Welcome to the I Can't Sleep Podcast,
Where I help you drift off one fact at a time.
I'm your host,
Benjamin Boster.
And today's episode is about Artemis II.
Artemis II is a lunar flyby mission under the Artemis program.
Launched from the Kennedy Space Center on April 1,
2026,
The 10-day mission is intended to carry NASA astronauts Reid Wiseman,
Victor Glover,
And Christina Koch,
Along with Canadian Space Agency astronaut Jeremy Hansen,
And a free return trajectory around the Moon and back to Earth.
It is the second flight of the Space Launch System,
SLS,
The first crewed mission of the Orion spacecraft,
And the first crewed mission beyond low Earth orbit since Apollo 17 in December 1972.
Glover became the first person of color,
Koch the first woman,
And Hansen the first non-U.
S.
Citizen to travel beyond low Earth orbit,
And planned to become the first person of color,
Woman,
And non-U.
S.
Citizen to travel to the vicinity of the Moon.
The mission is expected to set several human spaceflight records,
Including distance from Earth,
About 4,
700 miles,
Beyond the Moon,
And velocity,
Atmospheric re-entry speed of about 25,
000 miles per hour.
Artemis II is a flight test supporting subsequent Artemis missions,
Which are planned to return humans to the lunar surface in 2028 for the first time since Apollo 17.
The mission was originally designated Exploration Mission 2 and was initially intended to support the now-canceled Asteroid Redirect Mission,
Proposed in 2013.
Its objectives were revised after the establishment of the Artemis program in 2017.
The mission objectives are similar to those of Apollo 8 in 1968,
The first crewed lunar flight during the Apollo program.
However,
Its planned free-return trajectory more closely resembles that flown by Apollo 13.
In 2017,
Exploration Mission 2 was a projected single-launch mission of a Space Launch System Block 1B rocket with an exploration upper stage.
Lunar Block 1 Orion spacecraft and a payload insertion of 50.
7 tons.
The plan was to rendezvous with an asteroid previously placed in lunar orbit by the robotic Asteroid Redirect Mission and have astronauts perform spacewalks and gather samples.
After the cancellation of the Asteroid Redirect Mission in April 2017,
An eight-day mission was proposed with a crew of four astronauts sent on a free-return trajectory around the Moon.
Another proposal suggested in 2017 was to take four astronauts aboard Orion on an eight-to-21-day trip around the Moon to deliver the first element of the lunar gateway.
In March 2018,
It was decided to launch the first gateway module on a commercial launch vehicle because of delays in building the mobile launcher needed to hold the more powerful exploration upper stage.
The SpaceX Falcon Heavy was selected as the launcher.
The lunar gateway was cancelled in March 2026.
On February 11,
2023,
NASA rotated the Artemis II core stages engine section to a horizontal position,
Marking the final major milestone before integration with the rest of the vehicle.
On March 20,
The engine section was mated with the core stage in Building 103 at the Michoud Assembly Facility in New Orleans,
Louisiana.
In March 2023,
NASA initially expected to deliver the completed core stage to the Kennedy Space Center that summer,
But by May,
The timeline had shifted to late autumn 2023.
RS-25 engines,
Serial numbers E2047,
E2059,
E2062,
And E2063,
Were installed on the core stage in New Orleans by September 25,
2023.
However,
After a leak was discovered in its oxygen valve hydraulics,
Engine E2063 was replaced with E2061 in April 2025.
The fully outfitted core stage was delivered to KSC between July 16 and July 25,
2024.
The adapters required for integration of the full launch vehicle also reached substantial completion in June 2024 and arrived at KSC in September 2024.
The Artemis II crew was announced on April 3,
2023,
By NASA Administrator Bill Nelson during his State of NASA Address at a NASA facility at Ellington Field,
Outside Houston,
Texas.
And the crew made a public appearance that evening at nearby NRG Stadium during the 2023 March Madness Basketball Championship game.
NASA had originally targeted September 2024 to begin rocket stacking operations.
However,
The schedule was delayed by more than two months due to investigations into issues with Orion's life support system and unexpected damage to Orion's heat shield observed after the Artemis I re-entry.
Rocket stacking finally began on November 20,
2024.
Stacking was completed on October 20,
2025,
With the installation of the fully integrated Orion ESM and launch abort system atop the SLS rocket.
