Orion

Orion: the capsule built to bring a crew home from the Moon

Drawn from 21 sources: NASA (19), NASA Office of Inspector General and U.S. Government Accountability Office. About 9 minutes. Checked October 1, 2026.

Orion is the spacecraft that carries and sustains the crew on Artemis missions to the Moon and returns them safely to Earth. It never lands on the Moon; a separate lander does that.¹

Distance and duration both dictate the capabilities a deep space spacecraft needs, and they shaped Orion’s design. Astronauts at the Moon will not have the benefit of frequent resupply shipments bringing spare parts from Earth, as crews on the International Space Station do. So Orion carries highly reliable systems that take up little mass and volume, leaving room for the food, water and other consumables of a mission lasting days or weeks: life support, navigation, communications, radiation protection, a compact toilet, exercise equipment, spacesuits that can keep the crew alive for six days if the cabin loses pressure, and the world’s largest heat shield.¹

Three parts, each for a different phase of flight

Loading the model

One spacecraft, three main elements

Orion has three main elements: the crew module, where astronauts live and work; the service module, which provides power, propulsion and critical supplies; and the launch abort system, which can pull the spacecraft and crew to safety if something goes wrong during launch or the climb to orbit. In space its four solar array wings give it a span of about 63 feet.^1,17

A capsule that comes home

The crew module is the only part of Orion that returns to Earth. Its pressure vessel, the airtight structure astronauts live in, is made of seven large aluminum alloy pieces joined at NASA’s Michoud Assembly Facility in New Orleans by friction-stir welding. Orion’s original design required 33 welds; engineers reduced that to seven, saving 700 pounds. Twelve small thrusters steer the capsule after it separates from the service module for reentry.³

The service module and the escape tower

The European Service Module beneath the capsule holds water, oxygen and nitrogen, keeps the spacecraft at the right temperature and drives it with 33 engines: a main engine that once flew on the space shuttle, eight auxiliary engines and 24 small thrusters. On top, the launch abort system’s motor can produce 400,000 pounds of thrust to pull the crew away from a failing rocket. Once SLS clears most of the atmosphere, the whole tower is jettisoned.^4,5

330 cubic feet for four

Orion’s cabin has a habitable volume of 330 cubic feet, about as much living space as two minivans and nearly 60% more than the Apollo command module’s 210 cubic feet. For launch and reentry the astronauts lie on their backs with knees bent at 90 degrees: the commander and pilot face three display units an arm’s length away, and the two mission specialists sit on the other side of the cabin. The crew module can support four people for up to 21 days without docking to another spacecraft.^3,6,7

The largest ablative heat shield

The bottom of the capsule is covered by a heat shield 16.5 feet across, the world’s largest of its kind. Its surface is 186 blocks of Avcoat, a reformulated version of the Apollo material, bonded to a titanium skeleton and composite skin. On a return from the Moon at about 25,000 mph the Avcoat burns away in a controlled fashion at temperatures near 5,000°F, carrying heat away from the cabin. The sides are covered with 1,300 tiles similar to the space shuttle’s.³

Built on two continents

Sixteen years from the first test flight to the first crew

The spacecraft was first designed as the Orion Crew Exploration Vehicle. In May 2011, following the direction Congress set in the NASA Authorization Act, NASA announced that its next deep space vehicle, the Multi-Purpose Crew Vehicle, would be based on those designs, and Lockheed Martin continued under its existing contract. The spacecraft was to carry four astronauts on 21-day missions and land in the Pacific off California.⁸ It flew in stages:

1. May 6, 2010

   Pad Abort-1²

   At White Sands Missile Range in New Mexico, the launch abort system pulls a test capsule away from the pad in a 135-second flight.

2. May 24, 2011

   A new name for the design⁸

   NASA bases its Multi-Purpose Crew Vehicle on the Orion design; Lockheed Martin keeps the work.

3. December 5, 2014

   Exploration Flight Test-1²

   An uncrewed Orion launched on a Delta IV Heavy climbs to about 3,600 miles above Earth and returns at 20,000 mph, testing its heat shield.

4. July 2, 2019

   Ascent Abort-2²

   The abort motor fires 400,000 pounds of thrust to pull a test capsule from a climbing booster at more than 1,000 mph, certifying the system for crews.

5. Nov.–Dec. 2022

   Artemis I³

   Orion flies without a crew on the first SLS, past the Moon and back, a 25.5-day mission.

6. April 1–10, 2026

   Artemis II¹⁶

   Four astronauts fly Orion around the Moon, 252,756 miles from Earth at the farthest.

The path was expensive. In 2021 NASA put Orion’s development cost from fiscal year 2012 through its first crewed flight at $9.3 billion.⁹ The program had been rebaselined that year after adding a docking system, absorbing cost growth and the effects of COVID-19, and working through schedule and technical problems with the service module.¹¹ By GAO’s 2026 count, measured against the original 2023 launch target, Orion finished development three years late, with $6.8 billion in baselined development costs and about $3.5 billion in overruns, nearly three-quarters of all the development overruns in NASA’s portfolio of major projects. Its last overrun, $261 million, came from the seven-month delay of Artemis II from September 2025 to April 2026.¹¹

$9.3B

Orion development, fiscal 2012 to the first crewed flight, as NASA estimated in 2021⁹

