Space Launch System
SLS Block 1 with the Orion spacecraft launching from Pad 39B | |
| Function | Super heavy-lift launch vehicle |
|---|---|
| Manufacturer | |
| Country of origin | United States |
| Project cost | US$31.6 billion as of 2025 (excluding Orion) |
| Cost per launch | US$2.5 billion (excluding Orion) |
| Cost per year | US$2.6 billion (FY23) (excluding Orion) |
| Size | |
| Height | 98 m (322 ft) |
| Diameter | 8.4 m (27.6 ft) |
| Mass | 2,610,000 kg (5,750,000 lb) |
| Stages | 2½ |
| Maximum thrust | 39 MN (8,800,000 lbf) |
| Capacity | |
| Payload to LEO | |
| Altitude | 200 km (120 mi) |
| Orbital inclination | 28.5° |
| Mass | 95,000 kg (209,000 lb) |
| Payload to TLI | |
| Mass | 27,000 kg (59,500 lb) |
| Associated rockets | |
| Based on | |
| Comparable | |
| Launch history | |
| Status | Active |
| Launch sites | Kennedy, LC-39B |
| Total launches | 1 |
| Success(es) | 1 |
| First flight | 16 November 2022 |
| Carries passengers or cargo | Orion |
| Boosters – five-segment SRB | |
| No. boosters | 2 |
| Height | 54 m (177 ft) |
| Diameter | 3.7 m (12 ft) |
| Gross mass | 730,000 kg (1,600,000 lb) |
| Maximum thrust |
|
| Total thrust |
|
| Specific impulse | 269 s (2.64 km/s) |
| Burn time | 126 seconds |
| Propellant | APCP (Al / AP / PBAN) |
| First stage – Core | |
| Height | 64.6 m (212 ft) |
| Diameter | 8.4 m (28 ft) |
| Empty mass | 97,940 kg (215,910 lb) |
| Gross mass | 1,085,410 kg (2,392,910 lb) |
| Propellant mass |
|
| Powered by | 4 × RS-25 |
| Maximum thrust |
|
| Specific impulse |
|
| Burn time | 480 seconds |
| Propellant | LH2 / LOX |
| Second stage – ICPS | |
| Height | 13.7 m (45 ft) |
| Diameter |
|
| Empty mass | 3,490 kg (7,690 lb) |
| Gross mass | 32,066 kg (70,693 lb) |
| Powered by | 1 × RL10 |
| Maximum thrust | 110.1 kN (24,800 lbf) |
| Specific impulse | 465.5 s (4.565 km/s) |
| Burn time | 1,125 seconds |
| Propellant | LH2 / LOX |
The Space Launch System (SLS) is an American super heavy-lift expendable launch vehicle used by NASA. As the primary launch vehicle for the Artemis program, SLS is designed to send the crewed Orion spacecraft on trans-lunar injection trajectories for missions to the Moon. The rocket first launched on 16 November 2022, carrying the uncrewed Artemis I mission.
Development of SLS began in 2011 as a congressionally mandated replacement for the retiring Space Shuttle and the cancelled Ares I and Ares V launch vehicles of the Constellation program. The vehicle incorporates heritage hardware from the Shuttle program, including its RS-25 engines and solid rocket boosters, alongside newly developed elements such as the core stage. The project has seen mismanagement, budget overruns, and delays. The first launch, required by Congress to take place by 2016, occurred nearly six years later.
All SLS launches take place from Launch Complex 39B at the Kennedy Space Center in Florida. The initial missions use the Block 1 configuration, consisting of the core stage, extended Space Shuttle boosters developed for Ares I and the Interim Cryogenic Propulsion Stage (ICPS) as an upper stage.
Prior to February 2026, NASA planned to progressively introduce upgrades. The Block 1B configuration would feature the purpose-built Exploration Upper Stage (EUS), followed by a more powerful Block 2 variant equipped with new solid rocket boosters. However, amid delays and technical issues during preparations for Artemis II, NASA Administrator Jared Isaacman announced on 26 February 2026 that the agency would standardize to the configuration of Block 1 and cancel development of the Block 1B and Block 2 upgrades, citing risk reduction and schedule stability for the Artemis campaign.