The Rapidly Receding Rationale for NASA’s Space Launch System

Credit: Blue Origin

Blue Origin Booster Chart, Note SLS is Omitted


As he neared the end of the Tuesday presentation in which he introduced the world to SpaceX’s Interplanetary Transport System, Elon Musk was asked the inevitable question regarding what his plans meant for NASA.

The answer was both polite and encouraging, as Musk rightly pointed out that there is no one sure path to Mars, and NASA, which has been SpaceX’s most valuable supporter, should by all means proceed with its own plans. Tying back to another question regarding why foreigners couldn’t work for SpaceX (ITAR) he went on to suggest that in making the presentation before an international audience, he hopes other nations were inspired to work together to follow suit as well.

For obvious reasons, Musk could have hardly answered any other way, and even taken at face value, there is a certain logic at play. SpaceX after all, is now years behind in launching the original SLS killer in Falcon Heavy, which now will not make its maiden flight until sometime next year. With even the SpaceX founder himself acknowledging that the massive booster and spaceship he was proposing as improbable, albeit not from a technical standpoint, based on past history, it is quite possible that a decade from now, the booster will still not have flown, whereas NASA’s Space Launch System will be working towards its fourth or fifth flight.

SpaceX Booster Chart (heavierside shown) Notice SLS is omitted here too

SpaceX Booster Chart
(heavier side shown)
Notice SLS is omitted here too

It is not the proposed SpaceX rocket NASA should be fearing however, even if it has already seen an engine test firing and successful construction of massive LOX tank. The more immediate threat to the future of SLS can be found in Blue Origin’s New Glenn rocket, which Jeff Bezos formally introduced earlier this month.

While not as massive as SpaceX’s mega booster, it appears to be roughly on par with SLS, and somewhat more capable than Falcon Heavy, although until performance numbers are released, there is a lot of gray area.

New Glenn Wind Tunnel Model Credit: Blue Origin

New Glenn Wind Tunnel Model
Credit: Blue Origin

What is not in doubt however, is that New Glenn features a fully reusable first stage powered by 7 21st century BE-4 methane oxygen engines in an arrangement similar to that of the Falcon 9, and will be built in a shiny new factory located just outside the gates of the Kennedy Space Center itself. In terms of comparisons to SLS, there will simply be no avoiding it. Moreover, as the second commercial heavy lift rocket to be built without public funding, it removes any possible argument that cancelling SLS would be ceding the future to a single firm.

In some ways, it offers an even stronger case than Falcon Heavy. While Elon Musk is a rich man, Jeff Bezos is far richer. There is literally no indication that New Glenn, which Blue Origin hopes to launch by 2020, is nearly as dependent on the pre-sale of launch contracts to the extent SpaceX is now. Furthermore, and this is critical, the BE-4 engine is almost certain to be slated to power ULA’s new Vulcan rocket, gaining in the process a near automatic entry into NASA and DOD launch markets.

Also, unlike SpaceX’s Raptor engine, which is pushing the absolute boundaries of operating pressures while still being mounted 42 at a time, New Glenn’s BE-4 will operate at a much more comfortable margin. In spite of its enormous size and re-usable first stage, New Glenn is by comparison a much more conservative design.

In other words, New Glenn will fly, and it is highly likely to do so before SLS has made more than two launches, and possibly only one. What then for SLS?

Nothing but the tail lights Wind tunnel model of New Glenn in descent configuration Credit: Blue Origin

Nothing but the tail lights
Wind tunnel model of New Glenn in descent configuration
Credit: Blue Origin

Boxed in by the partially reusable Falcon Heavy at 75% of the capability and only a fraction of the cost, and the partially reusable New Glenn offering the same or greater capability at equivalent savings, NASA’s fully expendable rocket, powered ironically enough by 20 year old re-usable engines now being thrown away, may become the exact opposite of the Saturn V it is supposed to evoke. Not an example of what the American government can do, but what it cannot. Note that these are near-term comparisons which do not even take into account future developments as envisioned by SpaceX in ITS, or Blue Origin in its apparent counterpart, New Armstrong, for which we only have a name.

It is worth recalling that SLS has been presented as an evolutionary system, one which after years of gradual development and tens of billions more dollars flowing to the “Four Amigos” consisting of Boeing, Lockheed Martin, Orbital ATK, and Aerojet Rocketdyne, would eventually result in a 130 ton to LEO fully expendable booster.

The booster Elon Musk introduced on Tuesday would come in at some 300 tons in its reusable configuration, and 500 tons in a fully expendable version. It is probably a safe assumption that Blue Origin’s New Armstrong is along the same lines.  To put it plainly, the evolutionary tree for SLS is already being chopped down.

This would all be somewhat comical if not for the opportunity costs involved. The fact is that the government, or NASA at least, can still do some things pretty damn well. Its just that designing and building cost effective large rockets isn’t one of them. One can look out across the solar system, from the Dawn spacecraft at Ceres, New Horizons on its way to the Kuiper Belt, or my personal favorite, the Cassini spacecraft at Saturn, to see examples of smashingly successful space missions. On the human spaceflight side of the equation, COTS, CRS and and Commercial Crew stand as examples as well.

Even in the case of Commercial Resupply, where both suppliers, SpaceX and Orbital ATK, are recovering from major malfunctions, the case against NASA designed rockets is bolstered.  What rode to the rescue when the ISS supply line was threatened by those failures was not a wildly overpriced NASA designed rocket as the Ares-1 would have been, but a modestly more expensive, ultra reliable commercial booster in the form of the Atlas V. When applied to Mars ambitions, it serves as an example to underscore Musk’s answer which boiled down to “the more the merrier,” but it does not mean continuing to do that which makes no sense in the first place.

