Adapted from a video by Tim Dodd the Everyday Astronaut. Web version by Andy Law.
NASA is working really hard on getting humans back to the surface of the Moon. If all goes well, this could happen as early as 2024! It is probable that this timeline won’t hold. But we haven’t seen such an ambitious timeline for getting humans to the Moon since the Apollo program back in the 1960s.
Not to mention, the hardware exists. Checks have been written and the astronauts are already training to spend time on the Moon. It’s an exciting time to be alive!
Unlike the Apollo program, which wound up only landing 12 humans on the Moon at an astronomical cost, Artemis promises to be a sustainable program. Eventually leading to a lunar outpost and a permanent human presence at the Shackleton Crater on the South Pole of the Moon.
But this is the 21st Century! One would surely hope that we can get to the Moon more cheaply, using better technology and do it in a safer way than we did in the 1960s?
In this article we are going to answer these questions. “Why does NASA think Artemis will be a sustainable program when the Space Launch System (SLS) rocket and Orion spacecraft are so expensive? Why will it take at least two launches to get humans and their lunar landers to the Moon?”
What’s in this article
This can’t be more sustainable than Apollo, surely? We didn’t even begin to scratch the surface of the costs in the previous article. Therefore, in this article we’re going to really dive into the total costs, including development, infrastructure and hardware by giving SLS and Orion a full cost audit.
We will even show how the Apollo program and Artemis mission profiles differ. Including the specific orbits and their rendezvous and everything required to get humans to the surface of the Moon. We will even talk about the upgraded safety considerations and hardware involved.
Once we look at all these details, we can answer these questions. “Over 50 years later, is the Artemis program actually an improvement over the Apollo program? Or is NASA going completely in the wrong direction when returning humans to the Moon?”
This is part two of a series
Welcome to part two of “talking about SLS and comparing it to pretty much everything else”. Part one really focused on SLS vs Starship and explaining why the two programs exist at the same time. It helps to read that article first for context, but in any case we are just at the start.
To be clear, it’s really hard, almost impossible, to responsibly compare a government program with cost-plus contracting, against a private company’s incredibly ambitious and yet-to-be fully developed vehicle.
So instead, in part two, we’re going to focus more on comparing SLS and Orion to other government programs – mainly Apollo, since both have the same goal of getting humans on the Moon – and really dive into the weeds here. This is going to be a long article (based on the original YouTube video).
A lot of people probably assume Artemis is just “Apollo 2.0” and that we are basically just going to repeat what NASA did in the 60s, but hopefully cheaper. But that’s not really true at all; this time NASA is doing things quite a bit differently, and that “cheaper” part is certainly up for debate.
If we just look at the mission profiles, we can get a sense for how these different two vehicles and programs putting humans on the Moon stack up. Let’s recap the different vehicles in the same way that we did in the previous article.
There are three main vehicles for Apollo and Artemis. These are the launch vehicle, the lunar lander and the Command Module. Of course, the launch vehicle is the rocket (or rockets) that gets everything into orbit and heading to the Moon. Definitely one of the most exciting parts of each mission and the only thing you can really witness in person.
The lunar lander is pretty self-explanatory – it’s the lander that lands on the lunar surface, hence the name “lunar lander”. For each 1 kg of mass that you send to the surface of the Moon, it takes almost 200 kg of rocket to get it there. Therefore, the lunar lander has to be as lightweight as possible.
Where the Astronauts actually are
Because lunar landers do not ever fly through Earth’s atmosphere, they can be super stripped down. They can even have landing legs that are too weak to support the craft’s weight on Earth. They are designed only to be used on the Moon with its lower gravity.
The Command Module is where the astronauts will be located during the majority of the mission, but it is especially important during ascent and reentry. This is because sitting on top of essentially a giant bomb with a nozzle is quite dangerous; having a Command Module that can abort safely is generally considered to be a very good thing.
There are already a few videos/articles on abort systems, including:
- one about the Gemini capsule’s ejection seats,
- another about why SpaceX and Boeing are using liquid-fueled abort systems,
- and even one on why Starship doesn’t have one – and whether it should.
The Command Module needs to be able to handle atmospheric flight, specifically the brutal reentry and landing portions of the mission. For both programs, their Command Modules utilize an ablative heat shield, which intentionally flakes off material, taking heat away with it.
There’s already an article on the topic of how spacecrafts return from orbit, which discusses the systems involved. There’s always plenty to learn about all these fun little portions of spaceflight!
Let’s pull up both systems that will be taking humans to the Moon – starting with the Command Modules. Although they might look similar, the Apollo Capsule and the Orion Capsule are quite different.
Command and Service Modules
The Orion capsule is 5 m wide vs. the Apollo capsule’s 3.9 m. It sports an impressive 9 m3 (29.5 ft3) of habitable volume compared to 6.2 m3 (20.3 ft3), so it is around 50% larger by volume. It will be quite a bit roomier and capable of carrying up to 6 astronauts, although it will probably only fly 4 for the Artemis missions vs Apollo’s 3 – which could technically fit 5, for rescue missions – but just barely.
But what might be surprising is each vehicle’s mass. The Orion capsule and its Service Module are 26,520 kg when fully fueled, which is surprisingly lighter than the Apollo Capsule and its Service Module which are 28,800 kg together.
But just looking at these two, you can tell that they’re basically backwards from each other. The Apollo Command Module was pretty small and had a large Service Module, whereas Orion is pretty much the opposite.
This means the Orion capsule and its Service Module have much less “delta V” or DV, or the ability to change its velocity, than the Apollo capsule and Service Module. In fact the Orion Capsule and Service Module combination does not have enough DV to get into and out of low lunar orbit, with only around 1,200 m/s of DV vs the Apollo Command Module and Service Module which had twice as much, at around 2,800 m/s of DV.