$3.5B

development cost overruns by GAO’s 2026 count¹¹

$2.7B

production order for the Artemis III–V spacecraft, 2019¹²

$1.99B

production order for Artemis VI–VIII, 2022¹²

Life in 330 cubic feet

The seats are built to fit anyone from a 4-foot-10-inch, 94-pound woman to a 6-foot-5-inch, 243-pound man, and their pans, foot plates, head and arm rests and hand-controller mounts all adjust so a suited astronaut can reach every control. Each seat can slide six inches on rails to absorb the shock of splashdown. Once Orion is in space, the commander’s and pilot’s foot pans are removed and stowed to free room in the cabin.⁶

Air comes first on a deep space mission. Orion removes carbon dioxide and humidity with a regenerable system: exposed to cabin air, it absorbs them; exposed to the vacuum of space, it vents them overboard and returns to a clean state. The shuttle used expendable chemicals that took up the volume of nearly 143 basketballs; Orion’s system takes the space of 16 and saves more than 100 pounds. Oxygen and nitrogen come from high-pressure tanks, and water from four tanks of about 125 pounds each in the service module.⁶

The toilet, the Universal Waste Management System, is about 5 cubic feet, roughly 60% smaller and lighter than the space shuttle’s. Urine is pre-treated, stored and vented overboard each day; solid waste goes into canisters the crew replaces every few days. The exercise device is a flywheel about the size of an extra-large shoe box: a crew member pulls a strap for rowing, squats or deadlifts, and the device returns as much load as is put in, like a yo-yo, up to 400 to 500 pounds. It sits below the side hatch and doubles as a step.^6,7 The crew sleep in bags attached to the walls. If a solar storm threatens, they pull the stowage bags out of two large bays under the seats, pack them around themselves as shielding, and can shelter there for up to 24 hours.⁶

A heat shield that did not behave as expected

NASA · February 2023

NASA Ames · 2023

NASA/Cory Huston · June 22, 2023

NASA/Josh Valcarcel · April 10, 2026

December 2022: charred material missing

The uncrewed Artemis I mission returned in December 2022. The heat shield protected the spacecraft, and temperatures inside the cabin held steady in the mid-70s Fahrenheit, but charred Avcoat had broken off the shield in several locations, differently from what engineers expected.¹³

Two years of sampling and tests

Engineers removed about 200 Avcoat samples from the shield at NASA’s Marshall Space Flight Center and ran 121 tests in eight thermal campaigns at facilities across the country. In the spring of 2024 an independent team led by Paul Hill, the lead shuttle flight director for return to flight after the Columbia accident, reviewed the work and agreed with its findings.¹³

Gas with nowhere to go

Artemis I had flown a skip entry: Orion dipped into the upper atmosphere, used its lift to skip back out, and reentered for the final descent. Between the dips, heating rates fell and heat built up inside the Avcoat. The gases that ablation normally releases could not escape, because the material lacked permeability; pressure built, and the outer layer cracked and shed. Ground tests before the flight had used much higher heating rates, at which a permeable char forms and vents.¹³

Fly the shield, change the path

The Artemis II shield had been bolted on in June 2023. In December 2024 NASA decided to fly it, shortening how far Orion could travel between entering the atmosphere and splashing down so it would spend less time in the temperature range where the problem occurred. Shields for later missions are made for uniform, consistent permeability; all 186 upgraded blocks for Artemis III were installed by April 2026.^14,13,19

April 2026: much less char loss

After Artemis II, divers’ imagery and inspections on the recovery ship found that the char loss seen on Artemis I was significantly reduced, both in quantity and in size, and consistent with the arc jet tests run after Artemis I. The shield went to Marshall for sample extraction and x-ray scans.¹⁵

What the first crewed flight showed

Earthrise on April 6, 2026, from a camera on one of Orion’s solar array wings as the crew came out from behind the Moon.

NASA

Artemis II carried NASA astronauts Reid Wiseman, Victor Glover and Christina Koch and Canadian Space Agency astronaut Jeremy Hansen around the Moon from April 1 to 10, 2026. With people aboard for the first time, engineers put Orion through a full in-flight evaluation. The crew tested its life support systems, confirming that Orion can sustain humans in deep space, and tested the spacecraft during exercise, its emergency equipment and procedures, and the orange Orion Crew Survival System suits.¹⁶

Several tests looked ahead to docking. In high Earth orbit on the first day the crew flew Orion by hand for about 70 minutes around the spent upper stage, using its navigation sensors and thrusters for a series of approaches and retreats. Later piloting demonstrations, with the crew in manual control, collected data on Orion’s handling for the rendezvous and docking with landers planned from Artemis III onward.^18,16

From one capsule to a production line

A program that flies repeatedly needs spacecraft in production while earlier ones are still being tested. NASA ordered the Orion spacecraft for Artemis III through V in 2019 for $2.7 billion under its Orion Production and Operations Contract with Lockheed Martin, and the spacecraft for Artemis VI through VIII in 2022 for $1.99 billion. Ordering in groups of three was meant to use efficiencies in the supply chain and allow reuse: the Artemis III pressure vessel was to be refurbished for Artemis VI, along with flight computers, crew seats, switch panels and other avionics.¹²

In March 2026 NASA also asked industry how astronauts might be carried from launch to a docking with either lander and back to Earth, and invited new entrants as well as current providers.¹¹ Orion is, for now, the only spacecraft built to bring a crew home from lunar distance, and NASA has ordered it through Artemis VIII.^1,12