What is the working concept for dispersal of a constellation of cubesats launched together?

I understand that for the Flock satellites to be useful in providing frequent Earth observation revisit opportunities that they should all be in different orbits, whether spaced out within the same plane or in different planes altogether. EDIT: This spacing appears to me to be crucial to their business objectives, especially given the short orbital lifetimes.

The two working examples I'm aware of are:

  • Flock 1C deployment of 11 satellites from a Dnepr in June 2014
  • all other Flock deployments which I understand have been from the ISS

As there is no propulsion I can't see why all the released satellites won't simply accompany the dispenser (i.e. Dnepr upper stage or ISS) around in very slowly expanding cloud.

1) Is a substantial delta-V imparted by the dispenser release? (EDIT: 2m/s, thanks to the answer from PearsonArtPhoto)

2) How is deployment managed (within one launch batch) in terms of release timing so as to achieve satellite spacing? EDIT: What outcome in terms of orbital spacing was actually targeted and achieved, and by what means - is the dispenser's angle adjusted on the ISS or is the main control achieved by release at different times?

EDIT: Background: I've been looking at Flock TLEs. There has been some dispersion though they are still largely grouped according to their delivery to the ISS. Having an idea of the deployment strategy as per this question is simply a piece of the puzzle.


1 Answer 1


The most common Cubesat deployment mechanism is called a P-POD. The release velocity is up to 2 m/s, which is actually pretty substantial. The main goal is the launch them fast enough where re-contact with the primary launcher is unlikely.

As to how they are deployed, it is the same as for any satellite. Change the angle, the exit velocity, and you'll get different deployments, sufficient to protect against re-contact with either the launcher or the other satellites. The analysis is done on the ground to prevent that.

  • 1
    $\begingroup$ Thanks, I realised upon reading your response that I needed to clarify more of what I'm looking for. Question edited accordingly. I had a look at the P-POD documentation following your link, it appears that 2m/s is based on whatever stack of objects is in the tube weighing 4kg, hence a 3U and 3x1U get the same energy. $\endgroup$
    – Puffin
    Commented Jan 23, 2016 at 12:19

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