That's just it: There really hasn't been any actual R&D after NERVA shut down. There has been (to my knowledge, anyway) *ZERO* hardware built since the late 1960's.

Everything since then has just been paper studies.

We've already been doing it for decades. Mir, the ISS, and Tiangong weren't sent up in one piece, but were assembled in orbit from component pieces.

We know how to do this already.

You've got a major misconception there.

XE Prime, the last NERVA engine developed, weighed 40,000 lbs. Launch mass of a shuttle orbiter was 240,000 lbs, and it could loft 53,000 lbs to LEO. Dimensionally, you could have easily fit XE Prime in the cargo bay of a shuttle orbital vehicle.

So no, it's not "like in the same mass neighborhood". You're off by a whole order of magnitude.

Plus, we stopped development of NERVA in 1973. It is now almost 2023, fifty years later.

Today, we have advanced materials and manufacturing techniques like additive manufacturing that weren't available in the early 1970's. That means that we could make an NTR much lighter and more efficient than we could back then.

Plus, you can use the pusher plate as a shield. Once you're done thrusting, flip the craft around and fly plate-first, so any bits of dust you meet aren't going to destroy the craft.

>a bit sketchy at that (a hypothetical of the challenger event spreading radiation across the upper atmosphere of our globe, and what those ramifications would be comes to mind).

Except that things like RTG's for space use are designed to be strong enough that a Challenger-type event wouldn't result in the release of any radioactive materials. The RTG's themselves and the General Purpose Heat Sources (GPHS) inside them are designed to withstand re-entry from low Earth orbit without any release of radioactive material.

There is no reason why a spacecraft propelled by a nuclear thermal rocket in space couldn't be designed in a similar fashion, such that the heating elements are protected until they are deployed in the engine, which wouldn't happen until the spacecraft is actually in orbit.

Or maybe just send the engine up by itself, fully assembled but inactive and in a protective case designed to permit a safe reentry, and mate it with the rest of the spacecraft once in orbit.

If we had put the money into developing Nuclear Pulse Propulsion, and insisted that propulsive uses of nuclear explosions in space would be permissible, we could have had unmanned probes fly through the closest star systems already.

Apparently the upper theoretical limit for NPP is around 10% the speed of light.

Alpha Centauri is about 4.37 light years away, so travel time would be 43.7 years. If launched at the same time as the Voyager spacecraft (ie., in 1977), a probe like that would have made the fly-by of the system in 2020. We know how to make spacecraft that last that long, as both Voyagers are still kicking and would be more capable if not hobbled by decaying RTG's as a power source. NPP allows you to have a huge number of RTG's for the "cruise" portion, and also a nuclear reactor that can be activated during the exploration phase to provide plenty of power to enable relatively high data rates back to Earth.

Well, it *IS* winter. So yeah, it'll freeze for free, no problem.

Most of the dinosaur scenes in Jurassic Park were done with practical effects. The CGI used in Jurassic Park only totals about 4 minutes.

From what I hear the M-4 is going to still be issued to non-infantry troops, while the actual trigger pullers are going to get the XM5.

I'm still aghast at that decision. Fully loaded with the suppressor, that's an 11.24 lb rifle. That's actually the heaviest infantry rifle ever adopted by the US military.

And the cartridge is another matter. The practice rounds are still zippy enough to be used in combat, and I'm willing to bet that cost considerations are going to ensure that the reduced version gets used in combat. Which is still nothing to sneeze at: It's essentially a 7mm-08.

I mean, I'm one of those weirdos who likes the concept of a battle rifle, but they shouldn't be significantly heavier than an M-1 Garand or an M-14.

Lost? Have they looked in the cushions of the couch? That's where I usually lose stuff.

Ironically, though, the StG-44 is about 1 or 2 lbs heavier than an M-1 Garand. It doesn't *LOOK* like it, you'd think the Garand is heavier just looking at it, but it's not.

The other thing to consider is that the StG-44 is, essentially, a disposable gun. It's made largely of stampings, and they will wear out much quicker than a Garand. You can put tens of thousands of rounds through an M-1 with no difficulty, but a Sturmgewehr will wear out long before that. Plus, it's more prone to being damaged than an M-1.

But I think perhaps the biggest reason why is because the M-1 was a battle-proven platform which the US literally had millions of them in stock. Completely switching over from that to a new gun with new ammo (.30'06 Kurz?) would have been seen as an unnecessary waste of money.

>I seriously cannot stress enough how enormous Yellowstone is. It's not the largest national park, but it's up there.

This.

My brother is a supervisory park ranger there, and it took us several days of him showing us around, and while we hit all the major stuff, we still didn't see everything. But we also spent a couple days in Cody, and took a day trip to see the Grand Tetons and have lunch in Jackson.

