* Posts by cray74

1081 publicly visible posts • joined 29 Nov 2011

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Is Russia using Starlink in Ukraine? Congress demands answers

cray74

Re: Should be (relatively) simple...

I'm still puzzled why Congress is making such a big deal out of this given Russia doesn't exactly need Starlink.

Russia's invasion revealed a lack of decent communications systems in its military. Russia has spent the last 30 years developing advanced military technology but didn't follow through in deployment, allegedly because deployment funds went into the pockets of Putin's associates.

Communications gear is one of those deployment failures. While the Russians have advanced, jam-resistant, frequency-hopping software-defined radios (e.g., the R-187P Azart), most of their troops have been stuck using unencrypted radio, civilian walkie talkies, personal cellphones, and co-opted Ukrainian cell towers to communicate. This has resulted in the high death rate of Russian generals and the ability of every interested nation to listen in on Russian activity. Further, the focus on individual communication devices rather than a coherent system means the Russians have an incompatible stew of radios.

Deficient access to equipment has plagued Russian throughout its invasion. The early invasion saw inadequate clothing, food, fuel, and medicine, resulting in Russian troops - who should've been the most winterized force in history - suffering frostbite, starvation, and fuel exhaustion.

Since the Russians have been dependent on captured Ukrainian cell towers and civilian communications equipment, it's reasonable they'd exploit Starlink, too.

OSIRIS-REx probe sucked up more asteroid crumbs than hoped

cray74

Re: On the waiting list for Spring cleaning

It's basically made of unobtanium.

Or measurementerrorium. The 2012 study by Benoit Carry not only produced a density of 75-ish grams per cubic centimeter for Polyhymnia, but also some extremely high values for other asteroids of similar size (e.g., 675 Ludmilla, which had a density of about 73 g/cc). Carry considered his results unreliable. While Polyhymnia has not passed other sizable asteroids for additional gravitational measurements, a 2019 reanalysis of Lydmilla's orbit showed its density was more likely about 4g/cc (in the range of 2-6g/cc).

FAA gives SpaceX a bunch of homework to do before Starship flies again

cray74

Re: Moon landing

THey have openings where al lthe exhaust gases escape, stuff will get sucked in which is exactly what happened when in that Starship failure not that long ago

Rather longer ago, the largest rocket engines used on the moon did so without damage from flying debris. The Apollo LM descent engines and descent module never experienced dust/debris damage, though they did sandblast nearby structures (e.g., Apollo 12's damage to Surveyor 3). Apollos 12 and 15 had very dusty landings, with the crew commenting it felt like they were making instrument flight rules descents rather than visual. Despite that: no dust/debris damage.

Apollo 15 did experience engine damage but not from blown dust/debris. Apollo 15's LM was the first to use an extended engine nozzle to deliver more payload to the lunar surface. The nozzle extension was crumpled (as it was designed to do) when it crunched into the uneven lunar surface.

Europe's Ariane 6 rocket rated 'ready to rumble' after passing hot fire test

cray74

Re: ESA suffers from the same disease as NASA

There's that weird idea that SpaceX is competing with NASA again. NASA doesn't build or operate rockets, it runs air and space research programs. SpaceX doesn't have a space exploration program, it builds rockets and launches customers' payloads.

SpaceX had a designed, tested, and validated solution for around $250M.

SpaceX's initial Falcon 9 development costs of $400 million included about $250 million from NASA. Later reusability refinements on the Falcon 9 and development of SpaceX's Dragon capsule depended heavily on NASA's multi-billion dollar commercial launch services contracts and commercial crew delivery contracts. SpaceX's DragonEye docking system for the capsules was tested on shuttle flights (themselves run by a private company, the United Space Alliance) to the International Space Station (which was largely built by western private sector entities, like Boeing).

SpaceX is again getting billions of dollars from NASA to develop the Starship. As of last count, two loads of funding under NASA's Human Launch Services contracts have given SpaceX $4.04 billion to get Starship airborne and, eventually, deliver people to the moon.

SpaceX, like Boeing, Lockheed-Martin, Arianespace, and many other private entities, are contractors for NASA. NASA gets huge sums of funding from Congress to study space and then finds contractors to build and fly its rockets because the US public thinks it is uncool for government agencies to run, say, rocket factories. NASA's launch service contractors, meanwhile...

Companies like SpaceX are going to leave them in the dust, as they should.

...never created or ran space exploration programs. SpaceX hasn't put a penny of its own money into developing a deep space probe, running teams of space researchers and astronomers, or operating aerodynamics research labs like NASA has. SpaceX is a delivery service that builds its own delivery vehicles, with a developing side hustle in communications.

SpaceX has been groundbreaking in its advancement of launch services and cost reductions, which have pretty much knocked Boeing and Lockheed-Martin (operating as the United Launch Alliance) out of the market. Under Gwynne Shotwell, SpaceX has done some great work. And NASA is loving that SpaceX work: SpaceX lets NASA run redundant, competing lines of rocket and lander development to make sure Artemis gets to the moon whether the SLS tanks or Starship keeps blowing up.

It's just a misunderstanding to think that SpaceX is competing with NASA. They're doing completely different things.