On January 18,
2026,
The integrated SLS rocket Orion capsule and launch tower were rolled out from the Vehicle Assembly Building to Launch Complex 39B.
During preliminary reviews in 2011,
The launch date was placed somewhere between 2019 and 2021,
But afterwards the launch date was delayed to 2023.
In January 2024,
The mission was expected to launch in September 2025.
However,
In October 2024,
The NASA Office of Inspector General determined that the Exploration Ground Systems team had exhausted their time reserved for resolving any unforeseen issues,
Leading the office to determine that the September 2025 launch date would likely be delayed.
In December 2024,
Outgoing Administrator Nelson announced that the launch was delayed due to the months of engineering investigations into issues with the life support system and heat shield,
But they were targeting a launch in April 2026.
In March 2025,
America Space reported that the launch date might be accelerated by two months to February 2026.
NASA responded in a statement saying it could not confirm the revised date,
But noted,
We're looking for ways to enable an earlier launch if possible,
Potentially launching as soon as February 2026.
A February target allows the agency to capitalize on efficiencies in the flow of operations to integrate the SLS rocket,
Orion spacecraft,
And supporting ground systems,
While maintaining crew safety as a top priority.
By August 2025,
More mainstream outlets,
Such as NASA spaceflight journalist Eric Berger and U.
S.
Senator and former astronaut Mark Kelly,
Also reported that the mission had been moved to February 2026.
In September,
Space agency officials announced that they were pursuing a launch window that opens on February 5,
2026.
For the launch of lunar missions,
There are both monthly windows of a few days duration each lunar month,
And daily windows lasting a few hours on days within the monthly window.
The revised Artemis II plan,
Which calls for Orion to conduct a shorter skip re-entry,
Further constrains the days within a monthly window during which a launch can be conducted.
The earliest launch window for Artemis II was set for early February 2026.
The January 2026 North American winter storm delayed preparations for the launch.
A wet dress rehearsal of the countdown occurred February 2.
After the test,
NASA announced that the launch would be postponed to March due to liquid hydration leak that occurred during the simulated countdown.
In addition to the leak,
A valve associated with Orion crew module hatch pressurization required retorquing,
And closeout operations took longer than planned.
A second wet dress rehearsal occurred on February 19 and was successful.
On February 21,
A helium flow issue was observed,
Triggering a rollback to the VAB and delaying the mission to April at the earliest.
The rollback began on February 25 at 9.
38 a.
M.
EST and arrived at the VAB at about 8 p.
M.
NASA Administrator Jared Isaacman said that an actual launch date would be confirmed only after a successful wet dress rehearsal is complete and the results are analyzed.
On March 12,
After a flight readiness review,
FRR,
Seven two-hour launch windows were announced for April 1-6 and April 30.
The first one was at 6.
24 p.
M.
EDT,
April 1.
On March 18,
NASA announced that the Artemis II Space Launch System,
SLS,
Rocket,
And Orion spacecraft would be rolled out the next day to Launch Pad 39B at the agency's Kennedy Space Center in Florida.
Meanwhile,
The Artemis II crew entered quarantine in Houston to ensure they remain healthy ahead of the launch.
On March 20,
After a delay due to high winds,
The SLS was rolled out from the VAB to Launch Pad 39B a second time.
The mission launched on April 1,
2026.
After the uncrewed Artemis I mission in November 2022,
NASA identified unexpected erosion of the Orion spacecraft's ablative heat shield after atmospheric re-entry.
Post-flight inspections found areas of char loss in the avcode ablative material in which portions of the material eroded more extensively than predicted by pre-flight models.
NASA reported that temperatures within the crew module remained within design limits,
But the unanticipated behavior prompted further analysis.
Close-up imagery of the damage was not publicly released until May 2024,
When it appeared in a report by the NASA Office of Inspector General.
In April 2024,
NASA established an independent review team to assess the heat shield performance and the agency's proposed approach for the Artemis II mission.
The review concluded in December 2024,
After which NASA announced it would proceed with Artemis II using the existing heat shield.
NASA held a press briefing to outline its findings,
But the publicly released version of the review team's report was heavily redacted,
Prompting criticism from some former NASA engineers and astronauts regarding the level of disclosure.
