Spaceflight Insider

Fact checking rumors on NASA’s Space Launch System

Several statements about NASA's new heavy-lift booster have gained traction in the public consciousness - but are they based on fact? Image Credit: NASA

CAPE CANAVERAL, Fla – The internet is a wealth of information about NASA’s new heavy-lift booster, the Space Launch System or “SLS.” Google, Yahoo, Wikipedia – one can find out the statistics, amounts, dates and other data about the launch vehicle very easily. Just because it is easy however – does not mean everyone is doing this and some appear to be taking advantage of viewers desire to be provided with information for their own ends. With rumors born on the net, things appear to be cyclical. Statements addressed in the past – can crop up again. SpaceFlight Insider spoke with NASA’s Deputy Associate Administrator for Exploration Systems Development, Dan Dumbacher about some of the most prevalent of these rumors. While some were shown to not be accurate – others had at least a basis in fact.

We asked Dumbacher point-blank about statements ranging from whether-or-not other launch vehicles could compete with SLS, to if the launch date had slipped and more. The basis of these questions can be found in oft-quoted statements about SLS and Orion which have been posted on comment boards as definitive, as factual. But are they?

The first rumor we discussed with Dumbacher was a recent claim SpaceX’s Falcon Heavy rocket would fly a decade before SLS. As it currently stands, SLS is scheduled to conduct its first flight in 2017 with the first launch of the Falcon Heavy, set to launch either later this year or in 2015 – making the difference between the two launch dates – three years  – not the 10 that was claimed.

SpaceFlight Insider: This first question is a new one; there have been statements SLS won’t fly for a decade. Given that everything we have seen says 2017 – is that date still accurate?

Dumbacher: “Sure, that’s not a problem. We are working toward the first SLS launch in December 2017. The FY 2014 Omnibus Bill continues to help us along that path.

So, we’re on track for 2017, but, as everyone knows in this business,  you learn things along the way which could see that be pushed back. We could stub our toes on technical issues along the way. The team is working hard to make 2017. We also have some slack in terms of the schedule in some key places for that 2017 date.”

The 2017 launch date was also confirmed by NASA’s Associate Administrator, Robert Lightfoot during a media event at Kennedy Space Center on March 17, 2014. Therefore the statement Falcon Heavy will fly a full decade before SLS? Is totally false.

The next subject broached was one of capability. Was it even fair to compare SLS to the Falcon Heavy or United Launch Alliance Delta IV Heavy?

SpaceFlight Insider: As we understand it, it would take several launches of a Falcon Heavy rocket to compete with a single SLS launch. Is this an accurate assessment of what the rockets should be able to do once they start flying?

Dumbacher: “We need to make sure we’re comparing apples to apples there. A Falcon Heavy is comparable to a Delta IV Heavy, maybe it has a little more lifting capacity. It would take multiple launches of a Falcon Heavy to meet even the 70 metric ton version of SLS. Now, keep in mind that the 70 metric ton version of SLS – is just the initial version. We are working to eventually evolve that out to the 130 metric ton version for the Mars missions. In between those two steps will be a 105 metric ton version.”

SpaceFlight Insider: Okay, to that, if SpaceX’s proposed Falcon Heavy flies and flies successfully – could we potentially see the SLS contract opened up for bidding?

Dumbacher: “Right now we’re concentrating on building SLS and getting Orion ready for its flight test in a few months so we can learn more about its systems and high speed reentry—all so we can use the data we gather to build a rocket and spacecraft that will take humans to Mars and return them home. As you know, SLS has an incredible capability. We’re focusing our efforts on those activities rather than on what-ifs.”

Dumbacher discussed how the Space Launch System is being developed under a "Stepping Stone" approach. Under this path, NASA will have funds freed up for payloads and missions after the development of Orion and SLS are complete. Image Credit: Lockheed Martin

Dumbacher discussed how the Space Launch System is being developed under a “Stepping Stone” approach. By using this path, NASA will have funds freed up for payloads and missions after the development of Orion and SLS are complete. Image Credit: Lockheed Martin

SpaceFlight Insider: Going back to the various versions of SLS – there has not been a lot mentioned about why NASA is taking this incremental approach. Can you detail that for our readers?

Dumbacher: “Sure. The incremental approach to SLS is driven primarily, frankly, by the budget and the budget realities. Within the budget environment that we are operating in – you have to diligently plan out your development cycles. The 70 metric ton in the stage of development we’re currently in. That’s the core stage – because we’re using the boosters from shuttle and Constellation and the main engines from shuttle.

It’s like this, I can’t go and do all of the development at one time and so I get the 70 Metric Ton version first, I get the core stage developed and then, for the 105 Metric Ton version, I probably come in with the upper stage development that I need to do to allow me to get that class. And then for the 130 Metric Ton I have to have the upper stage and the advanced boosters. It’s all a matter of phasing out the development.

The other thing that I will caution people on is the Falcon Heavy is still in the conceptual phase – whereas the 70 Metric Ton version of the SLS and the core stage development, we have pathfinder hardware for the core stage coming off the line at Michoud. In a couple months we’ll be starting the Critical Design Review for the core stage itself. In a year we’ll be completing the design review for the SLS 70 Metric Ton version as an entire vehicle. So, the SLS effort is ahead of, in terms of hardware and design, where the Falcon Heavy is right now.”

