Short version: probably won’t be blogging at least through mid-February. Sorry guys.

[Note: I wrote this article based on publicly available information, without consulting with the Quest guys, so any errors are probably my misinterpretations.]

But before we jump into the technology, let’s do a refresher on what MLI is for those not so familiar with the area:

What is MLI?

MLI on a Mars probe (Credit: NASA)

MLI or Multi-Layered Insulation is a form of thermal insulation that uses alternating thin layers of metalized plastic (typically Kapton or Mylar) and spacer nets (usually made of Polyester or fiberglass) to slow the radiative heat transfer into or out of a spacecraft in a vacuum environment.  When you see pictures of spacecraft covered in what looks like gold foil, that gold-colored stuff is usually MLI.  Wikipedia has more details here.  MLI has been around for almost half a century, and is one of the key elements of spacecraft thermal control.

MLI is one of the best thermal insulators known to man, but there are several hitches to existing MLI:

• The thermal insulation performance of MLI tends to be variable.  One of the ULA guys (Frank or Bernard) related an anecdote that they once flew two back-to-back Atlas or Titan missions, using MLI as the thermal insulation on the Centaur tank, and they actually had 30% difference in boiloff rates, in spite of solar levels and mission profiles being almost identical.
• MLI is very structurally fragile because it is basically a bunch of plastic thin films only held together at the edges.  This means that they can’t be exposed to flight aerodynamic loads without getting quickly destroyed.
• MLI only works in a reasonably good vacuum (under 1 mPa or 8×10^-6 Torr). When combined with the previous challenge, this means that even though they’re much better insulators than say SOFI (Spray-On Foam Insulation), they can’t be used for insulating external faces of launch vehicle propellant tanks.

Quest, working with Ball Aerospace, has come up with a clever technology which they call Integrated MLI (IMLI), and several derivative technologies including Load Responsive MLI (LR-MLI), MMOD-MLI, and Launch Vehicle MLI (LV-MLI), which solve these weaknesses of traditional MLI, enabling many neat new space technology applications.

Integrated MLI

The core innovation that Quest and Ball came up with was the idea of replacing the plastic netting “scrim” layer with evenly spaced “micro-molded” snap-together polymer supports.  These micro-molded supports keep the MLI layers consistently spaced, transfer loads, and greatly reduce the conductive heat transfer between MLI layers.  To give you an idea of what these things look like, here are some pictures (borrowed from this brochure made by Quest’s micro-molding partner, Phillips Plastic Corporation):

[Editors Note: I'll have a picture here later when I can fix an upload bug with WordPress.  For now you'll have to read the brochure linked above to see what I was going to put here]

The neat things I see about this approach are:

• The IMLI blankets are now a lot more thermally deterministic, repeatable, and analyzeable.
• The IMLI blankets have much smaller thermal conduction contact area between each sheet, demonstrating around 30% better insulation than traditional MLI of a similar number of layers.
• The micro-molded snap elements tie the layers together and are anchored all across the surface you’re trying to insulate, instead of just along the edges, making IMLI significantly more robust than traditional MLI.
• By replacing the scrim layer netting with a few discreet micro-molded pieces, they’ve probably cut weight compared to traditional MLI blankets of the same number of layers.
• There’s some real potential for mass production and automated assembly that could drive down costs significantly.

And the technology behind IMLI also serves as the foundation for the other three derivative technologies.

Load Responsive MLI

While Integrated MLI was a big improvement over traditional MLI, you still could only use it in vacuum environments.  Quest and Ball developed what they call Load Responsive MLI (LR-MLI) to enable customers to have the benefit of MLI even in an atmosphere.  Basically, LR-MLI consists of a thin vacuum shell supported by some spring-loaded spacers, with a vacuum pulled on the space between the vacuum shell and the underlying structure. When the external pressure is non-vacuum, the spacers are forced flat, where the center of them rests on the center of the spacer below them.  This increases the heat leak through the spacers, but still provides a much better insulation than SOFI (their .25in thick test part provided better insulation than a 16in thick layer of SOFI!).  Once the external pressure starts falling off, the spacers push back apart in a way that greatly reduces the conduction path, resulting in a really good thermal insulation on orbit.  See this page and page 22 of this FISO presentation for illustrations of the concept.

