Space Launch Vehicles · Tool Face-Off

SpaceX Starship vs NASA SLS

Quick answer

Starship is the scrappy, reusable rocket that wants to eat SLS's lunch — and probably will. SLS is the gold-plated government workhorse that actually flies missions right now. Choose your flavor of space.

Our pick

SpaceX Starship

Fully reusable, fully audacious, perpetually 'almost ready'

4★

NASA SLS

Old-school power, new-school price tag, zero-school reusability

2.7★

Payload to LEO (target)

~150 t (fully reusable config)

~95 t (Block 1) / ~130 t (Block 2)

Payload to TLI (Moon)

~100 t (projected)

~27 t (Block 1)

Estimated cost per launch

~$10M (SpaceX target) / ~$100M near-term

~$2B–$4B per launch

Reusability

Fully reusable (booster + ship)

Fully expendable — every rocket is single-use

Operational flights

0 orbital flights completed (as of mid-2025)

2 (Artemis I uncrewed, Artemis II prep)

Height

121 m (397 ft)

98 m (322 ft)

Thrust at liftoff

~74.4 MN (Raptor engines)

~39.1 MN (RS-25 + SRBs)

Propellant

Liquid methane + liquid oxygen (Methalox)

Liquid hydrogen + liquid oxygen + solid boosters

Intended crewed missions

Artemis Moon lander + Mars colonization

Artemis lunar orbit + Gateway station

Development cost (total program)

~$3B (SpaceX internal + NASA HLS contract)

~$23B+ and counting

Launch site

Starbase, Boca Chica TX

Kennedy Space Center LC-39B

Flight cadence (planned)

Dozens per year (reuse goal)

1–2 per year (max realistic)

SpaceX Starship

Reusability★★★★★

Cost Efficiency★★★★★

Safety Heritage★★☆☆☆

Development Pace★★★★☆

Payload Capacity★★★★½

Mission Versatility★★★★★

Operational Readiness★★½☆☆

NASA SLS

Reusability★☆☆☆☆

Cost Efficiency★☆☆☆☆

Safety Heritage★★★★½

Development Pace★★☆☆☆

Payload Capacity★★★★☆

Mission Versatility★★½☆☆

Operational Readiness★★★★☆

Worth knowing

SLS uses upgraded RS-25 engines originally from the Space Shuttle — engines that are then thrown into the ocean after each use.
Starship's Super Heavy booster was caught mid-air by the launch tower's mechanical arms ('Mechazilla') in October 2024 — a world first.
NASA's Inspector General estimated SLS costs could reach $4.1B per launch through 2025, making it one of the most expensive rockets ever flown.
SpaceX has publicly stated a goal of launching Starship for under $10M per flight at scale — roughly 400x cheaper than SLS per launch.
SLS Block 1 is taller than the Statue of Liberty but shorter than Starship, which holds the record as the tallest rocket ever built.

SLS discards engines that cost ~$146M each into the Atlantic Ocean after every launch — SpaceX literally catches its booster with robot arms. One approach treats rockets like champagne flutes; the other treats them like rental cars.

If you want

You need a rocket flying crewed Moon missions RIGHT NOW

SLS has a proven flight record and is already manifested for Artemis crewed missions — Starship hasn't reached orbit yet.

→ Pick NASA SLS

If you want

You want the lowest cost per kg to orbit at scale

Starship's full reusability makes SLS's economics look like burning dollar bills for thrust.

→ Pick SpaceX Starship

If you want

You're planning a Mars colony or need truly massive payload

150 t to LEO fully reusable and in-orbit refueling capability make Starship the only realistic architecture for Mars.

→ Pick SpaceX Starship

If you want

You're a government program manager who values flight-proven hardware over future promises

SLS has institutional support, NASA crew rating heritage, and two launches under its belt — Starship's schedule has slipped before.

→ Pick NASA SLS

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