The Not-So-Great Compromise: Space Launch System and Multi-Purpose Crew Vehicle

In the previous posts in this series (see the tag below for the whole bunch), I speculated on what might be accomplished with a compromise between the Senate and the Administration in the Exploration areas of NASA's FY2011-FY2015 budget. My hypothetical scenario took the Senate Authorization bill as a baseline, since that bill gives some idea what would happen over several years. In particular, that bill a good idea what the Senate has in mind after the Shuttle is retired. In the other posts, I showed areas that could be made much better by shifting funds from the Senate's Heavy Lift rocket and Orion budget lines (or the Space Launch System and Multi-Purpose Crew Vehicle, as they are called in the bill). In this post, I'll look at what might happen to the HLV and astronaut spacecraft.

First, let's look at the funding that's available for the HLV and spacecraft in the Senate bill. Figures are in millions of dollars.

FY....MPCV........SLS.........Launch/Infrastructure
2011..1120........1631........428.6
2012..1400........2650........500
2013..1400........2640........400

The Launch Support and Infrastructure Modernization program is

a program the primary purpose of which is to prepare infrastructure at the Kennedy Space Center that is needed to enable processing and launch of the Space Launch System.

We are therefore justified in lumping this funding with the other SLS/MPCV budget lines.

If we project the trend here through FY2015, we have an SLS/MPCV program that would cost $21B or so over that period. That's after $10B or so invested in Constellation.

Ouch.

Now we know how the Commercial Crew, Exploration Technology Development and Demonstration, Robotic Precursor, Space Technology, and commercially-oriented KSC upgrade budgets all but vanished.

Our hypothetical example compromise reduced the SLS/MPCV budget by $1B/year, or $5B total. That still leaves about $16B dedicated to the SLS and MPCV over this period. It would still be a huge NASA effort. The question is, would cutting their budgets by this amount do the same thing to SLS/MPCV that SLS/MPCV did to Commercial Crew, Exploration Technology, Robotic Precursor, Space Technology, and the rest in the Senate budgets? I don't think so. I think we could still have a viable HLV and spacecraft program with $16B over this time period, perhaps building on some of the work already done for Constellation.

First let's take a look at some of the provisions in the bill:

Requirements in new launch and crew systems authorized in this Act should be scaled to the minimum necessary to meet the core national mission capability needed to conduct cis-lunar missions. These initial missions, along with the development of new technologies and in-space capabilities can form the foundation for missions to other destinations. These initial missions also should provide operational experience prior to the further human expansion into space. ...
It is the policy of the United States that NASA develop a Space Launch System as a follow-on to the Space Shuttle that can access cis-lunar space and the regions of space beyond low-Earth orbit in order to enable the United States to participate in global efforts to access and develop this increasingly strategic region.

In addition, the MPCV should have the

capability to conduct regular in-space operations, such as rendezvous, docking, and extra-vehicular activities, in conjunction with payloads delivered by the Space Launch System developed pursuant to section 302, or other vehicles, in preparation for missions beyond low-Earth orbit or servicing of assets described in section 804, or other assets in cis-lunar space.

This is exactly the sort of capability that I argue for in what I call "step 2", the centerpiece, of the Flexible Path to the Moon. The ability to usefully access destinations like GEO, lunar orbit, and Earth-Moon Lagrange points is crucial. Having a vehicle that allows EVAs, rendezvous and docking, servicing of space assets, and other jobs in cislunar space is a key enabler of future exploration, commerce, science, and security applications. I'm pleased the Senate focuses so much on this sort of capability, rather than Constellation which focused mainly on Ares I/Orion ISS access, causing the next step, straight to the lunar surface in decades-long slow motion, to be a leap too far. Lunar access needs to happen in a more incremental fashion, building on self-sustaining cislunar space capabilities.

