Possible Clues:

• Spacecraft gasket
• *Gasket type
• Defective shuttle part
• Certain NASA equipment … shown literally in the solution to this puzzle
• Faulty part of the shuttle Challenger
• Seal not interesting when head is submerged
• Part that failed on the space shuttle Challenger
• ... and the personality magazine created a new category of elite subscribers, the ___
• Letter-shaped bit of NASA equipment
• Seal drummer finally getting to the top