Got to stay in Ranger housing in the middle of the park. Pretty cool. And best of all, free! Even entrance to the park, since my brother is an employee and has a sticker on his vehicle.

One thing, though. If you're prone to altitude sickness like my father is, you're better off staying in Jackson or Cody and taking day trips into the park. Being at or above 8,000 feet 24 hours a day really kicked his ass. We even had to take him to Bozeman for treatment. The oxygen cans you can buy didn't help him much. The only thing that helped was getting him down to 6,000 feet or lower.

I was fine, but I definitely was shorter of breath than normal. I typically hike 3 to 4.5 miles a day carrying a 50 lb pack just for exercise, and walking there unencumbered felt like walking with the pack.

Just something to remember.

The Cody Firearms Museum which is part of the Buffalo Bill Center of the West is a top-notch firearms museum too. Not really related to OP's question, but the admission to BBCotW is with it just for that.

Also, plan for two days at the BBCotW. The admission covers two days, and it takes nearly that to appreciate all of it. You could get there right as they open and stay until closing and see everything, but it's better to break it up.

BTW, I know the park archaeologist. I once asked her about her research, and the sad truth is her job is taken up mainly by digging test pits near proposed construction or infrastructure upgrades in the park, and subsequently writing reports about it.

On the plus side, though, she sees this kind of stuff every day. I literally took those pics right outside of her office.

>He sailed on munitions ships and oil tankers, all high prizes to the German Wolfpack submarines.

High prizes, true, but for most of the war the Ubootwaffe sank an amazingly small percentage of ships. Something like 99% of the ships sailing to and from the British Isles managed to do so without being sunk over the entire course of the war.

Even at their height, the percentage sunk by U-boats was still just 5 or 6%. And that height wasn't very long lasting.

For all the talk about the German U-boats, it was US submarines in the Pacific that actually did what Germany was trying to do: Bleed the enemy merchant shipping fleet dry.

Gotta go with Orion. Betelgeuse, Bellatrix, Rigel, Saiph, Alnitak, Alnilam, and Mintaka, along with M42, just make such a distinctive and recognizable pattern.

I was going to mention the river thing, but sometimes that's not necessarily the best thing. If your destination is to the west but the river runs north/south, that's not really much of a help.

If your destination is "get me the *F* out of here, I don't care where", then yeah.

Pick a tree or rock that's ahead of you in the distance. Walk to it. Do it again once you get there. Repeat ad nauseum.

If you have to detour around something, do it at right angles. So say there is a pond in the way (or whatever. Get close to the edge, turn 90 degrees left or right and walk (while counting steps). When you can clear it, turn 90 degrees right (if you made a left initially). Then walk until you've cleared it, turn 90 degrees right, walk the same number of steps you did before, and when you hit that, turn 90 degrees right.

Also, keep an eye out for other clues. In *SOME* instances, moss will only grow on the north side of trees and rocks. So if moss is only on one side, that's generally north-ish. If it's all around the tree or rock, it's useless as an indicator.

Being able to see the sun and knowing the time is perhaps the best indication, absent a compass. If you have to go west, you want the sun at your back in the morning, to your left (north of the tropics) around local noon, and in front of you in the afternoon.

It's a practiced skill like any other. And like any skill, some people are inherently better at it with a given amount of practice. Also, it can degrade without practice.

I absolutely eschew GPS because it kills your sense of direction. You don't need to know what direction you're going if "Bitching Betty*" is telling you where to go all the time.

Some of it is understanding how a town is laid out. For example, in Manhattan, the roads that run northeast/southwest are Avenues, and they're numbered from 1 to 12 from east to west. The ones that run northwest/southeast are streets, and they're numbered sequentially going north. In general, that is.

Some of it is knowing that if the Sun is on your right in the afternoon, you're headed generally south, that sort of thing.

One time as a teenager I was in a folding kayak taking a trip down a river and when I got to the lake at the end, I couldn't go farther because the waves on the lake were too high (didn't have a spray skirt). But I knew the highway was to the west and that I could find a phone there (this is the 1980's). So I pulled the kayak out of the water and I walked to the west. Didn't walk in circles because I knew how to avoid that in the woods.

I probably should have had a compass, and generally carry one now if I know I'm going into the woods, but you can get buy without one if you are practiced enough, and I used to do a lot of walking in the woods back then.

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*Name I came up with for the GPS that was in a relative's car during a long trip. When I was driving (long enough that we took shifts driving) back towards home it tried to route me a way that I knew from experience wasn't the optimum way. I eventually turned it off.

Saw it this morning on my constitutional. Thought I was catching the tail end, but ended up seeing it up to and including the beginning of totality.

I also happened to see Tiangong go over head, but didn't know what it was at the time, only that it was a bright satellite. I looked it up on Heavens Above afterwards.