SpaceX celebrates Starship launch as a success – even with the explosion

cray74

Re: Self destruct

Boeing isn't a private company; it's a publicly-traded company (ticket "BA").

I meant that Boeing isn't a public sector entity like the US government. Boeing is a private sector, for-profit corporation like SpaceX and, yes, Boeing is a public corporation while SpaceX is private. However, news articles aren't gushing about SpaceX being a non-publicly traded corporation achieving spaceflight, they're gushing about it being a private sector entity achieving spaceflight.

I found the point weird since because Western space-capable rockets have been built by the private sector since Mittelwerk GmbH's MW 18014 reached space in 20 June 1944. SpaceX is doing much the same as every aerospace company before it: it's a private entity taking lots of government money to go to space.

cray74

Re: Self destruct

He's doing what NASA would never be allowed to do, rapidly progressing launch technology through testing prototypes

The Starship is being developed on $4.04 billion in NASA funding so, in fact, NASA is rapidly progressing launch technology through testing prototypes.

More generally, NASA rarely builds rockets. Ever since Alan Shepard popped above the atmosphere on a Chrysler-built Redstone rocket in a McDonnell-built Mercury capsule, NASA has relied on private contractors for construction and operation. NASA didn't build the Saturn V. NASA didn't build the shuttle. NASA didn't build the Atlas V. NASA didn't build the Falcon 9. But it definitely funded them to varying degrees, and then hired their launch services for publicly-funded missions.

Further, it's a mistake to think that a contractor like SpaceX (or Boeing, or Lockheed-Martin, or ArianeSpace) is a rival to NASA when they're doing different things. NASA doesn't build and launch rockets. Instead, NASA runs space exploration and aerospace development programs assigned to it by Congress. SpaceX doesn't have a space exploration program, planetary research centers, or researchers seeking to explore space. Instead, SpaceX is an aerospace company that builds rockets and uses them to launch payloads from paying customers like NASA.

cray74

Re: I can't help but feel....

...that investors will only put up with so much

One of those investors is the US government, which has contributed about $4.04 billion to SpaceX for Starship development via the HLS contracts. NASA has a different tolerance for risk and failure than profit-seeking investors.

SpaceX's history is an interesting study in the US government's tolerance for risk. The first three Falcon 1 flights had the following customers:

Flight 1: US government's Defense Advanced Research Projects Agency (DARPA)

Flight 2: DARPA

Flight 3: NASA, ORS (a US government multi-agency effort), and the commercial entity Celestis

While those three Falcon 1's were exploding over Omelek Island, NASA was funding SpaceX with hundreds of millions of dollars to get the Falcon 9 airborne. As SpaceX's President Shotwell noted, NASA's funding was vital to getting the Falcon 9 off the ground.

Now, 17 years after Falcon 1 first flight blew up and after 17 years of listening to SpaceX brag about its "learning by exploding" process, NASA is throwing billions at SpaceX for a working, lunar landing version of the Starship. Because Congress is feeling generous about space funding, NASA is addressing its assigned task of "get to the moon" with a risk reduction approach for its mission rather than profits: it is funding SLS, Starship, and Blue Origin. If one fails then NASA has alternatives in the development pipeline. Further, NASA knows that SpaceX is going to take a more explode-y approach to spacecraft development than other private competitors like Boeing and Blue Origin.

NASA, metaphorically like SpaceX, is having a blast.

before insurers stop carrying the risks

The insurance carried for the Starship test flights is liability insurance in case rocket confetti lands on someone or their belongings:

"...part of the FAA licensing process is a calculation of the “maximum probable loss” from third party liability—that is, liability for harm to anyone other than the launch provider and the owners of payloads carried by the launch. The launch provider is then required, by the terms of its license, to carry insurance for the maximum probable loss amount, up to a cap of $500 million."

Since the insurance isn't for the rocket, which is expected to explode, and because no one's been killed by Starship yet, the insurers haven't gotten annoyed with SpaceX.

Falcon Heavy sends NASA probe to metal-rich asteroid Psyche

cray74

Re: I have to admit

All these billionnaires have really shaken up the landscape when it comes to accessing orbit.

Billionaires did, they got the ball rolling again while older private aerospace companies like Boeing and Northrop-Grumman dawdled.

Yes, it was inevitable as soon as the US government lost interest in space when the race was won.

And, fortunately, some of those billionaires had Presidents and COOs like Gwynne Shotwell, who figured out how to get reliable, stable funding for the billionaires' space dreams: the US government. The Falcon 1 flew with US government payloads when no one else would launch a satellite on it. The Falcon 9's development was funded by US government contracts like the Commercial Resupply program - without those hundreds of millions the Falcon 9 wouldn't have flown. The Dragon capsules, funded on US government programs, tested and refined their Dragoneye docking system on the last US shuttle flights. Now Starship is ironing out its development problems on billions of dollars from US government contracts.

The US government is willing to fund multiple routes to the moon (SLS and Starship) just like it funded multiple competing companies to resupply the ISS, which means NASA has been having a blast this past decade. NASA isn't stuck with the old, overpriced ULA launchers for its space probes, freeing money and making Congressional negotiations easier. It gets to issue and manage more contracts for more private companies, meaning more money to skim for itself. And if one of its private contractors collapses because its billionaire CEO has a meltdown or because its airliners stopped selling then NASA has well-funded alternatives already underway.

