Artemis II
Moon Mission Tracker

Artemis II is NASA's first crewed mission to the Moon since Apollo 17 in December 1972. Launching April 1, 2026 aboard the Space Launch System (SLS) Block 1 rocket from Launch Complex 39B at Kennedy Space Center, it carries four astronauts on a free-return lunar flyby lasting approximately 10 days. The Orion Multi-Purpose Crew Vehicle (MPCV) will pass within 8,900 km of the lunar surface — closer than any crewed spacecraft since Apollo — before returning to a Pacific Ocean splashdown.

Unlike Apollo, Artemis II does not insert into lunar orbit. It uses a free-return trajectory: the Moon's gravity naturally redirects Orion back toward Earth without any additional engine burn, making the mission extremely robust to abort scenarios. This is the critical human-rating flight before Artemis III attempts the first crewed lunar landing since 1972.

Four astronauts fly Artemis II — the most diverse crew ever sent to the Moon:

Reid Wiseman (Commander, NASA) — U.S. Navy test pilot, ISS Expedition 40/41 veteran, and selected as Artemis II commander in 2023. Wiseman will be the first Artemis commander to leave Earth orbit.

Victor Glover (Pilot, NASA) — U.S. Navy test pilot, SpaceX Crew-1 veteran, and the first Black astronaut to fly to the vicinity of the Moon. Glover completed a six-month ISS mission in 2021 and brings critical long-duration operations experience.

Christina Koch (Mission Specialist 1, NASA) — Holds the record for the longest single spaceflight by a woman (328 days on ISS). Koch will become the first woman to travel to lunar distance, extending her historic milestone from Earth orbit to cislunar space.

Jeremy Hansen (Mission Specialist 2, CSA) — Royal Canadian Air Force fighter pilot and astronomer, selected by the Canadian Space Agency. Hansen becomes the first non-American to fly to the Moon, representing Canada's historic seat on the Artemis crew under the Artemis Accords.

Artemis II follows a Distant Retrograde Orbit approach rather than a direct insertion. The trajectory unfolds in seven phases:

T+0 — Launch: SLS Block 1 lifts off with 8.8 million pounds of thrust. The core stage and twin solid rocket boosters burn for ~8 minutes, placing Orion's upper stage into a low Earth parking orbit at ~190 km.

T+1.5h — Earth Orbit: The Interim Cryogenic Propulsion Stage (ICPS) circularises Orion's parking orbit. The crew performs full systems checks across all four Orion systems domains.

T+2.5h — Trans-Lunar Injection: The ICPS fires for approximately 18 minutes, accelerating Orion to ~10.2 km/s and placing it on a trajectory to the Moon. The ICPS separates and Orion deploys its four solar panel wings.

T+3 to T+4 days — Outbound Coast: Orion coasts 384,400 km to the Moon at a decelerating average of ~1–3 km/s as Earth's gravity decelerates the spacecraft. No major burns required.

T+~96h — Lunar Flyby: Orion swings within 8,900 km of the lunar surface (closer than the International Space Station's altitude above Earth). The Moon's gravity accelerates Orion and redirects it back toward Earth — no engine burn needed.

T+5 to T+10 days — Return Coast: Orion coasts back to Earth on the free-return trajectory, decelerating under Earth's gravity pull.

T+240h — Splashdown: Orion re-enters Earth's atmosphere at ~11 km/s (Mach 32), protected by its Avcoat ablative heat shield (the largest ever flown). Parachutes deploy and Orion splashes down in the Pacific Ocean off San Diego, recovered by USS San Diego.

The GRIP 3D Artemis II tracker integrates three live data pipelines:

NASA JPL Horizons (Primary — Orion position): JPL's Solar System Dynamics group maintains the Horizons Web API, which provides precise ephemeris data for every tracked solar system body and spacecraft. Orion Artemis II is catalogued as spacecraft ID -1032 in the J2000 Earth-centered inertial (ECI) reference frame. The GRIP 3D server queries this at /api/orion-position every 2 minutes, returning X/Y/Z position in kilometres and velocity components in km/s. The 2-minute cache reflects Horizons' own update cadence.

