One of the things that really strikes you about all the conversations between NASA and Congress about NASA’s attempt to help you know, follow its charter and “seek and encourage, to the maximum extent possible, the fullest commercial use of space” by funding commercial development of crew transport vehicles is the emphasis on safety. Shuttle ended up killing two crews out of 135 flights, which is actually about what you’d expect to get from flying crews on EELV-class vehicles without a launch escape system of any sort, yet in almost every Congressional hearing, you hear a ton of hand-wringing about whether these vehicles will be safe enough for NASA’s astronauts. And you can tell that NASA has taken these inputs very seriously, with all the requirements (and referenced requirements, and requirements referenced in referenced requirements, and requirements referenced in requirements referenced in referenced requirements), paperwork, overhead, and with their attempt to force things into a FAR-based mold closer to how NASA does major programs. It’s pretty clear that NASA and Congress both see safety as the top priority for commercial crew. I know this may be heretical, but I’m wondering if this is a misplaced priority.

Maybe I’m wrong, but here’s my concern:

1. NASA really wants at least two independent, self-sustaining, affordable ways of getting people to and from the ISS. Having this capability means that if anything happens to one system, you don’t get the standdowns like what you had with the Shuttle program.
2. Having at least two affordable and healthy competitors also means more price competition, and more incentive to innovation.
3. There’s no chance that Orion on SLS is going to be anything within spitting distance of “affordable” for routine crew rotations.
4. As NASA has been openly admitting for almost as long as this blog has been around, they know that they can’t afford to go beyond LEO if they can’t offload all of the ISS crew and cargo needs to commercial providers using firm, fixed-price contracts.
5. But NASA only wants to buy about 8 seats per year (two rotations of four crew each) from commercial providers, in order to meet their ISS obligations.
6. You’re only likely to get two affordable and healthy commercial crew providers if they have enough demand to spread their fixed costs out over (and if they can keep those fixed-costs within reason).
7. I can only see a few ways of doing that (though there may be others):
1. Have the commercial crew vehicles be affordable enough that they can enable significant non-NASA crew, cargo, and recoverable freeflyer (like DragonLab) services.
2. Having the commercial crew vehicle be similar enough to a commercial cargo vehicle that each provider can actually get a decent number of flights per year out of a mix of crew and cargo.
8. Only the first of those two options avoids the challenge of a NASA/commercial crew monopsony scenario, where the ISS is the only thing keeping the commercial crew providers afloat.
9. While there is a small, but non-zero, chance that you could get sufficient demand from what Bigelow calls “sovereign clients” to get non-NASA crew/cargo demand even at the old $20M/seat Soyuz price, the best analysis I have seen with the existing data (pgs 43-53 of this presentation) suggests that the price point commercial crew needs to get in order to reach a tipping point is $5M/seat max, and possibly as low as $1-2.5M/seat.
10. While it may be barely possible for NASA to eke out a minor victory by getting two independent  and semi-healthy commercial ISS crew providers who also do ISS cargo deliveries on unmanned versions of their rockets/delivery vehicles, even this minor victory is only possible if the fixed cost of the crew capability isn’t too excessive.
11. With only two flights per year worth of crew demand, there might not even be enough demand for one commercial provider unless they can find synergies with ISS cargo deliveries, or more preferably non-NASA customers.

I guess my big concern is that it doesn’t appear as though NASA or Congress are being realistic about how to properly prioritize safety. Ultimately you can always spend extra money on safety (one more test, one more certification, one more sign-off, one more review, etc)–the only way to have 0% chance of losing a crew on an ISS mission is to not do the mission. If you are actually going to fly, there’s a point where you have to accept some risk, and you have to say at some point that you’re only willing to spend a certain amount of money to potentially buy down tiny fractions of a decimal point safety-wise. If you have to make that decision anyway, then it makes sense to do it in the framework of the big picture of the mission risks and overarching goals.

This is something for instance that the Constellation program utterly failed to do–the core justification for Ares-I was that it’s launch ascent safety was supposedly going to be so darned good (a 1 in 2106.4823910293 chance of losing a crew on ascent, at a 50% confidence interval…), but in the light of a program that expected a 2% or greater chance of losing a crew on a given lunar mission, it’s pretty clear that spending money to go from a 1 in 1000 probability on existing LVs versus spending a decade and $10-20B on a new launcher to buy that risk down a bit was money very foolishly spent. The problem is I worry we’re going down the same path with commercial crew.

