Inara Pey: Living in a Modemworld

On Wednesday April 1st, 2026, NASA’s Artemis 2 mission launched on a 10-day cruise to the Moon and back (with time initially spent in Earth orbit), carrying a crew of four to test the capabilities and facilities of the Orion Multi-Purpose Crew Vehicle (MPCV). The mission was a key preparatory step to send crews to the surface of the Moon, starting with the flight of Artemis 4, currently targeting a 2028 launch.

In the first part of this 2-part series I covered Artemis 2 from launch to TLI. Here I complete the voyage in summary form.

Whilst marked by a number of on-going space health experiments, video calls to Earth and performing sundry tasks and s few minor fixes, the outward trip from Earth to the Moon was pretty much a claim affair. A 17.5 second mid-course correction manoeuvre was performed automatically by Integrity, the Orion spacecraft, on mission day 5 – which was actually the first to be performed, the initial correction burn having been cancelled due to Integrity being so precisely on course whilst under its own flight control software.

Day five also saw the crew test their dual-purpose Orion Crew Survival System (OCSS) suits – the orange-coloured space suits the crew wore during the Artemis 2. Designed for quick donning, the suits function as a contingency safety system during the crew’s time aboard and Orion spacecraft, providing up to 144 hours of life support in the event of a cabin depressurisation.

In their second role, the suits are intended to act as water survival suits in the event of an emergency evacuation of an Orion vehicle post-splashdown. In this role, the suits are intentionally coloured “international orange” so as to be more clearly visible in the water – just like survival suits used on ocean-going cargo vessels, oil rigs, deep sea fishing vessels, etc They additionally have inbuilt flotation devices. Each OCSS is custom made to fit an individual astronaut.

Day five also saw a series of discussions with Mission Control on the upcoming loop around the Moon to review lunar surface targets for observation and photography during the flyby and finalise observation techniques.

On flight day 6, Integrity officially entered the influence of the Moon, with lunar gravity now the dominant force in shaping the vehicle’s trajectory. Until now, Integrity had effectively (if slowly) been decelerating, due to the “pull” of Earth’s gravity behind it, effectively cruising at a few thousand kilometres an hour at it approached the Moon. Now, under the Moon’s influence the craft would start to very slowly accelerate, allowing the Moon’s gravity to swing it around the Moon and lob it back towards Earth without any significant engine burns.

Around the Moon

At 23:00 UCT on April 6th, Artemis 2 made its closest approach to the Moon, passing some 6,545 kilometres above the Moon’s far side. Shortly thereafter Integrity reached a distance of 406,771 kilometres from Earth, breaking the record for the furthest any humans had been from Earth and set by the crew of Apollo 13 in 1970. At this point, Integrity officially started its flight back towards Earth.

During the loop around the Moon, Artemis 2 was in communications black-out with Earth due to the bulk of the Moon being between the spacecraft and Earth, effectively blocking all signals. This blackout lasted 40 minutes, and ended with a successful recovery of comms and telemetry at the expected time.

Following the comms blackout, the crew of Artemis 2 witnessed a solar eclipse from deep space as the bulk of the Moon came between them and the Sun. This allowed the crew to observe both the eclipse from a unique perspective, and witness a number of “impact flashes” of meteoroids striking the semi-dark lunar surface facing them. The Moon was not fully dark as the Earth was off to one side relative to Integrity, and so was reflecting sunlight back onto one hemisphere of the Moon, bathing it in “Earthlight”.

Also during the flight around the Moon, the crew christened two previously unnamed craters on the Moon. They named one for their spacecraft, Integrity, whilst the second was – in a poignant moment – named Carroll, in honour of Reid Wiseman’s late wife, who passed away from cancer in 2020.

Between flight day 7 and flight day 9, Orion departed the Moon’s sphere of influence on its free return trajectory towards Earth, once again slowly accelerating. For most of Day 7 the crew were engaged in debriefing calls with Earth, recording their observations, feelings and emotions during their trip around the Moon whilst memories and reactions were still fresh. They also put in a call to astronauts aboard the International Space Station (ISS).

A further planned use of manual control by Wiseman and Pilot Victor Glover on Day 8 was cancelled in order to allow mission managers conduct a data-gathering exercise related to a non-critical helium leak within the Orion’s European Service Module (ESM), so that they might better analyse the issue post-mission. Two final trajectory adjustment burns were carried out on Days 9 and 10, lasting 8 and 9 seconds respectively. Most of Day 9 saw the crew packing and stowing experiments and equipment in readiness for re-entry and splashdown.

