Right, but who's to say though whether some breakthrough in space travel will lead to technology that ultimately helps cure cancer?

In fact, if you look at NASA's spinoff brochure (space technologies that have trickled down to daily life) for this year [0], two of the items are directly related to cancer research.

0: https://spinoff.nasa.gov/Spinoff2018/pdf/2018_Brochure_web.p...