Category: Engineering

Would it be more or less difficult to put a human on the moon today?

by philg

As part of a recent trip to D.C., I enjoyed seeing a projection of a Saturn V rocket on the Washington Monument:

What if we tried to do this again? Would it be easier or harder to accomplish? As part of the new Corvette announcement, a GM executive talked about the “women and men” whose designs and efforts got us to the moon. We still have women and men and now also have a rainbow of additional genders. If diversity is our strength, shouldn’t it be easier to get to the moon?

But what, specifically, would be easier to engineer?

It seems as though guidance would be much easier, but the MIT Draper Lab guidance systems in Apollo worked well, didn’t they?

Are we able to build life support environments much more easily and cheaply now that we’ve had all of this space station experience? Or does our reduced risk tolerance and love of bureaucracy actually make it harder and more expensive to build space vehicles for humans?

[Separately, here’s how one of the Facebook righteous thought about the glorious days of JFK and Apollo 11 compared to these dark times when our president cannot even get organized to get to the brink of nuclear war…

In awe about a President worthy about setting point and making Americans work towards that goal…what inspiration 50 years later…#apollo11…current drumph not worthy of even 1 year celebration. Seriously people…think…and change the trajectory…at least for our incredible chidren. In awe of their inspiring questions…give love and our children a chance…

JFK gave our children a chance to be incinerated in a nuclear war?]

Related:

Full post, including comments

Crazy cheap solar power plant

by philg

“World’s Largest Solar Power Plant Switched On” (Forbes):

The $870 million project was the result of a competitive tender process that will see electricity from the site sold to the Emirates Water and Electricity Company (EWEC) for around 2.4 cents per kWh, a record at the time of the auction and a record for any completed solar project. It was built by the Indian firm Sterling & Wilson with nearly 3000 people working on site during the peak of activity.

Can this be right? These profit-driven folks can recover their $870 million by selling power at 2.4 cents/kWh? That’s more or less free (the average cost in the U.S. to consumers is about 13 cents/kWh, which of course includes distribution).

Most parts of the U.S. are not as sunny as the UAE, but some parts are. Could we build a monster plant like this in Arizona or Nevada and run the power back to the cloudy East Coast? A friend who used to run a mutual fund that invested in this area said, “It would be a no-brainer economically to run a DC high voltage line from wind farms in Oklahoma to New York City. You could shut down every fossil fuel power plant in New York. But the U.S. power grid is fragmented and the people who stand to benefit from that have enough politicians in their pockets to keep it fragmented. So you’ll never see that power line built.”

Vaguely related: This investor considers Jeff Immelt to be the most incompetent executive in recent American business history. “GE actually made windmills so they knew that the price was going to drop below that of coal-fired power plants,” he said. “Yet still, GE bought Alstom, which has been disastrous. Even if the market for fossil fuel plants had held up, GE was locking itself into French labor, which any rational businessperson would seek to avoid. It is fair to say that the folks at Alstom were a lot smarter than anyone at GE.”

For the rest of the world, where they aren’t as plagued by cronyism in power transmission as we are, will it be time to go nuts with electricity (cars, planes, heat pumps, etc.)?

Also, does this mean we don’t have to worry about about climate change and CO2? Who is going to bother burning fossil fuels for any reason if they can get electricity for 2.4 cents/kWh plus reasonable transmission fees? (Aviation? Just turn the electricity into hydrogen and then run your electric motors off a fuel cell!) We were terrified in the 1970s about burying ourselves in nuclear waste. Then it turned out that we couldn’t operate nuclear plants economically, so the amount of waste generated was much smaller than anticipated (we just burned natural gas and dumped out CO2 instead!).

Full post, including comments

Solar panels failing after six years

by philg

Why let the amateurs at the power company generate and deliver power in exchange for a monthly subscription fee when you can go into the power generation business yourself?

A local friend (and MIT PhD in EECS!) put solar panels on his roof six years ago, responding to the massive government handouts on offer at the time (thanks, fellow Massachusetts taxpayers!). Roughly half of the panels have now failed, casualties of squirrels, UV light, etc.