NASA engineers determined that the char loss observed during Artemis I was caused by gases becoming trapped within the avcode material,
Leading to cracking and localized material loss during re-entry.
Rather than replacing the heat shield for Artemis II,
NASA elected to modify the re-entry trajectory by increasing the descent angle,
Reducing the time the spacecraft would spend in the thermal environment associated with the damage.
According to NASA,
Modeling and ground testing indicated this change would limit further char loss,
While remaining within structural and thermal margins.
As part of the certification process for Artemis II,
NASA conducted additional testing and analysis,
Including evaluations of scenarios involving more extensive heat shield damage.
NASA stated that these analyses showed the underlying structure of the Orion capsule would remain intact and capable of protecting the crew under conditions exceeding those expected during the mission re-entry.
In January 2026,
Isaacman stated that he supported proceeding with Artemis II using the existing heat shield after reviewing the agency's analysis and meeting with engineers and outside experts.
Some participants who had previously expressed concerns indicated that the additional data addressed their questions,
While others continued to object to flying the mission without a redesigned heat shield.
NASA has stated that design changes addressing avcode permeability are planned for the heat shield intended for Artemis III.
Artemis II is crewed by four astronauts,
Commander Reid Wiseman,
Pilot Victor Glover,
And Mission Specialist Christina Koch,
All from NASA,
Along with Mission Specialist Jeremy Hansen from the Canadian Space Agency.
On November 22,
2023,
Jenny Gibbons was named as Hansen's backup,
And on July 3,
2024,
Andre Douglas was named backup for the three NASA astronauts.
Glover would become the first person of color,
Koch the first woman,
And Hansen the first non-American to travel around the moon.
Hansen and Gibbons,
Both from Canada,
Were selected by the Canadian Space Agency as part of a 2020 treaty between the United States and Canada that facilitated their participation in the Artemis program.
This mission will break the record for the most people in deep space at once,
Set at three during Apollo 8 in 1968.
The Artemis II mission plan was to send four astronauts in the first crewed Orion spacecraft into a lunar flyby,
Using the Block I variant of the Space Launch System.
The mission profile is a multi-translunar injection,
Or multiple departure burns,
And includes a free return trajectory from the moon.
The Orion spacecraft will be sent to a high Earth orbit with a period of roughly 24 hours.
During this time,
The crew will perform various checkouts of the spacecraft's life support systems,
As well as an in-space rendezvous and proximity operations demonstration using the spent Interim Cryogenic Propulsion Stage as a target.
When Orion reaches Perigee once again,
It will fire its main engine to complete the TLI maneuver,
Which will send it onto a lunar free return trajectory before returning to Earth.
The crew arrived at KSC on March 27,
And the countdown started on March 30.
Artemis II's trajectory can be divided into several key phases over an approximately 10-day trip.
LAUNCH The mission launched aboard a Space Launch System SLS Block I rocket from Kennedy Space Center's Launch Complex 39B at 22 hours 35 minutes 12 seconds UTC.
The four main engines ignited about 7 seconds before liftoff,
Throttling to full power with the solid rocket boosters igniting at T0,
Providing the majority of thrust for the first two minutes.
Booster separation occurred at roughly 3,
100 miles per hour and an altitude of 30 miles.
Wiseman monitored the launch from the left seat,
Although the flight is fully automated unless intervention is required,
Which would likely be to issue an abort command.
The core stage burned for about 8 minutes before separation,
Leaving Orion in a highly elliptical orbit with an apogee of roughly 1,
200 nautical miles,
Nearly five times higher than the International Space Station.
The internal cryogenic propulsion stage did not fire during the initial ascent.
EARTH ORBIT AND SYSTEMS CHECKOUT Right after main engine cutoff,
Koch and Hansen were scheduled to unstrap from their seats and set up and test essential life support systems on the spacecraft,
Including the water dispenser,
Firefighting masks,
And toilet systems.
All systems checked out and the ICPS ignited at apogee about 50 minutes after liftoff to raise Orion's perigee.
PERIGEE When the spacecraft reached this new perigee,
It executed a 15-minute burn to increase the next apogee to 38,
000 nautical miles,
Establishing a 23.
5-hour high Earth orbit.