Benefits of this approach as I see it:

• You now have a non-SOFI method for insulating a tank that works in both atmosphere and in-space that doesn’t have the popcorning problems SOFI has, which both eliminates debris falling off during launch, and also eliminates the risk of insulation flaking off once in orbit.
• LR-MLI is a significantly better insulator both from a mass and a thickness standpoint compared to SOFI.
• You get rid of the need for GHe or GN2 purges on the ground.
• Enables fairly lightweight dewars to be constructed for applications that need it.

My only concern is the challenge of maintaining a vacuum for a long duration on the ground, though I guess dewars are used a ton in industry, so maybe this isn’t a huge deal.

Launch Vehicle MLI

The latest improvement on the IMLI theme, for which Quest just finished a Phase I SBIR contract for last year, is an MLI technology capable of being used on external aerosurfaces of launch vehicles.  This Launch Vehicle or LV-MLI appears to be a combination of the LR-MLI concept with a thin aeroshell surface.  There aren’t as many details on the concept, since it’s still in active development (here’s to hoping things went well and they get a Phase II award next month!), but here are the SBIR abstract and briefing chart.  The goal is to have an insulation system that weighs about a third of what a 1.9cm SOFI layer would, but with 85X the insulation value.

MMOD-MLI

One other related concept that Quest and Ball developed is an IMLI variant that includes integral MMOD (Micro-Meteor/Orbital Debris) protection capabilities.  This MMOD-MLI includes layers of Kevlar and Nextel cloth between layers of insulation, providing the same sort of multi-shock shielding capability that is what makes Bigelow’s modules so much more robust than older ISS designs, while still packaging things in a neat, multi-functional structure.  Basically, an incoming piece of MMOD would hit the outer layer, instantly vaporizing the MMOD, which would then have its energy absorbed and the momentum distributed as it passes through the multiple shield layers.  Like LV-MLI, MMOD-MLI just finished a Phase I SBIR a few months ago, so the results aren’t all out, but the goal was a design that would give a propellant depot a 95% chance of surviving its design lifetime without an MMOD-induced failure, without adding substantially to the MLI mass, or significantly decreasing the MLI thermal efficiency.  The neat thing about this technology is that it looks like it can be integrated with LV-MLI or LR-MLI without much additional effort.

So you could theoretically get an MLI shield that can function in both atmospheric pressure and on-orbit, could take aerodynamic loads, and when on orbit could double as a very effective MMOD shield.  Think about that one.

Some Random Applications

This is far from all the space applications enabled by these technologies, but here are a few less-obvious ones that I think are worth mentioning:

1. Cryogenic-fueled Air-Launched Rockets: One of the big challenges for externally-carried cryo-fueled air-launched vehicles (including even LOX/RP-1 designs) is that the heat transfer environment during the flight from the ground to the launch point is substantially worse than a vehicle experiences on the ground, due to convective heat transfer from air flowing over the launch vehicle during flight, which may very well be an order of magnitude or more than what is experienced on the ground.  And unfortunately, air-launch vehicles are typically much more sensitive to losses due to boiled-off propellants. The traditional thought on how to handle this is to have some sort of Airborne Service Equipment (tanks and plumbing and stuff) that either keeps the tanks topped up, allows you to only load the cryo propellants at the last second, provides some sort of sacrificial coolant, or provides an active cooling loop. With something like LV-MLI (or LR-MLI inside a separate aeroshell if your tanks aren’t conformal with the outside of the vehicle), you could cut down on the heat leak substantially.  Maybe to the point that you could eliminate or greatly simplify the required ASE complexity, cost, and weight.  Maybe combine pre-subcooling the propellants a bit with the insulation and you might be able to get rid of the ASE requirements entirely.
2. Wet Stations: One of the ideas that made the rounds a lot a few decades ago was that NASA should haul the Shuttle External Tanks all the way into orbit (instead of ditching them at just below orbital velocity to burn up in the Indian Ocean).  Two of the technical issues with this idea were that the insulation on the ET was liable to flake and pop off in orbit, potentially creating space junk issues.  There were probably solutions to this problem, but they likely involved either a lot more mass, or a lot of added complexity compared to just using an insulation system that isn’t prone to flaking off.  The other issue is that I don’t think SOFI makes a very good MMOD shield, meaning that a structure that big had a pretty likely chance to have an MMOD failure during its lifetime if some external MMOD shield wasn’t added.  Using a combined LV-MLI and MMOD-MLI solution, you could lower the weight of the insulation system overall, increase payload on normal flights, and completely eliminate this problem.  And this isn’t just limited to SLS, this could also be the case for any other core stage or large upper stage that reaches near orbital or orbital speeds, such as the core stage on a Delta-IVH or eventually an ACES upper stage. As an added bonus, you could even get the 60s-Retro Black-and-White stage coloring scheme without the weight penalty.
3. Bigger Single-Launch Propellant Depots: Along a similar vein, this approach could allow you to do one of the ULA single-launch, dual-fluid depot concepts where the LH2 tank is built into the upper stage’s payload fairing outer mold-line, enabling a 70-75mT LOX/LH2 capacity using Atlas’s Centaur, or over 100mT using Delta-IV DCSS as the starting point.  The nice thing is that not only do you get lightweight, high quality insulation, but you also get MMOD protection at the same time (which is critical for a depot).
4. Super Jumbo Single-EELV-Launch Propellant Depots: On the crazier side, you could combine ideas number 2 and 3, and say have a Delta-IVH place its core stage (with an LV/MMOD-MLI combo in place of its current SOFI) into orbit, with what payload remains being a docking node, temporary stay habitat, or additional propellant tanks for other more storable propellants if you want a multi-propellant depot.  That gets you up over 200mT of LOX/LH2 capacity in a single launch, without requiring an HLV to do it…  Though admittedly, a Delta-IV CBC would take a lot of modifications to get the passive cooling right compared to the Centaur-derived approach that ULA proposed originally.

