Appreciation, Giants, and Humanity's Legacy

March, 2023: NASA's integrated SLS rocket core stage for the future Artemis II mission (left); and a RS-25 engine undergoing its fourth full-scale hot fire test (right). The SLS core stage and the RS-25 rocket engines use liquid hydrogen and oxygen as propellants, the highest performance and most environmentally responsible propulsion system option for launch vehicles. (image credits: NASA)

NASA Roots

I'm currently participating in Charlie Pellerin's famous 4-D workshop on developing teams and leaders in four dimensions by measuring and managing social context fields with human physics. It was recommended to me by a retired NASA colleague I highly respect who said it was the best training he'd ever taken. The icing on the cake was it being offered free of charge to a small group of international participants remotely for one hour every week. Now at the midway point through the workshop, I think my colleague's high praise was an understatement.

Charlie was promoted to Director of Astrophysics at NASA in 1983, which was around the time my own career at NASA started as a recruited engineer from the electric power industry. While I was cutting my teeth on developing liquid hydrogen technologies and systems, Charlie was leading a multi-billion dollar program for a decade that launched twelve satellites, and included him inventing and implementing the $20 billion dollar Great Observatories Program.

His hero's journey included leading the development of the Hubble Space Telescope that was launched in 1990 with a flawed mirror. He overcame that unfathomable setback by mounting a successful repair mission that fixed the telescope. For this NASA awarded him his second Outstanding Leadership Medal. He was also awarded the NASA Distinguished Service Medal for leadership of the Astrophysics Program, and Presidential Rank awards from two past U.S. presidents. He later went on to teach leadership at the University of Colorado's business school and founded 4-D Systems to teach his methods to others.

Who Do We Appreciate?

All of this is offered as context to the assignment Charlie gave after last week's workshop session about the power of expressing appreciation. Completing the assignment got me thinking in broader terms with respect to the arc of my career; the progression of technology; and how things have evolved regarding who and what we appreciate.

I was very fortunate early in my career to work side-by-side with engineers from the Apollo era. Many of them had even worked for its precursor, NACA, that was formed after World War II to advance aeronautics and jet engine research. Besides learning a great deal from them about the technology of launch vehicles and spacecraft, they also modeled the behavior of humility despite their unique prowess as "rocket scientists".

To paraphrase and expand on Isaac Newton's famous quote, I've had the immense good fortune to not only stand on the shoulders of giants but to learn directly from them. Now it is my turn to teach (and continue learning) as a subject matter expert consultant to NASA's Human Landing System and other Artemis Program elements over the past several years. And the business of growing the next generation of giants continues with these new colleagues, teammates, and friends.

Artemis I launched on November 16, 2022 with the first spacecraft designed to take humans beyond earth orbit since the Apollo program. The mission successfully completed the journey to the moon and back with leadership from my friend and last boss at NASA (who was also my consulting collaborator before NASA stole him back :). An amazing accomplishment that will be followed by a crewed trip around the moon on Artemis II, and humans on the lunar surface on Artemis III for the first time since the 1970s. I could not be more proud of my colleagues and honored to have the privilege to continue working with them.

All of this has been accomplished by thousands of government workers, private sector contractors, and partners with public funds for a common shared goal. No other organization has ever put a human on another celestial body. With all its challenges, critics, and opportunities for improvement (don't we all have that?) - only NASA, its contractor team, and now its international partners has done it and is continuing to do it.

This is a good thing to remember at a time when our culture seems to promote the worship of capricious megalomaniacs who claim to have all the answers and take all the credit for the accomplishments of others. Humility, mutual respect, service to others, and collaboration in reaching important goals are worthy of our collective appreciation. On the other hand, hubris, intolerance, and the exploitation of others for self-enrichment and personal power is only worthy of our condemnation.

The Legacy of Our Species

In the much larger picture, if our space programs are building toward humans becoming an inter-planetary species, a reasonable question to ask is do we deserve it? Perhaps the answer is yes if we represent the galactic expansion of sentient benevolent beings. However, if we are metastasizing invaders that unsustainably exploit the resources of new worlds (and any inhabitants) in the way that we have throughout much our history, perhaps it would be better if we remain in the planetary womb of our creation.

I believe the ultimate test of that question is how we repair the damage we've inflicted, and continue to inflict, on our home planet. It is hard to justify moving into a new house and neighborhood when you've recklessly trashed your current home and continue to make it increasingly unlivable.

Crawl before you walk, walk before you run. As a species, we are still learning to crawl. Space exploration can help us learn how to begin taking our first steps, but it will be our progeny who learn to walk and eventually run. Perhaps even to other planets and extrasolar systems. In order for those future generations to thrive, we must learn how to live sustainably and re-establish a healthy global ecosystem or we will continue crawling toward our own extinction.