Very nice clear morning for it in Upstate New York.

Actually, we do, for the closest ones. Nuclear pulse propulsion. Basically, throwing thermonuclear bombs out the ass-end of the spacecraft and using them to generate thrust.

That gets you to about 10 or 12% the speed of light at the top end. If you're just interested in doing a fast flyby of the closest stars, that would get you to them in just X / .10 or X / .12 years, where X = distance in light years.

So for example, Alpha Centauri is 4.37 light years, so we could fly a probe through that system between 4.37 / .12 = 36.4 years to 4.37 / .10 = 43.7 years after launch.

We know that we can build space probes that are capable of lasting that long. The two Voyager spacecraft were launched in 1977, and are still operating. That's 45 years. Because of the huge amounts of payload that NPP allows for, we can have backups of backups of backups, and plenty of power generation.

But that's the maximum possible delta V, so if you want to actually slow down and explore the system over time, you're limited to using half that for acceleration, and the other half to decelerate at your destination, so you'll need between 72.8 years and 87.4 years before arrival. Conventional Plutonium powered RTGs won't be sufficient, but Americium ones would work, combined with a nuclear reactor activated to supply extra power to the systems during the exploration phase.

That's a problem for humans, though, because even a young, new engineer fresh out of school at launch is going to be 97 when the probe arrives. We don't really have will for multigenerational projects.

So there would have to be a compelling secondary mission for something like this. Measuring the parallax on nearby stars to refine our distance estimates would be a good one, and perhaps also super-dee-duper long baseline interferometric radio telescope observations would be another.

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Of course, there are two things I've ignored so far.

First is cost. This would be a hugely expensive undertaking. Would we want to spend the money to do something like this? There'd have to be a really compelling reason to do so.

Second is that it's literally illegal. The 1963 Limited Test Ban Treaty forbids any and all nuclear explosions in space regardless of the reason for them. At least, it does for nations that have signed and ratified the treaty. Both the US and Russia have done so.

China has not.

Naw, but my dad does. Can't even sit on the toilet some days.

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Joking aside, there are a lot of micrometeoroids out there, but relatively few asteroids. There have been experiments on spacecraft to detect the impacts.

For example, both Pioneer 10 and Pioneer 11, which were deep spacecraft that ventured into that part of the solar system had micrometeoroid detection systems. I don't know what the results were, but I know they did register some impacts.

As far as the larger debris, it's instructive that we've been sending spacecraft to the outer solar system and beyond since the 1970's and we've never had one disabled by a meteroid or asteroid impact. Space is just vastly huge and almost (but not quite) completely empty.

The real danger would be in the asteroid belt between the orbit of Mars and Jupiter, and there are also other areas of heightened concerns like the Jupiter trojans.

Just in time for the Age of Exploration, too. How could they have navigated without the stars?

Well, it wouldn't be bombarded with meteors, because meteors are an atmospheric phenomenon.

You're only partially right.

You are correct in that yeah, if you've got stable employment you've almost certainly got relatively easy access to healthcare. For some, like myself, it's built into my compensation along with my salary and the like.

For the elderly and disabled, we have Medicare. My father is retired, on a fixed income, and he's got Medicare. That's what paid for his ambulance ride and surgery. He paid very little out of pocket.

The distaffbopper is disabled, and is eligible for Medicare, but she hasn't bothered to sign up because she's covered under my insurance, along with the lifterbopper*. If I were to die right now, she could easily switch over to Medicare.

Back before we adopted the lifterbopper, he was a ward of the county, and I couldn't put him on my insurance back then because he was only our foster child. He was covered by Medicaid, which is like Medicare but it's for people with very low or no incomes. It paid for his medications, and even to have tubes put into his ears because he was getting constant ear infections.

Funny story about that, though: Because he was a foundling left under New York's Safe Haven law, he didn't have a name or social security number. Officially, until the adoption, he was known as "Boy Doe". That's who his Medicare card was made out to. But to the doctor's office, he was known by the name that we called him, but that wasn't made official until the adoption and issuance of a foundling birth certificate.

One day I'm at work and the distaffbopper calls me crying because the pharmacist accused her of trying to commit Medicare fraud, because the name on the antibiotic prescription didn't match the name on the Medicare card. He was new, and didn't know about our unique situation. A call to the head pharmacist at his home ended up clearing that one up, and the new guy apologized, but I could see where he was coming from.

Anyhoo, once we adopted him he went on my health insurance.

Oh, and we also lost WIC (I made too much), and Social Services no longer paid for daycare, nor did we get the monthly checks or clothing allowance.

And it was worth every penny that we lost.

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*Formerly the littlebopper, he's gotten into weight training. And he's in college, so "littlebopper" doesn't seem to apply anymore. Teenybopper doesn't seem right also.