[Of course the real reason I do stuff like that on Twitter is because my adult supervision at Altius doesn't do Twitter, which allows me to speak my mind sometimes about space policy issues without getting the "Dutch Uncle's talk" every day...]

• Updated our business plan based on feedback from the Newspace Business Plan Competition, and created a company profile on Gust.com/Angelsoft (sorry guys, for accredited investors only).
• We were able to close a deal with Lockheed Martin to use a really nice thermal-vac test chamber for testing our Sticky Boom™ gripper system as part of the SBIR Phase I effort.
• In about a month from closing that deal we designed, fabricated, installed, and ran tests with a thermal-vac test rig in the chamber that simulated capturing the Mars Sample Return Orbiting Sample canister over a wide range of temperatures.  Net result was that over 63 tests, all tests delivered sufficient pull-off force to have captured and retained the MSR “OS”.  Forces near ambient temperatures were on average over 10lb, using the same gripper we used for the Zero-G flight tests in May.
• Also improved the pad to gripper attachment method so the pads don’t pull-off accidentally.  Makes it so our demo unit can actually pick up the hollow stainless steel sphere we used in 1g, horizontally, without any problems.  Which is pretty darned cool when you realize this is using the same static cling forces you get from rubbing a balloon on your head.
• We also wrote about 160 pages worth of SBIR, BAA, and commercial proposal, final reports, and other related documents.  Basically did about a Master’s Thesis worth of writing in about a month…which brings back bad memories of my actual Master’s Thesis…
• In the process discovered a design concept that might enable us to do Sticky Booms™ with reaches in excess of 100-200m, and even started finding some potential terrestrial applications for some of the technologies that go into making Sticky Boom™ work.
• Did our first pitch at an actual Angel Investor meeting down in Houston on September 22nd, put on by the Space Angels Network and the Phillips & Company.  While there we also got to meet with several companies in the area, and got to visit Space Center Houston.  Really enjoyed the Skylab and Saturn V exhibits.
• And managed to get a few really good interviews that resulted in some pretty cool press for Altius this month (AvWeek, Tech Review, PopSci, and others).
• Discovered Pandora.com…
• Started weightlifting on a regular basis with a friend, who you might know from the Space Business Blog who recently moved out to the area.  I’m still definitely in the transition from wuss to wimp, but I’ve turned the corner (in a good way) on an exercise routine for the first time in my life.

