Enormity

We space opera fans like big things:  sweeping plots and intrigues, larger-than-life characters, huge explosions.  And big spaceships.  The bigger, the better.

You remember the opening of the original Star Wars.  At the top of the frame, the Imperial Star Destroyer looms into view.  And keeps coming, for what seems like forever.  With this visual cue, Lucas communicates immediately the sheer scale of his story.

In a long story, this can lead to a Lensman Arms Race in terms of spaceship size—each new construct eclipsing the last.  One might wonder:  How far can we go with this?  Who holds the record for Largest Spaceship of All?

Traditional spacecraft

Ordinary, garden-variety depictions of spaceships are long since out of the running—not just real vehicles like the Saturn V-Apollo, but fictional ones that are meant to be big.  Kate Wilhelm’s title “The Mile-Long Spaceship” (1957) doesn’t sound even slightly impressive any more.  According to Wikipedia, those Star Destroyers range up to 2,915 meters, almost two miles.  The famous size comparison chart by Dirk Loechel displays these, along with the Independence Day mothership, the Dune Spacing Guild Heighliner, the Borg cube, and many more—but Loechel set his cutoff for the image, arbitrarily, at 24,000 meters:  “I had to draw the line somewhere.”

That’s just getting started.

“That’s no moon”

The alien probe in Clarke’s Rendezvous with Rama, which I’ve mentioned a couple of times before, is 50 kilometers long and 16 wide (31 by 10 miles).  That’s bigger than a lot of Earthly cities.

Star Wars’ Death Star, famously misidentified as a moon, has been estimated at between 100 and 160 kilometers in diameter (62 to 100 miles), at least three times larger.  The second Death Star, from Return of the Jedi, spanned somewhere between 200 and 400 kilometers (up to 250 miles), according to the same Wikipedia article.

For a long time I idolized E.E. Smith’s Skylark of Valeron as the epitome of spaceship scale.  The ship (not the novel of the same name), “almost of planetary dimensions,” is a sphere one thousand kilometers in diameter—about 621 miles (ch. 20).  That’s over twice the size of the large economy-size Death Star.  (A blogger going under the title Omnivorenz has done a detailed analysis of the various Skylark series spaceships.)

However, we’re still in the moon category, not yet up to planet-sized.  (Of course, if astronomers keep changing the rules on what counts as a planet, the two size ranges can overlap.)

Planets in motion

At this stage, we need to think about what counts as a “spaceship.”  Surely one requirement is that it be able to move in a directed fashion—otherwise the International Space Station would count.  But does it have to be a construct, a made thing?  Or can you take an existing mass and equip it with motive power?

Quite a few science fiction writers have depicted mobile planets (not simply in the sense of moving in an orbit, but of guided, directed motion).  In Blish’s Cities in Flight series, the characters twice use spindizzy drives to send whole worlds careening through the heavens.  E.E. Smith’s Lensmen, after a point, deploy “dirigible” planets almost routinely—not to mention antimatter objects (“negaspheres”) of comparable mass.  In The Wanderer, Fritz Leiber has not one, but two, traveling planets approach the Earth.  (The original source of the word “planet” is a Greek word meaning “wanderer.”)

There’s a series of stories by Robert Reed about something called “the Greatship,” but I haven’t managed to read them yet.  The blurbs describe the Greatship as “larger than worlds” and “apparently built from a re-engineered gas giant” – which would put us into a distinctly different size class from even an Earth-type planet.

And beyond

Here’s a question:  Does a “spaceship” have to be a single contiguous object?  Or can it be an array of objects that travel together, but are not physically connected?

In Larry Niven’s Known Space universe, the species known as Puppeteers flees a coming galactic disaster, not by leaving their homeworld, but by taking their planet with them—along with four others, arranged in a “Klemperer rosette” around their common center of gravity.  That’s traveling in style!  This “Fleet of Worlds” moves slower than light, but not much—and it’s five times larger, altogether, than a Blish or Smith flying planet.

But Niven was writing hard science fiction, with some attempt at scientific plausibility.  The great space operas of earlier eras weren’t constrained by such trivial considerations.  For a long time, my list of giant spacecraft was topped by the so-called “comet” piloted by the adversaries in Jack Williamson’s 1936 classic The Cometeers.  It’s not a comet at all, but a green force-field shell enclosing an entire system of worlds:  the heroes count 143 planets, plus an artificial sun (ch. 13).  The eponymous alien Cometeers sail this congeries of worlds about the universe like space pirates on a grand scale.  It’s the biggest guided space-traveling object I’m run across that’s described with any precision.

The real prize, however, belongs to Arthur C. Clarke.  In the unthinkably far future of The City and the Stars (1956), a reconstruction of history shows the leading intelligences of a galactic civilization leaving the Milky Way on a voyage of exploration in what is apparently an entire star cluster, set into motion by energies on a galactic scale:

They had assembled a fleet before which imagination quailed.  Its flagships were suns, its smallest vessels, planets.  An entire globular cluster, with all its solar systems and all their teeming worlds, was about to be launched across infinity.

The long line of fire smashed through the heart of the Universe [i.e., the Galaxy], leaping from star to star.  In a moment of time a thousand suns had died, feeding their energies to the monstrous shape that had torn along the axis of the Galaxy, and was now receding into the abyss. . . .  (ch. 24)

That’s about as far as my imagination will go, to be sure.

The pursuit of wonder

TV Tropes collects a number of these references, and more, under the heading Planet Spaceship.

As we contemplate these logarithmic jumps in scale, we may note that after a point, the whole exercise can become meaningless.  If your “ship” includes whole planets and solar systems, why go anywhere?  It’s rather mysterious why Williamson’s Cometeers would need to roam the universe preying on other star systems (other than to provide a challenge for our dauntless heroes).  What are they getting that they haven’t already got ‘on board’?

The one likely answer may be, to see what’s out there (assuming you need this large a vessel to take you).  This is the primary reason Clarke’s far-future intelligences set out on their journey:

All we know is that the Empire made contact with—something—very strange and very great, far away around the curve of the Cosmos, at the other extremity of space itself.  What it was we can only guess, but its call must have been of immense urgency, and immense promise.  (ch. 24)

In a way, the exploration motive—“new life and new civilizations”—brings us back to where we started this exercise in scope.  Simply contemplating larger and larger objects brings us some degree of awe—a touch of that “sense of wonder” for which science fiction and fantasy are famous.  But a much greater wonder springs from the idea of meeting wholly new experiences—“very strange and very great.”

The grandest justification for leaving our world may be sheer discovery—even if we end up, like the Puppeteers, taking our world with us when we go.