Delta V is how much a spacecraft can change its velocity in space. It’s a combination of vehicle mass, payload and propellant, coupled with the amount of fuel available and engine efficiency. Think of it like the range of a car which factors in the engine efficiency, fuel tank size and how much the car needs to push around.
But if the difference in DV sounded confusing, don’t worry, we’ll get more into why this matters. Because this fact makes a big difference in how each system gets astronauts to the Moon, and why the orbits of these two programs are extremely different.
Lunar landing systems
Speaking of extremely different, let’s look at the lunar landers next. This is going to be fun to talk about, because we actually get to talk about 4 different lunar landers, since there are currently three of them selected for development for the Artemis program.
For the Apollo program, there is the iconic Apollo Lunar Module, sometimes called the LEM, or Lunar Excursion Module. This spidery-looking vehicle produced by Grumman stood 7 m tall, 9.4 m wide with its legs extended and weighed up to 16,400 kg when fully fueled. It could carry two astronauts to the surface of the Moon and stay there for up to 75 hours.
For the Artemis program, we have the “Human Landing Systems” program, which is a set of commercial contracts more akin to the Commercial Crew Program than what we are seeing with SLS and Orion. Basically, NASA left out any strict guidelines and instead accepted bids that thought they could get a system to the Moon and back within that ambitious time frame of 2024.
At the moment we do not have a ton of details on all of these systems, so for now we’ll just use a rough size estimation for all of these systems. They are intended to support up to 4 astronauts for up to 2 weeks per mission.
Currently, there are three incredibly different vehicles, although NASA might down-select to two in 2021. The three currently chosen, and into the next phase of development, are:
- The Blue Origin-led National Team,
- Dynetics and
- SpaceX, with a lunar version of their Starship
The National Team
The National Team lander features a Blue Origin Lander stage, a Lockheed Martin Ascent stage, a Northrop Grumman Transfer Element Vehicle and Draper Labs developing the descent guidance and flight avionics.
This system is about 2/3 reusable with only the lunar lander portion getting used once, at first. Although refueling it on the surface could eventually be, and if there’s enough DV they could maybe reuse the lander as well.
The National Team Lander will likely fly on a few of Blue Origin’s New Glenn rockets, but it might fly on some other rockets including segments being flown as co-manifest payloads on an upgraded SLS Block 1B – we really don’t have those details yet.
The Dynetics lander is a low slung, perhaps “dachshund/weiner-dog-esque” lunar lander that is a very unusual looking design. It features over 20 subcontractors with the most notable being Draper, Sierra Nevada, United Launch Alliance and Thales Alenia.
It features 8 landing engines that are fully reusable for multiple missions, with the only item thrown away with each landing being a simple pair of fuel tanks.
The lander can fit on a single SLS 1B cargo version, or they also mention that it could fly in segments on ULA’s upcoming Vulcan rocket. It is not clear exactly how many launches it would take. But it is likely that it would have to take at least 2 Vulcans to get a lander of that size to the Moon.
Lastly, to the shock of pretty much everyone, NASA has chosen SpaceX’s Starship as an option too. This version is a lunar lander only and so is missing the aerodynamic features and additional heat shielding needed for landing on Earth, but which features bonus landing engines near the top instead.
Starship’s reuse confuses a bit. Although it would be an awesome outpost to have 1000 m3 of habitable volume and land it just once and then never move it ever again. But in order to refly it and reuse it, it requires it flying back to low Earth orbit or at least some Earth orbit and refueling it through several refueling flights from a Starship Tanker, which is no small feat.
In order to pull off each and every mission, including the very first one, there will be many full-stack Super Heavy / Starship launches, back-to-back.
Further HLS thoughts
We’ll get more into this in a second here. In a further upcoming video and article, we’ll talk about ALL the commercial options to fly payloads to the Moon and dive into the potentials when refueling Starship vs kick stages.
The next phase of selection and more detailed proposals scheduled for February 2021. After this, we will then be able to do an update truly comparing the three landers in the Human Landing System program.
Remember that for the Artemis program, each of these lunar landers requires its own ride to the Moon. Also they can’t be launched on the same rocket that the astronauts will be launched on. This is different from what the Apollo program did with the Saturn V.
Rockets (or boosters)
Lastly, the rockets. As you know from the previous video/article, the Artemis program will be utilizing the Space Launch System or the SLS rocket to carry the Orion Capsule (and its Service Module) to the Moon. The Apollo Program utilized the mighty Saturn V, which could carry the Apollo Command Module and Service Module, and the Lunar Module.
As a reminder, here are the specifications of these main rockets. For the SLS, we’re going to show you both the Block 1 and Block 1B upgrade that may fly on later missions. Regardless, their lift-off thrust is the same at 39.1 MN (Mega newtons) which is above the Saturn V’s 35.1 MN.
The Low Earth Orbit (LEO) capacity for SLS is 95 tonnes, or slightly more at 97 tonnes for the Block 1B, and the Saturn V could put 140 tonnes into LEO.
The upgrade to the SLS 1B doesn’t change the LEO capacity much, because the core stage pretty much puts the upper stage into LEO. We will talk about this more in a second. But by having a more powerful upper stage, it increases the Trans-Lunar Injection (TLI) performance as we see here.
TLI performance of SLS is 27 tonnes, or 43 tonnes with the Block 1B, and the Saturn V was 48.6 tonnes. Yes, it is confusing that the less powerful Saturn V actually has more capability than SLS. But having a 3-stage rocket with two of those stages being huge high-energy hydrogen stages definitely paid off.
Then of course in the Artemis Program we will see an array of other launch vehicles from Starship, to Vulcan, to New Glenn. And who knows – maybe even some new rockets or smaller rockets might end up playing a part in the program.