While I don’t personally have any really sage advice on how best to ensure safe operations while still keeping the overhead low enough to keep commercial crew provider costs low enough to give a realistic shot at enabling a new market to emerge, I am worried that the current balance is a well-intentioned disaster waiting to happen (see also Wayne Hale’s previous warning on this topic).  If NASA and Congress continue down the path they’re going with safety, there’s a very real chance that they’re going to make commercial crew commercially unviable. And that would be the ultimate Pyrrhic Victory–having one or two “commercial” crew providers that in the end that are flying, but are so expensive that only NASA can afford them.

Let’s turn to the Augustine Report itself for some information. On pages 83 and 84 they discuss implementing the Program of Record on entirely unconstrained budgets–ie if we gave the program the full funding it needs to execute, and allot it to move at the full pace it can realistically move at, what do we get?

• A $145B pricetag over the 2010-2020 timeframe, which doesn’t even get us to the point of having Ares V and the LSAM ready for operations, much less a moonbase.  This would require almost $5B extra per year–ie a 25% increase in NASA’s topline budget.
• An international space station deorbited within 5 years of its completion, during which time the only method of access would be by paying the Russian government for flights.
• A crew launch vehicle that becomes available two years after its first destination is deorbited, and whose operational costs have to be carried for over half a decade until we have any of the tools that would be necessary to actually use it for anything.  But don’t worry, we can spend $2B+ per year to send even fewer astronauts flying in even more useless circles.
• A seven plus year manned orbital spaceflight gap in the US.
• Almost no investment in long-term technology development (not much more than the current SBIR budget, and entirely focused on short-term Constellation needs, not on making future missions safer, more affordable, and more valuable).
• No stimulation of commercial industry beyond the CRS contracts which wouldn’t be extended since the ISS would be gone by 2016.  No investment or early market for commercial crew delivery
• No money to actually develop hardware for actually doing anything on the Moon, since almost all of the money will go to figuring out how to go there while maximizing employment in Shelbyville.
• No more robotic orbiters or landers for years to follow-up on the work LCROSS did.

But hey, at least if we do it this way, sometime 15+ years from now, we’ll have the ability to send 8 people to the moon every year at the cost of an “exploration” program that costs almost as much per year as NASA’s entire current budget!

If you assume that there are parts of NASA outside of Huntsville that actually matter (ie that NASA != Northern Alabama Space Administration), the situation gets even worse.  In order to fund Constellation at full speed without splashing the space station almost as soon as it’s completed, you would need $159B over that timeframe, which constitutes a $7B per year increase for NASA.  That increase still:

• Gets you a space station you can’t access without the Russians for most of its operational lifetime (why does Congress trust Russian commercial space more than American commercial space, btw?).
• Gets you no real investment in long-term technologies, ensuring that the cost, safety, and efficiency of manned spaceflight will be stagnant for another couple decades.
• Gets you no real investment or encouragement of the commercial industry (in direct contravention of the laws of the land and NASA’s charter I might mention).
• Gets you no more robotic follow-ons for LRO and LCROSS for over 15 years.

Compare this with the Flexible Path option that Mark likes to mock so much.  For less than half as much of an increase per year, you get:

• Robust ISS utilization through 2020, with multiple methods of providing crew and cargo delivery that aren’t all dependent on Russia
• Investments in commercial space that can help keep the US in the forefront of space technology and utilization
• Robust investments in high-payoff medium-term technologies like propellant depots, space radiation, space nuclear power, aerocapture and other EDL techniques, ISRU, and other high-payoff technologies that can vastly lower the cost of future exploration missions, allowing us to accomplish more for less and at lower risk.
• A manned lunar landing program that at most is only 3-4 years behind the current PoR, but when it gets there, it provides a much more affordable, more commercially and internationally interesting program, and has much greater capabilities once you get there.
• A manned spaceflight program that is much more capable of exploring the whole inner solar system, and not just doing a few flags and footprints landing on the Moon.
• A manned spaceflight program that builds on and leverages our impressive achievements in robotic space exploration.
• A program that in spite of doing a lot more looking, also allows a lot more touching of new destinations like NEOs and Phobos/Deimos, all on about the same timeframe that the PoR would at best be going for its first lunar landings.

Where I come from, we tend to think that getting a heck of a lot less while paying a heck of a lot more is usually the sign of a sucker.  I just wish that a few space pundits and public figures didn’t keep enabling Senator Shelby and his ilk from hijacking NASA’s budget to enrich his campaign contributors at the rest of our expense.

