NASA’s Looking at Options for SLS’ Cargo Configuration

Artist’s concept of what the business end of NASA’s new Space Launch System or “SLS” will looks like. Image Credit: NASA/MSFC

NASA is continuing to take steps towards building its Space Launch System (SLS), the mammoth rocket that promises to surpass the Saturn V for size and power. Last week, the agency began looking at ways to make it even bigger, specifically its cargo capacity. In a Request for Information (RFI) published last Thursday, the agency put out a call for information on possible payload adapters and fairings already available in commercial industry to use with the SLS.

The SLS is poised to be an excellent workhorse for future missions, in large part because it’s so flexible. The initial Block 1 and Block 1A versions will be able to lift 70 metric tons into Earth orbit and use a small “kick” stage to punt the payload to further destinations. Later incarnations of the SLS – the “evolved” rocket – will be able to lift 130 metric tons into orbit. All three versions will be able to carry crews or cargo, depending on a mission’s demands, to destinations like the Moon, Mars, and even LaGrange points.

The possible SLS configurations. Image Credit: NASA

The payload configuration is what NASA is hoping to increase, though for now the agency is just looking. “This is a no-cost examination of the aerospace landscape to identify existing components that could augment the rocket’s architecture as we move beyond the initial Orion configuration,” said Todd May, the SLS program manager at NASA’s Marshall Space Flight Center in Huntsville. “SLS can make challenging human and science missions possible in large part because of the unprecedented size of the payload it can lift. We are hopeful industry may offer some innovative and affordable ideas about alternative fairing and adapter options.”

The large payload fairing already built into SLS’s design is set to reduce design complexity. The rocket’s high performance and powerful thrust should decrease travel time to faraway destinations. These factors should, by extension, lower the overall cost and risk associated with each mission.

But for the time being this is only a projection. SLS is still on paper, making it vulnerable to budget cuts and fickle political changes. But it’s on its way. On the plus side, whatever your political leaning, Obama’s reelection might see SLS move forward faster than if NASA were hit with a change in administration at this point in the rocket’s development. The first launch is currently set for some time in 2017, and if things are going to adhere to this schedule no change to the powers that be could be a good thing.

SLS is broken into parts. NASA’s Glenn Research Center in Cleveland is responsible for payload fairing development and is managing this latest Request for Information for increased payload adapters and farings. The Marshall Spaceflight Centre manages the SLS Program on the whole for NASA and it will, hopefully sooner rather than later, launch from NASA’s Kennedy Spaceflight Center in Florida.

For more information: SLS


  1. I remain mystified about NASA’s claim the “evolved” SLS, with its 130 mt to orbit capability, will “surpass the Saturn V” in this regard. The as-flown mass a Saturn V delivered to Earth orbit during an Apollo Moon mission was in the neighborhood of 140 mt. That’s how I define a rocket’s “power”. Has NASA cooked the books on this metric so I’m comparing apples and oranges? I hope Congress and the taxpaying public aren’t disappointed with the answer.

    • Dan, rocket efficiency has greatly improved throughout the years. Although it may not be as powerful as the engines on the Saturn V, it is way more fuel efficient, so it can burn longer.

      • Last summer, Dan commented on a rocket’s initial mass low earth orbit, or IMLEO, at 185km as a metric for comparing apples to apples when it comes to launcher performance. Below is part of his comment of last summer that bears on this discussion and forms the context for his comment above.

        “An Apollo lunar mission’s Saturn V launch targeted Earth parking orbits very nearly meeting these ideal IMLEO criteria. On these missions, IMLEO consisted of a partially depleted S-IVB third stage, Instrument Unit (avionics), adapter panels enclosing the Lunar Module, and the Command/Service/Lunar modules. Early lunar missions achieved IMLEO in the range of 133 to 136 mt. The last three missions used a parking orbit height near 167 km and an uprated Saturn V design to set IMLEO records slightly in excess of 140 mt. If anyone wants to check my bookkeeping, all the component masses are published in Orloff & Harland, ‘Apollo: The Definitive Sourcebook'”.

        I think part of the reason for the current NASA’s leadership continual harping on how much more improved SLS is over the Saturn V is a need to show that we are moving beyond, that we’re doing it better than did nearly 50 years ago, the “old” NASA.

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