These two programs have extremely different hardware choices and capabilities. In which case you would have to think these hardware choices affect the missions – and they most certainly do.
As you might know, getting to the Moon is not as simple as just pointing a rocket straight up, blasting into space and slowing down when you get to the Moon. Getting to the Moon is not a straight shot; it requires some orbital mechanics and a few maneuvers to get there precisely.
We are going to show you what the approximate eventual(ish) standard flight profile of SLS getting into its NRHO will be. Currently, the first two and maybe three missions to the Moon will either be flybys or slightly different orbits until the Lunar Gateway is operational.
But if the term “Near-Rectilinear Halo Orbit” sounds super-confusing and intimidating, don’t worry. By the end of this section you’ll understand how it is different and why NASA chose it for the Artemis missions.
Take this timeline and profile with a little grain of salt, because the Artemis specifics are not publically available yet. Although, the general idea will remain the same, even if our specifics aren’t exactly bang on with what happens by Artemis 3 and beyond. But also note that our Apollo profile is pretty generic (since each mission had some variances).
Let’s put both missions together and compare them side by side, and this which would theoretically be possible. SLS will take off from LC-39B and the Saturn V took off almost exclusively from LC-39A. (Apollo 10 was the only Saturn V mission to launch from LC-39B.)
At liftoff the Saturn V of course ran on its 5 mighty F-1 engines alone. In contrast the SLS will first fire up its 4 RS-25 main engines prior to take-off. Then it also lights its massive Solid Rocket Boosters (SRBs) when it is time to go.
Initially the two rockets ascend pretty much vertically to punch through the Earth’s atmosphere. However they also pitch over down range to start accelerating horizontally. “To get to space, you can just go up; to stay in space, you need to go sideways – really fast”. After 2 m 06 s in flight, the SLS’s side boosters run out of fuel and will jettison. At 02:39, the Saturn V loses its first stage (the S-1C) and lights up its second stage (the S-II).
The SLS runs its core stage with four RS-25 engines nearly to orbit at 8 minutes into flight. This places the upper stage and the Orion Capsule into a highly elliptical, sub-orbital trajectory with almost 2,000 km apogee.
Leaving no space junk behind
They do this to discard the core stage. This is so it can burn up on re-entry while still getting as much performance out of it as possible. The Space Shuttle did something similar, leaving the external fuel tank on a sub-orbital trajectory at separation.
The Saturn V’s S-II ran out of fuel just shy of orbit at 8 m 56 s into flight. This requires the third stage, the S-IV B, to fire for about 2 1/2 more minutes. This is until 11 m 23-ish s, to get into its parking orbit of 160 km x 160 km.
The upper stage of SLS will do an orbit raise maneuver at its highest point or apogee. This raises its perigee (or lowest point) from sub-orbital trajectory to around 160 km within about the first hour of launch. This is called the Perigee Raise Maneuver or PRM. This is what actually puts the Orion into a maintainable orbit while allowing the core stage to reenter.
From the Earth to the Moon…
Now we have got our two spacecraft in wildly different orbits around Earth preparing for their TLI. This is where they fire their engines, raising their orbit to intersect with the Moon when their orbits meet.
Artemis missions after Artemis 2 will do this on the first orbit, only about an hour and a half after launch. The burn will take a long time, about 18 minutes in duration, because of the low thrust of the RL-10 B2 engine.
Each Apollo mission did this via a 350 second TLI burn with its single J-2 engine on the S-IV B. This was at 2 hours and 44 minutes into flight, after having orbited Earth one and a half times.
Rendezvous with the Moon
As Kerbal Space Program players hopefully know, you actually raise your orbit ahead of where the Moon is currently. (This is specifically 67 degrees ahead for Earth). Thanks to orbital mechanics, your spacecraft reaches the same point in space as the Moon does at the same time.
But just to make this graphic look simpler, we are keeping the Moon in a relative position to the Earth. Animating where it is continually throughout the mission gets very confusing. Just know if you raised your orbit to where the Moon currently is, you would miss it. By a lot!
Within the first hour of coasting to the Moon, the Apollo mission did something that remains unique in spaceflight history. The Command Module, with its large Service Module, would detach from the S-IV B upper stage. The S-IV B would then open up a fairing that held the lunar lander.
Then the Command Module would turn around and dock with the lunar lander and extract it from the upper stage. Once the two spacecraft joined, they would do some mid-course correction burns. These would target about 100 km above the lunar surface on the far side of the Moon.
Believe it or not, this is the actual scale of the Earth and Moon – their size and distance is correct. So it is a good thing that we have high definition and 4K monitors now. Otherwise it is actually really hard to even see them together at this scale!
See how long it takes a radio message to get from the Earth to Moon and back at this scale. We can actually watch it travel back and forth in real time in the original video. And it is this distance that is the cause of transmission delays of around 1.3 seconds in each direction.
Staying at the Moon
After a few days of coasting, next up is the orbital insertion burn. This is where the spacecraft slows down enough to be captured into lunar orbit. If the spacecraft’s motor doesn’t slow down enough, the spacecraft could get slung out on a different orbit. This could put it very far from Earth – fairly terrifying!
Because of this, Apollo missions usually aimed at a “free return” trajectory. This means if nothing happened, the Moon’s gravitational pull would sling the spacecraft right back to Earth. (From Apollo 12 and on, after a systems check out after the TLI burn, they would do a course correction and target their landing sites. However but it wouldn’t be a free return trajectory from that point.)
Because the Apollo missions generally aimed for a free-return trajectory, their initial apogee around the Earth was higher, beyond the distance to the Moon. Despite this having a longer orbital period in total, it did mean that Apollo arrived at the Moon more quickly than Artemis will. Therefore, although both vehicles will end up orbiting the Moon, Artemis and Apollo orbit the Moon in completely different ways.