[Note: As an aside, am I the only one who finds Shelby's latest childish tantrum accusing the Augustine Committee of being compromised by biased by evil commercial lobbyists to be richly and hilariously ironic?  When it comes to lecturing people about the evils of lobbyists corrupting the political process for their own personal gain, Senator Shelby has about as much moral standing as Tiger Woods does when it comes to lecturing people about marital fidelity.]

To me one of the more interesting points is found at the top of page 11.  There were several misleading statements made by several people today about the relative safety of Ares-I compared to commercial crew vehicles.  As Brett put it (my emphasis added):

Second, some have claimed that NASA’s Exploration Systems Architecture Study (ESAS) shows that the current exploration vehicles are safer than commercial crew vehicles. In actuality, commercial crew vehicles were never even analyzed in the ESAS report – the ESAS report only looked at vehicles large enough to carry Orion, such as Ares I and variants of the triple-core Delta IV Heavy, and did not examine the smaller, simple, single-core vehicles, such as Atlas V Medium and Falcon 9 Medium that are sufficiently sized for commercial crew missions.  Moreover, even if ESAS had compared exploration vehicles to commercial crew-sized vehicles, the comparisons would be “apples vs. oranges,” because of the dramatically different tasks of these two types of vehicles.

When Jeff Hanley talks about how the Great Oz and supercomputers at NASA show that Ares-I is 3x safer than commercial launch vehicles, I wonder if he’s ever going to release their analyses for actually commercial crew vehicles, or if he’s being accidentally or intentionally dishonest. Because so far we haven’t been shown any data about the safety of actual commercial crew launchers. So far we have lots of data shown for the risks of using existing or modified commercial launch vehicles for launching a massive spacecraft designed to go to and return from the moon, including significant plane change maneuvers to allow anytime returns (ie Orion). It’s interesting to note that over half of the mass on Orion is the oversized launch escape system needed to get away from an SRB you can’t shutoff, and enough propellant for about 1500m/s of maneuvering to reach orbit and then to do in-space ops. That’s above and beyond the RCS propellant on the CM itself.

Most of the stuff that make Orion so massive are flat-out completely unnecessary for an earth-to-LEO crew capsule. You don’t need those kinds of delta-V capabilities. You don’t need as roomy of facilities, since by definition the flight times should be a lot shorter. Etc. There’s a reason why almost all of the proposed commercial crew systems are able to utilize single-stick launchers like Atlas V or Falcon 9–for an actual earth-to-LEO capsule you really don’t need anything bigger.

This realization that earth to LEO capsules can be much smaller than Orion leads to at least two important corollaries that I can think of:

1. Smaller capsules mean higher structural margins.  One of the existing vehicles most often suggested for commercial crew, Atlas V, was designed for the worst-case loading environment of any of its configurations (in this case I believe that would be the Atlas V 551 or 552).  The Atlas V 552 sees much higher max-Q’s than the 401/402 do, and has a much heavier payload on top, which exerts much larger structural loads on the Centaur stage than are seen in the 401/402 configuration.  While the Centaur structures may not meet the 1.4 magic number NASA likes in some of the bigger configurations, as I understand it, it actually exceeds that number in the 401/402 config most likely used for commercial applications.  The Falcon 9 was designed from the start to meet NASA structural margin specs.
2. No need for strapons.  Only one of the commercial crew ideas I’ve seen so far used a vehicle with strapons for crew launch (Dreamchaser).  This alone should make a huge difference in launcher reliability, since there are less things that can go wrong, less staging events, etc.  Most of the commercial launcher ideas they mentioned in ESAS assumed multi-core configurations.

There’s also the possiblity on the Atlas-V of using a dual-engine Centaur configuration to allow for some upper stage engine-out capability, or running the RL-10 at a derated performance level (not sure if that’s something it can do automatically, or if you’d have to make modifications–if you have to modify it it probably isn’t worth it).  With the much lower max-Q, and the ability to shut off the booster engine in case of an abort, I have a hard time believing that Ares-I is really that much more reliable than an actual commercial crew capsule launched on a commercial launch vehicle that has dozens of flights under its belt.

Food for thought.

Anyhow, Jeff managed in 25 minutes to address human rating, depots, whether or not we need heavy lift, technology maturation and R&T investment, and the need for NASA to find new ways to interact with business. I don’t think he could have hit more of my hot-button issues in 25 minutes if he had tried.

Anyhow, I hear that the HSF committee will have video of today’s proceedings up online soon (possibly tonight) for those who didn’t get up at 5:30am PDT to watch. I’ll comment more later.

Whew! I haven’t had this much hope for this nation’s space program in years!

