SLS v Saturn V: How NASA’s new rocket compares to Neil Armstrong’s launch vehicle

Standing taller than the Statue of Liberty and having cost an eye-watering $23 billion (£19 billion) to build, NASA’s brand new mega moon rocket is now just weeks away from its maiden launch.

The enormous Space Launch System (SLS) is scheduled to blast into space on August 29 as part of a six-week mission that will see it carry an uncrewed Orion spacecraft to lunar orbit and back. 

It will be the first of three planned trips to the moon that will culminate in returning humans to the lunar surface for the first time since the 1970s.

Known as the Artemis program, NASA wants to land the first woman and the first person of colour on the moon by 2025 — and the SLS will be the vehicle to take them there.

Weighing 5.5 million pounds (2.5 million kg) and capable of generating almost 40 Meganewtons of thrust, the rocket is the modern equivalent of the Saturn V, the huge launcher built during the Apollo era which powered Neil Armstrong, Buzz Aldrin and Michael Collins to the moon in 1969.

The two rockets may have been built more than half a century apart, but despite huge technological advances, the SLS doesn’t necessarily eclipse the Saturn V on every metric.

Here, MailOnline compares how the vehicles stack up against each other, from their height, weight and top speed, to cost per launch, fuel type and payload capabilities.

The first version of the SLS will be called Block 1, before undergoing a series of upgrades over the next few years so that it can launch heavier payloads to destinations beyond low-Earth orbit.

NASA hopes its mega rocket won’t just take astronauts to the moon, but will eventually be capable of blasting humans to Mars and beyond.

Height, weight and thrust

The Block 1 SLS will stand at 322ft (98m) and tower 23 storeys above the launch pad — meaning it is not quite as tall as the Saturn V’s colossal 363ft (110m) stature.

It also weighs less – at 5.5 million pounds (2.5 million kg) compared to 6.2 million pounds (2.8 million kg) – but the 2022 rocket is by no means a little brother to its iconic predecessor. 

‘It is truly an immense rocket. It is just jaw-droppingly big,’ said John Shannon, vice president and program manager for the SLS at Boeing, the rocket’s prime contractor.

Not only is it big, but it dwarfs Saturn V when it comes to the thrust it is capable of generating.

The SLS’s four RS-25 engines, which were also used on the space shuttle, can produce 8.8 million pounds (39.1 Meganewtons) of thrust — 15 per cent more than the Saturn V’s 7.6 million pounds (34.5 Meganewtons).

On thrust alone, the SLS will be the most powerful rocket ever built when it finally launches.

It also has a top speed of 24,500mph (39,500km/h), compared to 17,400mph (28,000km/h) for the Saturn V.

Cost and length of time to build

It may be an astonishing amount of money, but the $23 billion (£19 billion) that went into developing and building the SLS actually equates to about half of what was spent on the Saturn V, when inflation is taken into account.

The latter cost around $6.4 billion (£5.2 billion) in the 1960s, which in today’s money works out at about $51.8 billion (£42.3 billion).

Remarkably, however, the Saturn V went from paper design to flight in just six years — having entered formal development in January 1961 and launching for the first time in November 1967. 

The brainchild of German-born engineer Wernher von Braun, it successfully flew 13 times before being retired.

The SLS design was unveiled in 2011 but entered the formal development stage eight years ago. So despite the numerous technological improvements over the past five-and-a-half decades, it has still taken longer than it took von Braun in the Sixties.

Many of the delays have been caused by issues with the SLS itself, while the Artemis program has also been dogged by problems with the development of spacesuits and the human lander systems that will take crew to the lunar surface. 

Legal issues have held it up, too. Last year Jeff Bezos’ Blue Origin unsuccessfully sued NASA over a decision to award the human lander system contract solely to SpaceX. 

It may have taken longer to get to this point but NASA is now building the SLS rockets needed for several missions. 

To reduce cost and development time, the US space agency is also upgrading proven hardware from the space shuttle and other exploration programs, while making use of cutting-edge tooling and manufacturing technology. 

Some parts of the rocket are new and others have been upgraded with modern features that meet the needs of deep space missions.

Although the Saturn V may have cost more to develop and build, it is not as pricey to launch. 

It cost $185 million per blast-off in 1969 – the equivalent of $1.49 billion (£1.2 billion) in today’s money – while the SLS is estimated to be closer to $4.1 billion (£3.3 billion).

How the SLS works compared to Saturn V

NASA’s new mega rocket will be powered by a core stage that is flanked by two solid rocket boosters, and an upper stage called the Interim Cryogenic Propulsion Stage.

This is a different setup to the Saturn V’s three rocket stages. That vehicle didn’t use boosters in any form because it was sized so as to not need them.

Solid propellant technology was also still not very good in the 60s, so the Saturn V was powered by a mixture of kerosene, liquid oxygen and liquid hydrogen.

The SLS’s shuttle-derived solid rocket boosters contain the propellant polybutadiene acrylonitrile and provide more than 75 per cent of the vehicles thrust during the first two minutes of flight. 

Its core stage, meanwhile, stores 730,000 gallons of super-cooled liquid hydrogen and liquid oxygen that fuel the RS-25 engines.

What about the crew capsules?

As previously mentioned, the Saturn V was split into three stages. The first used five F-1 engines to lift the massive rocket off the ground, before it was jettisoned to allow for burns by the second and third stages. 

Ultimately these also separated from the Apollo spacecraft, leaving just the command module, service module and the lunar lander — complete with an ascent and descent stage.

In the case of Apollo 11, the command module was known as Columbia. This is what transported Collins, Aldrin and Armstrong to lunar orbit, before the latter pair made their journey down to the surface.