Arrival at the Moon
The Apollo program also did something undesirable. They would perform the spacecraft’s lunar orbit insertion burn while on the far side of the Moon. This means that there was no communications available during the entire 6-minute burn that put the astronauts into lunar orbit.
For the Apollo program, this would usually occur a little after 3 days from launch. The Apollo Service Module would first put the crew into a parking orbit of about 100 km by 300 km. Eventually they circularized closer to 100 km by 100 km around the Moon, and each orbit was nearly equatorial (ish).
But instead of going around the far side, Artemis will aim for about 100 km above the North Pole of the Moon.
After about 4 to 5 days getting to the Moon, the Artemis missions will do their insertion burn. However the Command Modules won’t ever end up in a circular orbit. Because of its small Service Module and low DV, the Orion capsule will barely get into lunar orbit at all!
It will eventually be in a highly elliptical orbit of about 3,000 km by about 70,000 km. It only requires about 250 m/s of DV to get into this orbit. But this might vary from mission-to-mission until the lunar Gateway is eventually in orbit.
Explaining this new NRHO orbit
This orbit in particular is called a Near-Rectilinear Halo Orbit or NRHO, as mentioned earlier. It has a large advantage for crew safety. Its unique orbit allows the spacecraft to be in constant contact with Mission Control back on Earth. This is because it never goes behind the Moon as seen from the Earth’s vantage point!
A NRHO’s elliptical orbit goes over the North and South poles of the Moon. But the orbit is also perpendicular to the Earth, so the Earth can always “see” the spacecraft. The lowest orbital point is at the North pole, which means the spacecraft spends most of its time South of the Moon. Its orbital periods will last 6-8 days versus the Apollo program’s 2-ish hours!
Believe it or not, a spacecraft or space station can stay in this orbit with relatively little station-keeping. The Earth pulls at it equally over the entire orbit. So it naturally wants to stay in that same orientation during the entire orbit. This is regardless of where the Moon is relative to the Earth.
The Apollo missions landed at various different locations on the near side of the Moon.
These ranged from 26 degrees to 9 degrees South. But the Artemis missions will all land on the South Pole of the Moon, at the Shackleton Crater.
Once the vehicles are in their wildly different orbits, they will hang out there for a bit of time. In the case of the Apollo missions, they would usually spend around a day in Lunar orbit. Then the crew of two would depart from the Command Module. After this, they’d fire up the Lunar Lander and begin their landing phase.
Landing on the Moon
Artemis’ journey from here will be quite different compared to Apollo. Once in lunar orbit, the Orion spacecraft will dock to the upcoming Gateway or lunar lander. Gateway will permanently be in this NRHO eventually. But, until that’s ready, it will dock with the lunar lander which will meet it in NRHO.
The crew of 2-4 astronauts that is going to land on the Moon will then transfer to the HLS. They then un-dock from either Gateway or the Orion module. Above the North pole of the Moon, the HLS will lower its apoapsis (or apolune for the Moon). This puts the vehicle into a circular polar orbit around the Moon.
Now that both landers are in a more circular orbit and ready to land, their actual landing phase is similar. They basically slow down just enough so that their trajectory intercepts their targeted landing site. Then they’ll burn until they eventually touch down softly, right on target.
The duration for staying on the Moon can and will vary a lot. From Apollo topping off at a maximum of 3 days, to Artemis planning up to two weeks per mission. But now let’s fast-forward and pretend that it’s time to get home. From here, the two programs are pretty similar.
Leaving the lunar surface
The lunar lander (or maybe just the ascent stage) will take off from the lunar surface after lining up with the Command Module. This is so that it can rendezvous with it in orbit. The Artemis missions will likely park in a low lunar orbit first. They will then raise their orbits to match the Orion and/or Gateway. Eventually it will dock back in the NRHO.
The Apollo lunar module would only use the ascent stage to get into lunar orbit and it would do so via a single burn that lasted just over 7 minutes. It would then circularize its orbit at its apolune using just its Reaction Control System (RCS) thrusters.
After the Apollo lunar lander would dock with the Command Module and transfer over all its “Moon goodies”. The lunar ascent module was jettisoned as the crew prepared for the Trans-Earth Injection burn. This would again occur on the far side of the Moon, away from radio communications during the entire 2 1/2 minute return-to-Earth burn.
Return to Earth
Back to Orion – it will do something fairly similar after it has un-docked from either the Gateway or the Human Landing System, and is preparing for its Trans-Earth Injection. However the ascent stage, instead of jettisoning or discarding it, will be reused.
Orion will do a ~220 m/s departure burn while flying over the North Pole of the Moon. Again, because of the Near-Rectilinear Halo Orbit, it will be within line of sight and communications with Earth the entire time.
It takes about the same time to get back from the Moon as it did to get to the Moon. The Apollo missions took about 3 days to get back. It will take around 5 days to return home for Orion.
Before reentry, each vehicle will discard its Service Module and flip around, facing heat shield first. Then, just as in the article about how spacecraft return from orbit, the Earth’s atmosphere does the rest of the work.
The destination is the same and the hardware looks quite similar. But these two programs go about actually getting to the Moon in incredibly different ways. This brings up the question “is Artemis going to be any safer than Apollo?”
Safety & Upgrades
Why haven’t we been back to the moon since 1972? This is a very common question, and there is a handful of reasons. There are way too many to go into here, but perhaps one of the most common thoughts is “Why don’t we just rebuild the Saturn V and the Apollo capsule again?”