[Update:  Here's the link to the subgroup's presentation (warning, it's a 14MB powerpoint presentation).  All of it is interesting, but Jeff's part starts on page 76 and goes through page 89.  Chris Chyba's section was the last three pages.]

Once people are back on the Moon, then there will be a good, core market for private enterprise, Lunar explorers will need all kinds of support that a lunar COTS program could readily provide.

Now, to be clear, I’m not saying that I don’t think NASA should use commercial vendors for lunar resupply. Or that having the government help invest some money into developing commercial systems to do so doesn’t have merit. My beef is with this idea that we should first allow NASA to build its lunar base the way it wants to, and only then start working with commercial industry for resupply.

I think this flawed line of thinking is based on the fallacy that COTS is only now possible because the ISS is almost finished, and without ISS being completed there wouldn’t be a market for COTS cargo and crew deliveries. To me, this line of argument misses one key point–COTS would’ve been useful almost from the beginning of ISS construction. Depending on how you count things, of the so far ~29 ISS Shuttle flights, it looks to me like 10 of them have been primarily for the purpose of delivering supplies. Had something like COTS been done in the late 90s (instead of take your pick of X-33, X-34, X-37, or X-38), it would have been a huge boon to ISS construction. If those shuttle logistics flights could have been instead dedicated to flying actual station hardware, ISS would probably be complete by now.

Not to mention that as was discussed a few months ago regarding the “COTS D-” concept, a vehicle capable of returning living cargo from the station is only a few steps away from an emergency crew return vehicle. Depending on the approach, from there it may only be a launch escape system and some emergency detection hardware standing in the way of launching crews commercially as well. If there had been one or two companies offering commercial cargo up- and down-mass when Columbia crashed, upgrading those systems for crew launch would’ve been a backup option at that point. Even without the ability to launch crews, just having a US source for emergency crew return might have allowed the move to six permanent crew-members to have taken place a lot sooner.

You could go even further than this, but the basic point was that the right time to do COTS would’ve been earlier, when you could have saved a lot of money compared to using the Shuttle for everything. The same applies for Lunar COTS. The right time to start involving commercial providers is today, not 15-20 years from now. Of all the flights necessary to put together a lunar base, a decent chunk of those flights will likely be delivering supplies, just like ISS. How much quicker could a lunar base be put together if there were commercial cargo resupply capabilities right from the start? Base resupply during construction is just as real of a market as supplying cargo after the base is in place.

Sure, right now commercial industry is no more capable of delivering cargo all the way to the moon than NASA or anyone else is. But commercial industry has been capable of, for over a decade now, delivering cargo and propellants to low earth orbit, and may soon be capable of flying people as well. If NASA actually cared about efficiency, promoting commercial industry, and delivering the most benefit per dollar, they’d be using an architecture that actually leveraged commercial industry from the start, instead of it being punted into the distant future.

The fact is, Constellation doesn’t field any infrastructure or develop any technologies that would make the lunar surface any more commercially accessible in 2025 than it is today. A lunar COTS program would be starting from that point not much further along than where it is today. A lunar COTS program undertaken after a lunar base was put in place using the CxP approach would require funding the development of pretty much the full commercial transportation system. But if that’s ok to spend all that money then, why isn’t it ok to fund that in the beginning, when you can maximize the benefit of having such a capability? If commercial industry isn’t going to be capable of delivering cargo to the Moon without NASA providing support in the form of a COTS-like project, then that lack of capability today is no argument against starting on a lunar COTS program immediately.

Lastly, once NASA has so many billions of dollars per year tied up in two standing armies for Ares-I and V, and marginal costs for the two launch systems, where are they going to get money for lunar COTS? Once KSC and JSC, and MSFC are getting that much money for flying the lunar base construction flights, do you really think that the Senators associated with those centers are going to be fine with having that money go to commercial providers at the cost of workforce within their districts? It’s not like Ares I and V are going to be retired as soon as the lunar base is fielded. No, NASA is going to be working on their next big mission. Do you really think in that kind of a funding environment that NASA is going to have a bunch of money sitting around available for funding a lunar COTS effort? No. The same Senators today who are trying to suck all the air out of the room to pack their centers with engineers for Ares-I and V at the expense of COTS will be at it in 2025 as well.

I could go on, but while a lunar COTS program is a good idea, the time for it is now, not after Constellation has locked us in to another couple decades of space transportation stagnation.

