Supersonic Man

July 15, 2021

a comparison guide to asshole space billionaires

Filed under: spaaaace! — Supersonic Man @ 9:26 pm

Elon Musk (SpaceX):

  • wealth comes from overvalued Tesla stock that he can’t sell without crashing the price, so it’s mostly illusory
  • forced the entire car industry to start shifting to electric motors, so he has probably done more than any other person to reduce global warming
  • approaches all problems by thinking first of basic physics, then engineering, then manufacturing at scale, then financial stuff last
  • the only private space entrepreneur to successfully sell satellite launches in quantity and make a profit at it
  • reusing boosters forced the other rocket builders to scramble just as hard as the auto companies
  • in that scramble, the ones who suffered the worst losses were the Russians
  • will soon send tourists on a multiday orbital flight, which makes the brief suborbital hops offered by the next two look pretty feeble
  • is now filling the sky with thousands of internet satellites which will make life tough for astronomers and might trigger a catastrophic space junk crisis (google “Kessler syndrome”)
  • wants to move a million people permanently to Mars
  • had a child with pop star and art dilettante Grimes; naming the kid “X Æ A-12” was apparently her idea
  • can’t keep his mouth shut when ordered by the SEC to stop tweeting things that influence stock prices
  • other mouthing off has gotten him in legal trouble… and he’s in court right now, arguing that it’s good for the company because being “entertaining” saves advertising costs
  • denied the severity of covid and tried to force all his workers to stay in factories at the height of the pandemic
  • generally overworks employees, and responds with threats if they mention unionizing
  • abusive tirades have been reported
  • has a hiring philosophy of “no assholes”, but is one

Jeff Bezos (Blue Origin):

  • wealth comes from paying people the lowest possible wages for the hardest possible warehouse labor, with intentionally high rates of burnout and turnover
  • Amazon makes very little profit, so all the money it makes somehow ends up owned by Bezos rather than the company
  • said to be intensely envious of Musk, trying to equal his accomplishments without realizing that you’d have to equal his brains first
  • a Trump-aligned tabloid once tried to blackmail him over infidelity, and found out that Jeff don’t blackmail
  • but what they found may have brought about the biggest divorce property division of all time
  • spent billions and billions on space for twenty years without launching a single thing for a paying customer
  • sold United Launch Alliance (the Pentagon’s favorite rocket builder) on a new engine for their forthcoming Vulcan rocket, and is now failing to deliver the engine, forcing the Vulcan to be delayed
  • also wants to fill the sky with thousands of internet satellites, but will probably fail to compete with SpaceX’s version, thereby rendering the satellite swarm useless as well as obtrusive
  • wants to move a million people to Earth orbit, along with heavy industry to relieve the environment down here
  • suckered some schmuck into bidding $26 million to sit next to him on the first brief tourist flight of the New Shepard
  • is a way bigger asshole than Musk… some of the time

Richard Branson (Virgin Galactic, Virgin Orbit):

  • wealth comes from selling music, airline travel, railroads, hotels, gyms, clothing, advertising, cellphone service, motorbike taxis, books, business services… just about anything they could think of, all under one name
  • but for some of those he just sells companies the right to use the Virgin name, like Trump does
  • why just have one space company when you can have two?
  • unlike Bezos, has actually delivered a satellite into orbit, and people to zero gee (though Bezos is days away from catching up on the latter)
  • started accepting money for SpaceShipTwo tickets back in 2006, but the first flight with private passengers was not until 2021
  • but on the other hand, was offered a billion dollar investment by the Saudis and turned it down over their human rights problems
  • has no plans to move a million people anywhere
  • was an “adventurer” before he ever dabbled in space… crossed the Pacific in a hot air balloon, etc
  • his love life is apparently adventurous too, with at least one open marriage, and a tendency to inappropriate behavior when drinking
  • likes recreational drugs and wants them legalized
  • likes to come up with creative ways to cheat on taxes, even after once being jailed for it
  • has gotten four people killed working on his rockets, and four more severely injured, in two separate incidents
  • yeah, these things qualify him as an asshole

