Space Launch System by Boeing: status and timeline

Milestones

Next · Artemis III (crewed low-Earth orbit test with lunar landers)

Artemis I (uncrewed test flight)Nov 2022Complete.
Artemis II core stage integrated with boostersMar 2026Complete.
Artemis II launch with 4-person crew1 Apr 2026Complete.
Artemis III (crewed low-Earth orbit test with lunar landers)Target 2027Not yet reached.
Artemis IV (crewed lunar landing with Centaur V upper stage)Target 2028Not yet reached.
Artemis V and beyond (sustained lunar cadence)Target 2028Not yet reached.

Most important updates

Upcoming

2027Artemis III (crewed low-Earth orbit test with lunar landers) (next)
2028Artemis IV (crewed lunar landing with Centaur V upper stage)
2028Artemis V and beyond (sustained lunar cadence)

Current obstacles

Production rate and costBuilding one rocket per year is the goal, but SLS is expensive and hand-assembled. Supply chains and workforce growth limit speed.
RS-25 engine availabilityThe four main engines are refurbished Space Shuttle engines; limited supply exists. New production or a different engine may be needed for high cadence.

Physics limits

Payload-to-orbit is constrained by fuel capacityEach stage can only carry so much fuel. Adding cargo means subtracting range, orbit altitude, or mission duration.
Requires massive ground infrastructureSLS is too large for most launchpads. Only Kennedy Space Center's LC-39B can accommodate it, limiting launch flexibility.

How it works

3 parts

Two-stage ascent

Core stage (RS-25s) plus boosters, then upper stage

Four RS-25 main engines and two solid-rocket boosters provide 39 MN of thrust. Core stage drops away after ~500 seconds, upper stage takes over.

Hydrogen fuel

Liquid hydrogen and oxygen for maximum specific impulse

The core stage carries 537,000 gallons of liquid hydrogen and 1.49 million gallons of liquid oxygen, burning them at extreme pressure.

Upper stage evolution

ICPS for Artemis II-III, Centaur V for Artemis IV onward

Artemis II and III use ICPS. NASA selected ULA's Centaur V for Artemis IV onward, replacing Exploration Upper Stage to reduce costs and risk.

Spec sheet

Spec	Space Launch System
Rocket height	98 m^R (reported)
Core stage diameter	8.4 m^R (reported)
Sea-level thrust	39 MN^R (reported)
Payload to LEO	95 metric tons^R (reported)
Payload to TLI (Block 1)	27 metric tons^R (reported)
Total launch mass	2,610 metric tons^R (reported)

^R reported by the company

Papers & demos

1 item

1916demo
Boeing Company founded in Seattle, Washington (opens en.wikipedia.org)Founded as Pacific Aero Products; built the first Boeing aircraft and grew into a major aerospace contractor.

Update log

3 updates

Wed 1 Apr

Major: Space Launch System lifts off with Artemis II crewed missionPressHardware
Major: SLS core stage performs nominal ascent, separates on schedulePressTest

Mar 2026

Major: Artemis II SLS core stage integrated with solid rocket boosters completePressManufacturing

About Boeing

The team behind Space Launch System

Boeing

777, 787, SLS rocket, defense, space systems

Boeing designs and manufactures commercial aircraft, defense systems, and space vehicles. Its Defense, Space & Security division builds the Space Launch System (SLS) core and upper stages for NASA's Artemis lunar program, and is a major supplier of spacecraft, missiles and satellites.

Boeing builds the Space Launch System (SLS), the world's most powerful rocket that enables crewed deep space missions.
SLS launched Artemis II in April 2026 with 4 astronauts on a historic crewed lunar flyby.
Under contract through Artemis XII with a $3.2B deal signed in 2022 to manufacture cores and stages.

boeing.com (opens boeing.com)Company profile →

Founded: 1916110 yrs
Headquarters: United States
Status: Public
Listed: BA (opens google.com)NYSE
Valuation: $172Bmarket capJun 2026
Staff: ~172,000
Works in: SpaceflightLaunch
Coverage: 1 program · 3 updateslatest 1 Apr 2026checked 10 Oct
Customers: NASA (opens nasa.gov)
Suppliers: Aerojet Rocketdyne (opens rocket.com)
People: Kelly Ortberg (opens boeing.com)CEO & President

Spec

Space Launch System

Rocket height

98 m^R (reported)

Core stage diameter

8.4 m^R (reported)

Sea-level thrust

39 MN^R (reported)

Payload to LEO

95 metric tons^R (reported)

Payload to TLI (Block 1)

27 metric tons^R (reported)

Total launch mass

2,610 metric tons^R (reported)