The Role of Research Infrastructure in the Antarctic Treaty  3

Selected Previous U.S. Antarctica Research Vessels Leased by the National Science Foundation  5

Antarctic Research and Support Vessel Laurence M. Gould  7

Research Vessel Icebreaker Nathaniel B. Palmer  8

Selected U.S. Academic Research Fleet Antarctic Voyages  10

Research Vessel Sikuliaq  10

Research Vessel Roger Revelle  11

Considerations for Congress  12

Short-Term Replacement Options  13

U.S. Academic Research Fleet  14

Reassigning an Existing U.S. Coast Guard Polar Icebreaker's Mission to Antarctica  20

Renewing the Palmer's or Gould's Lease  21

Foreign Antarctic Research Vessels  23

Purchasing an Existing Used Vessel with Icebreaking Capabilities  23

Long-Term Replacement Options  24

National Science Foundation Plans for a New U.S. Antarctic Research Vessel  24

Future U.S. Coast Guard Polar Icebreakers  27