Max Polyakov? (Firefly Aerospace):

  • I can’t verify for sure whether he qualifies as a billionaire
  • wealth comes mainly from commercial real estate and e-commerce
  • grew up in Ukraine, where his parents worked in aerospace, and where he has founded a new engineering school
  • moved to Silicon Valley and then to Scotland
  • was a co-owner of dating websites accused of being scams; for this reason, subject to distrust in the business world
  • …on top of the distrust they already have for the idea of mixing American national security work with Ukrainian aerospace companies that may be influenced by gangsters
  • Polyakov’s main goal other than profit is probably to revitalize high-tech industry in his homeland, which has suffered many setbacks
  • Firefly was sued by Virgin Orbit and bankrupted by legal troubles; that’s when Polyakov bought it and revived it
  • Firefly built their first completed rocket about eight months ago and delivered it to Vandenberg, but we’re still waiting for them to attempt to launch it
  • Firefly’s only advantage in competing with Virgin Orbit or Rocket Lab is that they can (theoretically) lift somewhat heavier satellites, at a substantial cost increase
  • much less public than the others, so I have no solid data on to what degree he’s an asshole

In summary, Musk is the most innovative, Bezos is the most despicable, Branson is the most reckless, and Polyakov is the most unimportant.

I haven’t mentioned the tendency to overpromise and exaggerate what their companies will do, because all new-space rocket company owners do that to roughly equal degrees, whether they’re billionaires or not.

April 28, 2021

Is Russia too broke to be a space power anymore?

Filed under: Rantation and Politicizing,spaaaace!,the future! — Supersonic Man @ 7:26 am

Long ago, Russia was the unquestioned leader in spaceflight. Even after we beat them to the moon at enormous expense, they still notched up lots of firsts in other areas. And even after we took clear leadership with shuttles and Mars landers and space telescopes, they were still the clear second best. But now the big space rivalry is USA vs China, and though Russia has many announced projects and plans, they’re having a harder and harder time following through on the execution. If it weren’t for their great heritage, and the national prestige that they’ve got tied up in spaceflight, they might by now be a minor space power, less active than the European Union, and surpassed by the rapid advances now being made in India.

But because of that prestige issue, they have to do their best to act the part of a space superpower, though it’s getting more and more difficult to keep up. The gap between what is planned and what’s possible in practice seems to be getting steadily wider. The Indians might surpass them yet, if they don’t pull off some of these projects.

Let’s run through their announced projects, and see where they’re at:

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April 22, 2021

SpaceX’s enormous Starship as lunar lander for Artemis — does that make sense?

Filed under: Hobbyism and Nerdry,Rantation and Politicizing,spaaaace!,the future! — Supersonic Man @ 10:48 pm

Surprisingly, it makes more sense than it appears to at first glance, both as an alternative to a small lander and — for the near term — as an alternative to just using Starships for the entire trip. But it’s not clear that it leaves us with any need to use the boondoggle SLS rocket. So NASA’s recent decision to use SpaceX’s next generation rocket to land on the moon with, but not for the rest of the Artemis mission, may not be perfect but is also not wrong.

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November 30, 2020

everything rockety is happening in December

Filed under: Hobbyism and Nerdry,spaaaace! — Supersonic Man @ 8:12 pm

This coming month, especially the middle part, has got a crazy concentration of innovative rocket events all scheduled around the same time. Of course many of them may see their schedules slip by a few days or a few months, but if not, it’s going to be kind of nuts keeping up with all the firsts happening in this brief period. Let’s run them down:

Dec 6: Japan’s Hayabusa 2 probe will reenter the atmosphere with rock samples from asteroid Ryugu.

Dec 11: Russia’s space agency will make a second test flight of their Angara A5 rocket, in which a central booster has four more of the same kind of booster stuck onto its sides. Why is it so significant if this is a second flight rather than a first? Because the first flight was in 2014. They’ve been reworking this thing for six years.

