Most expensive toilet system

The most expensive toilet ever constructed is the Waste Collection System (WCS) developed for the Space Shuttle Endeavour between 1988 and 1992. According to figures published by the United States General Accounting Office in October 1992, the total cost of the development and manufacture of the Endeavour WCS was around $30 million (from an initial estimate of $2.9 million). Endeavour made its first flight – with the multimillion-dollar toilet on board – on 7 May 1992.

Space toilets are extremely expensive and complicated pieces of machinery, with thousands of moving parts and several pressure vessels, all of which have to work close to some very sensitive places in a safe and sanitary way. Parting people from their waste without the aid of gravity requires suction and some ingenious design to prevent things escaping into crew spaces. The current generation of NASA space toilets (called the Universal Waste Management System) cost $23 million and the Russian ASU-8A toilet has a price tag of $19 million.

The GAO report highlights a number of factors in the exceptionally high cost of the shuttle WCS (the price of which works out to around $58 million adjusted for inflation to 2021 prices). These include mid-development redesigns, unclear specifications provided to subcontractors and the addition of several non-essential features (including a $200,000 "coffee can" for storing toothbrushes). The oft-quoted price of $23.4 million in fact only covered development costs, the actual price of the flight hardware had to be added on to that.