Following the course correction burn on Day 10, the ESM was jettisoned, its work done. The reaction control thrusters system (RCS) on Integrity then operated in sequence over 19-seond period, both manoeuvring the capsule away from the ESM and orienting it in readiness foe atmospheric re-entry.

EDS: Entry, Descent and Splashdown

Day 10 saw the most critical elements of the mission unfold: atmospheric entry, descent and splashdown. During Artemis 1, and as I’ve covered in numerous Space Sunday pieces, post-recovery, the heat shield showed some disturbing issues. As well as the expected ablation damage to the heat shield, it also showed signed of deep scoring and charring, with relatively large holes apparently seared through the heat shield material.

After extensive analysis, it was determined that an error in the fabrication process for the initial heat shields for Artemis 1 through 3 had resulted in pockets of gas being trapped in the layers of ablative material. Due to the original re-entry profile for Orion, as used on Artemis 1, which saw the vehicle “skip” in and out of the upper atmosphere to reduce its velocity prior to actual re-entry, these gases ended up being super-heated several times, weakening the heat shield’s structure and eventually blowing holes up and out of it as they outgassed.

While the fabrication process for the heat shields was revised to mitigate any issues of gases becoming trapped – Artemis 2, due to time constraints, would have to fly with its original heat shield. To compensate for this, NASA altered the mission’s re-entry profile to be more Apollo-like: a single direct re-entry. Whilst this might increase stresses on the vehicle and crew, it would reduce the time over which any trapped gases in the heat shield might have expand and contract and weaken its overall integrity, thus increasing the risk of failure.

As it turned out, the heat shield (subject to post-flight inspection) did its job in this new re-entry profile and protected Integrity and its crew, all of which descended by parachute post re-entry to splashdown off the coast of California, where a recovery operation overseen by the USS John P. Murtha out of San Diego saw the recovery of both crew and the space vehicle. Following initial medical checks on the Murtha, the four crew were then flown to the mainland for further check-ups, prior to proceeding on to the Johnson Space Centre in Texas to be reunited with families and loved ones.

Research related to Artemis 2 will continue post flight, and some of it will continue to focus directly on the four crew, comprising functional check-out tests, simulated space walks, exercises, etc., to further gain insight into the human body’s ability to adapt to low gravity operations and work, and its ability to recover from them. As well as this, all four will be a part of a media circus for some time to come. To them, and all those involved in Artemis and Artemis 2 – congratulations.

What Comes Next?

Originally, Artemis 2 was to be followed by the first attempt at landing an Artemis crew on the Moon. However, this idea both spoke to an unwarranted gung-ho attitude on the part of Artemis management at NASA (no crewed pre-testing of the lunar landing system (called the Human Landing System, or HLS) in Earth orbit), and assumed the mission would actually have a lunar landing vehicle (from SpaceX) available to meet its 2027 launch date.

In taking over at NASA, Jared Issacman saw the gung-ho approach of Artemis 3 as a step too far, and so  – with Congressional and White House approval – determined Artemis 3 should be an Earth-orbiting testy of the HLS vehicle by a crew. Also, in keeping with his predecessor, Sean Duffy, he indicated that SpaceX was no longer the sole provider of the Artemis 3 HLS; but would directly face off against Blue Origin, who had been awarded a HLS contract by order of Congress after NASA changed the scope and rules of the original HLS contract to favour SpaceX.

Given that the SpaceX HLS continues to exist as little more than a few disparate elements (such as the crew elevator – largely developed by NASA) and pretty computer renderings, this move to include Blue Origin – who are actively testing elements of their HLS, Called Blue Moon Mark 2 with NASA astronauts – is a wise one, given the SpaceX CEO appears to believe time frames and delivery dates are purely functions of his ego.

As it is, this year should see Blue Origin fly a Blue Moon “pathfinder” mission to the Moon. This will see a scaled-down version of the Blue Moon cargo lander fly a payload from NASA to the Moon, allowing it to test the flight control, navigation, and data communications systems and avionics which will all be part of both the Blue Moon Mark 1 cargo vehicle and Blue Moon Mark 2 HLS. If successful, the mission could put Blue Origin in a strong position to provide the HLS vehicle for both Artemis 4 and Artemis 5.

However, even if one (or both) HLS vehicles get successfully tested in Earth orbit in 2027, it does not mean NASA will be ready to send astronauts to the lunar surface – there is another hurdle to overcome, one entirely of NASA’s own making: cryogenic orbital refuelling.