Dec 17: China’s Chang’e 5 lunar lander will attempt to drop moon rocks back on Earth. If successful, these would be the first new batch of moon rocks anyone has retrieved since 1976, and would end any doubt that Russia has now been supplanted as the #2 space power. Hopefully it will also be a wakeup call for NASA, which thanks to Congressional pork-barrelry has wasted billions and billions on the SLS rocket and Orion capsule, which both look likely to be obsolete relics before they see much useful service.

Dec 19: Richard Branson’s Virgin Orbit (a distinct company from his Virgin Galactic) will make a second try at reaching orbit with their LauncherOne rocket, which launches horizontally at high altitude from under the wing of a 747. (The first attempt aborted early when a pipe failed.) Incidentally, Virgin Galactic is doing a suborbital test flight of its own on Dec 12 or 13.

Dec 20: China’s space agency will make a first test launch of a new midsized rocket which they hope to eventually make reusable, like a Falcon 9 — the Long March 8. This is actually coming earlier than expected, which is almost unheard of in rocket-land.

Dec 22: A new rocket company called Firefly will attempt to launch their Alpha rocket from Vandenberg. It’s a lot smaller than a Falcon, but bigger than Rocket Lab’s Electron — a large small rocket, you could say. Everybody’s been assuming that small rockets like the Electron would soon be competing in a very crowded market, but as yet no such crowding has actually happened — for the time being, the Electron still stands pretty much alone. If Virgin and Firefly both succeed, those days will definitely be over.

Dec ??: Another new company, Astra, is trying to make their second launch attempt by the end of the year. (Their prior attempt went off course and crashed.) If they succeed, they will have the world’s cheapest orbital rocket, and it’s designed to go into mass production. And they’re based right here in the Bay Area.

I might also mention that there’s a new Chinese company called Deep Blue Aerospace which has said they’ll try launching a new Nebula-1 rocket by the end of the year, but as yet I have no idea if this claim is to be taken seriously.

And before any of these we can probably expect to see SpaceX fly a Starship prototype to an altitude of 15 kilometers (50,000 feet) and then try to land it in a complicated belly-flop maneuver, which regardless of whether it succeeds or fails, should be quite a sight either way. They’re also debuting the Dragon 2 as a cargo carrier, so the space station will have two Dragons docked at once.

Meanwhile, ULA is going to attempt two launches of their Delta IV Heavy, the rocket that used to be the most powerful available before the Falcon Heavy came along. They only tend to do one or two launches a year, and aren’t planning any for 2021, so it’s weird to see two scheduled in the same month. After these, there are only three more Delta IV Heavy launches scheduled before the rocket (the last of the Delta series) is to be retired.


Update: How did things go?

Hayabusa 2’s reentry capsule was successfully retrieved from the Australian outback on Dec 6 in excellent condition. One sample container yielded “a good amount of sand… along with gases,” and the other had gravely chips. The total amount was about five grams.

The Dragon 2 cargo flight went up later that day, and docked on Monday the 7th. (Other routine Falcon 9 satellite launches went up on the 13th and 19th.)

The Starship test flight goal was lowered from 15 kilometers to 12.5 (the original plan had been 20). On Dec 8 the launch was aborted 1.3 seconds before ignition. On Dec 9 it went up, but the landing burn didn’t quite work, and it hit too hard and made a fireball. SpaceX says the fuel header tank had too little pressure. This caused one engine to shut down early, and another to burn out its insides with excess oxygen.  [In February, the next test crashed even harder.  In March, the next one touched down with only a slight crunch, then blew up on the ground a few minutes later.  Also in March, the one after that exploded in midair.  They finally landed one intact in May.]

Chang’e 5 successfully got its rock samples into lunar orbit and handed them over to the return vehicle on Dec 8. That vehicle spent several days raising its orbit and started its return trajectory on Dec 13. The canister landed early Dec 17 with 1.7 kilograms of samples. The orbiter then departed for an additional mission.