1. Overemphasis on Unmanned Cargo: I’ve previously discussed on this blog what I think is one of the key deficiencies of the current COTS approach–the focus on cargo delivery to ISS while ignoring the crew delivery issue.  The problem with a focus on just cargo delivery to ISS is that a cargo delivery capability doesn’t really open up many other markets.  Sure, there may be a few flights here and there for DragonLab, but the reality is that without a passenger delivery capability, there just isn’t much need for such capabilities, outside of NASA’s ISS needs.  Bigelow, for instance isn’t going to be providing much demand for cargo flights if he can’t get people to his station.  The ability to safely fly people to orbit, and to be able to deliver them to/retreive them from space stations is a lot more useful.  Not only would NASA be a potential customer, but also Bigelow, and even free-flights.  And once you start getting more demand for people flying to space, demand for cargo will increase as well.  Basically, by only funding the unmanned part of COTS, NASA is forcing those COTS competitors into markets for which there is little other non-NASA demand.Of course, NASA has lots of reasons for wanting to do things this way. NASA as an institution wants to build and fly its own rockets, and being able to continually point at a US manned spaceflight “gap”, and being able to point at other nation’s anemic manned spaceflight programs as threats, makes it that much easier to continue getting funding for their anachronistic manned spaceflight projects. Think about it. If there were one or two US commercial options for getting people to the space station, do you really think there would be as much urgency for continuing to throw good money after bad on Ares-I? Most congresspeople don’t have much of a vested interest in keeping the Shuttle Workforce humming along sucking up taxpayer dollars. But the idea of there being a “gap” in US manned spaceflight, and US access to the ISS resonates more. Especially when there is no non-NASA alternative. Take that unifying threat away, and all of the sudden convincing Congresspeople in states other than Alabama, Texas, and Florida that it’s a national priority to keep throwing billions of dollars a year keeping people in their district employed, doing something that the market is already providing, is going to be come a lot trickier.
2. The “Skin-In-The-Game” Provision: One of the defining features of NASA’s implementation of COTS under Mike Griffin’s tenure was the requirement that COTS companies match NASA funding, to “put some skin in the game”.  Jorge Frank (whose opinions I normally agree with) really liked this provision, calling it one of the best things about COTS, and stated that “It limits the field to serious providers that are confident that they have a business case for their spacecraft beyond selling rides to NASA.”  The problem is, that speaking from the record, this hasn’t been the case at all.  Look at Orbital Sciences.  They have pretty much stated that they don’t think that there’s any market for Cygnus other than ISS resupply.  SpaceX is trying to do Dragon-Labs, but even then it isn’t a big demand driver.  In both cases, they’re not expecting to make money selling their cargo delivery services to anyone else, but are expecting to make most of their money off of the new launch vehicle that will be developed in order to lift the capsule. Orbital wants to go after the Delta II market, and SpaceX wants to edge-in on the EELV market. But let me come back to that point in a second.Basically, when you combine these first two points, you can see all sorts of perverse incentives created. In order to raise a large amount of cash, you need to have a large and solid market to justify it to investors. But as I mentioned before, there’s not a big non-NASA market for cargo deliveries to LEO stations, and even the NASA market isn’t really that big, all things told. And more importantly, at the time the COTS contracts were handed out, it wasn’t obvious if a COTS competitor would actually get any of that follow-on demand, even if they delivered. Without having a realistic non-NASA source of demand for the capsule part of the equation, the skin-in-the-game requirements pretty much killed the case for anyone trying to propose doing a capsule on an existing launch vehicle. Without developing a passenger delivery capability, the only market that could justify the kind of skin NASA wanted in the game was possibly a launch vehicle market. Which is a good part of why all three of the COTS winners (SpaceX, RpK, and then OSC when RpK couldn’t raise money) were basing their actual market case on developing new launch vehicles.So, not only did the skin-in-the-game requirement make it really hard for entities that didn’t have billionaire backing (or large existing lines of business) to compete, but it also drove the technical and execution risk for the program up by biasing selection towards companies that had to develop both a launch vehicle and a prox-ops spacecraft. Low-technical risk approaches that used existing launch vehicles wouldn’t actually develop hardware that would provide enough non-NASA business to justify enough outside investment to meet NASA’s skin-in-the-game requirements.  Quite frankly, if COTS fails to deliver, there’s a high probability that it will be due to the fact that both COTS competitors need to develop both a launch vehicle and a capsule.
3. Payment for “Soft” Milestones: One of the other distinguishing features of COTS is that it is a firm, fixed-price contract, where payment is only given on achievement of specific milestones.  The idea being that in theory this gives the company a lot more flexibility on how to achieve its goals, while the government only has to pay for actual results, not just for effort.  Unfortunately, this is also a nice theory that got watered down in practice.  If you look at both company’s COTS contracts, you’ll notice that both of them make the vast majority of their money off of meeting “soft” milestones, such as performing design reviews, raising money, etc.  By the time you get to most of the hardware milestones, the government has already paid out most of the value of the contract–which greatly reduces the benefit of this approach.   In fact, if I read SpaceX’s contract information correctly, they get paid for the first two of three COTS demo flights for just getting the flight off the ground–even if it fails.  They don’t have to actually have a succesful COTS mission to collect any but the last payment.One of the key tenets of the original proto-COTS concept Gary Hudson had pitched to O’Keefe’s NASA was that other than an initial pump-priming kickoff payment, all other payments would be for hard technical milestones.  That would’ve reduced the government’s risk a lot, since until technical milestones start being achieved, it only has the kickoff capital at risk.  Second off, it would emphasize rewarding actual successful development of hardware, not just paying for paper analysis like it has always done in the past.There’s actually a fair deal of danger here for COTS and future COTS follow-ons. The worst thing that could happen would be for OSC and SpaceX to collect most of their money, and then have some high profile failures right at the end. The government would see it as having spent lots of money on small space firms, and then losing their shirt. Something like COTS wouldn’t happen again for a long time. Had they stuck to Gary’s suggestion, technical milestones would’ve been earlier in the program, and therefore, if there was a failure, it would’ve been a lot less costly to the government.

