The DoD National Defense Science and Engineering Graduate (NDSEG) Fellowship Program  https://ndseg.sysplus.com/    is a competitive fellowship that is awarded to U.S. citizens, U.S. nationals, and U.S. dual citizens who intend to pursue a Doctoral degree aligned to the DoD services Broad Agency Announcements (BAAs) in research and development at a U.S. institution of their choice.  Each service will have specific BAAs so it’s important to review AFOSR, ARO, ONR and Space Force BAAs to determine which one aligns with your research.
The application closes on Friday, November 19, 2021.
How to apply  https://ndseg.sysplus.com/NDSEG/Applicants/How-to-Apply

The broad research area disciplines include, but are not limited to:

• Aeronautical and Astronautical Engineering
• Biomedical Engineering
• Chemical Engineering
• Chemistry
• Civil Engineering
• Cognitive, Neural, and Behavioral Sciences
• Computer and Computational Sciences
• Electrical Engineering
• Geosciences (includes Terrain, Water, Air)
• Materials Science and Engineering
• Mathematics
• Mechanical Engineering
• Naval Architecture and Ocean Engineering (includes Undersea Systems)
• Oceanography (includes Ocean Acoustics, Remote Sensing, Marine Meteorology)
• Physics (includes Optics)
• Space Physics
  The Government may revise the aforementioned disciplines annually to ensure relevancy to the Defense mission is maintained. For the most relevant research areas please review the tri-services BAAs.