Ask a US resident to estimate what share of federal funding their space agency gets, and you'll get some widely varied answers.
In fact, some answers to this question were so wild that the top 5% and bottom 5% of responses have been removed (some were "0%" and others were "100%") to ensure the chart here shows a more representative result.
Still, less than two-fifths of the US-based respondents guessed within one percentage point of the correct portion. In reality, the agency's fiscal year 2018 budget was 0.5% of all annual federal spending. That translates to about $20.736 billion of some $4.173 trillion total.
The average respondent, however, thinks NASA currently gets about 6.4% of all federal dollars. If that were true for 2018, NASA would have $267 billion to work with — about 13 times as much as it currently gets.
When asked how much NASA should get, respondents suggested an even larger share: 7.5% of the federal budget, on average. That's about $313 billion, or more than 15 times the current level.
That preferred funding level is far more than NASA got during the peak of the Apollo moon-landing program. During that time (when the agency had its biggest budget share ever) NASA got nearly 4.5% of the federal budget.
If NASA really got 7.5% of the current national budget, that would be enough to build two football-field-size International Space Stations in a single year. (The one we currently have took about two decades.) One year's worth of this funding might also be enough to send a crewed mission to Mars, according to one government estimate.