It does not take long to realize that the way we went to the Moon with the Apollo program was incredibly risky. In hindsight, NASA maybe dodged a bullet, while driving a car on 2 wheels on the edge of a cliff, inside of a tornado, while buying lotto tickets and winning.
But oddly enough, the hindsight risks were not nearly as bad as the calculated risks of the Apollo program which were, wait for it – 5%. A 5% chance of surviving going to the Moon and coming home safely. That was the numerical estimate for the probability of success, at the beginning of the Apollo program.
But this was a race to the Moon, and fortunately it went much better than a 5% chance of success. But still, a lot of things did go wrong. You don’t have to be too familiar with the Apollo program to know how close almost every mission came to a full-blown catastrophe at one point or another.
Apollo accidents and near-misses
Here’s a short list of just a few notable events:
There was the Apollo 1 incident, which tragically led to the loss of 3 astronauts before the mission even started. They were involved in a test procedure on the ground. After Apollo 1, a pure-oxygen environment was reconsidered after the complete loss of crew before it even flew. This really changed the pace and safety considerations of NASA.
On Apollo 11, the computer set off multiple alarms right before landing on the Moon which almost caused the entire system to fail. Not to mention the switch that activated the ascent stage to get off of the Moon broke on return from a Moonwalk.
Buzz Aldrin had to use a felt pen to ensure the circuit breaker was in the correct position. This ensured that they could fire up the ascent motor and leave the lunar surface at all!
Apollo 12 was struck by lightning twice on ascent and it almost caused a mission abort; yes this of course is where the famous “set SCE to AUX” quote came from, which saved the mission.
Apollo 13 was a mission that by all accounts should have been lost. But thanks to excellent communication, quick thinking, determination and the plucky nature of Mission Control and the crew, they managed to make it home safely.
Apollo 15 only had 2 of its 3 parachutes open during reentry, resulting in a rougher than normal landing. Had one more parachute failed, it would have likely led to the loss of the crew.
Changes in understanding risk
NASA got really lucky that they took such big risks, but also reaped huge rewards. Modern-day NASA is much more aware of what failures can do to a program, especially one that does not have seemingly unlimited funding and support like the Apollo program did.
The two Space Shuttle disasters were not only huge tragedies for the crew, the families and those involved in the missions, but they were horrible politically and jeopardized NASA’s funding and future programs.
But as the Space Shuttle program was being laid out, NASA changed the way that they certified and calculated risks. Nowadays NASA calculates the exact failure rate of each and every single component and evaluates the risk involved of each component, sub-component and system failing.
Since NASA has improved how they calculate risk better, you would think it should be safe to assume that the Orion capsule, SLS and all other vehicles involved in Artemis will adhere to a much higher safety standard. Here are a few tangible upgrades in safety and performance to the Orion capsule compared to the Apollo capsule as a good example of changes.
Orion improvements over Apollo Command Module
Orion has a massive upgrade in its aluminum pressure vessel with not only a new alloy, it is also friction-stir welded for maximum strength and fewer defects. These upgrades allow the reuse of Orion’s pressure vessel up to 10 times.
The Apollo capsule ran on fuel cells. These famously all got knocked out during the Apollo 13 mission, and power consumption was one of the biggest factors in getting that crew home safely. Orion will instead run on solar power and 120 V lithium-ion batteries.
New computing power and communications
Of course the interface and the computers have had a massive overhaul. The interface is no longer heavy mechanical switches and hardware; instead it uses sleek, lightweight and highly configurable computers with minimal mechanical switches, only about 60 in total.
The computers on Orion are substantially upgraded from the computers from 50 years ago, as you would expect. Orion’s computer is over 1,000 times more powerful and more redundant than the Apollo computers.
Orion can communicate with the TDRSS satellites, or the Tracking and Data Relay Satellite System, using phased array antennas. It can communicate with ground sites as well.
Navigation is massively upgraded because Orion can utilize modern-day GPS satellites when close to Earth. When far away from Earth it has automatic star tracking equipment. This is much more advanced than even those on the International Space Station (ISS).
Even the docking system has a new TRIDAR or 3D laser range and a highly upgraded camera as well. This will enable auto-docking.
The thermal protective system features similar silica tiles to the Space Shuttle on the sidewalls of the spacecraft. Orion has the largest ablative heat-shield ever built at 5 m across and weighing a whopping 450 kg.
The seats in the Orion capsule, although they look like a downgrade, “TinkerToy” version of the Apollo seats, are much lighter and can actually absorb more impact on landing.
The parachutes are upgraded of course, but even the way that they are deployed are now run with redundant sensors. Apollo relied on barometric sensors only to determine chute activation; Orion will have GPS and Inertial Measurement Units as well.
Orion will also have better radiation shielding with materials better suited to absorbing and deflecting radiation. But there are also considerations to make a temporary shelter in case of severe radiation storms.
So NASA has a lot of new safety considerations and has made the upgrades that you would expect to make Orion much safer than Apollo. But how much does all this increased safety cost us? What happened to this new “sustainable” program? Well now, the cost rabbit hole is about to begin.
Let’s actually peel back the onion layers here and get really deep into this, because why not? And in the previous video and article, we made some pretty blanket assumptions so we should probably dig deeper into this. Because talking about price is insanely hard when programs include development, operations and hardware.
In doing this, we’ve had to make some assumptions in order to make some of these calculations. So that we can project into the future how much some of this will cost. Here is a really rough conservative estimate of how much Artemis will cost from Artemis 1 up through to Artemis 8.
Artemis costs for SLS
To date, the SLS program has cost about $16 billion. Separately, Orion has cost about $12.5 billion if you count from only 2011 on. This is not including the 5 years of development during the Constellation program.
Now based on the Office of Inspector General’s report in 2020 on:
- the cost and future costs of SLS, Orion,
- the mobile launch tower,
- and all the other infrastructure,
we can project what it will take to get us to Artemis 1, the first uncrewed flight around the moon.