MOXIE microwaved Mars air into oxygen, but now it's time for a breather

cray74

Re: What happens to lots of carbon monoxide

The main thing that happens to Mars' atmosphere is it gets blown away by the solar wind.

On time scales of 100 million to 4 billion years, yes. Mars has an additional issue with low escape velocity, which also makes it vulnerable to Jean's escape mechanism and impact-driven atmosphere ejection. A reasonable asteroid that is a non-issue to Earth's atmosphere (if of more concern to dinosaurs) can drive eject nearby Martian atmosphere at more than escape velocity.

The Earth's magnetic field protects our atmosphere.

It may help. However, Earth has a couple of other advantages: a much higher escape velocity and much larger reservoirs of volatiles than Mars.

a huge (but not planet sized) magnet at Mars-Sun L1 would to the trick.

A LaGrange magnetic shield would help protect Mars on giga-year time frames. It wouldn't make much difference to most terraforming schemes or reasonable periods of human occupation.

Scientists trace tiny moonquakes to Apollo 17 lander – left over from 1972

cray74

Did Lockheed-Martin also want to be paid for their work in goats?

Lockheed-Martin has figured out the utility of more fungible currencies than farm animals, but (as of today) is still using US customary units for many of its products like the F-35. So does Boeing.

Except when they don't. You can find a lot of scientific work, like optics, being handled in SI units and then applied to hardware measured in US customary units. Even US suppliers may work in metric - UTC Aerospace (nee Goodrich) delivers landing gear to Boeing that was developed in metric.

Scientists spot startlingly close black holes in Hyades star cluster

cray74

Re: "we'd probably already be dead"

The only question is, at what distance are we doomed by a passing star or black hole ? If it is two light-years away, are we safe ?

While Matthew McConaughey or Beowulf Schaeffer might experience extremes of gravity skimming the black hole, a black hole doesn't have a gravitational field of larger dimensions than a star of the same mass because gravitational force is a result of the distance between two objects and their masses. Same mass, same distance, same force. For example, instantly swapping Sol with a 1-solar mass black hole would leave all of the solar system's planets and lesser objects in unchanged orbits.

The most likely black hole to pass by is a stellar mass black hole, which would be 5 to 30 solar masses (give or take a few kilograms). Taking the worst case of 30 solar masses at 128,000 astronomical units (2 light-years with some rounding)...

1. The black hole has 443 times as much gravitational force on Earth as Pluto at 40AU

2. The black hole has 70 times as much gravitational force on Earth as Alpha Centauri A+B at 275,000AU

3. The black hole has 1/30th the gravitational force on Earth as Neptune at 30AU

4. The black hole has 1/650th the gravitational force on Earth as Mars at 0.5AU

5. The black hole has 1/14,806th the gravitational force on Earth as Venus at 0.3AU

6. The black hole has 1/20,850th the gravitational force on Earth as Jupiter at 5AU

7. The black hole has 1/1,720,000th the gravitational force on Earth as Luna at 0.0026AU

8. The black hole has 1/540,000,000th the gravitational force on Earth as Sol at 1AU

Another way to look at this is: a star 30 times as massive as the sun would need to get within about 5.2AU (Jupiter's orbit) to match Sol's gravitational force on Earth. It'd be a pain at some thousands of AU, too, probably bothering the Kuiper Belt.

So, while Jupiter and Venus warp Earth's orbit a bit over a 405,000-year period, a singular passage by a large black hole at interstellar distances won't do squat to Earth or the solar system. If the Oort cloud actually is out there then it might be disturbed and we'd need to deal with a flood of comets in a few million years, but close passages by stellar-mass objects have happened before. Scholz's Star buzzed Earth 70,000 years ago at a distance of 52,000 astronomical units.

There is a matter of radiation from the black hole's accretion disk, but that shouldn't bother Earth much unless the polar jets swept over us.

BepiColombo probe turns to the dark side … of Mercury

cray74

Re: So

Why did they put the camera in a position with an impeded view?

Yep, Monitoring Camera 3's view of the BepiColombo spacecraft is crowded by that photo-bombing planet, ain't it? ;)

BepiColombo has three spacecraft monitoring cameras meant to look for problems like failed antenna or solar panel deployments. While they're not the high-performance spectrometers and imagers of BepiColombo's SIMBIO-SYS package, the engineering cameras can generate some cool PR visuals.

Caltech claims to have beamed energy to Earth from satellite

cray74

Re: Misdirection

Large space-based, microwave power transmitters are generally designed for safe power densities, like 1 milliwatt per square centimeter. Further, the beams were designed lose focus if the beam strayed from the rectenna though the reference to that is eluding me.

Astronomers spot Earth-sized exoplanet probably 'carpeted' by volcanoes

cray74

Re: Any architects care to comment?

New houses on LP 791-18d...

I'd go with a pontoon house boat. Stainless steel pontoons should be able to handle the heat of the lava. You'd need a good amount of insulation under the deck and an impressive air conditioner. Also, you might end up on water so the pontoon system would give you flexibility.