One Delta IV Heavy launch — the one originally scheduled for August — went up on Dec 10. The other slipped to April of 2021.

Astra put their rocket on the pad and readied it for flight on Dec 11, but scrubbed due to excessive winds. They finally launched on Dec 15. It flew correctly but came up short of orbital velocity by 480 meters per second, meaning they got about 95% of the way there. The upper stage ran out of fuel with oxygen left over, meaning the problem was an incorrect mix ratio, which is easy to fix.  But they didn’t try again until summer.

Virgin Galactic’s suborbital test flight was aborted at ignition time on Dec 12, apparently due to a failed electrical connection. They had to glide to a landing.

But Virgin Orbit had to call off their December launch attempt due to covid. Too many employees were quarantined in the Los Angeles area’s surge of cases. They flew on Jan 17, and reached orbit successfully.

The Angara launch took place successfully on Dec 14.

The Long March 8 flew successfully on Dec 22. It may still be some years before they can make it reusable, but they are working now on making it quick and easy to launch with minimal prep work.

Last to go was the Firefly Alpha.  December ended with no word from the company on when to expect a launch attempt, and so did January, February, March, April, May, June…  Apparently the major holdup was not the rocket itself, but the launchpad.  Plus covid, of course.  They finally made the launch attempt on September 3, which ended in a Rapid Unplanned Disassembly about two minutes after liftoff.

Which is better than Astra’s retry went, about a week earlier: that one lost an engine immediately and left the pad more sideways than upwards.  Astra finally got to orbit in November.

November 21, 2020

small commercial rockets

Filed under: Hobbyism and Nerdry,spaaaace! — Supersonic Man @ 9:16 am

In the world of rockets, most of the attention goes to the big boys — the ones that do the prestige missions that carry live people, or send stuff to the moon or beyond. And most of these are still governmental, like the SLS being built for NASA’s Artemis program, or China’s new Long March 5. Even for purely commercial launches, such as communications satellites, until recently most were done by commercializing launches on rockets built for governments, like the Atlas or Soyuz or Long March, or India’s PSLV and GSLV.

As yet only SpaceX has made a successful business out of privately constructing a large rocket, the Falcon 9. One other company has tried this: Orbital ATK, recently merged with Northrup Grumman, built the midsized Antares with the help of a Ukrainian company called Yuzhnoye. But the Antares has yet to sell a launch to a nongovernmental customer. And one more company will be trying it soon: Jeff Bezos’s Blue Origin. Also, the United Launch Alliance is building the Vulcan as a replacement for their Atlas, and SpaceX hopes to obsolete the Falcon with the Starship. As far as big rockets go, that’s the whole list. No purely commercial large rockets are in the works outside of the United States. Some have plans on paper, but they’re future hopes, not current projects. And for that matter, none of these is without some degree of taxpayer subsidy, though the Starship is nearly so.

But with small rockets, it’s a very different story. As technology has enabled satellites to be built in much smaller sizes, there has been a great surge of interest in little rockets. And the number of companies trying to be pioneers in small rockets is countless — there are literally dozens of them around the world, and nobody knows how many of them should be taken seriously.

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January 4, 2020

the edge of space

Filed under: Hobbyism and Nerdry,science!,spaaaace! — Supersonic Man @ 12:32 pm

There’s a controversy about where “space” begins. The internationally accepted standard is the altitude of 100 km, which is known as the Kármán line. But in the USA, many advocate for the more lenient definition which says you’ve been to space if you rise to an altitude of only 80 km, or more traditionally, 50 miles. Which view is more correct? Well, when an orbiter reenters the atmosphere, the point when reentry heating starts to get significant is around 120 km, so in my view the 80 km line is definitely the less valid of the two. Though on the other hand, Kármán himself argued somewhat in its favor, as his research showed that it was around this altitude that trajectories become essentially ballistic rather than aerodynamic — that is, it’s where drag forces become minor even at orbital speeds.