Now, I’m not saying that COTS is doomed to failure or anything like that.  I’m hoping and praying that SpaceX and OSC are able to turn this into a success.  I am suggesting though that in the future, for COTS-like programs, that it would be a good idea to make sure that “skin-in-the-game” requirements are better matched with realistic expectations on the size of non-NASA markets, that we be more careful not to bias incentives in a way that encourages larger technical risks than ought to be taken, and that rewards actual hardware success instead of paying a lot for paperwork.

[Additional Thoughts: After getting a good night's sleep, I had a few additional thoughts I wanted to tack on.  First, I wanted to point out what I think is one of the best things about the whole COTS approach--the fact that the government is giving the COTS contractors a lot freer hand in how they go about their development projects.  When you compare this to how NASA's running Constellation, you can see how big of a difference this is we're talking about.  Also, by having fixed-price payments based on technical milestones, it removes the need for anywhere near as much direct oversight, both on company accounting (a big headache for cost-plus contracts), and on the technical side.  If the company doesn't take advantage of specialized NASA resources, and ends up botching a technical milestone, they don't get paid.  The incentives all point in a lot closer to the right direction.

One other comment on the skin-in-the-game question, is to remember the X-33 debacle.  One of the main reasons why LM was given the award (instead of the DC-X team) was that they were willing to put a lot more skin-in-the-game.  The problem is, the willingness to put in money doesn't necessarily correlate with mission success, competence, or even a desire to see the project succeed!  At least one anecdote said that LM put the money in more to prevent the competition from getting something to work than because they really believed on a corporate level that X-33 was going to lead to Venturestar.  On the other hand, I am somewhat wary of giving the whole contract with no skin-in-the-game requirements, and no actual requirements to commercialize things.  While using the other useful features of COTS (firm milestone based payments, less direct overhead/interference) is better than nothing, a good part of the point of COTS was as a pump-priming exercise.  Without incentives clearly placed pushing the COTS winners towards developing these services for commercial applications, a lot of the benefit is wasted.

Lastly, the basic concepts of COTS (fixed-cost milestone-based payments, focusing on areas with a potential for non-NASA customers, etc) could actually be a decent fit for developing other pieces of space infrastructure such as depot, tugs, etc.]

For those of you who were there for the propellant depot panel that I chaired at Space Access this year, the paper covers in more detail many of the things that Frank Zegler presented.

After an introduction where the benefits of propellant depots for the planned Constellation architecture (such as allowing the architecture to actually, you know, work…), a concept for a first-generation propellant depot was given.  This concept was designed around some of the work they’ve done on their ACES stage (aka the Wide Body Centaur that I’ve written about previously), combined with some recent work on deployable sunshields.