To explain: while techniques for transferring hypergolic propellants between space  craft has long been available (the ISS, for example, routinely takes on propellants for its manoeuvring thrusters), cryogenic propellant transfer in space is entirely new. It’s not been used before simply because cryogenic propellants are not exactly stable. For one thing, they don’t like heat (and in space, in direct sunlight it s very hot). Heat makes them revert to a gaseous state, expanding their volume. This puts greater and greater pressure on the tanks holding them, such that if the gas isn’t vented to some degree, everything is going to quickly vanish in a brilliant (if silent – in space, no-one can here you go pop!) explosion.

Cryogenic propellants are also heavy in their liquid state, making them somethings of a deadweight if you’re attempting to lift them to orbit rather than burning them as a means to get to orbit. This latter point means that in order just to get to Earth orbit or to the Moon, the SpaceX HLS and Blue Moon Mark 2 (respectively) must launch without the fuel needed to get to the Moon, land a crew and get them back to lunar orbit. Thus, the fuel must be ferried to them post launch.

For Blue Origin, this means launching a Blue Moon HLS to lunar orbit, but without the propellants it needs to operate between lunar orbit and the Moon’s surface. Instead, these must be delivered by a “tanker” craft called the Cislunar Transporter, being developed by Lockheed Martin. But here’s the catch: the Cislunar Transporter has to be launched without the propellants it needs to get to the Moon or those it must transfer to the waiting HLS. So, once in orbit it also has to be “refuelled” by at least two Blue Origin New Glenn rockets.

And if that sounds complicated – SpaceX much do much the same with their HLS, which will launch with only sufficient propellants needed to get to Earth orbit. After this it must either make up to sixteen individual dockings with Starship “tankers” to take on the propellants it needs to reach the Moon and perform its duties there, or it must rendezvous with a (also yet to be built) “orbital fuel depot” previously filled with the propellants it needs by multiple Starship “tanker” flights.

And this is where boil-off comes into play: all of these approaches will result in large volumes of cryogenic propellants spending a lot of time in direct sunlight, turning back to a gaseous state, expanding and requiring venting to prevent their storage tanks rupturing. So techniques and entirely new technologies need to be developed and tested in order to reduce the overall boil-off issues lest more time is spent on “tank top-up” missions than in actually sending humans to the Moon. Further, no-one knows if large volumes of cryogenic propellants can easily be pumped from one vehicle to another in microgravity.

Thus, even though Artemis 2 has been a huge success and NASA is turning its attention to Artemis 3, the programme as a whole still has some hefty hurdles to clear before it is close to being ready to send humans back to the surface of the Moon, and at the current rate of progress, I cannot see all those hurdles being cleared by “early 2028 – less than 2 years from now – when Artemis4 is supposed to launch on its crewed mission to the lunar surface.

On Wednesday April 1st, 2026, NASA’s Artemis 2 mission launched on a 10-day cruise to the Moon and back (with time initially spent in Earth orbit), carrying a crew of four to test the capabilities and facilities of the Orion Multi-Purpose Crew Vehicle (MPCV) when used for human spaceflight.

The mission marks a number of firsts for NASA, all critical to future Artemis missions, including:

• The first launch of a Space Launch system (SLS) rocket with a crew aboard.
• The first launch of the Orion spacecraft – this one christened Integrity by its crew – with people aboard.
• The first time an Orion spacecraft has flown under manual control.
• The first time an Orion vehicle will attempt a re-entry into Earth’s atmosphere carrying a crew aboard.
• The first time humans have surpassed 400,000 kilometres from Earth.
• The first time a vehicle intended for use in the vicinity of the Moon has carried an actual toilet on board.
• The first time a non-US citizen has travelled to the Moon.

The four crew in question are Mission Commander Reid Wiseman, Mission Pilot Victor Glover, Mission specialist Christina Koch (pronounced “Cook”), all from NASA, and Mission Specialist Jeremy Hansen of the Canadian Space Agency. If you’re interested in potted histories of the crew’s backgrounds, then please refer to my previous Space Sunday article.

Launch

Lift-off came at 22:35 UTC, some 11 minutes later than the target launch time after a couple of minor issues on the SLS vehicle had to be investigated and resolved. One of these related to one of the two battery systems powering the Flight Termination System. The latter is used to destruct the rocket once the crew have been pulled clear by the Launch Abort System (LAS), should a serious issue result in the rocket veering substantially off-course. This particular problem was identified as a sensor failure rather than any fault with the battery itself.