Perseverance rover shows up Curiosity with discovery of Martian water park

cray74

Re: Mars, what, where?

So we know quite well how to fsck Earth, let's find another target. In the meantime, let's spend an amazing amount of money on JSWT, Hubble and all types of muck leading to little else than pretty pictures feeding astronomers and astrologists alike...

The US is, hands down, the largest spender on space programs either in terms of totals or as a proportion of GDP. Currently, NASA's exploration efforts amount to about 0.3% of the federal budget, dwarfed by federal programs for the elderly, hungry, sick, and homeless. Saying "let's spend an amazing amount of money" on space when only tiny sums go to space programs therefore indicates one hasn't actually looked at government budgets or, worse, is being disingenuous.

Mars Helicopter completes 50th flight, 45 more than NASA planned

cray74

Re: COTS

Also, we may see smaller organizations, both private and public (such as amateur and universities) flying interplanetary missions.

Private organizations fly space exploration missions now. NASA and the ESA offer contracts with decent profit margins to their private contractors and university partners. Ingenuity, for example, was dependent on the design work of AeroVironment.

On their own, private organizations aren't going to do a lot of space exploration because there's no return on investment. SpaceX, often misconstrued as NASA's rival, has never built or operated a space exploration mission at all. Its in-house programs like Dragon, Starship, and Starlink are oriented toward the usual sources of money in space: communications, launch services, and government contracts.

If you're curious, NASA has some studies on the fun of getting COTS electronics into space systems:

COTS space hardware

You don't save as much money with COTS as hoped, there are reliability challenges, and testing over the full range of operating conditions inhales cash.

Launching soon: ESA's Juice to probe Jupiter's moons for signs of possible life

cray74

Re: A thought experiment for the class

I'm just wondering if for future missions To/Near Jupiter we can develop a power system that relies on that massive Jovian Magnetic Field?

Yes, they can, but you have to pay for that electrical energy from somewhere.

Electromagnetic Tethers can offer propulsion or power generation depending on current direction and the external magnetic field.

With electrical current flowing one way, perhaps from an RTG or solar panels, you can use an external magnetic field for propulsion and orbital reboost. Hubble uses a smaller, simpler Magnetotorquer system to aim itself and bleed down reaction wheels without rocket thrusters.

In the other direction, you can convert a spacecraft's velocity and kinetic energy into electrical energy. Basically, you trade speed for juice. This can be useful if, say, you wanted to de-orbit an old satellite with a lightweight system (some electrical wire and aging solar panels), slightly slow a space probe without aerobraking or rocket fuel, and so on. But you are trading away kinetic energy to get that electricity.

David Brin's 'Tank Farm Dynamo' is a short, 1983 hard science story looking at the utility of excess solar power and some long cables in orbit.

SpaceX calendar marked with big red circle for 'first Starship launch' this month

cray74

Re: New Reg unit required

16.5 million pounds of thrust - where's the metric for the rest of the world?

El Reg's unit converter says that's 22,812 Norrises. My TI-85 says it's 73.4 million Newtons.

cray74

Re: Stay up late

Anybody been recently?

I'm close enough that traffic makes it too troublesome to drive to Cocoa. Instead, I step into my back yard to watch.

It is very cool to see launches this frequently. We were supposed to have frequent shuttle launches by the late 1980s but Challenger ended that pace. It's been almost 40 years of waiting to see it get this fast.

I wonder if it is as busy these days with the routine launches?

I've got some friends in the Cocoa Beach-Titusville area who say that it's getting less crowded for regular launches. Something novel like an SLS or crewed launch gets major crowds. Cocoa was manic for the 2022 SLS launch.

Reg fashion: Here's what the well-dressed astronaut will wear on the Moon in 2025

cray74

Re: Looks aren't everything

Mobility and comfort of spacesuits have definitely improved since the Apollo A7L.

On the other hand, SpaceX doesn't have space suits. SpaceX has only produced pressure suits for emergencies, like depressurization during launch, and they're not intended for spacewalks or moonwalks.

The cause of last December's failed satellite launch? Nozzle material, says ESA

cray74

Re: Failing to compete?

ESA is not competing with SpaceX just like NASA isn't competing with SpaceX.

NASA and ESA do not build rockets. They hire private companies like Boeing, Lockheed-Martin, Arianespace, and SpaceX to build rockets and, often, space probes. Their job is to run space exploration missions as funded by associated governments, usually without a concern for profit.

SpaceX is a delivery company (with a side hustle in communications) that builds its own delivery vehicles. It doesn't build, design, or operate space exploration missions. It doesn't have the labs, networks of astronomers, and university researchers to conduct basic space exploration.

'Brittle' Twitter suffers bad case of the Mondays: Links, pics, vids fail

cray74

Re: Space X model

Seems that old Elon is treating Twitter like space X, test until failure then fix what needs to be fixed.

There's a bit of a difference between what Elon did at SpaceX and Twitter:

1. At SpaceX, Elon hired skilled engineers to build rockets. Then he got lots of DARPA, NASA, and investor money to design and test rockets. Then, yes, they tested rockets that exploded and learned from the test failures.