By Artemis 1, the SLS program will have spent about $18.3 billion and the Orion program will have gone through about $13.6 billion. But now some of that budget has already gone into purchasing of future missions and hardware.
The first flight with humans onboard will be Artemis 2. Again, this features an SLS and an Orion capsule going out around the Moon on a free return trajectory. Again, from the OIG report, if that happens in 2023, NASA will have spent about $38.4 billion on the program in total. That doesn’t sound too good, does it? But hold on, here comes some better news.
At this point, the program will have a more stable production line. NASA has already agreed to purchase SLS boosters at $870 million and three more Orion capsules at $900 million. After that, Orion will come down to $750 million.
Beyond Artemis first flights
Now being conservative with these numbers and annual budgets, we can make some estimates. If NASA only spends about $300 million a year to run and operate SLS and about $200 million to run and operate the Orion program, we can project all the way out to Artemis 8. This assumes one mission per year after Artemis 2 for a total of about $51.6 billion in total. That would be about $6.5 billion per mission.
But there is one very important thing missing from our numbers. Only that will make landing on the Moon possible. That’s a lunar lander! That’s right, that might be necessary!
Artemis costs for the landing system
NASA has already budgeted $4 billion for the first year of the Human Landing System portion of the Artemis program. A conservative estimate of the amount of money that it will take to finish the project, get the first lander built and the single rocket or multiple rockets to carry the lander system out for Artemis 3, would be $10 billion. That is a very conservative estimate.
Now, let’s add the Lunar Lander, the launch and the annual program costs which would be about $3 billion a year, being conservative.
Once the Human Landing Systems are up and running and in a reusable state, we can lower the cost of operations to only $500 million, which would help factor in general program costs and refueling launches and other considerations. Again, this is a conservative estimate. Luckily these services will be fixed-price contracts, so once we know the actual costs, it’ll be virtually impossible to have cost overruns.
Now, running that math on total cost of the program divided by mission, Artemis 1 would cost about $32 billion and Artemis 2 would come down to about $19.2 billion, but Artemis 3 would bring the per-flight cost of the program down to about $16.9 billion dollars because of the Lunar Lander.
If Artemis gets to Artemis 8, it comes down to below $9 billion average cost for each mission, factoring in the development costs. (Now, reuse of landing system hardware could bring the eventual costs down even further to something a lot more reasonable.)
This still sounds pretty expensive – but we do not really have anything to compare it to, yet. How does it compare to the Apollo program?
Comparing Artemis costs with Apollo
The Apollo program cost about $28 billion between 1961 and 1973 according to a very thorough report by the Planetary Society; in today’s money that’s about $283 billion.
But this insane cost was not just for the missions to the Moon; this includes all Gemini launches, lunar probes, all Apollo development and launches, all Saturn 1, Saturn 1B and Saturn V development and launches up until 1973.
Now, that also includes the entire modern infrastructure that is the Kennedy Space Center including of course the Vehicle Assembly Building, the launch pads, the crawlers, the press site and dozens of huge office buildings.
Plus basically everything at the Johnson Space Center in Houston, Texas, the ground tracking stations, the Stennis Space Center for testing the rocket engines, almost everything out at Marshall Space Flight Center, and so on.
What Apollo gave us that we still have
Basically, everything “NASA” was built during the Apollo era with some of that $283 billion. The Apollo program got us a lot more than “footprints on the Moon”.
But if we break that down to just the actual physical costs of the Saturn V rockets, the Apollo Command and Service Modules and the Lunar Lander’s development and building budget seen below, that total comes out to be over a half of that, at around $155 billion, in today’s dollars.
The next step is a little like trying to compare apples to light bulbs. Just be forewarned, there is almost no way to fairly compare these two, but all costs are shown adjusted for today’s dollar.
Apollo cost breakdown
If you take the $38.3 billion spent to develop and build the Apollo Command and Service Module, add its share of costs from Guidance, Navigation and Instrumentation and divide it by the 34 articles that were built, tested and flown, then you get a real rough per-unit estimate of $1.4 billion, in today’s dollars.
Then, if we take the Lunar Module’s $23 billion for development, building and its share of Guidance, Navigation and Instrumentation, divided by the 25 articles that were built, tested and flown, then we end up with about $1.3 billion. Again, in today’s dollars.
Lastly, the Saturn V; if we take the total development cost of $66.1 billion, plus its share of engine development and divide it by the 17 that were built, tested and flown, we get about $4.5 billion per Saturn V.
Artemis cost breakdown
Now, if we assume we’ll get to Artemis 8, we can take the program costs of Orion at $21.8 billion, then divide it by the 20 or so units that will have been built, tested and some flown, we arrive at a total price of $1.1 billion per unit.
Then for the Human Lander System, if we take what will likely be at least $17.5 billion by Artemis 8 and estimate a total of 12 units will have been built, tested and some flown, we get a total of $1.5 billion per lander – but again this also does account for the rockets that would get them to the Moon too.
Notice that we have factored in 12 lander units here. Even though we don’t need one for the first two Artemis missions, there might still be multiple landers involved, since there will most likely be some uncrewed flight tests, and some landers might end up sitting on the lunar surface.
But don’t forget, these are at least partially or fully reusable, so it actually would get cheaper and cheaper by a lot, the more times that they are used!
Lastly, SLS. Let’s take the $29.8 billion and divide that by the 10 articles that would be built, some just tested and some flown by then, and we wind up with a total cost of about $3 billion per rocket. Interesting!
What have we learned?
Now, there were substantially more flights and physical hardware units built, tested and flown during the Apollo era than there are today for the Artemis missions.
