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Rocket Doc Notes for Week of August 1, 2021

Miscellaneous Notes

I’ve enclosed the following article from the Wall Street Journal. My comments are in parenthesis.

Utilities Eye Mini Nuclear Reactors as Climate Concerns Grow

Despite the enticement of carbon-free power, critics say small modular reactors have the same safety and cost challenges of big nukes


Elena Shao

Aug. 2, 2021 8:00 am ET

U.S. utilities are looking to miniature nuclear reactors, as they seek a steady energy source that can help reduce the carbon emissions linked to climate change.

While power companies have stopped building big nuclear reactors because of cost overruns and construction delays, not all utilities are giving up on nuclear power. Several U.S. utilities and power consortia—including Energy Northwest, Utah Associated Municipal Power Systems, and PacifiCorp, part of Warren Buffett’s Berkshire Hathaway Inc. have entered into partnerships with manufacturers to build small modular reactors, or SMRs, because of their potential to produce 24-hour-a day, carbon-free, process heat and electrical power.

Dozens of SMR developers world-wide—ranging from 22-person startup Oklo to Bill Gates-founded TerraPower—are testing designs for the reactors, which have less than a third of the generating capacity of traditional nukes and have components that can be mass-produced in factories.

Their development is backed by the U.S. Energy Department, which said last fall that it would invest $3.2 billion over seven years to support such projects to boost cleaner technologies and decarbonize the power sector.

However, SMR makers are still years away from proving that the technology can live up to its promise. None of the designs being tested across the country have fully made it past the U.S. regulatory review process, and the first miniature reactors likely won’t start delivering power to customers until the end of the decade, at the earliest.

This is a bit pessimistic and shows the author’s biases. Factory-built SMRs can proceed very quickly from design, to fabrication, to test.

Opponents question whether the shrunken nuclear reactors can shed the issues that have plagued the now aging fleet of full-size plants, such as costly development times, nuclear waste management and safety concerns.

Some power companies, including Ameren Missouri, say they see promise in the technology but have stopped short of committing to any agreements until it is proven cost-effective.

The major unknow here is regulatory. 90% of the “problems” with existing nuclear plants have been caused by operator error. The new SMRs are largely automated and use different cycles to eliminate this problem

Many SMR makers are keeping the exact price tag on their projects confidential, citing competitive reasons, but analysts think costs could range from tens of millions for the smallest microreactors to low billions for larger projects.

For example, TerraPower’s 345-megawatt Natrium reactor will cost about $1 billion, with a levelized cost of electricity—or generation cost over the plant’s lifetime—estimated in the $50 to $60 range per megawatt-hour, according to a company spokesperson. The same metric for a new combined-cycle natural-gas plant ranges from $44 to $73 per megawatt-hour, according to 2020 estimates from global investment bank Lazard Limited.

There is only one full-size nuclear plant under construction in the U.S.— Southern Company’s expansion of its Vogtle facility in Georgia. The project is more than five years delayed and billions of dollars over its initial projected cost. Numerous plants around the country are in the process of being closed or decommissioned, as the industry faces political opposition to nuclear power and competition from low-cost natural-gas power plants and renewables such as wind and solar.

There are numerous horror stories of large nuclear plant developments. They are caused by a combination of inexperienced developers (we haven’t build that many nuclear powerplants in the last thirty years) and cumbersome regulations (for the same reason). The current approach is broken and it insane to continue and try and make it work.

Utilities that have bought into the SMR promise say that relying on renewables and storage technology alone isn’t enough to reach goals to slash carbon emissions within the next couple of decades. And they are correct without the breakthroughs in storage technologies discussed last week.

The Utah Associated Municipal Power Systems, a consortium of city-owned utilities serving the Intermountain West, has joined with SMR developer NuScale Power and aims to bring six miniature nuclear reactors online by 2030, each producing 77 megawatts of electricity, or enough to power over 350,000 homes.