Given the rising cost of labor (a bundle of wages and health care expenses), will it turn out that America’s big rooftop solar experiment was a colossal failure from a total lifecycle cost perspective?

Already it seems to me that single-family homes are unaffordable for a typical family because the cost and challenge of bringing contractors in to maintain all of the systems has been growing every year. Adding an electricity generation plant on the roof makes this problem worse.

Related:

Full post, including comments

Titanic Museum, Belfast

by philg

Posted on Facebook under “Heard it might be a Boeing 737 MAX on way back from Ireland so decided to take a ship for safety.”:

Could this be the world’s most lavish museum devoted to engineering failure? The science turned out not to be settled, unfortunately. Folks in Belfast do like to point out “She was alright when she left here.”

The museum does disclose how badly the first voyage turned out for most people on board:

This was despite substantial government regulation:

Also despite the latest in wireless communication technology:

Yet the skill of management, engineers, and workers is celebrated:

Is it a bad thing when a country goes from being a world industrial leader to irrelevant compared to South Korea, China, and Japan? Barack Obama says “No problemo:”

Passengers were arbitrarily divided into only two genders:

Not every movie about the Titanic is an unimaginative derivative:

Then, as now, the migration industry was highly profitable for some…

A reminder to be humble…

… considering that the best humans could do lasted less than two weeks against Nature. From notes typed up by a shipyard office worker:

The building is a beautiful work of engineering in itself and includes a gratuitous Disney-style ride:

More: Visit Titanic Belfast

Full post, including comments

Another airplane that fights the pilot if one AOA sensor is bad: Cirrus Jet

by philg

In another triumph for American engineering, it seems that the Cirrus Jet‘s stick pusher activates if a single AOA sensor fails mechanically (FAA Emergency Airworthiness Directive 2019-08-51). The system isn’t quite as badly designed as the Boeing 737 MAX’s silent gradual pusher, but it is nowhere near as robust as the early 1990s design on the Pilatus PC-12 (Swiss engineering). An important difference is that it is obvious to the pilot(s) when the Cirrus system is operating and the disconnect button is right on the yoke (just the usual A/P disconnect button).

Full post, including comments

Disney World shows that VR is pointless?

by philg

If you’re trying to save a few dollars, maybe a head-mounted display is a good idea. What if you don’t care about capital cost? Disney World has a lot of immersive simulators that don’t require any headgear for the park guests. They just project a virtual world on big curved screens.

What about for home use? Why not build a small room in a house with a curved screen that completely surrounds the player? Use whatever tricks they’re using at Disney to make the projection work, but with $100 LCD projectors instead of the super bright ones needed for the monster domes that hold hundreds of people simultaneously.

If you’ve got your head-mounted VR system on, you’re not going to be a great asset to the rest of the folks in an apartment or house. Why not declare that immersive gaming is an activity that happens in its own room? Maybe it costs $5,000 instead of $500 for the hardware, but people used to pay $5,000 for the then-new plasma TVs.

Readers: Would this be better or worse than the VR headsets?

Full post, including comments

Boeing 737 MAX crash and the rejection of ridiculous data

by philg

“Boeing 737 Max: What went wrong?” (BBC) contains a plot showing the angle of attack data being fed to Boeing’s MCAS software. Less than one minute into the flight, the left sensor spikes to an absurd roughly 70-degree angle of attack. Given the weight of an airliner, the abruptness of the change was impossible due to inertia. But to have avoided killing everyone on board, the software would not have needed a “how fast is this changing?” capability. It would simply have needed a few extra characters in an IF statement. Had the systems engineers and programmers checked Wikipedia, for example, (or maybe even their own web site) they would have learned that “The critical or stalling angle of attack is typically around 15° – 20° for many airfoils.” Beyond 25 degrees, therefore, it is either sensor error or the plane is stalling/spinning and something more than a slow trim is going to be required.