SLS’s next-generation crew vehicle, known as Orion, will actually cater for four astronauts rather than the three on top of Saturn V. 

While the end of this month will be the first launch of the SLS, it will be the second for the Orion capsule, which was involved in a test flight in December 2014 when it went to space on a ULA Delta IV Heavy.

When it launches, Orion won’t have any crew on board but will instead carry dummies to the moon and back.

These are designed to replicate human weight, and give scientists and engineers and insight into flight performance, without putting humans at risk.

Unlike the Apollo capsule’s single flight computer, Orion is equipped with two redundant flight computers that operate simultaneously. Each one is also equipped with two redundant computers. 

Orion’s computers also hold significantly more memory and operate at much faster speeds than an Apollo-era computer. 

In fact, NASA says they operate 20,000 times faster and the memory capacity is 128,000 times greater.

And the rest of the payload?

In terms of a maximum payload to low-Earth orbit, the SLS is slated to be able to carry some 210,000 pounds, the equivalent of 95 metric tonnes.

As a comparison, the Saturn V could transport 260,000 pounds (118 tonnes). 

The former’s max payload to lunar orbit, meanwhile, is 59,500 pounds (27 tonnes) – the equivalent of 11 large SUVs – while the latter’s was 90,000 pounds (41 tonnes).

Although the Saturn V technically wins here on paper, the SLS payload capability is expected to grow with newer iterations of the design.

What is more crucial, however, is not necessarily the maximum payload a vehicle can transport but the cost that it takes to do so. 

This is often seen as one of the most prohibitive things about space travel, particularly when it comes to longer duration human missions to places like Mars. More on that later.

How do the test missions compare to the main event? 

During Artemis I, Orion – which was primarily built by Lockheed Martin – will stay in space ‘longer than any ship for astronauts has done without docking to a space station and return home faster and hotter than ever before,’ NASA has said. 

The mission is designed to show that SLS and Orion are ready to carry astronauts.

If Artemis I is a success, NASA will then send Artemis II on a trip around the moon as early as 2024, this time with a human crew on board.

The Artemis II mission plans to send four astronauts into a lunar flyby for a maximum of 21 days.

Both missions are test flights to demonstrate the technology and abilities of Orion, SLS and the Artemis mission before NASA puts human boots back on the moon.

With the Saturn V – before any Apollo mission flew – NASA dealt with a major tragedy in January 1967. 

As astronauts Gus Grissom, Ed White and Roger Chaffee were carrying out a simulation on the launch pad in Florida, a flash fire broke out in their capsule and killed all three.

The disaster caused NASA to re-examine all aspects of the program and rework many of the spacecraft’s systems, meaning it wasn’t until October 1968 that the first Apollo mission got to space.

Apollo 7 was followed by three more flights that operated in a similar way to the plan for Artemis, with 10 being the second to orbit the moon and acting as a dry-run for the famous lunar landing that took place two months later.

Are there any other contenders to rival the SLS and Saturn V?

Yes there are. Elon Musk has been trumpeting his much-anticipated Starship, which could be a game-changer for space travel.

Like Saturn V, SLS is not a reusable launch vehicle. But Starship will be.

It is being developed as a fully reusable transport system that is capable of carrying up to 100 people to Mars.

Starship is a rocket and spacecraft combination that when added together will stand at 394ft (120m).

Because it will be reusable, the rocket will be able to return to the ground after launch and then blast off a short time later – much like an aircraft – once it has been re-filled with propellant.

This is a huge development because it brings down the cost of rocket launches and stops parts being discarded in the sea or burning up in the Earth’s atmosphere like with other launch systems. 

The spacecraft, which is also called Starship, will sit atop a rocket called Super Heavy. 

This will be powered by around 32 Raptor engines and should achieve more than 16 million pounds (70 Meganewtons) of maximum thrust. 

The rocket will also be able to lift at least 220,000 pounds (100 tonnes) of payload, and possibly as much as 330,000 pounds (150 tonnes), to low-Earth orbit.

Musk hopes Starship will be used for long-haul trips to Mars and back — which could take up to nine months each way. He is looking to install around 40 cabins in the payload area near the front of the upper stage. 

The first orbital test flight of SpaceX’s Starship is planned to launch as early as next month.

It is not just the US that is looking to build mega rockets, however. 

China is also planning to develop the latest, biggest and boldest version of its Long March series of rockets.

The Long March 9 will be Beijing’s version of the SLS: a super heavy-lift rocket intended to launch large pieces of infrastructure into orbit and even help construct the joint China-Russia International Lunar Research Station. 

It will use the same fuel (methane-liquid oxygen, or methalox) as SpaceX’s Starship, while the two designs also share heavy-lift capabilities. However, beyond that their structure is wildly different.

Reports suggest that the Long March 9 will have a payload capacity to low-Earth orbit of around 308,000 to 330,000 pounds (140 to 150 tonnes).

There has also been talk that Russia is building its own mega rocket, too.

Where can I watch the SLS blast off?

NASA will provide livestream coverage of Artemis I’s move to the launch pad ahead of its targeted no-earlier-than-August 29 liftoff. 

Ten shoebox-size secondary payloads, called CubeSats, are hitching a ride to space on Artemis I’s SLS rocket, and several other investigations are flying inside the Orion spacecraft during the flight test. 

Each of the payloads will perform science and technology experiments in deep space, expanding understanding of lunar science, technology developments, and deep space radiation.  

The US space agency is targeting August 18 to roll the SLS and Orion spacecraft to Launch Pad 39B in Florida.

It will provide a live stream on the NASA Kennedy You Tube channel, beginning at 18:00 ET (23:00 BST). 

More information about the timing of the Artemis I launch will follow in the coming weeks.