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Mission Timeline

53 years of silence, broken by four voices
Apollo 17 (Dec 1972) → Artemis II (Apr 2026) · The longest gap in human deep-space exploration
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days since humans last traveled beyond low Earth orbit
Apollo 17 splashed down December 19, 1972. Since that day, every human spaceflight has remained within 600 km of Earth's surface. Artemis II ends that streak.

The 53-Year Gap

From the last Apollo moonwalk to Artemis, humanity confined itself to low Earth orbit. This timeline traces every milestone in the long road back.

Apollo Era — End of an Age
December 11–19, 1972
Apollo 17 — Last Humans Beyond LEO
Gene Cernan and Harrison Schmitt spend 75 hours on the lunar surface at Taurus-Littrow valley. Cernan becomes the last person to walk on the Moon. Schmitt, a geologist, is the only scientist to visit another world.
July 15–24, 1975
Apollo-Soyuz Test Project
Last flight of an Apollo spacecraft. American and Soviet crews dock in low Earth orbit — a Cold War handshake 222 km up. LEO only.
Space Shuttle Era — LEO Only
April 12, 1981 – July 21, 2011
Space Shuttle Program
135 missions over 30 years. Launched Hubble, built the ISS, proved humans could work in orbit. Never left LEO. Maximum altitude: ~620 km (Hubble servicing).
November 20, 1998 – present
International Space Station
Continuous human presence in space since November 2000. Orbiting at ~400 km altitude — less than the distance from New York to Boston. An extraordinary achievement, firmly in LEO.
The Road Back — False Starts
January 14, 2004
Constellation Program Announced
President Bush directs NASA to return to the Moon by 2020 with new vehicles: Ares I, Ares V, and the Orion crew capsule. An ambitious plan.
October 11, 2010
Constellation Cancelled
The Augustine Commission finds Constellation over budget and behind schedule. President Obama cancels the program — but Orion and the heavy-lift concept survive, redirected.
September 14, 2011
SLS Officially Authorized
NASA announces the Space Launch System, rising from Constellation's ashes. Shuttle-derived engines and boosters. The rocket that will eventually carry Artemis crews beyond Earth orbit.
December 5, 2014
Orion EFT-1
First flight of an Orion capsule. Uncrewed, launched on a Delta IV Heavy. Reaches 5,800 km altitude — farther than any human-rated spacecraft since Apollo. Heat shield tested at 80% lunar-return speed.
Artemis Program — Return to Deep Space
November 16 – December 11, 2022
Artemis I — First SLS Flight
Uncrewed. SLS flies for the first time. Orion orbits the Moon for 25.5 days, traveling 2.25 million km. Returns at 40,000 km/h. Heat shield performs — but post-flight analysis reveals unexpected ablation patterns.
April 1, 2026
Artemis II — Humans Return Beyond LEO
Four astronauts — Reid Wiseman, Victor Glover, Christina Koch, Jeremy Hansen — fly a 10-day free-return lunar flyby. First humans beyond LEO in 53 years. First woman and first Canadian in deep space.

Artemis II Development Timeline

From its original 2023 target to the April 2026 launch window — delays, problems solved, and the long march to the pad.

Schedule Evolution
2019–2021
Originally Targeting 2023 Launch
Early Artemis II planning targets a 2023 crewed flight, contingent on Artemis I success and vehicle readiness.
January 2024
Slipped to September 2025
NASA formally delays Artemis II to no earlier than September 2025. Artemis I heat shield analysis and life support system work drive the schedule.
October 2024
Inspector General Warning
NASA's Office of Inspector General reports that the September 2025 date is unlikely, citing ongoing technical challenges with the Environmental Control and Life Support System (ECLSS).
December 2024
Delayed to April 2026
NASA announces April 2026 launch window. Two driving issues: life support system maturation and resolution of unexpected heat shield charring discovered during Artemis I post-flight analysis.
Vehicle Integration & Testing
November 20, 2024
Rocket Stacking Begins
SLS core stage and solid rocket boosters begin assembly in the Vehicle Assembly Building (VAB) at Kennedy Space Center.
October 20, 2025
Stacking Complete
Full vehicle assembly — SLS with Orion and launch abort system — complete atop mobile launcher in the VAB. 11 months of integration.
Pad Operations & Rehearsals
January 18, 2026
Initial Rollout to LC-39B
The full stack rolls out to Launch Complex 39B, the same pad that launched Apollo 10 and the final shuttle mission. 4-mile journey from VAB takes ~10 hours.
January 30, 2026
Winter Storm Delay
Unusual cold weather at KSC forces a brief hold in pad operations. Vehicle remains safe on the mobile launcher.
February 2, 2026
First Wet Dress Rehearsal
Propellant loading test — liquid hydrogen and liquid oxygen flow into the core stage for the first time on the pad. Validates fueling procedures and ground systems.
February 19, 2026
Second WDR — Success
Full wet dress rehearsal completes successfully. Countdown proceeds through terminal count. All systems nominal.
February 21, 2026
Helium Flow Issue → Rollback
Post-WDR inspections reveal a helium flow control issue requiring repair. Decision made to roll vehicle back to the VAB for maintenance in a controlled environment.
February 25, 2026
Back in VAB
Vehicle returns to VAB. Helium system repaired and tested. Final closeout inspections performed.
March 12, 2026
Flight Readiness Review — GO
FRR concludes: Artemis II is approved for launch. Seven launch windows identified, beginning April 1. All open work items closed.
Final Countdown
March 18–20, 2026
Rollout to Pad
Final rollout to LC-39B. Originally planned for March 18, delayed two days due to high winds at the Cape. Arrives at the pad March 20.
March 27, 2026
Crew Arrives at KSC
Commander Reid Wiseman, Pilot Victor Glover, Mission Specialists Christina Koch and Jeremy Hansen arrive at Kennedy Space Center for final launch preparations.
March 30, 2026
Countdown Begins
The 48-hour countdown clock starts. Propellant loading, final vehicle checks, and crew timeline begins.
April 1, 2026 — 6:35 PM EDT
Launch Window Opens
Instantaneous launch window. 8.8 million pounds of thrust. Four humans leave Earth orbit for the first time since 1972.

