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Could it be....RAMA?
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Bud Brewster
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PostPosted: Sun Oct 02, 2022 2:04 pm    Post subject: Reply with quote

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Trekriffic recently told me about the Star Trek: Deep Space Nine episode called Explorers, in which Benjamin Sisko and his son Jake (also known as The Sisko Kid . . . yuck, yuck Laughing) took a voyage together in a homemade lightsail they constructed.

I found out that the story took great liberties with the science; the lightsail is far too small to be effective, and the design is deliberately made to look like the sails on a boat, rather than a solar sail.






But it does demonstrate one interesting idea for how a real lightsail-driven spacecraft could arrange the sail when not in use, and how it could be deployed when needed.

The sails on the DS9 ship were folded back against the spacecraft before being deployed, somewhat like the wings of a dragonfly.






Oumuamua's lightsail might have been composed of a half-dozen sections, each of which were collapsed into narrow strips which clustered around the ship when they were not deployed, trailing back for many miles behind the vessel— like Japanese fans in the closed positions.



But when deployed, they would swivel forward and slowly open up until they resembled the overlapping pedals of a flower.






Gee, I was hoping to show a "sunflower" for obvious reasons, but it just didn't look like what I have in mind. Cool
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Gord Green
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PostPosted: Sun Oct 02, 2022 2:27 pm    Post subject: Reply with quote

That "Japanese fan" concept IS used in some spacecraft for solar / electric supply. Great idea!

For use in a smaller "sports model" a self-contained laser could give it a boost!

How about a story about a "Lightsail Regatta"? Hundreds of personal lightsail yachts in an interplanetary race to win the Champions' Cup! Having to deal with solar obstacles as well as fellow racers!

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Bud Brewster
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PostPosted: Sun Oct 02, 2022 4:30 pm    Post subject: Reply with quote

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Terrific idea!_

As soon as I read your concept, I had a flood of ideas inspired by it!

Instead of racing gigantic, slow-moving solarsails, the racers are much smaller. They're thrusts is provided by six powerful lasers that are positioned in space many miles apart, forming a circle.

In a normal sailboat regatta, the crew must quickly perform vital tasks aboard the boats, such as trimming the sails, steering the craft, and preventing the boat from capsizing by tacking over the edge to add weight on the high side.

In the lightsail regatta, the crew are wearing trim, highly advanced spacesuits aboard small craft which are open to space. They must frantically perform tasks similar in some ways to the ones which sailboat crews must do.

These task include either deploying-or-withdrawing the lightsails at just the right moments, and firing on-board thrusters to turn the craft to a new angle each time they reach a point on the "racing circuit" where two laser beams cross, so that they're direction will be changed by the next "booster laser" in the circle.

The diagram below will give you an idea of how the racing circuiting would be laid out.






Imagine what the crews would have to do to steer their crafts from one laser boosting beam to the next one and stay in the race without sailing off the course and wasting time trying to get back in the race by using their thrusters! Shocked

I have ideas about how the lightsail craft would be designed to protect the crews from the intense beams behind them as they power the lightsails, and of course their spacesuits would be designed to provide some protection as well.

The craft themselves would have artificial gravity in their open decks, so the crews would move about just as they would on sailboats in an ocean race! Very Happy


Damn, I am so good at coming up with cool stuff like this! _
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Bud Brewster
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PostPosted: Sun Oct 02, 2022 6:15 pm    Post subject: Reply with quote

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The video below illustrates what I have in mind for the lightsail regatta that Gord Green envisioned!

Gentlemen, please close your eyes and try to imagine a dazzling sci-fi version of the video below — but in space!

However, you're in a skintight spacesuit, standing on an open-deck solarsailer racing boat, with the stars around you, and a blazing laser booster behind you, powering your lightsail spacecraft!