ULA's Proposed Propellant Depot Concept

The paper hit on several of the key concepts that I’ve mentioned on this blog:

1. The benefit of “settled” cryogenic fluid management (CFM) instead of “zero-G” CFM.  To reiterate, if you can force the propellant to assume a preselected orientation, almost all CFM tasks go from being science projects to being straightforward adaptations of terrestrial CFM techniques.  Basically you want to keep liquid from going out the vent, and gas from being ingested into the transfer lines.  They propose a combination of the propulsive settling that they’ve demonstrated over almost 200 Centaur flights, combined with a rotational settling technique similar to what we’ve discussed on this blog in the past.  This rotational approach, and the transition to and from the axial settling to rotational settling is set to be demonstrated after the DMSP launch this next year.  They’ll have almost 11klb of unused propellants to play with after delivering the primary payload, and they plan to squeeze as many experiments as possible out of that excess propellant.  There’s another approach that Frank Z. and I were working on for an SBIR proposal a year ago that could potentially also work if this one doesn’t turn out.
2. Proper thermal design can allow for passive systems that minimize or eliminate boiloff.  While you can add an active cooling system to compensate for a poor passive thermal design, it’s much better to do what you can first with a good passive design.
3. Almost all of the technologies for propellant depots are already developed, many of them to high TRLs.  Especially if you go with settled cryo handling instead of insisting on zero-G.
4. If NASA opened up its lunar architecture to allow for the use of propellant depots, it would greatly expand the current demand for orbital launches.  As the authors point out, even just topping-off the Earth Departure Stage’s LOX tanks would provide something like 10x the mass demand as COTS will.
5. They also discussed the importance of having experimental facilities for flight testing and maturation of these technologies before they’re implemented on real systems.  They mention their Centaur Test Bed concept for cryogenic experiments as secondary payloads on Atlas V, but they also link to an interesting paper by Dr. Chato of Glenn Research Center about the history of suborbital and orbital flight testing of CFM technologies.  I think this is one of those areas of research for which a low-cost, unmanned suborbital vehicle like we’re developing at Masten could greatly aid the development and maturation of critical spacefairing technologies.

There were a few issues I had with their presented concept that are probably worth mentioning.  First, they focus on only providing LOX.  While this may still be useful for NASA missions, it’s not as useful for commercial missions.  Since hydrogen boils off a lot faster than LOX, not having a way to top off your LH2 tank on orbit eliminates one of the big benefits of propellant depots.  Even if you don’t go with LH2 for your fuel, having both oxidizer and fuel at the depot gives you far more flexibility than just the one fluid.  Of course, this disagreement is mostly just a matter of taste on my part.

My other concern is more substantial.  They only briefly mention this in the paper, but the sunshields they’ve been working with use aluminized plastics.  Unfortunately, the LEO environment is somewhat nasty on plastics due to atomic oxygen.  In order to minimize degradation of their sunshield, as well as minimizing damage from space debris, they selected a 1300km altitude for their analysis.  While this makes the sunshield work better, that altitude is not a great place for a depot operationally.  First off, it’s inside the edges of the inner Van Allen belt.  Once you get much higher than about 500-600km, the radiation dosage goes way up.  This makes it a lot trickier on the electronics, and I don’t know if you could keep the rendezvous, docking, and transfer periods short enough in such an environment to avoid radiation damage to the crew (the point of this depot after all was for providing propellant for crewed lunar missions).  Ideally, a propellant depot should be a place where you can loiter for a while in case something comes up that delays the mission.  Lastly, 1300km is high enough up that there’s a significant penalty for delivery to that altitude.  Especially for future potential RLVs.  Now of course, a tug could relax that constraint a bit (and as I mentioned in my previous post would make operations a lot better in general).  But I think the reality is that in order to close this case operationally, they really need to find a way to make the sunshield survivable at lower altitudes.  For non-LEO propellant depots (L1/L2, LLO, Mars Orbit, etc) this shouldn’t be a problem, and the idea can probably be used as-is.  But the concept probably needs some rethinking if they can’t get it to work at a reasonable orbital altitude.

[Update:  I was able to dig up a bit of additional information about the concept.  Apparently the 1300km number was somewhat arbitrary.  The concept can work at more reasonable altitudes (ie 400km would probably be fine), it's just a question of how long of a lifetime you want for the sunshield.  With the petals concept as Frank explains it in the comments section, it sounds like down the road you might be able to replace the sunshield if it wears out, but depending on the lifetime, it may make more sense to just retire the module at that point and launch a new one.  Basically, it sounds like a tradeoff between lower altitudes for easier access vs. more maintenance/replacement costs due to more wear.  But this information more or less ends that key concern of mine with the concept.]

