U.S./Foreign Military and Other U.S. Government Satellite Resources

Mr. Phil Sobolewski, SPAWAR Charleston, presented and led a discussion on potential U.S./foreign military and other U.S. government satellite resources to meet South Pole Station communication requirements. Over forty satellites were examined by SPAWAR for present and future capabilities and are summarized in Table 9.

Satellite bandwidth capability varied from Milstar and EHF Polar (0.000075 MHz) to DSCS (85 MHz). Geo orbit satellite inclinations ranged from UFO-7 (4 degrees) to FLTSAT-1 (13.8 degrees). South Pole daily visibility was a minimum with FLTSAT-4 (6.5 hrs) to a maximum with GPS 2A-13 (9.5 hrs). South Pole/CONUS Mutual Daily Visibility varied from GPS 2A-13 (3 hrs) to FLTSAT-4 (5.5 hrs). Daily theoretical data transfer capability ranged from a minimum with FLTSAT-4 (9.9 GB/d) to a maximum with GPS 2A-13 (12 GB/d).

SPAWAR concluded that the current possibilities are the FLTSAT F1 and F4, GPS NAVSTAR 2A-13, and NRO satellites, and future possibilities are, Advanced EHF Polar Follow-On System, and DSCS-3 F1 and NATO III-D following replacement (see Table 9 for details).

Table 9 : U.S./Foreign Military and Other U.S. Government Satellite Resources for Potential Communication Use at South Pole Station

U.S. Military Communications Systems

DSCS Series FLTSAT Series UFO Series MDLSTAR LDR and MDR EHF Polar Adjunct

SDS EHF Polar Follow-on Advanced F Series


FLTSAT F1 and F4

  • Mediumband Capable (500 kHz)

DSCS 3-F1, if preserved, would be visible at Pole in 2002

Very broadband capability

  • Both Visible for 6.5 Hours/d
  • F4 Mutually Visible from Pole and CONUS for 5.5 Hours/day

EHF Polar Follow-on System

Will launch 2006 19.6 kb/s Projected Communications Package; not considered relevant to Pole broadband requirement


Advanced EHF System for Polar Follow-on

Polar Orbit planned for 2006-2010; Polar Follow-on could be Broadband; planning ill defined at present

Allied Military Systems

NATO Series SKYNET Series


NATO III-D, if preserved, will become visible at South Pole circa 2006

Broadband capability, similar to the DSCS system.

U.S. Military non-Communications Systems

GPS Series



One-way broadband (~ 1Mb/s) may be possible using ranging transponder. Used for testing and checkout. Visible for 9.5 Hours/day between McMurdo and Pole. Mutually visible from Pole and CONUS for 3 Hours/day.


Classified Intelligence Satellites

NRO Satellites


NRO Satellites

One Geosynchronous satellite may be usable; Additional dialog with NRO required to assess concept of NRO support


SPAWAR recommends that NSF/OPP consider taking these next steps:

  1. Pursue authorization to use FLTSAT F1 or F4, and GPS NAVSTAR 2A-13.
  2. Pursue the NRO geosynchronous satellite possibility.
  3. Research the ground equipment requirements for current and future communication scenarios.
  4. Prepare for future possibilities.
  5. Execute the down selection process.

Presentation and Discussion of Possible Options

Mr. Erick Chiang, NSF/OPP Section Head, Polar Research Support Section, led the participants in a review discussion of possible options and detailing summary recommendations. NSF/OPP is transitioning from an ad hoc process to a systematic approach to addressing communications, which is learning a different mode of doing business at South Pole.

The following questions were presented for clarification by the participants of the workshop:

  1. Is there anything more to add regarding bandwidth?
  2. How reliable should communication systems be?
  3. What should the degree of connectivity be?
  4. What are the short-term (FY02)/long-term (beyond FY02) options?
  5. What should the strategy be for implementation with risk mitigation — backups?
  6. What are the costs and benefits of the various communication options?
  7. What should be the short-term allocation of resources?

The recommended availability, reliability, and bandwidth for communication systems at South Pole Station were defined (Table 10).

Table 10: Recommended Availability, Reliability, and Bandwidth for Communication Systems at South Pole Station
Telephony 24 99% 2 T1s (30 GB/d)
Internet 24 99% 4 T1s (60 GB/d)
High Data Rate 12 99%+ 25 GB/d
Total     115 GB/d

A 99% availability translates into an annual acceptable total outage of 87.6 hours per year (based on continuous 24 hour/day coverage), or equivalently 7.3 hours per month or 14.4 minutes/day. In the case of the Internet, outage would have to be defined as the service not being available due to whatever causes, to include performance degrading below some pre-defined acceptable level (a present issue with the service provided via LES-9 - the link is highly available when the satellite is visible, but link quality is often marginal, meaning that many kinds of applications cannot be performed over the Internet link).

Short-term (FY02)/long-term (beyond FY02) options were identified and three categories of capability recommended: minimum, acceptable, and wish list. To meet short-term communication requirements, while the long-term options are being identified, the following primary satellites are recommended to be maintained with backup satellites:

  1. current mix of satellites
    1. GOES-3
    2. TDRS F1
    3. Iridium
    4. LES-9
  2. backup satellites
    1. MARISAT
    2. GOES-2
    3. Military alternatives

Last, it was recommended that NSF/OPP consider installation of a flexible ground station to take advantage of the various satellite systems presently available and potentially available in the future.

The workshop concluded with nine summary conclusions being made to NSF/OPP for review and action (see Executive Summary and Summary Conclusions).