2. At Twitter, Elon is firing every engineer and manager who knows how the system runs while cutting expenditures that might be used for system improvements. The resulting failures aren't from deliberate testing but rather lack of maintenance and dwindling system knowledge. Even if the failures were from deliberate tests then Elon has laid off the skilled personnel who know how to use the resulting test data.

NASA finds crashing spacecraft into asteroids is a viable defence strategy

cray74

Re: Worrying.

Perhaps they don't know the the mass of the asteroid? But 4x!?

That was addressed in El Reg's article. Besides the momentum transfer of DART's impactor, the plume of debris ejected by the impact had a stronger rocket-like effect than expected. It's hard to model the behavior of a milli-G pile of dust and gravel during a deep impact.

Oh, 07734! Internet Archive debuts vintage calculator emulator

cray74

Get off my lawn!

I use my college-era TI-85 at work daily and my TI-81 is around the house. However, the age of the two calculators is recognized by the younger generation.

"Your graphing calculator is older than I am." --Random Intern

Twitter tries to lure brands back with spend-matching scheme

cray74

Citing a Rupert Murdoch rag like the NY Post, notorious for leaving out details, does not make your case.

Additional details, references, and analysis

US think tank says China would probably lose if it tries to invade Taiwan

cray74

Re: Russian Army Numbers

If they do all out conscription, then Ukraine and Poland don't have sufficient manpower. At least England and Germany would have to start conscription, too. Sweden and Finland will be happy to defend themselves.

Ukraine has demonstrated that it has sufficient manpower to halt Russia. A trickle of NATO aid is enabling the Ukraine to recover land.

From a year's worth of observations, conscription isn't necessary for the West if the war broadens and Russia sends millions of barely-equipped conscripts into Poland. Maybe an expansion of munition production would help.

Space startup ABL emulates Virgin Orbit failure by crashing

cray74

Isn't it more usual for a first attempt to carry a dummy payload such a concrete block, a wheel of cheese or a sports car?

Many first rocket launches carry working payloads from customers who can handle losing the satellite or are willing to invest in the rocket's development. For example, before SpaceX launched a sportscar on its Falcon Heavy, it launched three live payloads to Valhalla on the buggy Falcon 1. DARPA and NASA were the original customers.

NASA starts assessing Orion capsule for refurb

cray74

Re: Would I fly to the moon in a reused spaceship?

It also changes the material costs, since materials to better handle the heat cycle tend to cost more.

That's true, but it's an very well solved problem in aerospace engineering.

Orion's heat shield is ablative so it doesn't get reused. The interior side of the heat shield only reaches 200F / 93C. That means the majority of the Orion spaceframe and systems are unlikely to exceed 175F, which is around the peak operating temperature for the aircraft systems I work with. On the cold side, spacecraft interiors generally stay around room temperature as a deliberate design choice. Even the Voyagers' buses were running around 20-25C until RTG power output started drooping. So other than the disposable heat shield the temperature swing of a reentry-capable spacecraft like Orion isn't that large.

For comparison, cycling from a 160F (71C) Saudi airstrip to -70F (-56C) at flight altitude is normal for exterior systems and structures of a commercial aircraft, and commercial aircraft make ~100C temperature swings with every one of the thousands of flights in their lifetime. Does it take attention to detail during design and somewhat more expensive design choices? Yes, and every product I work on goes through environmental stress testing to make sure that it is proven to survive that cycling. Optics are particularly finicky but we get them to work.

Voice assistants failed because they serve their makers more than they help users

cray74

Re: The same applies to tv series and games

Best example of a current series stretched out for cash has to be the Dresden Files. Damn but that is dragging on

I'd vote for the Honorverse novels by David Weber as the posterchild of milking a series for a paycheck. While the Dresden Files are running long, Jim Butcher is keeping the writing animated and engaging. Most of the current Honorverse novels have become lifeless: when the good guys or villains sit around a table and discuss Big Plot Points the books don't have dialogue. Instead, their "dialogue" consists of chapter-long political or military analyses. The lively character interactions of the first few books like "A Short Victorious War" are gone and the new books read like a machine churned them out for the next paycheck.

Self-imposed climate change may have killed Martian life

cray74

Re: Kickstart terraforming

A planetary magnetic field won't add much to Martian terraforming. Mars' escape velocity is high enough to retain an Earth-like atmosphere for 100 million+ years without the magnetic field, and an Earth-like atmosphere is a robust radiation shield of it own. Earth's atmosphere is equivalent to some ten meters of rock shielding.

NASA's Artemis mission finally launches after faulty Ethernet switch delayed countdown

cray74

Re: Flawed

It is easily confusing.

SLS refers to the Space Launch System, a launch vehicle developed by American aerospace companies Boeing, Lockheed-Martin, and Orbital ATK. Starship is another launch vehicle being developed by an American company.

Both the SLS and Starship have a single customer currently: NASA, an organization that has never built an orbital launcher of its own.

cray74

I'll second "Ignition." It's not only an informative read, but it can be very funny at times. For example, the discussion of chlorine trifluoride also documents the first person to break the sound barrier on foot, a feat that immediately followed tipping over a 55-gallon drum of ClF3.

cray74

Aren't those engines Russian by the way?!

