are loaded onto a freighter for exportation. The precedent for exporting wastes began in 1971. The United States shipped out tons of radiation-contaminated soil after officials shut down a small nuclear power plant. Tourism Antarctica's extreme remoteness and hazardous travel conditions limit Antarctica tourism to an expensive niche industry largely centered on the Antarctic Peninsula. The number of seaborne tourists grew fourfold during the 1990s, reaching more than 14,000 by 2000, up from 2,500 ten years earlier. More than 46,000 airborne and seaborne tourists visited Antarctica during the 2007–2008 season, according to the International Association of Antarctic Tour Operators (IAATO). This confederation of tour operators reports that only 5% of Antarctic tourists visit the Ross Sea area, which encompasses McMurdo Sound. Tourists congregate on the ice-free coastal zones during summer near the Antarctic Peninsula. The peninsula's wildlife, soaring mountains, and dramatic seascapes have drawn commercial visitors since the late 1950s, when Argentina and Chile operated cruises to the South Shetland Islands. Tourists flights began in 1957, when a Pan American Boeing 377 Stratocruiser made the first civilian flight to Antarctica. Commercial flights landed at McMurdo Sound and the South Pole in the 1960s. Routine overflights from Australia and New Zealand took place between 1977 and 1980, transporting more than 11,000 passengers, according to Antarctica New Zealand, which manages Scott Base. One such flight, Air New Zealand Flight 901, crashed into Mount Erebus on the eastern shores of McMurdo Sound. The crash high on the slopes of the active volcano took the lives of all 257 people aboard the aircraft. In 1969 the MS Explorer brought seagoing tourists to Antarctica (British Antarctic Survey). The cruise's founder, Lars-Eric Lindblad, coupled expeditionary cruising with education. He is quoted as saying, "You can't protect what you don't know" (IAATO). In the decades since then, ships engaged in Antarctic sightseeing cruises have grown in size and number. Infrequent Antarctic cruises have included passenger vessels carrying up to 960 tourists (IAATO). Such vessels may conduct so-called "drive-by" cruises, with no landings made ashore. The Russian Kapitan Khlebnikov has conducted voyages to the Weddell Sea and Ross Sea regions since 1992. High-latitude cruises in dense pack ice are only achievable during the summer season, November into March. In 1997, the vessel Kapitan Khlebnikov claimed the distinction of being the first ship to circumnavigate Antarctica with passengers (Quark Expeditions). Passengers aboard the icebreaker make landings aboard Zodiac inflatable