Guardians of the Galactic Sentinel 1: The Deimos Artifact by Phillip Nolte Page A

"After our first hyperjump, we'll have several hours on reaction drive before we go to sublight again. Traffic is usually pretty thin out in the system we'll be jumping into. You might be able to practice with the guns a bit after we jump if you're careful where you aim them. What's the range on these weapons anyway?"
    "These are thousand gigajoule projectors, aren't they, Cliff?" Cliff nodded in agreement. Zack continued, "On full power, in vacuum...they'll dissipate to pretty much harmless after a couple thousand kilometers or so."
    "I'd still hold off doing any shooting here in Haven space. The people on the orbital station would be able to detect something out of the ordinary and they might start asking embarrassing questions. If we want to keep these weapons a secret, I wouldn't be doing any test firing until we're out of this system."
    "Makes good sense to me," replied Zack.
    The three of them threaded down through and out of the gun emplacement and out into the offset corridor.
    "How long until we go to sublight?" asked Cliff.
    "About a half hour," replied Beth.
    "I'd better get back down to engineering and check that sublight system over one more time," said Cliff. "I'll see you two later."

 
    Chapter 8. Physics Lessons.
    Deep Space, Barnard's Star System, July 5, 2676
     
    Zack and Beth went forward and grabbed their gear from the suit-prep area, near the main airlock, where they had dropped it when first boarding. They then threaded their way back up to their opulent quarters on deck three. After taking a couple of minutes to stow their gear, they joined back up on the bridge. Beth had gotten there first and was already at the pilot's station.
    "Have a seat, Zack," she said, "You can watch while I get ready for our sublight transition."
    Zack stepped up onto the command platform and slipped into the first officer's station where he watched as Beth consulted readouts and made subtle adjustments on her control consoles.
    "I spent a lot of my time on the Starliner that brought me to Haven watching the stars while the ship was in sublight," said Zack. "Everything looked...different, distorted somehow, and there seemed to be a lot of stars shifting against a stationary backdrop. So, what exactly is a sublight drive?"
    Beth thought for a moment before replying, "It's a special drive unit that interacts with the magnetic force lines of the galaxy itself. Do you know what 'surfing' is?"
    "Yeah, I tried it a few times when I was a kid. There's not a lot of places on Haven where you can do it though."
    "When we phase into sublight, we shift into a region that's outside of normal space but runs parallel to it. For lack of a better explanation, the ship sort of 'surfs' the currents there. Don't ask me how it all works, I don't know myself. What I do know is that while we're in sublight transition, we'll be traveling at a velocity somewhere between 0.11 and 0.215 of the speed of light, relative to normal space. The velocity varies from star system to star system but remains pretty much constant within the different systems. Once we go to sublight, I'll have to check our actual speed and have the navigation computer calculate how long it will take to get to the hyperjump zone. Then we let the computer bring us out of sublight at the proper distance. By the way, sublight currents here in the Haven system run at about 0.195."
    "I had no idea it was that complicated," said Zack.
    "Interplanetary and galactic space travel would be pretty much impossible without it."
    "How so?"
    Beth thought again for a few moments before replying, "It has to do with the extreme distances involved. The standard unit of interplanetary distance is the 'astronomical unit' or 'AU,' which is, believe it or not, the distance from Old Sol to the planet Earth. That's a distance of 150 million kilometers."
    "Yeah," said Zack, "I remember that from high school."
    "Good," replied Beth, "Now, if you could accelerate a ship up to the speed of light or 'c' --