Zipper Drive

Imagine using the universe to push your ship

The year was 2047, and the stars had never felt closer.

Aboard the prototype vessel Eventide, Captain Dirk Hansen stood on the bridge, hands clasped behind his back, watching the forward viewport as the dry docks of Lunar Orbital Yard receded into blackness. The ship was sleek, matte-black, and deceptively small, but what it carried in its spine changed everything.

Dr. Amrita Singh and her team had cracked the impossible. The Zipper Drive did not extract zero-point energy; it parted it. The drive temporarily separated the quantum vacuum fluctuations along a precise corridor ahead of the ship, creating a steep potential gradient. The vacuum rushed forward to restore equilibrium, pulling the Eventide along at relativistic speeds. The zero-point field supplied nearly all the propulsion, but there was a catch.

Opening the corridor required a massive pulse of stored power. Closing it behind the ship required exactly the same amount again. The field itself could not be tapped for that symmetric act of resealing; the laws of quantum symmetry demanded an external source for both the parting and the knitting. Between the two, the drive harvested the restoring rush to recharge almost everything except the energy needed for the next closure.

That missing piece came from the ship’s heart: a bank of ultradense superconducting batteries buried deep in the keel. They had to be at full charge before the zipper could open. After arrival, the batteries would be half-empty, needing hours to replenish from the slow trickle the drive could safely draw during transit.

Dirk turned to Amrita at the central engineering console.

“Battery status?” he asked.

“Ninety-nine point nine percent and holding,” she replied. “We’re green for opening.”

Dirk nodded. The crew knew the limitations as well as he did. A single jump left them with exactly enough reserve for emergency systems, but no second jump until the batteries climbed back above the safety threshold.

“Navigation, course for Proxima Centauri. Single hop. Helm, steady as she goes.”

Lieutenant Chen locked in the coordinates. “Four point two nine light-years. Estimated transit seventeen hours, forty-two minutes. Battery recharge to full will complete approximately thirty minutes after arrival.”

Dirk allowed himself a tight smile. “Dr. Singh, whenever you’re ready. Open the zipper.”

Amrita’s fingers danced across the controls. A deep, resonant pulse thrummed through the hull as the batteries discharged their carefully hoarded energy. The zero-point field parted ahead like silent curtains.

The stars did not shift or blur. They simply waited.

Then the Eventide was no longer near Luna. The Moon’s bright crescent vanished, replaced by unfamiliar constellations. The vacuum’s restoring surge had carried them forward while the drive sipped the gradient to refill the batteries for everything except the final closure.

Half the stored charge remained, waiting for the moment they reached journey’s end.

Seventeen hours passed in quiet vigilance. Diagnostics ran clean. The field behind them showed no disturbance; the parting would only become invisible once the zipper closed.

On the bridge, Dirk and Amrita watched the charge indicator creep upward.

“Sixty-eight percent,” she reported. “We’ll be at full thirty minutes after dropout, just like the sims.”

“Good,” Dirk said. “We jump once, we prove the concept, we come home. No heroics.”

At the seventeen-hour, forty-two-minute mark, Proxima’s dim red light filled the scopes. The Eventide emerged precisely on target, three million kilometers from Proxima b.

Amrita initiated closure sequence without waiting for the order. The batteries discharged their remaining fifty percent in one symmetrical pulse. The zero-point field resealed behind them, fluctuations knitting together as though the ship had never passed.

The indicator dropped to zero, then began its slow climb again as the drive harvested ambient restoration.

Cheers were subdued this time, tempered by the knowledge that they were now tethered to the recharge clock.

Dirk addressed the crew. “Well done. Log the jump. Begin full recharge cycle. We’ll hold position here until the banks read green, then plot the return leg.”

Amrita met his gaze, tired but satisfied. “It works, Dirk. We just have to be patient between jumps.”

He gave her a wry grin. “Patience is the price of silence. The universe doesn’t mind waiting.”

Outside, the vacuum lay undisturbed, no signature, no wake, no evidence.

The Eventide drifted quietly beneath an alien star, batteries drinking in the slow trickle of power, waiting for the moment they would be whole enough to part the dark once more.