Lockheed Martin Skunk Works and NASA have admitted that technical problems encountered with design of the X-33 suborbital-technology-demonstrator for a potential re-usable satellite launcher have delayed its first launch to the third quarter of 1999. The problem center mainly on 40% excess weight and unstable aerodynamics. A critical design review for the project is scheduled for this third quarter of this year, but may be delayed further.
Source: Flight International