SPACE INDEX COMPANIES INSIGHTS SECTORS PRODUCTS NEWS BLOG ANSWERS RESEARCH ABOUT FOR COMPANIES BUILD / 2026.06.04
Phase Four logo Phase Four Developed electrodeless radio-frequency and multi-mode electric propulsion systems for satellites vs Starfish Space Develops autonomous satellite servicing vehicles using electric propulsion for life extension, disposal, and on-orbit maneuvering Starfish Space logo
HEAD-TO-HEAD1 shared sector
Phase Four Starfish Space
Founded 2015 2019
Headquarters Hawthorne, California Tukwila, Washington
Type private private
Status closed operating
Employees 5 75
Total funding $35.8M $70M
Latest round Series C Series A
Sectors Space Propulsion, Satellite Components & Subsystems In-Orbit Servicing & Assembly, Space Propulsion, Space Sustainability & Debris Removal
Products listed 4 6
Federal contracts
Launches
Leaders listed Steve Kiser, M. Umair Siddiqui, Simon Halpern Austin Link, Trevor Bennett, Ari Juster
News mentions 0 0
SHARED SECTORS
FREQUENTLY ASKED

How do Phase Four and Starfish Space compare?

Both companies work in Space Propulsion. Phase Four was founded in 2015 and Starfish Space in 2019.

Which is larger, Phase Four or Starfish Space?

Starfish Space reports the larger workforce, with 75 employees versus 5.

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