10-Day Flight Plan

From ignition to splashdown — every critical event in the Artemis II free-return lunar flyby.

Pre-Launch
T-48h to T-0
T-48h
Countdown begins Launch team enters console positions
T-24h
Crew health checks Final medical evaluations and suit fit checks
T-6h
Crew ingress Astronauts board Orion via crew access arm
T-2h
Hatch close & leak check Cabin pressurized, seal verified
T-10m
Terminal autosequence Automated countdown — computers in control
Launch & Ascent
T-0 to T+18m
T-0
Liftoff 39 MN thrust — 8.8 million lbs. RS-25 engines + twin SRBs
T+1m
Max-Q Maximum aerodynamic pressure on the vehicle
T+2m 06s
SRB separation 3,100 mph, 30 mi altitude. Twin boosters jettisoned
T+8m
Core stage MECO & separation Main engine cutoff. Core stage falls to the Atlantic
T+18m
ICPS orbit insertion Interim Cryogenic Propulsion Stage achieves 200 km parking orbit
Earth Orbit & TLI
T+1.5h to Day 1+
T+1.5h
ICPS perigee raise burn Raises orbit to HEO: 200 km x 70,000 km, 23.5-hour period
Day 1
HEO systems checkout Life support validation, systems testing in high orbit. CubeSat deployment
Day 1+
TLI burn — ESM OMS engine AJ10-190 fires. Orion reaches escape velocity. Leaves Earth orbit
Outbound Coast
Day 2 to Day 4
Day 2
Outbound coast begins Mid-course correction burn. Crew settles into deep-space routine
Day 3
Approaching lunar sphere of influence Moon's gravity begins to dominate trajectory calculations
Day 4
Lunar flyby Closest approach: ~4,067 mi (~6,546 km) from the far side surface. Crew sees the far side
Return & Entry
Day 4+ to Splashdown
Day 4+
Free-return gravity assist 7,600 km beyond Moon. Peak distance: 392,650 km from Earth
Day 5–8
Return coast Trajectory refinement burns. Earth grows larger each day
Day 9
Earth approach Final trajectory corrections. Entry corridor narrowing
Day 9.5
Service module jettison ESM separated. Heat shield exposed for the first time since launch
Entry
Atmospheric entry 40,000 km/h (Mach 32). AVCOAT ablative heat shield. Peak 4g deceleration
Splashdown
Pacific Ocean, near San Diego Recovery by USS San Antonio-class amphibious transport dock
Backup launch windows: April 2–6 and April 30, 2026

Launch Day Coverage

Where and when to watch Artemis II launch on April 1, 2026.

Time (EDT) Feed Platform
7:45 AM Tanking operations coverage YouTube
12:50 PM Official launch broadcast NASA+ Prime Video YouTube
4:45 PM Spanish-language broadcast NASA platforms
6:35 PM Launch window opens All feeds
Where to watch: NASA+ (free, no account required) · YouTube @NASA · Amazon Prime Video · NASA App (iOS & Android)

What Comes After

Artemis II is the beginning, not the destination. The program aims for sustained human presence at and around the Moon.

Artemis III
First crewed lunar landing since Apollo 17. Two astronauts descend to the south pole using a SpaceX Starship Human Landing System. First woman on the Moon.
Target: 2027+
Artemis IV
First mission to dock with the Gateway lunar space station. Crew arrives aboard Orion, transfers to the station in a near-rectilinear halo orbit around the Moon.
Target: Late 2020s
Artemis V+
Sustained lunar presence. Regular rotations to Gateway, extended surface stays, in-situ resource utilization, and preparation for eventual Mars missions.
2030s and beyond
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Sources: NASA Artemis II Press Kit · NASA OIG Reports · Kennedy Space Center Media Center · nasa.gov/artemis-ii
Artemis II Mission Timeline — tibsfox.com Research · NASA Mission Series