SpaceFlight Insider: There are more than a few statements out there that NASA is spending so much on the SLS booster that the agency won’t have the funding left over for a payload, for the missions that SLS would fly. Can you talk about that? Is that a valid argument about SLS? Is it so expensive that NASA can’t afford the missions or the payloads that would fly on it?

Dumbacher: “First, we’re doing everything to keep the operations and production costs of SLS as low as possible. For example, we changed on SLS the material for the cryogenic tanks from what we used on the shuttle external tank, to a commercially available aluminum in order to minimize our production costs so that NASA wouldn’t have to cover all of the infrastructure costs to get that shuttle material like we did before.

We are on a regular basis looking for ways, as part of the design in order to get the vehicle operational expenses as inexpensive as we can get. Once we start the RS-25 (formerly known as the Space Shuttle Main Engine or SSME – which will be used on the first flights of SLS) effort to build engines beyond four flights as we have. The key driver on that restart is; ‘what improvements do we need to make to that engine solely to reduce its cost?’

Productions operation cost is a very large objective and minimizing the production and operations cost is a very large objective of the SLS program. So much so that it has been ingrained into all of the design trait studies and design and analysis that we have done thus far and we continue to do so. We continue to put cost challenges out to the contractors from a production and operations perspective.

What we are trying to do is get SLS into that $500 to $700 million per-flight range and some of us are working to actually get it even lower than that. We recognize the reality of the current economic situation and we obviously want to have the money to do the missions and the payloads. Now, the criticism is somewhat true today – simply because we have both the SLS and Orion development going on in parallel. Once those get done and become production operations? Then we start to open up the wedge in the future for habitats and whatever else we need to go to exploration missions. We’re still looking out ahead as to what we need and when we need it.

Another key point is that once we get out there? Right now we’re living in a budget environment that is basically flat-lined with no inflation included in the flat-line. We know that there are modest increases; particularly inflation needs to be planned in because by the time you get to where we are today to the early 2020s – we’ve lost a third of our buying power by that point – just because of inflation.

So we’re working to get inflation planned back into the budget and also to figure out what is needed and start to lay in the requests for those modest increases to get the next element that we need to build beyond SLS and Orion. All of that is in parallel to keep the production and development costs to a minimum.”

The driving force behind SLS' development policy is the current economic environment. Image Credit: NASA

According to Dumbacher, the driving force behind SLS’ development policy is the current economic environment. Image Credit: NASA

SpaceFlight Insider: Is it fair to suggest what has happened is some have taken the current development status, but not considered the stepping stone approach that NASA has been forced to take?

Dumbacher: “Yes, you got it. We’ve got to get through the development of SLS and Orion, get that behind us and then we open up a wedge and then we start working in parallel with the wedge to size it for what we need to do for the next elements for exploration as well as executing the missions. We are in the early throes of sorting all of that stuff out because that is in the 2021 and beyond time frame. But, basically? You got it. We have to get through the development of SLS and Orion first and then the funding wedge opens up once we get past their developments.”

SpaceFlight Insider:  We know you’ve stopped what you were doing to discuss this with us and we wanted to let you know we appreciate you speaking with us today, thanks again.

Dumbacher: “No worries, anytime!”

In summary? Both Dumbacher and Lightfoot rebuffed claims there would be a decade separating the launches of Falcon Heavy and the Space Launch System. At worse, three years will pass between the two (some estimates have placed the launch of Falcon Heavy in 2014, others in 2015). As to the claims NASA cannot afford payloads when SLS and the Orion Multi-Purpose Crew Vehicle are ready to ferry them – are based on what appear to be selectively-chosen facts.


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Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology,, The Mars Society and Universe Today.

Reader Comments

Arthur D. Little

Your article should have been titled “Addressing rumors comparing aspects of the Space Launch System (SLS) versus SpaceX’s Falcon Heavy (FH)”. For why are there no other “rumors” addressed, “facts checked” or companies mentioned?

Three issues from your article I will address:

Number 1: “The Falcon Heavy will fly at least 10 years before the Space Launch System.”

The article concludes this is not true because, as of March 2014, the SLS will fly in 2017, unless no issues with SLS arise to delay the launch, and the FH will fly in late 2014 or early 2015.

True today but not when the “rumor” first arose. Elon Musk announced the FH at a press conference in 2011 and said the FH would fly “probably” in 2012; however the launch date for the first FH has slipped to 2014 or 2015; and before the US Senate mandated NASA to greatly speed up the SLS project, everyone was predicting that if the SLS flew at all it would probably do so around 2025 or maybe a couple years earlier.

Number 2: “The payload capacity of the SLS is many times that of the FH and comparable to the Delta IV Heavy (D4H).”

The FH at 53mt to LEO is more than twice as capable as the D4H at 25mt to LEO. The 70mt to LEO SLS is just 1/3 more powerful than the FH. And, the FH is $100M while the SLS is $500M to 700M (hopefully says NASA), so unless you have a super heavy payload that absolutely cannot be modularly designed the benefit of the SLS is questionable. Any version of the SLS used just to put an Orion Capsule in LEO would be a waste

Number 3: “The SLS has “pathfinder hardware” coming off the line while the FH is just conceptual.”

This point seems to suggest that the SLS is a “real” rocket because NASA is “cutting metal” and the FH is only a design on paper at best; an interesting contortion of reality.

That neither the SLS nor the FH have yet flown is true.

However as the FH is made up of three Falcon 9 first stages it can justifiably be said the FH not only has “pathfinder hardware” but moreover that hardware has been flight proven 9 times; notably three of those payloads have been beyond LEO.

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