“Our cities have a desire to distribute carbon-free electricity to their citizens, and we’re looking to replace our coal plants and eventually natural gas plants with carbon-free energy,” said UAMPS spokesman LaVarr Webb. Coal power made up 61% of Utah’s total electricity net generation in 2020, compared with 19% nationwide, according to data from the Energy Information Administration.

Some opponents aren’t persuaded, saying the project represents a big risk for consumers. “A city-owned power company shouldn’t be acting essentially as venture capital investors with ratepayer money,” said Rusty Cannon, president of the Utah Taxpayers Association. The group has been urging cities to withdraw from the program, and several have done so.

Even for utilities that don’t operate coal or gas plants, some power companies say that mini reactors could still play a role in supporting a transition to a clean energy grid. SMRs have the ability to “load follow,” or ramp up and down quickly to match electricity demand throughout the day, said Jason Herbert, strategy director for new nuclear development at Energy Northwest. This characteristic makes them a good partner for renewables, whose output is dependent on weather conditions and time of day.

Decarbonization goals, propelled by growing concern over carbon emissions’ contribution to climate change, are likely to play in the technology’s favor, said Robert Rosner, physicist and professor at the University of Chicago.

“The outstanding question is how far you can push down the price,” he added. “And there I think the jury’s still out.”

I agree and that’s why it’s vital for the Atomic Energy Commission to fund development and test for several of the SMR concepts.

Copyright ©2021 Dow Jones & Company, Inc. All Rights Reserved. 87990cbe856818d5eddac44c7b1cdeb8

Who's going to fix the space junk problem?

I am enclosing an article from, not because I agree with him, but because we should be educated on this topic to make wise decisions.

By Paul Sutter 5 days ago

Paul M. Sutter is an astrophysicist at SUNY Stony Brook and the Flatiron Institute, host of "Ask a Spaceman" and "Space Radio," and author of "How to Die in Space." Sutter contributed this article to's Expert Voices: Op-Ed & Insights.

There are over 20,000 known and tracked pieces of space debris orbiting Earth, each one traveling at about 15,000 mph (24,000 km/h). They pose a risk to future space missions, and nobody is bothering to clean it up. Why? Because it's too hard.

It’s too hard because the Earth isn’t perfectly round. This causes precession of orbits so that objects in different orbits precess around the Earth at different speeds. Hence objects that may have started at the same point in space might eventually find themselves traveling in directions almost 180 degrees apart. At 7 km/second this makes a collision a serious issue and makes a mission to collect both pieces physically impossible.

In the early 1960s, the U.S. military wanted to devise a new way of communicating with its forces around the globe. If an enemy severed undersea cables, they could only rely on bouncing radio signals off of the ionosphere, which was an unreliable method. The Cold War-era solution? A program called Project West Ford, a plan to launch 480 million tiny slivers of copper needles into space, giving Earth an artificial ionosphere and a reliable way to communicate.

After the first batch was successfully launched, however, the program was canceled. One reason was the accelerated development of communications satellites. The other was that everyone realized that sending countless bits of random junk into space was probably a bad idea.

Since then, the amount of space junk has only grown. In Earth orbit, there are more than 23,000 objects larger than about 4 inches (10 centimeters), another half a million objects larger than about 0.4 inch (1 cm) and possibly 100 million more smaller than that, according to NASA. And there's all sorts of stuff up there: dead spacecraft, spent rocket boosters, lost gear from space missions (including a glove, a camera, a blanket, a wrench and, somehow, a toothbrush), random bits of wrecked gear, paint flecks, bits of metal, frozen propellant, and a lot of screws and bolts.

Space is getting messy, and it's making life dangerous.

On April 24, 1996, the U.S. Ballistic Missile Defense Organization used a Delta II rocket to launch an infrared monitoring satellite into orbit. About a year later, Lottie Williams of Tulsa, Oklahoma, was minding her own business in a park when she was struck in the shoulder by a 6-inch-long (15 cm) piece of fiberglass and aluminum. Minutes later, more pieces of the second stage of that Delta II rocket crashed a couple hundred miles away.