No, the SLS's engines are all US-developed and -built. The boosters are 5-segment versions of the shuttle's 4-segment solid rocket engines. The core uses four RS-25 engines, which was a US-developed hydrogen/oxygen rocket used on the shuttle. This SLS flight used an "interim upper stage" with RL-10 engines, a venerable US hydrogen/oxygen rocket.

Basically, the SLS repackages a lot of shuttle hardware and technology.

cray74

Re: Flawed

However, Starship too can fulfill this role and it will be very difficult for SLS proponents to keep this rocket alive after it has successfully demonstrated its capabilities.

The SLS, for better or worse, is protected by shields of government lobbying and the bureaucratic inertia of the century-old corporations building it. The Starship is tightly wedded to Elon Musk, who is one public meltdown away from badly damaging his businesses. His Starlink program is an additional risk to SpaceX - one bad business report could spook investors to dumping it faster than you can say, "Iridium."

Which leads to the thought that you shouldn't bet on Starship until it is making circumlunar flights.

NASA's meteor avoidance plan for James Webb Space Telescope: Turn it around

cray74

Re: WTF?

and they've only just figured this out?

From the second paragraph of the article: "Webb has suffered 14 measurable micrometeoroid hits to its primary mirror, which is about what NASA has expected"

When it was decided that Hubble's successor was going to ditch the enclosing baffle c. 1995, the risk of micrometeoroids was understood by the designers and future owners. The cis-lunar micrometeoroid environment has been thoroughly characterized for decades so the impact rate on JWST's mirrors was understood and addressed in the design. For a telescope that's more powerful than Hubble with entire segments missing, the effects of micrometeoroids over decades of service will be trivial.

However, the public is just waking up to the risk of micrometeoroid damage. Hubble and now James Webb are unusually high profile platforms and words like "meteoroid impact" in conjunction with "$10 billion mirrors" gets a stronger public reaction than, say, the steady rain of micrometeoroids on communication satellites or GPS satellites. It's enough to pressure NASA into Taking Measures, like assigning a committee to study the problem and suggest something like, "turn it backwards."

NASA details totally doable, not science fiction plan for sending Mars rocks to Earth

cray74

Re: China's Moon Mining is a better idea

NASA never done dooed that...

Correct, because NASA doesn't build rockets. NASA didn't build the Redstone rocket (from Chrysler Aerospace) that carried Alan Shepard (in a McDonnel-built Mercury capsule) on a suborbital flight. NASA didn't build the Saturn V (Boeing, North American, Douglas), the Apollo capsule (North American), or Apollo LM (Grumman). NASA didn't build the Rockwell International space shuttle, the Lockheed external tank, or the Morton-Thiokol solid boosters. NASA did, however, pay for their development.

Just like NASA has pumped a fortune into SpaceX's development efforts. SpaceX was broke after all the Falcon 1 failures. Falcon 9 was a pipe dream without outside funding, and NASA stepped up with juicy contracts for Falcon 9 launches, resupply and crew delivery contracts, and flew Dragon automated docking hardware on some of the final shuttle missions. As SpaceX CEO Shotwell has said repeatedly, SpaceX's existence and success was due to NASA's money.

People give a lot of credit to NASA for the moon landings, visiting Mars, and other feats of rocketry, but those efforts depend on the engineers and researchers of numerous private contractors. SpaceX is just the latest of many NASA contractors and it is WEIRD that people treat SpaceX as somehow different than the ones before it, or think that NASA is trying to compete with SpaceX.

NASA doesn't build rockets. It hires companies to do that for it, like its current fair-haired contractor SpaceX.

cray74

Re: China's Moon Mining is a better idea

Solar Cells deplete 30% in Five years.

Is there an abrupt drop between years four and five? My 4-year old panels are still churning out the same kilowatt-hours per day as in 2018.

cray74

Re: Here's hoping that it will work out

Space programs have consistently used tiny percentages of the world's spending annually. The US, far and away the biggest space spender, still puts over $150 of federal money into helping people on Earth for every $1 spent on NASA. Picking on NASA as your source of funds for solving hunger, poverty, housing, and healthcare is equivalent to rooting around in the federal couch for loose pennies.

To put it another way: suggesting liquidating space spending to fix problems on Earth shows you're not actually looking at government budgets like a voter should, but rather looking at memes from teh interwebs.

Was there life on Mars? Perseverance scrapes up promising samples

cray74

Re: This does not sound like a good idea

Obviously these guys didn't learn the lessons of colonial times, about bringing potential microbes to people with no immunity.

The virgin field pandemics in the Americas were caused by bacteria and viruses that had spent billions of years adapting to life on Earth, tens of millions of years in primates, and hundreds of thousands of years in modern humans. They were battle-hardened veterans familiar with fighting and defeating human immune systems.

Bringing an extremophile bacteria or virus that has spent billions of years surviving in the cold, nutrient-poor, perchlorate-laced, UV-blasted Martian soil to Earth isn't going to cause a virgin field pandemic in humans. These will be germs that have never (not in the last 4 billion years, anyway) dealt with sophisticated immune systems with terrestrial temperatures, free oxygen, moisture, and competing microbes. It'd be like picking a microbe out of Antarctica and dropping it into a Yellowstone geyser. It won't thrive, it'll be sterilized.

