Close Encounters with the South Pole

1
Close Encounters with the South Pole

• Thom Stone - Raytheon/NREN
• NREN Workshop 2001

2
Video Conference with Amundsen/Scott South Pole
Station

• Pre-recorded Wednesday, June 20th
• Station is isolated by Austral Winter
• Ken Freeman, NREN Project Manager, from ARC
• Dr. Chris Martin Harvard/Smithsonian, and
  others, from the Pole

3
South Pole Station
4
South Pole Station Front Door
5
Thom at the South Pole
6
The Challenge of the Pole

• 500 miles from the coast of Antarctica
• Out of range of equatorial (geostationary)
  satellites.
• Cold, dark and isolated half of the year
• Not long ago, HF radio and a few relay polar
  orbiters were all the communications the Pole had

7
And the Rewards

• Unique opportunity for science
• Astronomy (clear skies, dark half the year)
• Weather studies
• Astrobiology
• Mars analog
• Tracking polar orbiters

8
How it Was Done South Pole TDRSS Link

• Developed by Dave Israel of GSFC
• Cooperative effort of NASA/NSF DPP
• Installed and working in 1998
• Uses TDRSS I, an old, NASA geo-stationary
  satellite in inclined orbit
• Uses S Band 2-4 GHZ
• Full IP functionality at 1 Mbps

9
SPTR IP Connection
10
Inclined Orbits

• Geosynchronous satellites orbit at the equator at
  about 24,000 miles up
• They move at the same speed as the Earth turns,
  so they appear to be stationary above a single
  point on the Earth
• Some fuel is needed for station keeping,
  stopping the bird from drifting out of orbit

11
Drifting Satellites

• To conserve fuel on older satellites, especially
  ones with a backup or reserve role, they are
  allowed to drift North and South (are inclined)
• They are kept geostationary East/West
• They complete a North-South cycle every day
• At the bottom of their inclined orbit they can
  be seen at the South Pole
• The time they can be seen changes a little every
  day

12
TDRSS 1 at the Pole

• TDRSS 1 now gives about 5 hours of service at the
  South Pole
• Service starts at 930 p.m. PDT at this time
• We pre-recorded this video session so we did not
  have to force attendees to stay late to see it

13
Technology Used

• Proof that satellite communications could be
  available anywhere
• Shows that IP works well over satellites and
  provides many benefits
• MBone tools and IP Telephony were used for the
  teleconference.