Call your Congressperson. Ask them to support an appropriation specifically for Nasa's DSN. It only takes 5-10 minutes.
https://www.congress.gov/members/find-your-member
"Hello, my name is $name. I am asking you to either sponsor legislation or to support legislation sponsored by another memeber of Congress to increase funding for NASA's Deep Space Network to an appropriate level, which to my understanding is roughly $700M, about $500M more than current allocated. I'm sure you are aware of the enormous amount of value that we enjoy from space science [1], and therefore why it is crucial NASA has the capability to continue to operate this communications network in order to enable that ongoing science. Thank you for your time."
They will ask for your zip code and possibly contact info to follow up (you'll usually get a letter or email from your rep on the topic).
> The agency's internal watchdog said a project to upgrade the three DSN sites with more 34-meter antennas and higher-power transmitters is five years behind schedule, and the cost of the upgrades has increased to $706 million. That expense takes a long time to pay off for the DSN's budget account, which has fallen from an annual level of about $250 million in 2010 to about $200 million today.
[1] https://www.nasa.gov/sites/default/files/files/Benefits-Stem... (if you want specific value talking points)