Is Starship cheaper than NASA’s SLS?

Per flight, almost certainly — SLS costs roughly $2B+ per expendable launch, while even Starship test flights are estimated near $100M with a target far lower. But Starship has not yet proven full reusability, so the final gap is not settled.

Which one actually works today?

SLS is operational (it flew Artemis I in 2022) but launches very rarely. Starship is still in flight testing, though it has already demonstrated a tower "catch" of its booster — something SLS, being expendable, never attempts.

Space

Starship vs NASA SLS

Two super-heavy-lift programs with opposite philosophies: SLS is a fully expendable, contractor-built system descended from Shuttle hardware; Starship is a privately funded, fully reusable vehicle still in flight testing.

Metric	SpaceX Starship	NASA SLS
Payload to LEO	100+ t (reusable target)	~95 t (Block 1)
Reusability	Designed fully reusable (in development)	Fully expendable
Est. cost per launch	Test flights ~$100M; target far lower	~$2B+ per launch
Status (2026)	Flight testing; V3 debuted May 2026	Operational but very low cadence
Booster recovery demonstrated	Yes — first tower catch Oct 2024	N/A (expendable)

Takeaway

SLS works today but at roughly $2B per expendable flight; Starship is still maturing and has not yet proven full reusability. If Starship delivers on reuse, the per-launch cost gap will be enormous — though that case is not yet closed.

Sources

Wikipedia — Space Launch System
Wikipedia — SpaceX Starship

Starship vs NASA SLS

Frequently asked

Starship vs NASA SLS

Frequently asked