The space around you is surrounded with other solarsail boats, and they're all "riding the light" of the laser boosters at our backs. That means the only way you can win this race is to find a better way to "ride the light" to victor, fame, and fortune!
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By God. this would be an amazing scene in any movie that Hollywood chose to make. Gee. I sure hope my agent can convince them to return his calls . . . Sad


________________ "You have to do this race!"


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Last edited by Bud Brewster on Mon Oct 03, 2022 8:40 am; edited 5 times in total
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scotpens
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PostPosted: Sun Oct 02, 2022 6:33 pm    Post subject: Reply with quote

Gord Green wrote:
How about a story about a "Lightsail Regatta"? Hundreds of personal lightsail yachts in an interplanetary race to win the Champions' Cup! Having to deal with solar obstacles as well as fellow racers!

Arthur C. Clarke wrote a novelette-length story, "The Sunjammer," based on that concept. It was published in the March 1964 issue of Boys’ Life magazine.

Link: https://bookzone.boyslife.org/arthur-c-clarke/


Last edited by scotpens on Sun Oct 02, 2022 8:08 pm; edited 1 time in total
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Bud Brewster
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PostPosted: Sun Oct 02, 2022 7:11 pm    Post subject: Reply with quote

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Hey! I look forward to reading it. Very Happy

I'm eager to learn just how it holds up in view of modern technological advancements . . . and boat racing. Very Happy

And I'm impressed by the illustration by young Bob McCall, one of the best "science/science fiction" artists of our time!





Thanks, Scot!
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Bud Brewster
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PostPosted: Sat Oct 08, 2022 1:00 pm    Post subject: Reply with quote

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It's been five years since Oumuamua left the solar system, and scientist are still arguing over the lightsail theory. Cool.

The video below inclues a quick CGI video of these guys. Cool.





Have Aliens Found Us? Scientists’ Discovery of a Mysterious Interstellar Visitor


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Bud Brewster
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PostPosted: Sat Feb 11, 2023 4:04 pm    Post subject: Reply with quote

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Here's a fine example of the difference between the way science fiction writers think, compared to the way scientists think.

A science fiction writer likes to look at all the evidence and consider possibilities by "thinking outside the box". Cool

A scientist looks at all the evidence and considers ways to "cram it all INTO the box." Rolling Eyes

Consider the excerpts below from an article about Oumuamua, which I've intersperse with my own reactions as a science fiction writer.

We'll start with what The Scientists are thinking.

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Could ‘Oumuamua Be an Extraterrestrial Solar Sail?

October 31, 2018 by Matt Williams

On October 19th, 2017, the Panoramic Survey Telescope and Rapid Response System-1 (Pan-STARRS-1) in Hawaii announced the first-ever detection of an interstellar asteroid, named 1I/2017 U1 (aka. ‘Oumuamua).

In the months that followed, multiple follow-up observations were conducted that allowed astronomers to get a better idea of its size and shape, while also revealing that it had the characteristics of both a comet and an asteroid.

Interestingly enough, there has also been some speculation that based on its shape, ‘Oumuamua might actually be an interstellar spacecraft. Breakthrough Listen even monitored it for signs of radio signals!

A new study by a pair of astronomers from the Harvard Smithsonian Center for Astrophysics (CfA) has taken it a step further, suggesting that ‘Oumuamua may actually be a light sail of extra-terrestrial origin.
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The Science Fiction Writer: Well, so far, so good. A few bold folks were brave enough to suggest that the asteroid/comet that was wandering through the solar system was not actually an asteroid or a comet . . . and furthermore, it wasn't wandering either!Shocked
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The Scientists: The study —“Could Solar Radiation Pressure Explain ‘Oumuamua’s Peculiar Acceleration?“, which recently appeared online — was conducted by Shmuel Bialy and Prof. Abraham Loeb.

To recap, ‘Oumuamua was first spotted by the Pan-STARRS-1 survey 40 days after it made its closest pass to the Sun (on September 9th, 2017). At this point, it was about 0.25 AU from the Sun (one-quarter the distance between Earth and the Sun), and already on its way out of the Solar System.

In that time, astronomers noted that it appeared to have a high density (indicative of a rocky and metallic composition) and that it was spinning rapidly.
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The Science Fiction Writer:: Whoa there, fellars! Let's make sure we're gettin' our facts straight.

