Even with SpaceX's work on reusability and reduced launch costs, chemical rockets are still too expensive for large-scale space colonization. Starship's estimated launch prices could be as low as $500–1,000 per kg to LEO (without refueling) and $2,000–5,000 per kg to cis-lunar space (with orbital refueling, which is not yet flight-tested).
As of mid 2025, SpaceX's rideshare program offers launch to SSO (sun-synchronous orbit) for $6,500 per kg while a Falcon Heavy launch costs about $97 million for a ~41 t payload (expendable) i.e. ~ $2,350 / kg to LEO.
The ULA Vulcan Centaur is priced around $97 million per launch with ~27 t to LEO capacity (roughly $3,600 / kg) while the ULA Atlas V launch price is about $110–160 million for ~18 t to LEO, giving a unit cost of $6,100–8,900 / kg.
Ariane 6 is expected to cost $80–120 million per ~20 t launch ($4,000–6,000 / kg).
Rocket Lab Electron costs $7.5 million for ~300 kg (about $25,000 / kg) while the future Rocket Lab Neutron aims at ~8 t for $50–55 M (~$4,300 / kg).
However, commercialization of non-rocket space launch is critical for large-scale space colonization. For example, SpinLaunch is developing a centrifuge-based suborbital booster with an orbital payload cost projected at $1,250–2,500 / kg.