The power of the SLS was immediately apparent following launch – at just thirty seconds into the flight, the launch system has completed its roll to pitch over to the correct ascent angle and was punching through 4.8 kilometres altitude as a speed in excess of 1,920 km/h.  From there:

• At T+1 minute the vehicle passed through ”Max Q”, the period when the rocket encounters the peak atmospheric dynamic stresses as it continues to accelerate through the denser portion of the atmosphere, the four RS-25 motors of the core stage throttling back to reduce the load on the rocket.
• At T+ 90 seconds, with Max Q passed and the RS-25 motors running at 100% thrust, the SLS went supersonic and passing through 22.4 km altitude.
• At T+2 minutes, with the RS-25 motors had again throttled to 85% thrust, and the two massive solid rocket boosters, their fuel expended, separated to continue on their own ballistic trajectory, eventually falling into the Atlantic Ocean.
• By 3 minutes into the ascent, Artemis 2 was at 78.4 km altitude, and closing on the 80 km Kármán line, the conventional definition of “the edge of space”. Travelling at some 8,000 km/h, the rocket jettisoned the two fairings that had protected Integrity’s European Service Module (ESM).
• This was followed almost immediately by the unlocking of the couplings between the LAS at the top of the rocket, and the Orion capsule. The motors on the LAS fired, pulling it clear of the SLS, exposing the Orion capsule to space.

• MECO – main engine cut-off – occurred at 8 minutes 2 seconds after lift-off, with Integrity and the Interim Cryogenic Propulsion Stage (ICPS) continuing to ascend, the reaction control systems (RCS) on the ICPS sufficient to pull it and Integrity clear of the SLS core stage, which, like the SRBs, continued on its own ballistic trajectory, prior to starting a long fall back to Earth, breaking up in the process and falling into the Atlantic Ocean.

At this point, Integrity was travelling at 27,200 km/h – slightly above the speed required to achieve Earth orbit and on a trajectory intended to put it into an elliptical orbit around Earth with a perigee (closest point to Earth) of around 200 km. At this point, operations switched from launch to initial mission activities.

The latter comprised two major elements: inside the Orion capsule, Christina Koch and Jeremy Hansen left their seats to set-up critical equipment and services. These included unstowing the fire-fighting equipment and mounting it on its assigned racks and then doing the same with the drinking water dispenser, toilet (which had its first malfunction, requiring Koch and Hansen to carry out a fix (the Toilet would again have issues on Flight Day 4, with the crew reporting it was depositing unpleasant odours in the main capsule) and other crew-related equipment. At the same time, Wiseman and Glover remained in their seats and ran through the protocols and check sheets for deploying the ESM’s solar arrays – vital for supplying Integrity with electrical power.

The solar arrays were deployed some 25 minutes after launch, and powered-up to start producing electrical power. At 50 minutes after lift-off, Hansen and Koch were back in their seats, the solar arrays were producing power and the go was given for two orbit-changing manoeuvres.

The first was a short burst of the ICPS RL-10 engine, raising the perigee of Integrity’s orbit whilst maintaining its elliptical form. This was followed by a second 15-minute burn of the RL-10, extending Integrity’s perigee and apogee (the latter to some 70,000 km from Earth, placing the vehicle in a high Earth orbit.

This second RL-10 burn expended almost all remaining fuel in the ICPS, accelerating Integrity almost to the velocity required to complete a trans-lunar injection (TLI) manoeuvre. However, this is not what happened. Instead, with the ICPS separated and orbiting Earth independently of Integrity, Glover and Wiseman commenced what NASA normally refers to as an RPOD simulation, but which for Artemis 2 was simply called “proximity operations”.

RPOD Simulations / Proximity Operations

RPOD – Rendezvous, Proximity Operations and Docking – is a core part of modern day space operations with NASA, being fundamental to crews and supplies being able to launch to and reach the International Space Station (ISS) and then dock safety with it either under automated or manual control.

For the Artemis programme, being able to carry out a successful RPOD is vital to all the lunar surface missions, as they must be able to rendezvous and temporarily dock with the Moon- orbiting Human Landing System (HLS) vehicle which will actually deliver nominated crew members to the surface of the Moon, and then re-dock with the HLS vehicle to allow the surface mission crew return to their Orion craft for a return to Earth.