I am concerned with the development cost of the SLS and MPCV and its effect on other priorities, and I am also concerned with the eventual operations costs of these systems. However, at least they are focused on appropriate goals, even if those goals might better be achieved with commercially-derived launchers such as the ideas based on EELVs. However, in the spirit of compromise, let's see if we can make this Shuttle and Orion-derived cislunar space capability work with $16B through FY2015.

The Senate bill requires

The initial capability of the core elements, without an upper stage, of lifting payloads weighing between 70 tons and 100 tons into low-Earth orbit in preparation for transit for missions beyond low-Earth orbit. ... The capability to carry an integrated upper Earth departure stage bringing the total lift capability of the Space Launch System to 130 tons or more. ... Developmental work and testing of the core elements and the upper stage should proceed in parallel subject to appropriations. Priority should be placed on the core elements with the goal for operational capability for the core elements not later than December 31, 2016.

This brings up a number of areas where the Senate could relax requirements, and thereby increase the ultimate chance of success for the SLS while allowing other programs like Robotic Precursors and Exploration Technology to function. First, the Senate could relax the December 2016 date. I don't think there's anything urgent planned that day, so why not push it back a year or 2? The same goes for the MPCV, which has similar schedule requirements.

Another item that could be postponed is the upper stage. Do we really need to work on the upper stage in parallel with the core elements? Relaxing that requirement will allow the program to concentrate on the core elements, and thus increase the chance of success in that area, while at the same time allowing other programs (potential SLS payloads in some cases?) to survive, thus removing several sources of political opposition to the SLS. The core elements should keep us busy for quite a while. The upper stage could be considered much later.

The SLS also has a requirement to launch the MPCV. The Senate could change that requirement so the SLS doesn't have to go through the expense of crew rating. The MPCV could be morphed into an in-space only vehicle, with crew space access enabled by commercial crew services.

The MPCV could be scaled back to a CRV as the Administration suggested this Spring. This could be a temporary move to allow funding for other areas, and the MPCV could later reach full functionality (as an Orion-like vehicle or an in-space only - perhaps even reusable - vehicle).

The 70 and 130 ton requirements also present a potential difficulty. They seem to lead NASA to an inline SDHLV, since the sidemount options can't reach 130 ton capability with reasonable upgrade paths. However, NASA's sidemount and inline development cost estimates (PDF; see slide page 7) are $11B and $15B, respectively, if Shuttle is cancelled. The same charts show sidemount being delivered 2 years earlier than inline, and being a low-risk development compared to what they assess to be the high risk of inline options. In addition, the sidemount has an early Block I variant that could be performing missions even earlier, and that variant could be developed for much less than the combined Block I and Block II, perhaps allowing much of the Block II development work to be done after our years of concern FY2011-FY2015. A chart from the NASASpaceflight.com article Completed SD HLV assessment highlights low-cost post-shuttle solution shows the Block I development costs as $2.5B, although there would be other costs such as KSC infrastructure work.

In the universe of Shuttle-derived HLVs, inline options have their own advantages over sidemount variants (perhaps including growth options as well as safety if crew launch is to be supported), but if we put a premium on lower development costs because we want a compromise between the Senate and Administration plans, and thus want to have more funding for Exploration Technology Demonstration and Development, Robotic Precursors, Commercial Crew, or other Administration proposals, sidemount may be preferable overall, and good enough to meet the goals of the Senate.

In short, there are many ways the Senate can relax SLS and/or MPCV requirements, including schedule, performance, and functional capabilities. Depending on which of these options are taken, doing so could leave enough funding to bring other NASA budget lines from the Senate's non-viable condition to adequate, if limited, health. Even with such a compromise, the SLS and MPCV would still have every chance to succeed and contribute to NASA's work, and in fact they may be even healthier because they might gain payloads and spacecraft technology, as well as political support, from the other budget lines.

On the other hand, a stubborn line-in-the-sand approach would likely leave the SLS and MPCV with no technology and robotic precursor payloads, no exploration technology infusion into the MPCV, numerous political enemies, impossible schedules, difficult performance requirements, and expected functionality that will have to be dropped during development.