General Advice
Apply early and apply often. Have a backup plan. It matters less where you go and more about how much you put into your experience. There are many high-quality internship programs not listed here.
NASA
Apply on the One-Stop Shopping Initiative (OSSI) website: https://intern.nasa.gov/ossi/web/public/main/
The NASA Multi-disciplinary Aeronautic Research Team Initiative (MARTI) program is not listed on OSSI (for bureaucratic reasons) and can be applied for here: https://www.martiapp.com/
YUAA members have interned at various NASA locations, feel free to contact the following people to discuss their experiences:
Lauren Chambers: Goddard Research Center
Andrew Arkebauer: Langley Research Center
Devin Cody: Ames Research Center
NB: NASA will not notify you if you are not selected for an internship.
Research Experiences for Undergraduates (REUs)
REUs are federally funded, paid internships at national labs and universities across the country. Interns are paired up with a mentor and given research/projects to work on.
https://www.nsf.gov/crssprgm/reu/reu_search.jsp
Some sites you might be interested in:
Arecibo Observatory
National Optical Astronomy Observatory
National Radio Astronomy Observatory
SETI Institute
California Institute of Technology (Laser Interferometer Gravitational-Wave Observatory)
Alcoa
As one of our sponsoring organizations, YUAA has a strong relationship with the recruiters at Alcoa. If you are interested in interning/working for Alcoa, please email Devin or Gerardo.
Some big names in aerospace manufacturing
Boeing: http://www.boeing.com/careers/college/engineering-internships.page
Lockheed Martin: http://www.lockheedmartinjobs.com/college-students.aspx
United Launch Alliance: http://www.ulalaunch.com/Internship.aspx
Northrop Grumman: http://www.northropgrumman.com/Careers/StudentsAndNewGrads/Pages/Internships.aspx
Aerojet Rocketdyne: https://jobs4-aerojet-rocketdyne.icims.com/jobs/intro?amp%3Bhashed=0&mobile=false&width=610&height=500&bga=true&needsRedirect=false
Aerospace Corporation: Does a lot of advising for the US government about all things aerospace. Also runs a number of research labs. YUAA has a contact here, let us know if you would like more information. http://www.aerospace.org/careers/college-students/
Samller names in aerospace manufacturing
Ball Aerospace: http://www.ballaerospace.com/page.jsp?page=40
Honeywell: http://www.careersathoneywell.com/en/job-search-results/?keyword=internship
Sikorksy: One of the pioneering companies in helicopter design and manufacture. https://jobs.sikorsky.com/search-jobs/intern/United%20States?orgIds=1736&kt=1&alp=6252001&alt=2
Made in Space: A company that was recently founded. Based in Mountain View California, Made In Space is a company devoted to building 3D printers capable of manufacturing parts in space.
http://www.madeinspace.us/careers/
Generation Orbit:http://www.generationorbit.com/careers.html
Hawker Pacific Aerospace: http://www.hawker.com/internship
Commercial rocketry
SpaceX: http://www.spacex.com/careers/list?category%5B%5D=361
Blue Origin: https://www.blueorigin.com/careers/job/8a87142e4c5a35ad014c76061bf817f7
Virgin Galactic: https://careers-virgingalactic.icims.com/jobs/intro?branding=live&hashed=-435771411&branding=live
The satellite industry
PlanetLabs: A San Francisco startup that is building a constellation of CubeSats (called doves) able to take pictures of anything at anytime. https://www.planet.com/careers/
Other aerospace-related internships
Spire: https://spire.com/careers/
STEM-related Internships
Google: http://www.google.com/about/careers/students/
Tesla: https://www.teslamotors.com/careers
More Job Listings
SEDS: http://talent.seds.org/browse_jobs
Wolfram Summer Programs: http://education.wolfram.com/summer/school/
Student competitions, scholarships and awards
Space Club: http://www.spaceclub.org/scholarship/
Google Scholarships: https://www.google.com/edu/scholarships/
http://astronautscholarship.org/scholars/scholarship-program-details/ (Apparently Yale Students, cannot apply, we are working on it)