Saturday, December 18, 2010

Servicing Iridium's Satellite Constellation: Business Case (Part 3)

In my last post, I described Part 1 of a business case for a tug service for LEO satellites.  In my post I described how Jon Goff and I had come to the conclusion that Iridium may make a powerful first customer for such a tug service. 

Jon not only provides additional arguments for the value of Iridium as a first customer, but delivers a compelling argument for why an entrepreneur may want to consider pursuing such a service, and why Iridium might want to listen if they do. 

Additionally, call it perfect timing (too arrogant to call it a response to our post?), this spacenews article came out yesterday describing Iridium's belief their fleets CAN make it to 2017 (3X) design life.  A few interesting nuggets from the report (and my commentary):
  • Fleet deemed “viable” with only 36 satellites (but Iridium did not describe what viable means).  Viable must mean less than optimal or they would have only launched 36 sats to begin with.  If fleet is productive with only 36 satellites, there may be even more value in selling the current fleet upon successful transition to NEXT.  This give Iridium a more "robust" constellation to offer to a buyer.
  • Iridium says, "Now, once every couple of weeks we do a maneuver” to avoid orbital debris.  How much debris mitigation maneuvers was factored when calculating the hydrazine needed to make it to 2017?  How much is life shortened if maneuvers increase?
  • Fleet can survive on current fuel until 2017 (and if there are launch delays beyond 2017?)
  • 114kg of hydrazine on board each satellite (back in 1997 when they were first launched)

Good luck Iridium.  If you want a heck of a backup plan, read Jon's post on Part 2 of the Iridium Business Case.  Thanks Jon for your work on this.

1 comment:

  1. read all 3 parts,awesome case!

    I'm unsure of how quickly a propellant tugging system can be designed, manufactured, launched and deemed operational, versus the implementation of solar sail technology.

    I see solar sail as the ultimate killer for any propellant tugging for LEO/GEO satellite stationskeeping. However, the tech itself isn't as responsive as hydrazine thrusting, plus the huge sails are going to get hit my micro meteors.

    The "responsive" nature of a propellant tug system looks compelling!

    Recent developments in solar sail: NASA has got the NanoSail-D tested, and JAXA the IKAROS.