Final answer:
Parallax measurements were dramatically improved with the use of space telescopes, as they bypass the Earth's atmospheric distortions.
Step-by-step explanation:
Parallax measurements of distant stars were significantly improved with the use of space telescopes. Ground-based telescopes, whether reflecting or refracting, have to contend with the distorting effects of the Earth's atmosphere which can blur the stellar images. However, space telescopes like the Hipparcos satellite launched in 1989 allow for more precise parallax measurements by observing stars outside the Earth's atmosphere, enabling astronomers to obtain more reliable and accurate distances to stars. These measurements are crucial for understanding the scale of our galaxy and the universe.