One aspect of Oumuamua this article doesn't mention is the way the object's brightness fluctuated a great deal — and quite regularly too. They came up with a theory that was based on . . . well, on the fact that they really wanted to have a theory.

The theory was that the brightness fluctuated because the object was rotating. And they knew it was rotating because . . . the brightness was fluctuating. Confused

Once they had that all figured out, they decided that (a) the object was long and skinny, and (b) it was spinning end-over-end — thus giving us a constantly shifting viewpoint, as shown below.






But remember, the only reason they assume it's a skinny, spinning thing is because the brightness varies! No other real evidence indicates either the shape or even the approximate size.

Also, notice how the animation shows Oumuamua squirting gases out in all directions while it spins. And yet the astronomers clearly state that no "outgassing" had been detected, even when it was closer to the sun. Confused

In short: they came up with a reason for the variation in brightness and decided it just HAD to look like this —.






— when in fact what it actually looks like through the telescopes is THIS!





Obviously, pictures just don't do it justice. Rolling Eyes
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The Scientists: While it did not show any signs of outgassing as it passed close to our Sun (which would have indicated that it was a comet), a research team was able to obtain spectra that indicated that ‘Oumuamua was more icy than previously thought.

Then, as it began to leave the Solar System, the Hubble Space Telescope snapped some final images of ‘Oumuamua that revealed some unexpected behavior.

After examining the images, another international research team discovered that ‘Oumuamua had increased in velocity, rather than slowing down as expected.

The most likely explanation, they claimed, was that ‘Oumuamua was venting material from its surface due to solar heating (aka. outgassing). The release of this material, which is consistent with how a comet behaves, would give ‘Oumuamua the steady push it needed to achieve this boost in velocity.
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The Science Fiction Writer: Okay, lemme get this straight.

It's long and skinning and spinning like a propeller, so that makes it vary in brightness. And it's speeding up because its got little rockets along the sides, caused by outgassing — even though no out gassing has been detected.

Frankly I have a serious problem with that shaky line of reasoning.

If it's doing loop-the-loops through space, then the little gas rockets are firing in all directions! How the hell could this "give ‘Oumuamua the steady push it needed to achieve this boost in velocity"?

Fortunately, two bright fellows came to my rescue. Very Happy
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The Scientists: Bialy and Loeb offer a counter-explanation.

If ‘Oumuamua were in fact a comet, why then did it not experience outgassing when it was closest to our Sun? In addition, they cite other research that showed that if outgassing were responsible for the acceleration, it would have also caused a rapid evolution in ‘Oumuamua’s spin (which was not observed).
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The Science Fiction Writer: Ah, at last! A voice of reason cries out in the wilderness! Smile

. . . Except for a few minor glithces. Sad

Even though they discount the outgassing (which is good), they seem to buy the unproven assumption that Oumuamua is spinning — which is based solely on the variation in brightness. The article even adds "which was not observed" after the comment on the spin! Shocked

But wait! Bialy and Loeb prove themselves to be "smarter than the average bear" (as Yogi would say), when they proposed this. Very Happy
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The Scientists: Basically, Bialy and Loeb consider the possibility that ‘Oumuamua could in fact be a light sail, a form of spacecraft that relies on radiation pressure to generate propulsion — which is what Breakthrough Starshot is working on.

Similar to what is planned for Starshot, this light sail may have been sent from another civilization to study our Solar System and look for signs of life. As Prof. Loeb explained to Universe Today via email:

“We explain the excess acceleration of `Oumuamua away from the Sun as the result of the force that the sunlight exerts on its surface."

[Email continues]

"For this force to explain the measured excess acceleration, the object needs to be extremely thin, of an order a fraction of a millimeter in thickness, but tens of meters in size. This makes the object lightweight for its surface area and allows it to act as a light-sail. Its origin could be either natural (in the interstellar medium or proto-planetary disks) or artificial (as a probe sent for a reconnaissance mission into the inner region of the Solar System).”
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The Science Fiction Writer: Now we're gettin' somewhere!