One last thought is that ULA is still pulling its punches on this technology.  They talk about how it could help aid the existing Constellation architecture, but the reality is that once you have this technology, you could completely transform the Constellation architecture, or get rid of large chunks of it entirely.  Once you have propellant depots you no longer nead super heavy lifters like Ares V.  Depots allow you to store the propellants you need for long durations, so that the ESAS concerns about losing a mission if a given launch is delayed or failed are greatly reduced.  Depots allow you to split propellant launches up over as many redundant launchers as you want.  If you look carefully, you’ll notice that the ACES stages they mention at the end of the paper could carry quite a bit more propellant if you have a Depot to top them off than an un-topped EDS stage.  And if you launch that stage dry, you can have a system that has better cryo thermal properties, much better performance overall, and it would be part of a system that was commercially useful for other markets.  Once you go to a propellant depot architecture, you could launch all of the actual dry hardware from the ESAS architecture on two existing or near-term EELV Heavies, and then the rest of your launches you really don’t care about launcher reliability.  Basically with a propellant depot architecture, you can keep the number of mission-critical rendezvous and docking opportunities to the same number as ESAS, while greatly increasing performance, reducing cost, and stimulating the private launch industry.

Like Space Tugs, propellant depots are an idea whose time has come.

One of the main ideas presented in the paper is a “Payload Bay Fairing” that would allow a heavy EELV to interface and launch payloads originally designed to launch on shuttle. The EELV would deliver the PBF with its encapsulated payload to just outside the ISS “visiting vehicle stay-out zone”, and then a tug of some sort would provide “last mile” services, hauling the PBF and its payload to the station, where it would be unloaded. They mentioned using Soyuz/Progress as the tug (like Constellation Services proposed), but decided to focus on ATV due to concerns about ITAR and INKSNA issues.

Payload Bay Fairing© (courtesy United Launch Alliance)

The PBF would be derived from the current 5m payload fairing used on the Atlas V. The PBF would have docking/berthing mechanisms on both ends, and would have structure to allow it to transfer loads into the payloads in a manner similar to the shuttle payload bay. I imagine it would also provide the necessary services for maintaining those payloads until they were ready to be installed at the ISS. By launching this on Delta-IV, you could pretty much deliver any payloads that the Shuttle was supposed to deliver, and probably at a far cheaper price. This includes the MPLMs, the AMS module that has received so much attention, and any other modules that isn’t going to get a shot at getting launched due to the 2010 shuttle retirement.

This is an interesting idea in several ways:

1. For small payloads that the COTS providers can deliver, a Delta-IV/ATV derived solution isn’t going to be cost competitive so it doesn’t necessarily step on toes as much.  If the Shuttle is kept running after 2010, being a government jobs program it doesn’t have to be economically competitive with COTS, and therefore could easily squash the nascent efforts by SpaceX, OSC, and others in this area.  With a Delta-IV based system, procurements would have to be handled in a competitive manner if the payload is one that could be flown on other commercial options, and therefore it’s much less likely to interfere in that key initial market.
2. This provides a commercial method for replacing the key functionality that we’ll be losing when the space shuttle retires.  This might allow us to drop the albatross sooner.  More importantly it might allow for some of the other modules that were deselected to be restarted and launched.  If Atlas V ever gets built there would even be some redundancy.  Building a station out of 20 tonne chunks isn’t a crazy idea so long as all those chunks aren’t stuck flying on the same system.
3. Space Tugs for proximity ops are an idea whose time has come.  If you start with an ATV-based tug system, that might provide enough of a market for other more affordable competitors to start filling that niche.  Once you have space prox-ops tugs available, lots of things become much, much easier.  Most of the mass launched with Shuttle or Progress (or even ATV or HTV) ends up being used to handle things like prox-ops, rendezvous and docking, cargo handling, reentry, etc.  The more of those functions can be offloaded to something that can stay in orbit and not have to be relaunched every time, the higher a percentage of your delivered mass can actually go to paying cargo, propellants, or passengers.  Also, by removing offloading a lot of the Visiting Vehicles requirements to the tug, it makes it removes a big barrier to entry by new suppliers.Space tugs would also benefit people like Bigelow. If he didn’t have to design each of his modules as maneuvering, independently operable spacecraft, I bet his task would be a lot easier. Also, tugs would make it much easier for different groups that want to dock/berth with his stations to do so.

It’s also amusing to note that I tossed out such an idea on usenet back in 2003 right after Columbia.  Now, I’ll admit that at the time, I really had no clue of all the challenges involved.  And accusations that I sounded like an “engineering undergrad with lots of imagination but very little experience with real world considerations?” were probably more accurate than I’d like to admit now. But it’s always cool finding out that one of my ideas I had years ago actually was a good one after all.