For decades, NASA has been an undisputed leader of space technologies, but the 21st-century space race, with private companies at the forefront of tech innovation, has cast some doubt on this supremacy. Whenever one thinks about innovation in the private space sector, SpaceX is the first company to come to mind. For a good reason, too – after all, it’s one of the top companies overseeing a huge share of NASA contract work – from resupplying the space station to designing technologies for the Moon and Mars exploration.
However, this does not mean that NASA is subcontracting all of its work – the agency keeps developing new technologies using decades of past rocket-building experience. Its current undertaking, the Space Launch System (SLS), should be the most powerful rocket ever built – that is, compared to NASA’s past creations. SpaceX is not wasting any time either – according to the company, Starship will become the most powerful rocket ever built.
So, in this battle for the title of most powerful, who’d win? Below, we will give you a detailed SLS vs Starship comparison of thrust, payload capacity, development progress, and intended mission span so that you can decide for yourself!
SLS vs Starship thrust
Thrust is one of the most important parameters in rocket building – after all, how much power a carrier generates defines how much it can carry and how high it can go. There are several ways to measure a launcher’s thrust, but in this SLS vs Starship comparison, we’ll stick to the metric system unit – the Newton, or a force necessary to accelerate 1 kg of mass at 1 m/s speed.
Even though SLS is still in development, NASA has already announced three different configurations – Blocks 1, 1B, and 2. Here is how NASA’s current thrust estimates look when converted to the metric system:
● Block 1: 39.1 MN (meganewtons)
● Block 1B: 39.6 MN
● Block 2: 42.3 MN
Starship should also have several configurations that differ in the number of Raptor engines and, so, thrust capacity. However, its total thrust is expected to be 75-80 MN – almost twice as much as SLS’s most powerful configuration!
SLS vs Starship payload capacity
Impressive thrust is all good and sound, but let’s not forget that a rocket, first of all, carries its own weight into space. But what about useful weight, as in cargo or passengers, referred to as payload? Let’s start with NASA – how much payload can SLS carry?
Here, a lot depends on how far we’re going – for example, space news online magazine Orbital Today explains that SLS should be able to carry up to 130 metric tonnes to translunar orbit, which is only ten tonnes less than NASA’s previous most powerful (and most famous) rocket Saturn V. But to make a landing, the system will need to reach a lunar orbit, and here, SLS payload capacity drops to 27-46 metric tonnes, depending on the exact configuration.
Starship once again beats NASA’s creation in carrying capacity. It should be able to deliver up to 100 metric tonnes to our satellite’s surface, but there is a catch – first, it will need to refuel in LEO. Considering that NASA’s rocket will not need to stop for refuelling, is SLS better than Starship? There is no definite answer here because, unlike SLS, Starship has a wider mission range. Besides cargo deliveries to the Moon, it eventually aims for Mars and maybe beyond. Plus, it should also be able to carry up to 100 metric tonnes to LEO and up to 21 metric tonnes to GTO without refuelling.
SLS vs Starship cost of launch
Another important question, especially for the US taxpayers, is – how much does SLS cost per launch vs Starship? Currently, both rockets are still in their development and testing stages, but NASA claims the launch cost would be between two and four billion, depending on the exact configuration and mission details.
SpaceX has not made any numbers public yet besides an estimated cost per kilo of cargo delivery to orbit, which currently stands at about $2,000. But one should also remember that Starship will be a fully reusable system, which should keep decreasing its launch and maintenance costs, whereas SLS is not designed for relaunch.
Judging from these parameters, it certainly looks like Starship will be a more advanced and more economically feasible launcher, which is not all at all surprising considering SpaceX’s past creations, especially Falcon 9 – the most budget-friendly and most often-used rocket right now. Besides, when comparing the SLS vs Starship mission range, the latter also promises to be a more versatile development.
Once launch-ready, will Starship make SLS obsolete? Right now, it is too soon to jump to any conclusions, especially considering that neither will fly until 2025 – and even then, the crewed launch might yet be delayed. So, all we can do is wait – and in the meantime, you can stay tuned for more updates on our website!
Author: Emma Thorpe
