Originally Posted by
Lord Torath
The hypothetical Hydrogen Scoop Fusion Ram Jet was supposed to be able to maintain a 1G acceleration indefinitely using a huge (10,000 km) electromagnetic scoop to collect hydrogen from in front and funnel it into the ramjet. Of course, I read about it in one of those Time-Life books which were cutting edge about 2 years before they were actually published in the 1980s, if I recall correctly, so take that with a grain of salt. Half-way to your destination you were supposed to turn the ship around and re-engage in reverse. I'm not certain how well that would work if you're thrusting into your magnetic scoop, though.