To this end, the ICPS had been equipped with a rendezvous and docking target, allowing Wiseman and Glover to test out the docking heads-up display whilst also using Integrity’s RCS thrusters to make simulated rendezvous approaches to the ICPS, aborting before the two vehicles actually made contact. In addition, Wiseman and Glover used manual control of the Orion to test proximity manoeuvring and close formation flying around the ICPS – both the POD and proximity operations marking the first time Orion had ever been manually flown. Both astronauts praised the vehicle’s handling qualities prior to returning the craft to its autopilot.

With Integrity well clear of the ICPS, the latter deployed two CubeSats then fired its RL-10 for a final time, placing it on a destructive re-entry into the upper atmosphere. At this point the crew moved to the next phases of initial operations.

Initial Mission Highlights

First, the Orion’s “gymnasium” – a flywheel device capable of allowing multiple exercises – was set-up and crew members took it in turns exercising, putting Integrity’s life support system through something of a stress test. After this, the crew set-up the food reheater and had dinner together from their rather impressive menu of meal choices. A 4-hour sleep period was then taken, allowing the crew some much needed rest.

The sleep period was short as a further orbital manoeuvre was required to again raise Integrity’s perigee away from Earth and place it on a trajectory suitable for a TLI burn. With this complete, the crew settled back for another 4-hour sleep period whilst NASA mission control reviewed the overall performance of Orion and its systems to determine if Integrity was good to go for a free-return flight for the Moon.

Authorisation was given for TLI on flight day 2 after the crew had risen and eaten. The manoeuvre comprised a burn of the ESM’s AJ10 main engine of just under 6 minutes, using some 450 kg of hypergolic propellants. It pushed Integrity out of Earth’s orbit and on its way to pass around the Moon. This free return trajectory meant the vehicle would not need to use its AJ10 engine as it passed around the Moon in order to head back to Earth – gravity would do the work for the mission. However, the ESM’s propulsion systems would be required for various mid-course correction manoeuvres.

The first of these course corrections was due on Flight Day 3. However, such was the accuracy of the SLS’s performance coupled with that of Integrity itself, this manoeuvre was discarded – the vehicle was precisely on the course it needed. On Flight Day 4 Hansen (a Canadian fighter pilot) and Koch (a jet-qualified civilian pilot) took the controls of Orion and put the vehicle through a further series of RCS tests, evaluating its ability to complete both 3- and 6-degrees of freedom of movement manoeuvres (that is, rolling, pitching and yawing around various axes without altering its general trajectory). Both Koch and Hansen reported the vehicle presented excellent and stable  handling.

Currently, the crew is due to pass around the Moon on Monday, April 6th. 2026 as they do so, they will reach a distance of approximately 406,773 kilometres from Earth, beating the previous record for the furthest humans have travelled from Earth to date – set by the abortive Apollo 13 mission in 1970 – by some 6,000 km. At this point, Integrity will be some 7,600 km beyond the surface of the Moon’s far side as it starts its journey home. The closest Artemis 2 will come to the surface of the Moon is approximately 6,513 km.

During the intervening period, the crew continue to test Integrity’s systems and capabilities and carry out a range of experiments, notably related to crew health and welfare. As a part of this work, Integrity carries two key experiments: AVATAR – A Virtual Astronaut Tissue Analogue Response, and an experiment system called ARCHeR (Artemis Research for Crew Health & Readiness (if there is one thing you definitely can say about NASA is that they work very hard at their acronyms!)

AVATAR can mimic individual astronaut organs, allowing medical experts evaluate tissue and other responses to various aspects of spaceflight and monitor essential biomarkers. AVATAR has been flown aboard the ISS several times, but this mission marks its first deep space mission – one that carries it and the Artemis 2 crew through the Van Allen radiation belts – thus offering the opportunity to gain further insight into the potential impact of these highly radioactive zones as Integrity zooms through them at several thousand km/h.

 ARCHeR (which I cannot help think was named by an NASA fan of Star Trek (see Jonathan Archer (Scott Bakula), first commander of the Star Ship Enterprise, NX01) uses movement and sleep monitors worn by the crew to gather real-time health and behavioural information for crew members so scientists can study sleep patterns and overall health performance.

Further, Artemis 2 is testing and demonstrating the Orion Artemis II Optical Communications System (O2O). This is an optical communications system uses laser beams for two-way communications between Earth and the mission. Smaller and lighter than a conventional radio system, O2O also uses less power and increases transmission rates (up to 200 Mbits per second). If successful, O2O could become a feature of future Artemis missions from Artemis 4 onwards and used in potential human missions to Mars.

I’ll have more on Artemis 2 next week. In the meantime, you can follow the mission in real-time, via NASA’s 24/7 livestream.