But then again, everything was more expensive back then. They had to pretty much invent everything from scratch. You would really hope that we can make a cheaper spacecraft and rockets today than we could over 50 years ago.
And it might be easy to say “well, look at how much more we got out of the Apollo program, considering we started from scratch. Is it going to take us roughly the same amount of money and time to do it again in the 21st century?”
So what is Artemis really?
Artemis is not Apollo 2.0 (despite being Apollo’s sister in Greek mythology); Artemis is substantially safer, roomier and designed to spend a lot more time on the surface of the Moon.
We haven’t discussed this so far, since mission planning is still very much up in the air with Artemis, but even the shortest lunar missions for Artemis will be nearly a week long, or over twice as long as Apollo 17 spent on the Moon, the longest lunar mission to date.
Artemis can potentially take up to 4 astronauts to the Moon at a time for up to two weeks per mission. If Artemis fully pans out and utilizes its full potential, it could be over 10 times cheaper by human-dollar-per-hour on the surface of the Moon compared to the Apollo program.
Maybe what Artemis lacks in actual cost savings and timely schedules, it makes up for in just sheer raw time and capabilities on the Moon. Let’s do a quick look at some of the things that slowed down and made SLS and Orion so over budget in the past, and see if we’re doomed to see more of this stuff going forward in the future.
One of the biggest frustrations that I have with the Artemis Program, besides the ridiculous cost of SLS and the fact that it is barely even capable of getting Orion to the Moon, is the fact that it is using hardware that is not only mostly developed, but it is even pulling from an existing inventory of hardware to use as the basis of the vehicle.
It’s not the fact that they’re reusing old hardware – in theory that does makes sense. Although of course you would really only do this to save money, surely? So that is where there is such a big disconnect for me, between the re-usage of parts, contracts and infrastructure and the cost.
Solid rocket booster costs
The solid rocket boosters, which literally have all the hardware necessary to make a whopping 16 boosters, have cost $2.4 billion. To take the empty shells of existing boosters and refurbish and upgrade them to be five-segment boosters (instead of four on the Space Shuttle). Yes, they had to change out to a new propellant, yes they had to upgrade some avionics and a plug.
But for $2.4 billion, you would have thought that they must have started from scratch and built a brand-new type of rocket booster. Oddly enough, Northrop Grumman claims that, when they get to the replacement booster (the BOLE booster which is basically their core stage of the “OmegA” rocket), they will be able to produce those brand-new boosters more cheaply than the original reused ones.
Reused Shuttle engine costs
We can also look at the RS-25s. Aerojet received $570 million to revamp the RS-25Ds to be re-certified for flight. Alright, yes, there was a lot of work that went into this, testing dozens of engines and re-certifying them for the new profiles.
But again, the hardware already existed, and to spend over half a billion dollars to get some engines ready to fly that have already flown on the Space Shuttle is just difficult to swallow.
NASA has officially paid for 24 more RS-25 engines for a total of $3.5 billion, which includes $1 billion to restart production. After the restart and initial 6 engines, $1.8 billion was spent for just 18 engines, so the cost per engine is about $100 million. That’s right, about as expensive as a reusable Falcon Heavy launch, for just one engine.
Other expensive ticket items
There is also the Interim Cryogenic Upper Stage that will cost right around half a billion dollars for 3 flight units and 1 test unit. We’re looking at an upper stage that will cost about $125 million. Just the upper stage!
What about the Mobile Launch tower? This one tower has wound up costing almost $1 billion. This steel-constructed tower with some umbilicals, hold downs and the crew access arm has somehow ended up costing over half as much as the world’s tallest building, the Burj Khalifa.
Thoughts on the above
How? How does that happen? You could literally stack the nearly one billion dollar bills it took to build the mobile launch tower and it would literally reach space – seriously.
Lastly, the most damning thing has been the amount of money that Boeing has received to build the core stage. Boeing has received about $6.7 billion to design, build and test just two core stages. How is that possible?
This is what I don’t get, and I’m sorry, but it just doesn’t make sense to me. Yes, they are using a new material, yes they set up the world’s largest friction-stir welding machine and assembly, and had problems with it. And yes, a tornado ripped through Michoud in Alabama. Also yes, they dropped a tank once (oops).
Still, that’s just ridiculous. Why was there not a much firmer price cap on all of this that put a little fire under Boeing to get this done on time and at a better price?
Observations on these costs
Frankly, NASA is going to have to make up for the cost of SLS. At best, the costs for SLS seems irresponsible and frustrating, at worst it’s a blatant misuse of taxpayer money and feels borderline criminal. It took until 2019 before NASA’s newest administrator, Jim Bridenstine, really came in and finally whipped things into shape.
Jim started threatening to use commercial rockets to get us back to the Moon by 2024. Boeing seemed to “get the memo”, because all of a sudden we saw them finally get into gear. But should he have followed through with his threat? What options are there really in the commercial world that could do the job that SLS and Orion will be doing?
We’re saving that for part 3 of this video and article series, when we look at what could actually do the same amount of work and safely replace SLS for getting humans to and from the Moon. We’ll go over all the commercial options including Starship and Falcon Heavy (since I am asked about this all the time) and actually look at the feasibility and costs associated with those.
A reminder here, if your blood is boiling, if you need more of an understanding of why there is the cost-plus contracting and how SLS exists at all, I did dive into how the program was set up, why it exists and why it’s a bit of a necessary evil.
Speaking of commercial options, let’s talk about the good parts of the Artemis program.
The Good Parts of Artemis
No, actually I take that back, for all the negativity and costs overruns we’re seeing with SLS, I actually am really glad we’re going to have that capability. I don’t want it cancelled before we have another readily available vehicle, so although insanely and frustratingly expensive, SLS is a good thing right now.
