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Japan Aerospace Exploration Agency:JAXA
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JEM Small Satellite Orbital Deployer (J-SSOD)



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JEM Small Satellite Orbital Deployer (J-SSOD) is a mechanism for deploying small satellites designed in accordance with CubeSat design specification (10cm×10cm×10cm) that transfers the satellites from the Japanese Experiment Module Kibo's airlock to space environment and releases them on orbit. J-SSOD is composed of the Satellite Install Cases, Separation Mechanism and Electrical Box. J-SSOD is used by attaching it with Multi-Purpose Experiment Platform (MPEP).

Item Specification
Installable satellite size CubeSat size 1U, 2U, 3U or 6U*
Installable satellite mass 1.33 kg or less per 1U, 6U size satellite is 14 kg or less
Insertion orbit Elliptical orbit with altitude of 380 km - 420 km (depends on ISS altitude)
Inclination: 51.6°
Ballistic coefficient 120kg/m2 or less (to make satellites decayed faster than ISS orbit)
Insertion direction Nadir-aft 45° from the ISS nadir side, in terms of ISS body coordinate system
(to avoid collision with the ISS)
Insertion velocity 1.1 - 1.7 m/sec
Life expectancy on orbit about a year (depends on ballistic coefficient, released altitude, solar activity, etc.)

*1U~3U : 10cm(W)×10cm(D), Height: 1U: 10cm, 2U: 20cm, 3U: 30cm, 6U : 10cm(W)×20cm(D)×30cm(H)

JEM Payload Accommodation Handbook. - Vol. 8 -. Small Satellite Deployment. Interface Control Document Rev.C[PDF: 3.74MB]

JEM Payload Accommodation Handbook. - Vol. 8 -. Small Satellite Deployment. Interface Control Document Rev.B[PDF: 2.70MB]

※English Rev.C coming soon

CubeSat deployment mission using J-SSOD

CubeSats are released from Kibo, taking advantage of its unique function having both airlock and robotic arm among modules on the ISS.

Mission procedure


CubeSats set in a Satellite Install Case.


Multi-Purpose Experiment Platform (MPEP) with Satellite Install Cases is installed on the airlock's slide table.

  1. Satellite Install Cases with pre-installed CubeSats are delivered to the ISS as part of spaceship (such as HTV) cargo.
  2. On Kibo, Satellite Install Cases are installed on the MPEP. Then the MPEP is installed on the airlock slide table. Mechanism checkout and preparation are done.
  3. The J-SSOD attached with MPEP is transferred to the outboard. Then, Kibo's robotic arm Japanese Experiment Module Remote Manipulator System (JEMRMS) grapples the MPEP and transfers it to the releasing point.
  4. MPEP is faced to the direction of nadir-aft 45°, opposite side of the ISS travel direction. Then, spring on the Satellite Install Case deploys CubeSats.

Compared with satellites launched by rockets, J-SSOD mission has the following advantages.

  • Launch condition is not severe (since they are launched as part of pressurized cargo to the ISS, launch condition such as vibration is loose.)
  • More opportunity for launches (various ISS visiting vehicles can be used.)
  • After the launch, ISS crew can perform the checkout (realizes more reliable mission.)

Overview of the technology demonstration mission to establish the mission procedure

enlarged photo

CubeSats deployed in the technology demonstration mission

In order to validate technology and establish operation procedure, technology validation mission was performed from October 4-5, 2012. During two-time deployment, 5 CubeSats were deployed.

1st deployment: WE WISH and RAIKO were deployed at 11:37 pm, Oct. 4th from Satellite Install Case No.1.
2nd deployment: FITSAT-1, F-1, and TechEdSat were deployed at 0:44 pm, Oct. 5th from Satellite Install Case No.2.

The first deployment was operated by astronaut Hoshide on orbit. The second deployment was operated by Kibo's Mission Control Room on ground.

Small Satellites Deployment from Kibo were success

Following the success of the technology validation mission, JAXA now accepts CubeSats to be deployed from Kibo.

List of deployed CubeSats using J-SSOD

* All times are Japan Standard Time (JST)

* All photo credit: JAXA

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