There is a lot of fellowships and student research grants you can apply. These experience not only shine on your CV but also enable you to explore fun projects that align with your career goal. Here is a list of fellowship and grants I recommend you to consider.
NSF GRFP
(Typical Due Date - Mid November)
This is probably the most prestigious PhD fellowship program in the US. Definitely worth applying. Michigan Tech has workshops to support students work on it. You even get a small money prize for finishing it ;) You can apply during your senior year or during the first year of your first graduate degree program.
https://www.nsf.gov/funding/opportunities/grfp-nsf-graduate-research-fellowship-program
DOD NDSEG
(Typical Due Date - October November)
This is the DOD program for PhD students focusing on STEM subjects. You can apply during your senior year or during the first two year of your first graduate degree program.
DOD SMART Scholarship Program
(Typical Due Date - December)
This is the DOD Schorlarship for Service Program for students focusing on STEM subjects. You have opportunity to work on DOD facilities during summer. After graduation scholars begin their one-for-one service commitment on DOD civilian careers.
https://scholarshipamerica.org/scholarship/smart-scholarship-program/
NASA Space Technology Graduate Research Opportunities (NSTGRO)
The NASA fellowship that support graduate research.
https://www.nasa.gov/nasa-space-technology-graduate-research-opportunities-nstgro/
Michigan Space Grant Consortium - Graduate Fellowship
(Typical Due Date - November)
A small grant that support shorterm graduate study.
https://www.mispacegrant.org/funding/faculty/graduate-fellowship/
Michigan Space Grant Consortium - Undergrad Research Grant
(Typical Due Date - November)
A small grant that support shorterm undergraduate study.
https://www.mispacegrant.org/funding/faculty/undergraduate-fellowship/