National and commercial expeditions continued to expand the detail on maps of the Arctic through the eighteenth century, but largely neglected other scientific observations.

Since commercial expeditions began in the early 1990's, wealthy clients have lined up to pay up to $65,000 to companies that organize expeditions.

Some of the people on the commercial expeditions didn't allow themselves enough of a safety margin to get down from the summit.

He led a commercial expedition from Bristol in 1457-58 to break the Italian monopoly on trade to the Eastern Mediterranean.

Everest, now, is besieged each year by commercial expeditions that offer individuals rather than national teams an opportunity for glory, usually at around $45,000 a head.

But the deeper issue is this: What is included in the price tag of a commercial expedition?

Hall had brokered a deal with Outside for advertising space in exchange for a story about the growing popularity of commercial expeditions to Everest.

And the commercial expeditions actually deserved much of the credit for the cleanup.

Many who succeeded did so in recent years as commercial expeditions have built a multimillion-dollar business out of guiding clients, who pay up to $60,000 each.

Acting for American investors, Fanning was agent for more than 70 commercial expeditions and voyages.