In the end, I say both are bogus: you aren’t fully in space until you get to at least 200 km up, high enough so that it’s possible to orbit the Earth a few times without promptly falling down from drag. You can’t orbit for very long at 200 km up — useful satellites start at about 300 km — but it is at least possible to orbit for a while at that altitude. There are plans afoot to orbit very low satellites between 160 and 200 km up… but only by using continuous power to compensate for drag. At 100 km altitude, you are in the ionosphere, not in space, and might not make it around the Earth more than once. At 80 km, a few dips at the bottom of a tall ellipse are possible (and this has actually been done), but a full circle definitely isn’t possible. Those arguing for the 80 km line are basically drawing the boundary at the dividing line between where you’re in a decaying orbit vs where you’re doing reentry.

In fact, the ionosphere actually extends above most satellites… which is intentional, as this means they will eventually come down. Keeping most satellites this low is a policy which reduces the long term risk of “space junk”. But I would say that if you can orbit for a week or more, you’re in space.

June 3, 2018

Trends in rocketry

Filed under: Hobbyism and Nerdry,spaaaace! — Supersonic Man @ 11:07 am

I’ve been taking an interest in the space industry and orbital rockets — a field which is evolving very rapidly nowadays. So far this year we’ve seen the debut orbital flights of the Electron, the Falcon Heavy and Falcon 9 Block 5, and seen a new record set for the smallest rocket to put up a working satellite. In the remaining months, we’re expecting the maiden flights of the LauncherOne, the Kuaizhou 11, the Vector R, and the Starliner and Dragon 2 crew capsules. We just might see one of those capsules take live astronauts to the Space Station by the end of the year. And the next couple of years will have plenty of action too, with several lunar landers being sent up by different countries, and more new vehicles making their debut: the SLS, the Vulcan, the New Glenn, the Dream Chaser, and more.

With so much short-term activity, it may be hard to spot the longer term trends, but I think I can lay out a few here:

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May 10, 2018

if the solar system fit in a stadium…

Filed under: Hobbyism and Nerdry,science!,spaaaace! — Supersonic Man @ 12:00 pm

(I wrote a post about this a few years ago somewhere else, but now I can’t find it, so I am redoing it here, and expanding it.)

How big is the Solar System?

Let’s start by assuming that we all have some general idea of how big the Earth is. If we fly from coast to coast in the United States, we’ve gone almost one eighth of the way around it. A day of driving in a car, say 500 miles, goes about one fiftieth of the way around. So the Earth is very large compared to your local town or neighborhood, but it’s of a scale that can be grasped and managed with common means of travel, such as cars and planes. Even preagricultural people sometimes traveled and traded over distances of a thousand miles or more, and that’s not tiny compared to the size of the Earth.

The Moon is a good deal smaller than the Earth, but quite far away from it. It takes well over one second for a beam of light to travel from the Moon to the Earth. The distance to the Moon is enough to wrap around the Earth nine or ten times (I say “nine or ten” because the Moon’s distance varies over that range during each month). It’s the sort of distance that an old car might accumulate on its odometer after twenty or thirty years of driving — over a quarter million miles when the moon is furthest out. People are capable of traveling such distances over many years, or in just a few days with our most powerful rockets.

To appreciate the scale of the rest of the solar system in comparison to this, let’s imagine a scale model, sized to fit into a big football stadium. The scale of this model will be 1/100,000,000,000 of life size.

Let’s look at how each part of the solar system would appear at this scale. The Sun, which hangs over the middle of the fifty yard line, is a bit over half an inch across — about 14 millimeters, to be more exact. It’s the size of an olive. Mercury, the innermost planet, has an eccentric elliptical orbit around it which is eighteen inches (46 cm) from the sun at its closest, and twenty-seven and a half inches (70 cm) at its furthest. The planet itself is a practically invisible speck, only one five hundredth of an inch across, or a twentieth of a millimeter. Venus, the second planet, circles our olive-sized sun at a distance of about three and a half feet (108 cm), so its orbit crosses the 49 yard line on each side. The size of the planet is about 1/200 inch, or an eighth of a millimeter, a speck which is probably big enough to see if you get close enough.