So, even without checking the left and right AOA sensors against each other (what previous and conventional stick pusher designs have done), all of the problems on the Ethiopian flight could potentially have been avoided by changing

IF AOA > 15 THEN RUNAWAY_TRIM();

to

IF AOA > 15 AND AOA < 25 THEN RUNAWAY_TRIM();

About 10 characters of code, in other words. (See the Related links below for the rest of the flaws in the MCAS system design, which the above tweak would not have fixed.)

We fret about average humans being replaced by robots, but consider the Phoenix resident who sees that the outdoor thermometer is reading 452 degrees F on a June afternoon. Will the human say “Arizona does get hot in the summer so I’m not going to take my book outside for fear that it will burst into flames”? Or “I think I need to buy a new outdoor thermometer”?

Related:

Full post, including comments

Green New Deal will not cost as much as feared

by philg

It turns out that a powerful Vestas wind turbine can be purchased for $199 on Amazon.com.

Related:

Full post, including comments

Certification process for the 737 MAX silent gradual pusher system

by philg

A reader was kind enough to send me “Flawed analysis, failed oversight: How Boeing and FAA certified the suspect 737 MAX flight control system” (Seattle Times), which gives some more detail on how the world’s first “silent gradual pusher” system was unleashed on airline passengers and crew. (See https://philip.greenspun.com/blog/2018/11/11/boeing-737-crash-is-first-mass-killing-by-software/ for my description of how the conventional stick pusher works; it requires two sensors to agree before it will activate and the pushing is readily apparent to the pilots; disabling the pusher in a simple turboprop aircraft is as simple as pushing a button on the yoke).

The Seattle Times article describes the delegation process by which an employee of Boeing can actually do a lot of the work that members of the public imagine FAA employees would be doing. Boeing is an “Organization Designation Authorization” holder (“ODA”). A Boeing employee puts on an FAA hat periodically and checks work done by fellow Boeing employees.

Putting government workers in the critical path for engineering improvements slows things down so much that safety ends up being compromised. And having people pay designated or delegated authorities cuts the cost to taxpayers. But I wonder if it is time to say that certification scrutiny should be done by an independent private engineering team, not by engineers employed by the manufacturer.

Full post, including comments

Theranos was an immigration and H-1B story

by philg

Bad Blood, the authoritative book on the rise and fall of Theranos, describes American- and British-born engineers and scientists being fired for saying “the goal is too ambitious” or quitting when realizing this. Who replaced them? According to the book, almost all immigrants from India, either folks who’d recently completed a degree in the U.S. or coming over on H-1B visas, all managed by Ramesh Balwani, Elizabeth Holmes’s boyfriend.

During the “grand fraud” stage of Theranos, therefore, it was a primarily immigrant show except for the young impresaria.

[I’m going to guess that neither Mr. Balwani nor any of these engineers and scientists make it into the children’s book First Generation: 36 Trailblazing Immigrants and Refugees Who Make America Great…]

The money to fuel the craziness of Theranos seems to have been all domestic. Walgreen’s kicked in $100 million(!) as an “innovation fee” and then loaned the company another $40 million, according to the book. The credulous yet imperial CEO Steve Burd (Wikipedia shows him hanging out with Barack Obama) drained huge amounts of Safeway shareholder cash to help Theranos. The idea in both cases was that Theranos devices were supposed to be placed in these retailers’ stores.

If the end result is a tech staff that is mostly Indian, I wonder if the Silicon Valley location makes sense. Why not have all of the engineers and scientists work from Bangalore or Delhi? Instead of 8 people sharing a two-bedroom apartment in Menlo Park, each of those 8 workers can enjoy his or her own comfortable house (rent for a 3BR apartment in the center of Bangalore is about $570/month (source), 1/10th the price of Menlo Park (source)). What’s the advantage of bringing H-1B slaves over to toil on a Silicon Valley plantation compared to running the tech farm in India?

(Another interesting aspect of the book is learning just how much room there is for human error in traditional medical lab tests, e.g., in the handling of reagents. Elizabeth Holmes was not wrong in thinking that a fully automated process could potentially be more reliable.)

Related:

Full post, including comments