Now, even though I’m pretty libertarian, I can at least empathize with the goal of not letting poor widows get screwed by unscrupulous privately-traded companies…but we put the people in the 90th and 95th and 98th percentile in this same category?  Sure, privately traded companies, and especially startups can be pretty risky–even in strong and growing industries.  But really these days, investing only in publicly traded companies is no guarantee that you won’t get screwed.  There are all sorts of ways investors are allowed to do financially suicidal things with publicly traded companies, but aren’t allowed to take any risks with privately traded ones, even if they’ve managed to build net worths of several hundred thousand dollars not counting equity in their primary residences.

I just wonder what the investment environment would be like if the accredited investment rules had a cutoff bar of $500k vs. $1M.  Not that it’ll ever happen, just surprised to realize how high of a bar current accredited investment rules really are for investment.

That is all.

We’ve still got a long way to go, but here were some of the highlights that have happened since after I made the plunge:

• We’ve found, signed, and fulfilled over $200k worth of contract engineering work
• I invented Sticky Boom™ which has the potential of changing the way rendezvous, docking, and space servicing are done (and which got us mentioned in New Scientist today).
• We took that idea, won a NASA contract to mature it, and also raised about $50k to accelerate its development
• We built two generations of prototypes, got invited by NASA to show one of them off in Washington DC at the US Capitol Visitors Center, and took the other one and flight demonstrated it on a Zero-Gravity aircraft.
• And just today we got invited to present our business plan as one of the finalists at the 2011 New Space Business Plan Competition later this month.

It’s been a pretty spectacular year, and we’ve gotten a lot accomplished in a short time, especially considering that I’m still learning the ropes. That said, I don’t at all miss the 13,000 miles worth of driving I did in the second half of last year, or spending six months crashing on friends couches bouncing back and forth between California, Colorado, Utah, and Oregon.

Hopefully I’ll soon be able to start getting more active in the space technology and policy blogging scene again here on Selenian Boondocks. Thanks for the patience and support.

Unfortunately, I’ve been hearing rumors that NASA may not even bother releasing the study results this time around, due to potential “ITAR” concerns. Unlike the military, NASA can’t so easily “classify” away things they don’t want people to read, but over the last half decade, the ITAR card has served as a sort of purgatory/Memory Hole where inconvenient information can be banished. I hope NASA does the right thing by making this taxpayer-funded research public. Seriously, how much truly ITAR-sensitive info is there really likely to be in these presentations? NASA has made studies like this public for decades, even since ITAR got ratched up into its current pain in the neck back during the 90s. If there really is a concern that some of the material might be ITAR sensitive, couldn’t they just redact the specific information that they deem ITAR sensitive (and then give US citizens info on where they can get access to the full, unredacted version)? Heck, I’d be willing to start a donation drive to pay for the lawyer’s time to go through and figure out what actually needs to be held back. My guess is that if they really redact anything it’ll probably be less than 5-10% of the content.

Hopefully I’m making a mountain out of a molehill, but I really hope this info sees the light of day. When NASA embarks on a $20B+ multi-year project, especially one where they’re trying to use sole-source contracts and lock in providers without performing an honest re-competition, doesn’t the public deserve a right to see what the contractors came up with, and if they actually agree with NASA? Sure, I wouldn’t be surprised if this time around several of the usual suspects actually come out supporting NASA, but I think the public deserves to see dissenting opinions as well. How can US citizens make informed oversight of their federal government, if the federal government isn’t transparent even with non-national-security issues like what architecture NASA should use for exploration?

Am I being paranoid or unreasonable?

Jeff made the point that you can look at space policy from a framework that has Goals at the top, with Strategies that help you achieve those Goals, Objectives that provide you measurable steps to gauge your progress at those Strategies, and then Tactics that determine what tools you use for meeting those Objectives. I really like this framework, and in fact it helped me clarify my thinking about Altius’ corporate goals and strategies (but that’s a blog post for another time, and probably over on the ASM blog).

After giving a few analogies (WWII military policy and the Space Race), Jeff then made the argument that “space settlement” was actually the policy of the United States. For me, my motivating goal for space development is a very closely related but slightly different focus–tapping the resources of space for the benefit of mankind here on earth. Now, there are challenges for both of these goals. As Jeff right pointed out, there are many who are afraid of openly proclaiming goals like these, because they are afraid that they might not actually be realistically achievable. In the case of settlement, there are questions of whether humans can actually reproduce outside of a 1g field, or if we can ever get to the point where we can economically support life indefinitely off planet. In the case of tapping space resources for humanity’s benefit, there’s the “minor technical detail” that most of these resources are extremely subeconomic right now.