It's already a known fact that viruses

Replicate by inserting new RNA or DNA into a cell with which they're familiar. If the cell doesn't have the surface proteins for the virus to lock onto and doesn't have DNA that the virus has encountered before then it's not going to replicate. For example, a virus that has evolved to infect archaebacteria doesn't jump kingdoms and infect humans. Likewise, a Martian virus won't even know human cells are viable targets.

Prions are thought to work by modifying certain types of proteins that they've developed around. Fungal prions don't jump kingdoms to humans, and fungi don't come down with spongiform encephalopathies. Martian prions are unlikely to find compatible protein targets in humans.

Earth might become lifeless practically overnight.

I'm more inclined to bet on "Martian life is accidentally sterilized" than Earth get overwhelmed by a red Martian bacterial goo scenario.

cray74

Re: Not collected until 2033?

And they will be there for 10+ years until something collects them and brings them back to Earth...so will these samples have been irradiated from being exposed to radiation from beyond Mars atmosphere?

There are two significant forms of radiation that get through Mars' atmosphere to its surface and could modify samples:

1. Ultraviolet light

2. Cosmic rays

The Perseverance sample tubes are opaque to ultraviolet light. Their layers of alumina, titanium, and titanium nitride will easily block ultraviolet light. Thin sheet metal would do the job.

Cosmic rays, on the other hand, can go through several meters of water or a meter of rock. Earth's atmosphere is sufficient to stop them since it's equivalent to about ten meters of water. Mars' atmosphere is hardly a distraction to cosmic rays, which is why hypothetical Martian habitats like to hide in lava tubes or heap meters of soil atop their crew areas.

Over 10 years, those samples sitting on the surface will be bombarded by 0.77 grays of cosmic rays. Or 77 rads, if you prefer. However,

1. It usually takes several million rads to modify minerals significantly, and

2. Perseverance is only able to drill out near-surface samples a few centimeters into rock

Seems a bit dumb to be expecting to see "formerly pristine buried soil samples" in its original state if it has then been "damaged" from being left on the surface for so long?

Given the penetration of cosmic rays, and given that Perseverance only drills a centimeters into rock, those rock samples will effectively get equal doses of cosmic radiation whether they're in the original rock for 10 more years or sitting in sample tubes. Further, minerals won't notice at that modest level of dosing for 10 more years. After all, in the past 4 billion years they've picked up about 300 megarads (3 million grays) of cosmic radiation.

Tesla Megapack battery ignites at substation after less than 6 months

cray74

Look to Dinorwig

All those hills and mountains around Monterey Bay would've supported a much less flammable, much less expensive pumped storage facility. The unsubsidized, levelized cost of pumped storage dams is about $128 per megawatt-hour versus $414 per megawatt-hour for lithium-ion batteries.

Xcel smart thermostat users lose their cool after power company locks them out

cray74

Re: "I'll let my badly-insulated apartment reach 82ºF (28ºC) but there are no people"

and the fun fact is people setting their temperature very low on Summer are the same keeping it very high in Winter...

The common southern US domestic AC setpoint of 78°F / 26°C is higher than the monthly average outdoor temperatures of London from June to August. Non-rhetorical question: Does 26°C truly count as "very low" for air conditioning?

Can't you stand 28°C without AC?

"Without AC..." that depends on the conditions. Usually, 82°F is perfectly fine if you're in the shade and there's a breeze or a fan. However, that's a temperature I see outdoors primarily in winter. Even 86°F / 30°C is a mild day during the rest of the year. Last week it was 106°F (41°C) in the parking lot at work.

Further, those outdoor temperatures usually arrive with uncomfortably high humidity unless you're in Arizona or Colorado. Texas, Mississippi, Louisiana, Florida, Georgia, the Carolinas have plenty of humidity to go with spring, summer, and autumn. (Not to mention pollen.) The heat indices from those combinations of temperature and humidity are awful.

Air conditioning doesn't just control temperature. It also keeps humidity below 50%. (And lets you stay in a closed environment free of pollen.) Dehumidified, cool air works wonders for comfort.

Going back to the origins of my 82°F comment, my poorly insulated apartment would not level off at 82°F during the summer if, as you specified, I was "without AC." The last time my apartment AC broke during summer, it hit 95°F/35°C indoors. During summer months, I deliberately run the AC at 82°F to save ~$10 on my electrical bill compared to a daytime setpoint of 78°F.

I suppose you could say that settling the southern US was a "First World decision" that comes with "First World problems" like a dependency on air conditioning for comfort, but dealing with winter temperatures like 82°F "without AC" isn't the challenge. The challenge is dealing with summer heat and humidity, which aren't so mild as 82°F.

cray74

Re: Wait, what?

If the outside temperature is 32ºC as it said at the start of the story then setting the air conditioning to 25-26ºC is perfectly fine.

In fact, 78ºF (26ºC) is a popular daytime air conditioning setpoint across the southern US, including Texas. (Lower setpoints are often used at night.) I'll let my badly-insulated apartment reach 82ºF (28ºC) but there are no people or pets present during the day.

If this is how air conditioning is used in Texas then I'm not surprised there are so many brownouts.