Williams became the first (and so far, only) person to be struck by falling space junk. But an estimated 100 tons of space junk makes it to Earth's surface every year (though most of it falls into the ocean and does not pose a risk to humans).

And there's more. In 2007, China tested its anti-satellite technology, hurling a massive, hypervelocity slug at a weather satellite. The test worked — and created more than 3,000 pieces of tracked junk in orbit. In 2009, a (functional) Iridium communications satellite was supposed to sling silently by a (dysfunctional) Russian military Kosmos satellite with almost 2,000 feet (600 meters) to spare. It didn't, and that one event triggered another avalanche of 2,000 debris objects.

About once a year, the International Space Station (ISS) must maneuver to avoid a dangerous piece of junk while the astronauts hide in safety in a Soyuz capsule. The Space Shuttle famously collected holes and craters in its windows, radiators, and thermal tiles from collisions with … mostly paint chips.

Despite their small size, the incredible velocity of space junk objects gives them a serious punch, creating a very real risk to future space missions. With the launch of mega constellations of broadband internet satellites from the likes of SpaceX, OneWeb and Amazon, many rightly fear the coming of “Kessler Syndrome” when enough debris causes enough collisions to trigger even more debris, cascading to the point that Earth orbit is an unsafe, unusable wasteland.

The Kessler syndrome is named after an old friend, NASA Scientist Donald Kessler, who first pointed out that with enough satellites in Earth Orbit, one collision could generate enough debris to trigger many more collisions.

Laser brooms, boosters, nets and harpoons

Unfortunately, private companies and national governments are slow to act. Most of the efforts focus on mitigation and avoidance of generating space junk in the first place. For example, rockets have to use up all of their fuel and reactants, to minimize the risk of an unexpected explosion. And when satellites reach the end of their lives, they can either deorbit and (hopefully) burn up in the atmosphere or, if they're high enough, push themselves into the "graveyard orbit" hundreds of miles above anything useful.

While these mitigation strategies may help control the spread of space junk, they don't do anything to clean up what's already up there. Earth's own atmosphere will do some of the work as it drags down on anything in low Earth orbit, but depending on the orbit, that process can take anywhere from a few months to a few decades.

Space agencies and private companies have come up with a variety of cleanup ideas. Special missions could push other satellites down into the atmosphere or up into the graveyard, using technology as old as civilization itself: harpoons and nets. Other plans call for ground-based lasers to heat up one side of a satellite, causing it to shift its orbit and get caught in Earth's atmosphere.

But besides the ground-based laser, amusingly nicknamed a "laser broom," all of the proposals call for launching new satellites, thus making satellite cleanup uncomfortably expensive. Besides, there's also the fact that any "satellite cleanup" technology automatically becomes a "remove an enemy's satellite from the sky" technology. This means that any proposal quickly moves into the murky waters of defense, international diplomacy and the militarization of space.

For now, our best strategy is to track, monitor and warn, using a network of ground- and satellite-based observatories — and cross our fingers.

This best long-term plan is to go out and capture the biggest and most massive pieces first. This could be done using the Earth’s magnetic field and electromagnetic tethers (EMTs) for propulsion, so no propellants are required. The EMTs would return the defunct satellites and empty stages to a centrally located “Salvage Yard” where parts could be recycled. It is not worth pursuing the tens of thousands of small debris, but they could be swept out of key orbits using the laser broom. Eventually the orbits of all the small debris will decay and they will reenter, but this could take hundreds of years.

Starship Bulletin

August 6, 2021 - SpaceX stacked the Starship on the Super Heavy Booster for the first time today.

The Super Heavy has 38 Raptor engines (count em) as shown in the figure below.

Raptor Engines on the Super Heavy Booster

Building the largest rocket ever on Earth by stacking Starship SN20 on Super Heavy booster B4. Saturn V rocket which took humans to the moon in 1969 was the largest rocket before this one. Unlike Saturn V, this one is fully reusable. I continue to be amazed at the rate of progress for the Starship Program. I wish them godspeed.

Now checkout begins for a TBD orbital launch date.

Thanks for Reading,

Dana Andrews

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