I actually discussed the topic of subeconomic resources back in the early day of this blog, but I figure a revisiting of the topic is worthwhile. To recap, a subeconomic resource is one that you can’t profitably extract and sell under current conditions. Pretty much all space resources currently fall under this category. While you hear a lot of comments on space forums about the importance of better space property rights, the reality is that even if there was a clear way you could homestead a chunk of the Moon or a NEO or Mars, and sell anything you could harvest for it, I still don’t think you could actually close an honest business case around resource extraction today. With how much it would cost and how long it would take to go from where we are right now to the point where you could actually sell your first kg of lunar platinum or put the first drop of lunar derived LOX or LH2 into a customer’s tank in LEO, there’s no way you could actually make the ROI work for doing that privately, stand-alone. In fact, I’ve even got a certain coblogger who has made the argument that it’s impossible to ever mine a resource in space and send it back to earth for a net profit.

While I’m pessimistic on the current economics of space resource extraction, I think my friend is wrong. The point I made in my previous article on the topic and that I wanted to remake today is that resources that are currently subeconomic don’t have to stay that way. What got me thinking about this was actually reading a sign at the Hogle Zoo last week while on vacation. One of the donors for the zoo was the Kennecott Copper Mine, a major open-pit mine located in the mountains on the west side of the Salt Lake Valley. While this mine is one of the most productive mines in the world, there was still a time in the not-to-distant past, where even if you knew exactly how much gold, silver, copper, and molybdenum there was in there, that it wouldn’t have been possible to economically exploit that. But as transportation systems became more mature, affordable, and reliable, commerce spread, and eventually mines like it or deep-sea oil rig operations also became feasible and even profitable.

Now don’t get me wrong, just because it’s possible for some subeconomic resources to become economic over time, that doesn’t guarantee that a specific resource will do so. Personally, I’d be really surprised if anyone ever harvests Helium-3 from the moon for use in fusion reactors, for instance. But I think there’s a reasonable case that a space program run with the goals I mentioned earlier (settlement and resource utilization), and with a suitably well-thought-out and implemented strategy, can enable at least some extraterrestrial resources to become economically extractable for mankind’s benefit.

Imagine for a second that the White House actually proposed such a goal, and a strategy like Jeff’s “planet hopping” strategy, and found a way to get Congress on-board with such a strategy, and NASA to competently execute it’s part of that strategy long enough to get us past our first two major objectives (depots in LEO and L1 and a working lunar ISRU operation capable of delivering respectable amounts of LOX/LH2 to L1). Also imagine that the idea of prepping these new capabilities for a handoff to commercial operations was built-in from the get-go instead of being an afterthought like it usually is. By that point, we would have already started some virtuous cycles. By providing an anchor tenancy need for propellant in LEO, you’ve now provided a large enough stable market to close the business cases for several lower-cost launch providers. You’ve also helped establish infrastructure and systems to allow sending large amounts of crew, cargo, and other materials to the lunar surface. You’ve also established the first market for propellant in L1 (servicing missions both to the Moon and also to NASA’s next steps in the “planet hopping” strategy). If the price point of propellant in L1 from lunar sources really is cheaper than shipping it from home, you’re also getting the start of a transportation system that has a made a lot of progress towards being able to extract and ship home Lunar PGMs at an economically useful price point. While you might not yet be all the way there, you’ve now lowered the amount of additional work that has to be covered by a lunar PGM extraction business plan substantially, and also removed a lot of content and time between fundraising and when that first bar of platinum can be sold on earth. Also, by providing steady demand for propellant in L1, NASA has also provided an economic incentive for people to improve the cost of delivering stuff to L1 (say by improving the reusability of lunar landers, building a small lunar mass driver, rotovator, launch loop, sling, or a lunar beanstalk). By providing an anchor tenant for LEO and L1 propellant, NASA has also made it easier for other people with business ideas to factor those into their company’s plans, or their country’s space program.

To summarize what has now become a much longer blog post than I intended, I think a properly done settlement/resource extraction goal with a “planet hopping” strategy could actually start making lunar resources economically extractable even before we’ve managed to put a human foot on Mars, even if such resources are currently nowhere near economically feasible today.