The Earth’s orbit is found at a distance of a bit under five feet (150 cm) from the sun. And the orbit of the Moon makes a little circle around the Earth. The distance from the Moon to the Earth, which in real life is up to a quarter million miles, and is the farthest distance that any human being has ever voyaged, is only about 5/32 of an inch, or 3.9 mm, in this scale model. The entire circle traveled by the Moon around the Earth is barely half as big across as the Sun is. It would fit inside a pea. The distance to the Sun is almost four hundred times as large. The diameter of the Earth itself in this model is about 1/200 of an inch, the same as Venus, and likewise would be a barely visible speck. The Moon, being smaller than Mercury, would be very difficult to see.

Mars circles seven and a half feet out (2.3 meters), and is about 1/400 inch or 1/16 of a millimeter across — a dust speck. The asteroid belt spreads in a hollow disk around the sun, with the bulk of it starting about ten feet out, and then it thins out at a distance of around eighteen feet (3 to 5.5 meters). None of the individual asteroids are big enough to see.

Jupiter, the largest planet, sits a little over 25 feet (7.8 meters) out from the Sun. Its orbit crosses past the 42 yard line on each side of midfield. The planet itself is plenty big enough to be more than a speck: it’s 1.4 millimeters in diameter, or somewhat under one sixteenth of an inch — the diameter of the head of a pin. If the Sun is an olive, Jupiter might be a large poppyseed, or a small millet grain. It has a number of moons, the four large ones being Io, Europa, Ganymede, and Callisto. The orbit of Io sits about 5/32 inch (4 mm) from Jupiter, and the orbit of Callisto is about 3/4 inch (18 mm) out.

Saturn is 46 feet (14 meters) from the sun. Its orbit crosses the 35 yard line. It’s smaller than Jupiter, but if you include its rings, it looks bigger. You might model it with a small flat sesame seed. Its major moon Titan sits half an inch (12 mm) out from the planet. Uranus is much further out, 98 feet (30 meters) from the Sun, so it nearly reaches the 17 yard line, and on the sides it spills over the out-of-bounds line into the sidelines. Its diameter is half a millimeter, so you might represent it with a grain of fine sand.

In this model, the orbit of Neptune, the most remote true planet, has a span that just about reaches the one yard line, but can’t quite reach the goal lines, orbiting 148 feet (45 meters) from the sun. Its size is about the same as sand-grain Uranus.

From this you can see that the Solar System is very empty. Besides the olive-sized sun, everything else on the field is just some specks which, all added together, wouldn’t amount to a grain of wheat.

Now the Sun and all the planets pretty much fit onto the playing field, but that’s not the whole Solar System. Beyond all the planets are a number of icy bodies, large and small. They constitute a sort of second asteroid belt. It’s called the Kuyper belt. Pluto is one of these icy bodies, and it isn’t even the biggest one. As far as we presently know, it’s the second biggest.

In our scale model, the Kuyper belt fills the rest of the stadium, beyond the playing field. Pluto is down in a good low seat right near the sidelines, and some of the others are way up in the cheap seats, hundreds of feet from the field.

The light of the Sun doesn’t reach up there very well. It casts a good bright illumination in midfield, but the goalposts are pretty dim, and in the top row of the seats you can’t see much when you look away from the sun. If I have this figured correctly, at this scale, it puts out about five thousand watts of light. But don’t compare that to a 5000 watt lightbulb — your ordinary traditional bulb puts out mostly heat, so the 100 watt lamp in your living room is only emitting about ten watts of actual light, and if you use a modern bulb such as a compact fluorescent, it will say “100 watts” on the box while only actually using about 25 watts. The Sun puts out at least three quarters of its energy as visible light. Think of it more as a 5000 watt welder’s arc than a 5000 watt lamp.

