi)
Inclination98.23 degrees
Period98.05 minutes
Epoch30 October 2013, 08:31:20 UTC[3]

SDS-4 (Small Demonstration Satellite 4) is a small satellite (50 cm cube with mass of 50 kg) developed by JAXA. It was launched as a secondary payload on the Shizuku mission on 17 May 2012 UTC.[4]

In 2019, its ownership was transferred to the SKY Perfect JSAT Corporation (JSAT).[5]

There are four rather specialised systems on the satellite:

  • SPAISE (SPace-based Automatic Identification SystEm) - test on-orbit a receiver for picking up signals from Automatic Identification System transmitters on ships well out to sea, and determine how space-based reception is affected by interference between nearby transmitters and by environmental conditions.
  • FOX (Flat heat-pipe on-orbit experiment) - to test whether flat heat pipes work in space in accordance with theoretical models and with tests on Earth
  • IST (In-flight experiment of Solar absorption rate with THERME) - to acquire information about the effect of sunlight in space on thermal coatings, re-flying the THERME instrument developed by CNES for testing different thermal coatings [6]
  • QCM (Quartz Crystal Microbalance) - to test whether a Japanese-manufactured quartz microbalance works well in monitoring contamination of the satellite from assembly to on-orbit operation.


  1. ^ Krebs, Gunter. "SDS 4". Gunter's Space Page. Retrieved 31 October 2013.
  2. ^ McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 31 October 2013.
  3. ^ "SDS-4 Satellite details 2012-025C NORAD 38339". N2YO. 30 October 2013. Retrieved 31 October 2013.
  4. ^ "Small Demonstration Satellite-4 (SDS-4)". JAXA. Retrieved 3 December 2019.
  5. ^ "JAXA and SKY Perfect JSAT Conclude an Agreement on the Transfer of the Small Demonstration Satellite-4". JAXA. 24 April 2019. Retrieved 3 December 2019.
  6. ^ "In-flight thermal coatings ageing on the THERME experiment" (PDF).