Matt Moran is the Managing Member at Moran Innovation LLC, and previous Managing Partner at Isotherm Energy. He's been developing power and propulsion systems for more than 40 years; and break-through liquid, slush, and gaseous hydrogen systems since the mid-1980s. Matt was also the Sector Manager for Energy & Materials in his last position at NASA where he worked for 31 years. He's been a co-founder in seven technology startups; and provided R&D and engineering support to many organizations. Matt has three patents and more than 50 publications including the Cryogenic Fluid Management series. He also leads the monthly LH2 Era™ Webinar.

No-Loss Liquid Hydrogen and LNG Systems (Zero Boil-Off)

Last December, we completed the analysis and design of an integrated cryogenic refrigeration system for the new 1.25 million gallon liquid hydrogen dewar at NASA Kennedy Space Center. The system enables zero boil-off long term storage for an electrical cost that is a fraction of the expense of replenishing hydrogen normally lost to venting. It also provides liquefaction and subcooling in support offloading, conditioning, transfer, and other critical operations.

Liquid Hydrogen Dewar at NASA Kennedy Space Center (source: NASA); and Isotherm Energy design process

The capability to economically eliminate boil-off gas at such a large scale is a game changer for many liquefied natural gas (LNG), liquid hydrogen and other cryogen applications.  Benefits include elimination of storage losses, improved system performance, increased safety, and mitigation of unwanted emissions. However,  a systematic approach is required to insure an optimal solution. This post provides an overview of the process we use at Isotherm Energy.

Needs, Goals and Objectives

The first step is establishing the why (needs), the what (goals), and the how (objectives) for the system. There's a common tendency to overlook this step and dive into a point design based on past projects or preconceived configurations. The result generally ranges from suboptimal at best, to infeasible at worst.

Questions to ask at this point include:

1. Why is this system or capability needed? What is the overarching problem being solved?
2. What addresses the identified needs? Performance, cost, efficiency, compliance, or other goals?
3. How do we achieve the stated goals? Specific system objectives to be meet?

It's imperative that the documented answers to these questions are formally agreed upon by the key stakeholders. There must be a clear understanding of the needs,  goals and objectives at the start of the project. They form the compass that keeps the development process pointed in the right direction. A simple example to illustrate from the NASA hydrogen dewar project:

• Need: Mitigation of hydrogen losses in a new 1.25 million gallon dewar
• Goal: Long term storage with zero boil-off operation for 30 years or more
• Objective: No-loss integrated refrigeration and storage system design

Top Level Requirements and Concept of Operation

With the needs, goals and objectives identified, top level system requirements can be defined. These top level requirements will provide the basis for lower level requirements, and must be verifiable (e.g. by analysis, test, inspection, or some other method). They must also be upwardly traceable to the objectives, and flow down to lower level requirements. Requirement definition and analysis is generally an iterative process, but the top level requirements should document the primary system drivers that often come from the key stakeholders as "non-negotiable". Without this step in the process, there is no definitive measure to assess whether the system solution is acceptable.

An equally important step is drafting a system concept of operation. What are the nominal operations for the system? What are the key duty cycles and time frames over which the operations occur? What off-nominal operations are anticipated for maintenance, repair, etc.? By thinking through the specifics of these and other operational questions, the range of feasible solutions begins to come into focus. Bypassing this important step can lead to over-designed or under-designed solutions that become more costly to correct later in the development cycle.

A simple example of one top level requirement and a brief concept of operations summary:

• Requirement: The system shall be capable of removing 3000 W of thermal energy from the dewar continuously at 20 K. Rationale: Cooling capacity must be sufficient to overcome environmental heat leak and thermodynamic conditioning heat loads. Verification: by analysis and test.
• Concept of Operation: During nominal operations, the refrigeration system maintains tank pressure without venting. For tanker off-loads, roadable tankers fill the large stationary dewar while the refrigeration system conditions the hydrogen to maintain tank pressure without venting. When rapid depressurization is needed, the refrigeration system cooling flow is reversed to provide maximum cooling in the ullage for liquefaction. During fueling operations, the refrigeration system is in bypass mode. After fueling (post launch), the refrigeration system may be used to re-liquefy hydrogen vapor and depressurize the dewar.

System Trades and Analysis

The next step is to identify system design options that are within the feasible trade space, and then analyze critical performance and economic parameters. There are many possible trades to consider, but the primary ones from a thermal performance standpoint can be broadly grouped as passive, hybrid, active, or some combination thereof. Note that many options may fit into more than one of these categories depending on the implementation.

