SPACE INDEX COMPANIES INSIGHTS SECTORS PRODUCTS NEWS BLOG ANSWERS RESEARCH ABOUT FOR COMPANIES BUILD / 2026.06.03
EnduroSat logo EnduroSat Designs, builds, and operates software-defined small satellites and shared satellite platforms for commercial and scientific missions worldwide vs Phase Four Developed electrodeless radio-frequency and multi-mode electric propulsion systems for satellites Phase Four logo
HEAD-TO-HEAD1 shared sector
EnduroSat Phase Four
Founded 2015 2015
Headquarters Sofia, Bulgaria Hawthorne, California, USA
Type private private
Status operating closed
Employees 325 5
Total funding $181.6M $35.8M
Latest round Series C Series C
Sectors Satellite Manufacturing, Satellite Components & Subsystems Space Propulsion, Satellite Components & Subsystems
Products listed 37 4
Federal contracts
Launches
Leaders listed Raycho Raychev, Victor Danchev, Emmanuel Sauzay Steve Kiser, M. Umair Siddiqui, Simon Halpern
News mentions 6 0
SHARED SECTORS
FREQUENTLY ASKED

How do EnduroSat and Phase Four compare?

Both companies work in Satellite Components & Subsystems. EnduroSat was founded in 2015 and Phase Four in 2015.

Which is larger, EnduroSat or Phase Four?

EnduroSat reports the larger workforce, with 325 employees versus 5.

Numbers refresh on every render against the live Space Index database. Federal contract data from USAspending.gov; launches from LaunchLibrary2.