Let’s try again, onto the better part of the Artemis program, the Human Landing System, which will utilize the fixed-price contracting scheme. We talked about this a little in the previous video and article, but it’s awesome to see NASA utilizing it on a more ambitious scale!
Commercial providers as part of Artemis
After all, NASA didn’t really give any direction on how these companies were to build their landers, didn’t say how big or small to make them, didn’t say which rockets had to take them to the Moon; they just let the companies innovate and submit proposals.
This is much more akin to the Commercial Crew Program – NASA had a set of requirements and accepted proposals. Through this commercial partnership, it will allow for multiple partners to innovate and deliver so that NASA can always have some non-commonality and redundancy in providers.
In the same way that the Commercial Crew Program (which led Boeing and SpaceX to develop totally different vehicles with different parts and components, and virtually no commonality between them) has been a good thing, because seeing how one provider has had major problems and is now behind schedule, it allows NASA to continue their missions with the other partner.
Since we don’t really have the exact numbers on how much the Human Landing Systems will cost, we can’t truly project if they can make up for the costs of SLS. My gut feeling is that if Artemis truly becomes a sustained and continually funded project, and if the landers end up being reused, they could be a huge win for NASA.
Even the least reusable vehicle, Blue Origin’s National Team lander, only ditches the descent stage and reuses both the orbital tug stage and the ascent stage, which means that there is potential to save a lot of money when you don’t throw away 100% of your $1 billion lunar lander with each mission.
Then you have Starship which, if fully reusable and launched on a fully reusable rocket (which of course is the plan), could end up being a huge cost saving with the potential to truly change the game.
Unlike Apollo, which had very little chance of becoming cheaper as time went on, the Artemis program is built around the evolving technologies, reuse and eventual cost savings. The longer the program lasts, the cheaper and more sustainable it should actually get – it is baked into the program, which is awesome.
Artemis vs Apollo. A part of me really wishes NASA had just rebuilt the Saturn V, found ways to make it cheaper than before and just done things “the old way”. It really seems to me that SLS is hard to justify.
If reusing the literal left-over hardware was meant to make the rocket more cost effective, it really didn’t seem to help. And then once they had to open up new and old lines of manufacturing, why not just build F-1 engines and the whole Saturn V with slightly updated and modern technology?
It is also a shame that Orion has such a small and relatively incapable Service Module, since SLS can’t even take anything bigger to the Moon, for now. Of course, if it gets upgraded, it could eventually do more. But even with the SLS 1B, it would still be less than with the Saturn V.
It just feels like this is the 21st Century; the rockets should by no measure be going backwards. They shouldn’t be less capable and more expensive. We should be getting cheaper and more capable rockets. Now, I know that it doesn’t really feel as though this is the case. But by the time that you actually factor in all of the development costs including the development rockets, SLS is actually cheaper than the Saturn V. Even more so if you only consider the Saturn Vs that flew and overlooked the development rockets. In this scenario, SLS is substantially cheaper than the Saturn V.
Commercial buy-in from NASA
But as far as the Artemis program goes, at least NASA is already strongly leaning into the commercial sector and I think that’ll be a huge win. Although they’ve already ordered up way more SLS rockets than I think any of us would prefer, it at least ensures that we won’t have a gap in provider coverage. Such as the 9-year gap that the USA had when the Space Shuttle program ended before the Commercial Crew Program was ready to fly.
This is vital. It’s too easy for NASA to get the carpet pulled out from underneath them with each administration change. Therefore, by committing to something, even if it’s expensive, it at least gets the ball rolling.
Changes to risk
When comparing Apollo to the Artemis Program, a lot has changed. Perhaps the biggest change is with the risks. Because the risks have shifted. The Apollo program’s biggest risks were mostly human lives risk, whereas the Artemis Program’s biggest risk is more funding and the constant fear of cancellation.
Maybe this just is not as sexy. After all, NASA had what feels like unlimited funding to get the Apollo program sprinting ahead of the Soviet Union and now NASA has to play far more politics to ensure a program survives.
I think my generation, and future generations, just craves the excitement, the pace and the innovation of the Apollo era and we end up scratching our heads at why everything is taking so long for what feels like a bad sequel to the first movie.
Reflection on Apollo
After all, there is no way to deny that the Apollo program isn’t easily one of humanity’s greatest achievements to date. It might forever be one of the biggest “bookmark” events in history. It’s still absolutely incredible that humans figured all this stuff out at a time when a computer was the size of a room and most calculations were done using a slide-rule. To even compare the two programs side by side is perhaps unfair.
Since we haven’t seen humans on the Moon in almost 50 years, it is important to weigh in all the facts to see if we’re actually going to do it this time, or just get our hopes up and then see another program get cancelled and another decade slip between our fingers.
It’s just a weird convergence in history that by the time we have a program up and running that can actually return humans to the Moon, it just so happens that the commercial industry is booming and has matured to the point of being able to do so much of the work and it starts to make the program that has been in works for almost a decade suddenly look 45 years old.
But the good news is that just because we’ve already paid for these vehicles, it helps ensure the success of the many commercial partners involved – and other future commercial partners.
For me, Artemis is not Apollo 2.0. I would say that Artemis is more like the first commercial flights across the Atlantic on the FW200 Condor compared to Charles Lindbergh’s daring and dangerous flight on his single-engined “Spirit of St Louis”.
Artemis is setting itself up to be sustainable in a different way, hopefully aligning the program to survive multiple administrations while paving the way for cheaper and more competitive commercial options. And that’s definitely something to be excited about!
Did you notice those awesome 3D renders in this article? Those are provided by Caspar Stanley. He has done some awesome work and is constantly making impressive things. Be sure to follow him on Twitter and check out his Rocket Explorer app as well!