Passive techniques minimizing heat treat transfer into the system through structures, insulation, and penetrations are always important to explore first. These methods rely on good cryogenic design and material selection, and do not need any power input. Depending on the requirements and concept of operation timelines, an optimized passive thermal design may be sufficient to develop a no-loss system within the operational parameters of the application.

The hybrid category often relies on driving pressure differentials or power input for pumps, mixers and valves to provide cooling. The Joule-Thomson effect can be used in single stream cooling lines, or augmented with a heat exchanger and pump for cryogen flow on the warm side. Thermal de-stratification with any method that induces circulation of the liquid cryogen can prolong storage times by bringing the tank to equilibrium conditions (and avoiding venting). Manipulation of the boundary temperature can significantly reduce the effective environmental heat leak. This can be accomplished using a thermodynamic vent system during cryogen use, or by storing or flowing a complementary higher temperature cryogen in a jacket around the tank.

Finally, active cooling techniques require significant input power to make use of cryogenic refrigeration or cryocoolers to intercept or extract heat from the system. These refrigerators must interface with some form of heat exchanger, and perform in an integrated dynamic fashion for all required operations. These systems can also be used to subcool (densify) the cryogen for increased storage density and thermal capacity. The result is much longer storage times since significant environmental heat leak is absorbed before the cryogen reaches saturation conditions.

Design and Development

Based on the system trades and analysis performed in the previous step, each feasible design trade is ranked based upon key quantitative and qualitative criteria. Ranking methods and criteria selection should be established by consensus with the stakeholders prior to comparing design trades. This helps avoid the temptation to tweak the process in real time which can result in selection bias.

The highest ranked trade that meets all the requirements can then be selected for detailed system analysis and design. It's important during this step to document key assumptions, system interfaces, boundaries conditions, analysis approach, parametrics, optimizations, detailed results, etc. This step may require more than one iteration, or selection of the next highest ranked design trade, if the initially selected trade doesn't result in an acceptable solution.

When the design is deemed satisfactory, verification and testing is performed to validate that all the requirements are are met by the system. The project scope dictates the details of the verification and validation effort (e.g. verification of all analysis results; component and subsystem testing; and integrated system testing). The subsequent final design and system specification provides the information required to build, install and operate the system.

Optimal No-Loss Liquid Hydrogen and LNG Systems

Of course, this brief overview doesn't address all of the detailed considerations and customization needed for a specific liquid hydrogen or LNG application. However, following the overall approach helps to insure that the needs, goals and objectives are addressed in a systematic way that meets the requirements and is consistent with the concept of operation.

Furthermore, exploring the feasible trade space - and selecting the best design within it - also mitigates the risk of a sub-optimal design. Such an approach is key to economically minimizing or eliminating boil-off losses for  cryogenic systems.

Matt Moran is the Managing Member at Moran Innovation, and previous Managing Partner at Isotherm Energy. He's been developing power and propulsion systems since 1982. Matt was also the Sector Manager for Energy & Materials in his last position at NASA where he worked for 31 years. He's been involved in seven technology based start-ups; and provided R&D and engineering support to many industrial, government and research organizations.  More about Matt here…

Largest Liquid Hydrogen Dewar Tank (Ever)

NASA Kennedy Space Center Liquid Hydrogen Dewar Tank (credits: NASA/Kim Shiflett)

Isotherm Energy has been awarded a subcontract to provide support for development of the largest hydrogen dewar tank in history at the NASA Kennedy Space Center (KSC). As previously reported by NASA, the new dewar will hold well over one million gallons of liquid hydrogen and is 50% larger than the current record holder that supported space shuttle launches for 30 years (see above).

A primary focus of Isotherm Energy’s support is the analysis, design and integration of a new technology that eliminates hydrogen loss during storage. Shawn Quinn, assistant program manager of NASA KSC Ground Systems Development and Operations (GSDO), explained how the dewar and its unique capabilities will support the new Space Launch System [1], “…GSDO will fill the rocket's core stage and interim cryogenic upper stage with hundreds of thousands of gallons of liquid hydrogen. An important feature of the new zero boil-off technology is the potential to reduce long-term energy costs and liquid hydrogen commodity costs."

This key capability will build upon previous research demonstrations done by NASA to investigate an integrated system that can provide liquefaction, propellant densification, and zero boil-off. “The goal would be to integrate the unit's heat exchange system into the new tank, saving GSDO money by eliminating the loss of hydrogen”, according to Bill Notardonato, principal investigator for the 33,000 gallon demonstration unit (shown below) [2]. “By accomplishing zero boil-off of liquid hydrogen, we could save one dollar in hydrogen for every 20 cents spent on electricity to keep it cooled.”