As for the opportunity costs, one example should suffice, although there are many.

Earlier this week, NASA announced a major finding regarding water jets on Jupiter’s moon Europa. It naturally sparked interest, already high, in mounting a dedicated mission to that body, nominally slated to launch in 2022, but not yet fully funded. Yet Congress, so wedded to the status quo that led to SLS, wants to insist in legislation that any mission to Europa must launch on its pet booster. For the cost difference, how much more robust a spacecraft could lift off on Falcon Heavy, New Glenn, Atlas V, Delta IV or Ariane V for that matter?

Why not let NASA’s highly capable and well respected Launch Services group make the decision?

It is a question which can be repeated again and again, in different contexts, throughout the agency. Yes, funding for SLS, Orion and Ground Systems comes from a different account than the one which pays for Planetary Science, but it all comes from NASA’s overall budget, which is more or less on autopilot in overall terms.

There are many, many things that NASA can, and should be doing, that private industry cannot. Resurrecting the nation’s almost expended stock of PU-238 for nuclear power, upgrading and bolstering the Deep Space Network, and maybe, finally, testing tethered artificial gravity generation all come quickly to mind. Falcon Heavy and New Glenn, which taken together offer the previously inconceivable advantages of true affordability, partial reusability and dissimilar redundancy in the super heavy lift department, strongly suggest that it is time to put SLS aside, and begin working on that list.


Posted in: Blue Origin, NASA, SpaceX

About the Author:

7 Comments on "The Rapidly Receding Rationale for NASA’s Space Launch System"

Trackback | Comments RSS Feed

  1. 1. NASA is not building the SLS. Three private companies: Boeing Aerospace, Orbital ATK, and Aerojet Rocketdyne are building the SLS.

    2. NASA operated a partially reusable spacecraft (the Space Shuttle)for more than 30 years. So there’s nothing new about a reusable spacecraft

    3. Both Democrats and Republicans in Congress commissioned the building of the SLS to aid in human cis-lunar missions and eventual human missions to Mars. In fact, Congress required the Executive branch to inform them as to how the SLS will be used for cis-lunar missions in the near future.

    But since the current administration was hostile to any human cis-lunar activity by NASA, especially a lunar return, they tried to delay the development of the SLS, then they made it impossible for the SLS to conduct a two launch human lunar mission by leasing out Pad 39A exclusively to Space X. Finally, the administration proposed the extremely unpopular ARM mission as a way of satisfying Congress’s cis-lunar requirements.

    Then the administration tried to make the SLS economically unsustainable by planing launches only once every few years with no serious plans for a Deep Space Hab (DHS). And once again Congress had to force NASA to propose a time schedule for the development of a DSH.

    So I find it rather ironic that those who argued that the SLS was– way too big– for any practical use are now fully embracing super heavy lift vehicles being developed by Space X and Blue Origin:-)

    • Nestos says:

      I’ve heard a lot of critics about SLS, but never that it was “way too big for any practical use”…

  2. Zed_Weasel says:

    The SLS is just too expansive to be affordable.

    AIUI each SLS Block-1B flight will cost about $2B each. Mostly due to the mandated use of legacy technology by the Senatorial design committee to retain aerospace jobs in certain Congressional districts.

    And NASA is building the SLS since they oversee all designs and manufacturing steps. In effect the prime contractor.

    The SLS needs payloads. But the Congress still have not started funding any payloads with the possible exception of the Europa orbiter.

    • The cost of the SLS will depend on how frequently its launched. Since the SLS is a system that is largely derived from the Space Shuttle program, we would expect the fixed and variable cost to be somewhat similar.

      The annual fixed cost for the Space Shuttle in 2009 was about $1.5 billion (~1.7 billion in today’s dollars). An additional cost of about $1.5 billion a year could be added to that for about four launches (the variable cost). So for about 4 launches per year, the Shuttle cost about $750 million per flight ($375 million per unit launch minus the fixed cost).

      Annual development cost for the SLS program plus ground systems is running about $2.4 billion a year. Including the Orion for crew missions adds an additional $1.3 billion. So SLS/Orion development is currently running about $3.7 billion a year within an annual human spaceflight related budget that fluctuates at around $8 to $9 billion a year.

      I doubt that annual fixed cost will be more than $2 to $3 billion a year and unit launch cost will be more than $500 to $1 billion. So for a minimum two launch per year scenario, cost could be $1.5 billion per launch for a $3 billion a year budget or up to $2.5 billion per launch for a $5 billion a year budget. Both would still be well within NASA’s annual humans spaceflight related budget.

  3. Dave Huntsman says:

    Stewart, a well-written article. You could have gone on and on, of course. While you only gave one example of the lost ‘opportunity cost’ in following SLS to the exclusion of everything else, the real lost opportunity cost has been to NASA space tech R&D account. Gone are the days of a strong space applications program; and gone is any NASA support to advancing reusable technologies. (In fact, NASA’s technology roadmaps specifically exclude RLV R&D; something I tried, in my own tiny way, to change, but failed).

    What should be pointed out that the truly holy grail of economical RLV systems that would benefit all space activities, could be closer now than ever before, if we just seized the opportunity. For example, the COTS program helped birth the creation of new new American launch vehicles and American spacecraft, quicker and at only a fraction of the cost of the traditional NASA way of doing things (this, according to NASA’s own study of the situation). We now are at the point where, using the COTS model, there are several companies who would likely be willing to partner with NASA to advance RLV development and bring it forward by years, to the benefit of all. That we’re not trying to do that is a crime.

Post a Comment