After this burn,
Which expended nearly all of the fuel in the ICPS,
Glover moved into the left seat at the primary controls of Orion and conducted a series of proximity operations with the ICPS,
Performing maneuvering and close-formation flying to evaluate Orion's handling qualities using the Cooper-Harper rating scale.
After these tests,
Orion will back away and the ICPS will burn its engines to place it into a graveyard orbit as Orion enters automated control.
At this time,
The ICPS will also deploy its rideshare cubesats.
After these operations,
The crew will convert the cabin from launch to spaceflight configuration,
Set up exercise equipment,
Conduct stress tests of life support systems through physical activity,
And have a meal.
The first sleep period of the mission is broken into two 4-hour periods,
Interrupted by the need to monitor a burn by the European Service Module to raise the spacecraft's perigee.
After this burn,
NASA managers will review the performance of the spacecraft before authorizing the final translunar injection burn.
TRANSLUNAR INJECTION After completing high-Earth orbit operations and system verification,
Orion will perform a TLI burn using its Service Module,
Placing the spacecraft on a trajectory toward the Moon.
This precise maneuver sets Orion on a free-return trajectory,
Allowing it to loop around the Moon before returning to Earth.
LUNAR FLYBY Orion will fly around the Moon,
At a closest approach of about 4,
047 miles from the far side lunar surface.
The outbound journey and lunar flyby are expected to take about four days,
During which the crew will monitor spacecraft systems,
Gather data on the effects of deep space travel,
And perform trajectory correction burns as needed.
During the flyby,
Orion will use the Moon's gravity to assist its return to Earth on a free-return trajectory.
NASA anticipates performing further trajectory correction burns during the four-day return flight to ensure accurate Earth re-entry.
RE-ENTRY AND SPLASHDOWN Orion will re-enter Earth's atmosphere at about 25,
000 miles per hour,
The fastest re-entry ever attempted.
Initially,
The mission was planned to use a skip re-entry,
Briefly dipping into the upper atmosphere to use its lift to bounce back outward,
Dissipating energy,
And enabling the spacecraft to return to Earth.
Enabling a more precise landing.
However,
Due to the heat shield spalling observed during Artemis I,
Mission managers eliminated the skip re-entry in favor of a steeper entry profile.
Splashdown is planned in the Pacific Ocean off San Diego,
Where the U.
S.
Navy will recover the crew and spacecraft using a San Antonio-class amphibious transport dock.
The mission is expected to last about 10 days from launch to splashdown.
NEWS CONFERENCE On January 16,
2026,
NASA announced at a news conference that the mission was expected to last 10 days.
Officials said the Artemis II rocket would roll out to the Kennedy Space Center the next day and would take up to 10 hours to be set up on the launch pad.
The journey to the lunar vicinity was expected to last three days,
And astronauts would spend one day in lunar observation of the far side of the moon,
With some parts seen up close by humans for the first time.
NASA would also fly a payload titled AVATAR,
A Virtual Astronaut Tissue Analog Response,
Which can mimic individual astronaut organs,
With Artemis II marking the first time that AVATAR is tested outside of the International Space Station and the Van Allen Belt.
Crew health for this mission is critical for missions in deep space in the future.
NASA will also launch a new payload titled ARCHER,
Artemis Research for Crew Health and Readiness.
For ARCHER,
Crew members will wear movement and sleep monitors before,
During,
And after the mission to study real-time health and behavioral information for crew members,
So scientists can study sleep patterns and overall health performance.
Scientists will test immune biomarkers,
With crew providing saliva samples before,
During,
And after the mission to test their immune system and how they are affected by radiation,
Isolation,
And the distance away from Earth during deep space flight.
This mission will also allow astronauts and scientists to understand space weather that will be faced in future missions,
As well as how humans can survive and sustain themselves in space.
Upon completion of the mission,
The astronauts will make a three-day journey back to Earth.
They are slated to land in the Pacific Ocean near San Diego,
Where the U.
S.
Navy will conduct assessments to ensure a safe recovery of the astronauts.
Once they are safely removed from Orion,
The capsule will be towered by the Navy and the astronauts will be sent to a medical center for evaluation.
Once the astronauts are safely back on Earth,
They will be tested in an obstacle course to see how quickly they can function during a gravity spacewalk.
The astronauts will also perform a simulated spacewalk to investigate how quickly they can adjust to a change of gravity for the landing on Moon and possible mission to Mars.