And notice that the statement completely discounts both the unproven long/thin shape and the unobserved out gassing. Very Happy

Hooray for our side! Mr. Green

However, the next statement below is a bit confusing. Bear in mind that I've been proposing a spacecraft that could, on command, deploy a gigantic lightsail when needed — such as after it entered the solar system and rounded the sun, before heading back towards interstellar space.

However, what Bialy and Loeb describe seems to be a lightsail only, without regard to a spacecraft that would extend or retract it.
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The Scientists: Based on this, Bialy and Loeb went about calculating the likely shape, thickness, and mass-to-area ratio that such an artificial object would have.

They also attempted to determine whether this object would be able to survive in interstellar space, and whether or not it would be able to withstand the tensile stresses caused by rotation and tidal forces.

What they found was that a sail which was only a fraction of a millimeter thick (0.3-0.9 mm) would be sufficient for a sheet of solid material to survive the journey through the entire galaxy — though this depends greatly on ‘Oumuamuam’s mass density (which is not well-constrained).

Thick or thin, this sail would be able to withstand collisions with dust-grains and gas that permeate the interstellar medium, as well as centrifugal and tidal forces.
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The Science Fiction Writer: Well, darn it — here again we see the scientists trying to stuff the facts into the box instead of thinking outside it. Rolling Eyes

First of all, the entire "artificial object" (as they referred to it) can't be composed the lightsail alone.

There must be a separate spacecraft (manned or automated) that includes a propulsion system which allows it to maneuver independently while within a star system, without needing the light sail.

What they describe above sounds a bit like a sail boat which has plenty of sails . . . but no boat! Shocked

And the last part of the excerpt, shown below, seems completely wrong.

"Thick or thin, this sail would be able to withstand collisions with dust-grains and gas that permeate the interstellar medium, as well as centrifugal and tidal forces."

Aw, come on, guys! A lightsail is as fragile as cobwebs, so it would need to be protected from space debris in all high-risk areas — such as close to the sun during it's 0.25 AU flyby. Ideally the super-thin lightsail material could even be brought in the spacecraft and repaired when damaged. Very Happy
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The Scientists: As for what an extra-terrestrial light sail would be doing in our Solar System, Bialy and Loeb offer some possible explanations for that.

First, they suggest that the probe may actually be a defunct sail floating under the influence of gravity and stellar radiation, similar to debris from ship wrecks floating in the ocean. This would help explain why Breakthrough Listen found no evidence of radio transmissions.
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The Science Fiction Writer: Wow. A "lost lightsail" that drifted into the solar system, whipped around the sun, and cruised off into the night — like The Lone Ranger!

Ummm, right . . . Rolling Eyes

And the part about Breakthrough Listen not getting any signals from it proves nothing. Who knows what kind of communication device an alien ship would us?

Thankfully the scientist had other ideas that make more sense.
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The Scientists: On the other hand, as Loeb told Universe Today, ‘Oumuamua could be an active piece of alien technology that came to explore our Solar System, the same way we hope to explore Alpha Centauri using Starshot and similar technologies:

“The alternative is to imagine that `Oumuamua was on a reconnaissance mission.

According to Loeb, there’s also the fact that ‘Oumuamua’s orbit brought it to within 0.25 AU of the Sun, which is a good orbit for intercepting Earth without experiencing too much solar irradiation. In addition, it came to within 0.15 AU of Earth, which could have been the result of orbital corrections designed to facilitate a flyby.
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The Science Fiction Writer: Well, it appears that Bialy and Loeb are seriously considering this idea and doing some work to back it up. The reference to "orbital corrections" to fly close by Earth shows that they agree with what I stated about a spacecraft being part of the lightsail.

If Oumuamua was an automated probe that surveyed our neighborhood and liked what it saw, perhaps it sent a "subspace message" back to the homeworld with a full report.

We might just get a visit from some out-of-towners one of these days!

Whether that turns out to be a good thing or not remains to be seen . . .

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