The DC-X was a one-third-size VTVL experimental rocket, built by McDonnell Douglas under a 22-month, $58 million contract.
The vehicle was a demonstrator for a proposed SSTO VTVL DC-Y program. The DC-Y program was to cost $300 million.
The DC-X vehicle was extremely low cost. Unusually in aerospace, the vehicle development budget was hit on the nose. The number of people needed to prep it for launch was 25, the number of people needed to control it from the ground was just 3. This is very important as, contrary to popular belief, fuel cost is currently irrelevant to space launch costs. Wages are the main cost. For example, the Space Shuttle has about 10,000 people working on it; the source of its high costs are clear.
The DC-X vehicle stood 33 feet high and weighed 22500 lbs unfueled, - 41,630 lbs fully fueled. By rocketry standards those numbers are very unremarkable, but heck, this was just a demonstrator.
Funding for the project was extremely hard to find. There is a reason for that- the aerospace industry looks at space as a cash cow, and they milk it for all they can. The DC-X would have reduced the income from space per flight. This together with the aerospace industry's probably misplaced belief that the launch market consists of a fixed number of launches per year, this means that aerospace is extremely hostile to anything that could reduce costs.
The project managed to get $1 million from NASA to keep the project going- just barely going.
There are documented stories that the only reason that NASA gave the money was because they were essentially "blackmailed" by the space enthusiasts that if they paid up they would allow the ISS to go forward; the vote was extremely close and the enthusiasts were able to control the tiny minority that made the difference; NASA agreed and DC-X (and the ISS) went forward.
The test flights were remarkable by their unremarkability. The rocket took off on almost invisible hydrogen/LOX engines , hung in mid-air (causing some old hands to gasp- their rockets only did that before exploding!), then glided earily around, spat out 4 landing gear and then gently descended and landed with a small puff of fire as the engines shut down.
However on the final planned flight, the vehicle only spat out 3 of the 4 landing gear and promptly fell over and was consumed by the fire. Post flight analysis indicated that it was probably a mistake by an overworked technician failing to connect up a hydraulic pipe.
Attention was conveniently directed away from this technical triumph off to other proposals; the ill-fated X30 program; programs that paid an order of magnitude more money to the aerospace companies than DC-Y was to cost, and then more money again on overruns. And no flight hardware was left to show for this. The aerospace companies were doubtless very happy indeed.
The nearest thing to DC-X since that time is John Carmack's manned launcher.