There is a little on-street parking nearby, but your best bet is to park in one of the parking structures that serves the Metro Station or Old Town Pasadena. 

View a Google map showing the HackAspace location and parking.

All locations are open 24/7, and the rates are: 
First 90 minutes free, $2/hour, $6 daily max, $5 flat rate after 10pm

Del Mar Station Parking Structure

(2 min walk to HackAspace)

198 South Raymond Avenue.

626.817.0827 

Schoolhouse Park & Walk Structure

(7 min walk to HackAspace)

33 East Green Street.

626.577.8963

De Lacey Park & Walk Structure

(10 min walk to HackAspace)

45 South De Lacey Avenue.

(626) 577-8963