NASA JPL Horizons (Moon position): The Moon (body ID 301) is queried separately from the Earth geocenter (500@399) in the same J2000 ECI frame. This gives the precise Earth-Moon geometry rather than using mean orbital elements. Updated every 10 minutes — the Moon moves ~1.4 km/s.

NASA Image and Video Library (News feed): NASA's public multimedia API is queried for recent "Artemis II" imagery without authentication. The gallery drawer shows the latest 12 items returned, updated hourly.

Mission-Elapsed-Time Fallback: If Horizons has not yet catalogued the Orion spacecraft (typical within the first 12–24 hours after launch), the API falls back to a physics-interpolated position derived from published mission waypoints (LEO insertion, TLI completion, closest lunar approach, splashdown) using linear interpolation between known distance and velocity at each milestone. A banner on the visualisation indicates which data source is active.

Unlike the Earth-surface use cases (UC15 Starlink, UC17 Aircraft) which use globe.gl, Artemis II required a custom Three.js scene to represent the full Earth-Moon system in 3D space.

Scale: 1 Three.js unit = 5,000 km. At this scale, Earth has a radius of ~1.27 units, the Moon is ~0.35 units, and the Moon sits ~77 units from Earth (real average 384,400 km). The vast scale difference is why the Moon appears small but far away.

Earth: SphereGeometry with a Phong material, a translucent atmosphere shell, and a subtle wireframe grid overlay. The KSC launch site is marked with an orange dot at 28.6°N, 80.6°W, computed from lat/lng using the corrected polar2Cartesian formula (theta = (90 - lng) * π/180, positive X component).

Moon: SphereGeometry positioned at real-time coordinates from NASA JPL Horizons. A TorusGeometry ring provides a visual locator ring around the Moon, and the approximate lunar orbital path (inclined ~23.4° to match the ecliptic tilt approximation) is drawn as a closed LineLoop.

Orion Spacecraft: A compound Three.js Group built from primitives to approximate the real Orion MPCV: a truncated CylinderGeometry crew module, flat heat shield disc, service module cylinder, engine bell nozzle, and four BoxGeometry solar panel wings with CylinderGeometry struts — matching the real European Service Module layout. A PointLight child of the group illuminates surrounding geometry as the spacecraft moves.

Trajectory Arc: A CatmullRomCurve3 spline through mission waypoints (launch → LEO → TLI boost → outbound coast → lunar flyby → return coast → splashdown) sampled at 240 points and rendered as a Line primitive.

Camera: Spherical orbit controls via mouse drag and scroll wheel, starting at r=110 (550,000 km equivalent) to show both Earth and the outbound trajectory clearly.

Artemis is NASA's programme to establish a sustained human presence at and around the Moon for the first time since Apollo. It represents a fundamental shift from flags-and-footprints exploration to long-term cislunar infrastructure.

Artemis I (November 2022) was the uncrewed shakeout flight. Orion flew 40,000 km beyond the Moon — farther from Earth than any human-rated spacecraft — for 25.5 days, validating heat shield performance, life support, and deep-space communications at full system scale.

Artemis II (April 2026) proves that humans can survive the transit, perform the flyby, and return safely. No new orbital hardware is tested; the mission is entirely about validating crew operations and Orion's human-rating.

Artemis III (NET 2027) will land two astronauts on the lunar South Pole — the first lunar surface landing since Apollo 17. The SpaceX Starship Human Landing System will serve as the descent vehicle, refuelled in low Earth orbit by SpaceX Starship tankers.

Artemis IV and beyond will assemble the Lunar Gateway station in near-rectilinear halo orbit (NRHO), providing a permanent staging point for Moon operations and eventual Mars preparation missions.

The Artemis Accords, signed by 50+ nations, establish the diplomatic and operational framework for this multi-decade return to the Moon — one of the largest coordinated human endeavours since the International Space Station.