The JWST has a history of major cost overruns and delays which have resulted in part from outside factors such as delays in deciding on a launch vehicle and adding extra funding for contingencies. By 2006, US$1 billion had been spent on developing JWST, with the budget at about US$4.5 billion at that time. A 2006 article in the journal "Nature" noted a study in 1984 by the Space Science Board, which estimated that a next generation infrared observatory would cost US$4 billion (about US$7 billion in 2006 dollars). By October 2019, the estimated cost of the project had reached US$10 billion for launch in 2021.