(Photo credit: NASA/Cory Huston)

The successful design and operation of a liquid hydrogen storage system at this scale with zero boil-off, liquefaction and densification capabilities has far reaching implications even beyond the space program. For example, Isotherm Energy has developed a hydrogen energy storage architecture and associated system development software for renewable power sources (among other applications). The demonstrated ability to economically eliminate hydrogen losses for such a system – not to mention liquefy gaseous hydrogen and subcool the resulting liquid – would be a significant game changer.

[1] “Ultra-Cold Storage – Liquid Hydrogen May Be Fuel of the Future”, Amanda Griffin and Linda Herridge, NASA KSC, Dec 14, 2016.

[2] Ibid.

Matt Moran is the Managing Member at Moran Innovation, and previous Managing Partner at Isotherm Energy. He's been developing power and propulsion systems since 1982. Matt was also the Sector Manager for Energy & Materials in his last position at NASA where he worked for 31 years. He's been involved in seven technology based start-ups; and provided R&D and engineering support to many industrial, government and research organizations.  More about Matt here…

NASA Johnson Space Center Hosts Engineering Course

Matt Moran taught his popular course on Excel VBA for engineers at the NASA Johnson Space Center on August 8-10. The course provides in-depth details on principles, practices, and implementation of Excel and its integrated programing language – Visual Basic for Applications (VBA) – for analysis and engineering model creation.

Techniques and methods taught in the course allow the creation of custom engineering models for: analyzing conceptual designs, creating system trades, simulating operation, optimizing performance, and more. Matt has taught this course to hundreds of participants since 2007, and hundreds more have purchased his published course notes in paperback and Kindle versions.

Newly remodeled training building at NASA Johnson Space Center where course was held.

Matt Moran is the Managing Member at Moran Innovation, and previous Managing Partner at Isotherm Energy. He's been developing power and propulsion systems since 1982. Matt was also the Sector Manager for Energy & Materials in his last position at NASA where he worked for 31 years. He's been involved in seven technology based start-ups; and provided R&D and engineering support to many industrial, government and research organizations.  More about Matt here…

Power and Water the NASA Way

We’re sometimes met with a puzzled look at Isotherm Energy when we describe our hydrogen energy system architecture and its ability to store energy, generate power, recover heat, and produce potable water.  It seems the combination of functions – particularly energy and water together - is unfamiliar to many.  After three decades of working at NASA where these types of systems have been routine since the mid-1960s, I hadn’t considered that it might sound odd to those outside the aerospace industry.

A recent article about the famously jinxed Apollo 13 mission describes an early example:

“Apollo 13 lost its electricity, light, and water supply… The loss of an oxygen tank was crippling to an Apollo spacecraft because the oxygen tanks powered the fuel cells that powered the spacecraft… The electrochemical reaction of combining cryogenic hydrogen and oxygen produced electricity, heat, and potable water as byproducts.” [Popular Science, Apr 15, 2016]

Part of an unflown Apollo fuel cell [National Air and Space Museum]

The Space Shuttle also used fuel cells in a similar manner:

“Fuel cells are used in the space shuttle as one component of the electrical power system. Three fuel cell power plants, through a chemical reaction, generate all of the electrical power for the vehicle from launch through landing rollout… are individually coupled to the reactant (hydrogen and oxygen) distribution subsystem, the heat rejection subsystem, the potable water storage subsystem, and the electrical power distribution and control subsystem. The fuel cell power plants generate heat and water as by-products of electrical power generation.” [NASA]

One of the three fuel cells that provides electrical power to the space shuttle orbiter [NASA]

As another more personal example, I was asked in 1991 by NASA Headquarters to conduct a study on launching water to low earth orbit for processing into hydrogen and oxygen propellants to support missions to the moon and Mars.  The published system concept I designed used an electrolyzer to produce the propellants, and then liquefy them for storage until a spacecraft docked for refueling (see schematic below).  We would revisit aspects of this configuration later at NASA when I worked on designs to provide power, propulsion, water and environmental control for lunar surface systems.

Source: “Conceptual Study of on Orbit Production of Cryogenic Propellants by Water Electrolysis”, Moran, 1991.

So the integration of proven aerospace technologies into a combined energy-water-heat recovery architecture was a natural extension of my personal experiences and background.  And I’m convinced it will serve us well as we begin to view our energy, water and food systems here on earth from a more integrated sustainable perspective.

Matt Moran is the Managing Member at Moran Innovation, and previous Managing Partner at Isotherm Energy. He's been developing power and propulsion systems since 1982. Matt was also the Sector Manager for Energy & Materials in his last position at NASA where he worked for 31 years. He's been involved in seven technology based start-ups; and provided R&D and engineering support to many industrial, government and research organizations.  More about Matt here…