Texas has hit an Enron-like combination of poor regulation and unchecked profit-chasing that has led to inadequate power reserves and inadequate weather hardening in its grid. In the mid-1980s, Florida had winters comparable to Texas's 2021 winter storm (which hit -10ºF / -12ºC) but without Texas's grid problems. Florida also regularly handles extended heat waves at similar temperatures (104ºF / 40ºC) and humidity (70%+) without similar power shortages.

Point being: Texas needn't have this problem during summers, and the root cause isn't air conditioning set to ~26ºC.

ESA declares the Sentinel-1B mission over after payload resuscitation ends

cray74

Cheap when compared with the launch costs.

The repair of the Sentinel 1B could've been handled better, but you're not going to launch a satellite at all if you demand zero defects throughout manufacturing. Satellites that went through manufacturing without any flagged defects don't exist.

cray74

Repair? They launched a spacecraft with less than pristine components?

Very tight aerospace requirements are going to generate lots of quality failures during manufacturing. Repairs are one of several ways of addressing such failures. It's just part of the industry.

Common means of fixing defects include Repair, which (in my facility) means fixing something so that it works as required, even if it doesn't look exactly like the blueprint. Rework: fixing something so that it works and matches the blueprint. Scrap: give engineers a conversation piece for their desks. Not a Defect: the quality control inspector was being too uptight and imagined the problem.

Capacitor blew during a test of a $50,000 circuit board? Remove and replace (rework). Solder has more voids than tolerated? Resolder it to print (rework) or, if that risks damaging the board, put a dab of sealant on it and notify the client of the blueprint deviation (repair). Platinum-cured silicone RTV didn't cure because someone used a wooden stick to mix it? Clean off the dripping goop, scrub the bonding area, apply correctly-mixed silicone per print, update work instructions and remove wooden mixing sticks from work area (rework). New aluminum parts don't have the golden sheen of hexavalent chromium chemical conversion coat (Iridite or Alodine)? Not a defect: engineering changed the part to use new eco-friendly, transparent trivalent chromium chem film so Erin Brocovich didn't sue the company but didn't warn the factory that the parts would look different, like bare aluminum.

You're never going to get everything right the first time during manufacturing, but with good quality control checks and final product testing then you can be sure that you deliver hardware that works to spec.

Of course, some perfectly sensible repairs don't cause problems for years. Apollo 13's explosion was caused by a repair: a dropped liquid oxygen tank was replaced with an older spare. The spare had internal damage that wasn't apparent until Kevin Bacon stirred the cryotanks. Sentinel 1B worked fine for 5 years with that soldering repair.

NASA's Lunar Orbiter spots comfortably warm 'pits' all over the Moon

cray74

Re: Hmmm...

but damping it so that it doesnt spring straight back out would be a challenge

Shock absorbers and dampers are old, established technologies. Use a piston to launch your hopper and then separate legs with damping to cushion the landing.

electronics are not normally fans of bouncing.

Solid state electronics are pretty good about bouncing. If you don't have spinning rust in the system and take care to prevent the components from flexing such as by potting them in epoxy then you can get functional electronics launched from cannons at thousands of Gs.

I work with aircraft systems that can handle 11Gs in hard landings with a safety factor of 2 and an additional customer-is-antsy factor of 1.5. There are additional flight turbulence and operational requirements to handle more sustained bouncing than a brief hard landing. The microchips, components, and other circuit board doodads don't have weird aerospace-grade packaging, either. In fact, most of the electronics aren't even shock-mounted unless they incidentally share a mount with more delicate systems like optics.

Smart thermostat swarms are straining the US grid

cray74

Re: "why not rev up ready for it"

You talking about the UK or Florida??

UK or Texas? Texas can't handle cold or heat .

Florida can handle a long run of hot days. Despite the abject stupidity in the Crystal River nuclear plant shutdown and the recent utility push to undermine solar panel owners, Florida has enough gas- and coal plants to meet extended summer demands. The grid is also relatively robust unlike, say, Texas and its experiment in deregulation. High CO2 and now less renewable friendly, but stable.

cray74

Re: Great if you want to hand out free cash!

"I want to replace the windows before I consider solar" for various reasons.

Definitely, insulation can work wonders for electricity bills and it's generally cheaper than solar panels.

I have solar panels on my roof but the real electricity savings on my new home are heavy insulation and low-E double glazed windows. Without the benefit of solar panels, my electricity bill is just 1/3 what my parents paid in the late 1980s (same part of Florida, same size home, no inflation adjustment.) All the insulation I added to my home above the builder's minimum is about 1/4 the cost of the solar panels.

cray74

"Unsurprisingly all this "Smart" techy shite is turning out to be rather less smart and in reality no better, if not worse than the long-lived things they have replaced."

I was annoyed when the homebuilder stuffed my new house with smart everything - garage door opener to thermostat - but the gizmos have worked out well. My elderly father, who also lives there, has vision issues. The smart devices let me check the home's status and fix settings from my office desk. I've been able to change the air conditioning from my father's accidental selection of "emergency heat" to "cooling" on several summer mornings.

But, no, the smart controls haven't radically altered my home or utility bills. They just work well for my particular home situation.

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