One thing this idea of an arc lamp in a football stadium fails to convey is how slow the light is. You have to remember that the light from our tiny Sun takes minutes to reach Earth just five feet away, hours to reach Neptune, and most of a day to reach the upper seats. If there were a snail crawling around on the grass, it might well be moving at several times the speed of light. And the fastest rockets never approach even a thousandth of that speed. (The fastest moving objects we’ve ever launched into space, or will launch soon, are solar probes that drop inside the orbit of Mercury. That inward fall can give them a speed dozens of times faster than, say, the Apollo moon rocket.)

There’s more stuff beyond the Kuyper belt, also consisting mainly of icy bodies. But I don’t really count this as part of the solar system. This is where long period comets come from (short comets, such as Halley’s, come from the Kuyper belt). This zone is called the Oort Cloud. It’s found out in the stadium’s parking lot, and some thin parts of it probably extend out into the surrounding city, perhaps miles from the stadium. While the Kuyper belt is similar to the asteroid belt in that it mainly lies in the same plane as the orbits of the planets and rotates in the same direction that they do, the Oort cloud is spread in all directions, and appears to have no net orbital direction shared in common among the various objects. For all we know this spread of icy bodies may extend throughout the space between the stars, and not constitute a part of our own solar system at all, except to the extent that the Sun’s gravity causes a thickening in nearby parts of it.

Speaking of other stars, how far away is the nearest other solar system? It would be about 250 miles away at this scale… about the distance you might find between your hometown football stadium and that of a rival team in the next state. For instance, the distance between Cleveland and Cincinnati, or Green Bay and Minneapolis, or Chicago and Detroit.

As an afterthought… What if we changed scales in the opposite direction? What if we magnified everything so that a football stadium engulfed the solar system? How big would individual atoms be then?

As big as a house, it turns out — unbound hydrogen atoms would be around twelve meters across, carbon atoms about seventeen meters… Counterintuitively, heavy metals aren’t much bigger than light elements: uranium is just a bit bigger than carbon, and gold is actually smaller. The stronger the positive charge of the nucleus, the more densely the electrons pull in around it, so the overall size has remarkably little variation.

Green light would have a wavelength of fifty kilometers. One of your intestinal bacteria would stretch from Columbus to Pittsburgh. A red blood cell would sprawl over several midwestern states. If you have a good thick head of hair, your individual hairs might be as big around as the Earth. A flea would reach halfway to the Moon. And if you stood on the Sun, your head might reach past the orbit of Earth.

May 10, 2017

no Apollo

Filed under: Hobbyism and Nerdry,spaaaace!,thoughtful handwaving — Supersonic Man @ 9:21 am

If NASA had not been hurried into building the Apollo mission by the “space race” against the USSR, how might we have arrived at the Moon? Space development might have proceeded a good deal more slowly and less expensively, building on the X-15 rocket plane experiments. I think that program would eventually have arrived at something fairly close to the Space Shuttle. If you solve all the problems of the X-15 one by one to make it orbit-worthy, it would have had to be much larger and blunter, because any adequate heat shield is going to be around four inches thick, and that doesn’t scale down for something skinny or pointy. That sounds a lot like the shuttle to me. Perhaps we would have come up with something reusable in place of its solid boosters.

So let’s say we were trying to send a mission to the moon using space shuttles. The shuttle itself could in theory go there if you filled the cargo bay with fuel, but that would make it far too heavy to reach orbit, and even if you could fly it that way, it would be wasteful anyway as you don’t need most of its eighty ton bulk. So I think the bits that actually go to the moon would be much as they historically were in Apollo: a lunar module, command module, and service module. Why not just stick those into a shuttle bay?

The shuttle’s cargo bay is 60 feet long and 15 feet across, though for a cylindrical cargo the cross section needs to be a bit smaller, as the space isn’t fully round. The mass limit for a flight to low orbit is a hair over 30 English tons, or 27.5 metric tons. (I don’t think any real flight ever exceeded 83% of that capacity.) What can we work out based on these limits?

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