Hubble's headaches multiply.

Presents a discussion of the problems of the Hubble Space Telescope and indicates that clearing the telescope's vision may be more difficult than anticipated. Improved estimates of the spherical aberration of the primary mirror; Uncertain tilt and position of the secondary mirror; NASA's plans to send up astronauts in 1993 to replace the wide-field/planetary camera; Comment of John Mangus, deputy director of the space sciences directorate at the Goddard Space Flight Center.