CD-R Solves NASA's Space Race

CD Recordable (CD-R) technology has emerged at the right time to help solve many of NASA's data-storage problems. For example, the Magellan mission to Venus produced more than 100 CD-ROMs of now-well-known mosaicked images. That mission also generated tens of thousands of 9-track data tapes that NASA must preserve for future processing. The cost of storing and maintaining the tapes per Government Accounting Office specifications is about $140,000 per year.

To avoid this huge maintenance cost, the Data Distribution Lab (DDL) at the Jet Propulsion Laboratory developed a high-speed tape-conversion system to transfer the data to CD-R. The figure shows the Automated Tap e-Conversion Syste m (ATCS). It consists of three VAXstation minicomputers, four 9-track tape drives, 20 GB of hard disk space, and a CD recorder.

Two of the minicomputers host two tape drives each and transfer data from tapes to staging disks. In a 6-hour period, they can process 50 tapes. The third minicomputer records CD-Rs from the image files that were produced during the previous shift. The system runs unattended for 4 hours while it premasters the accumulated data into 10 image files that will record onto CD-R discs on the next shift. During the next shift, 50 more tapes are processed, and simultaneously the 10 image files record onto CD-R.

Staffed by two part-time students, the ATCS converted a terabyte of digital data (12,000 tapes, with a physical storage volume of 1200 cubic feet) to 1800 CD-Rs (5 cubic feet) at a cost of less than $20 per tape. DDL expects that CD-R will continue to be an important archiving medium for the rest of the decade.

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NASA's CD-R Assembly Line

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NASA's tape-to-CD transfer process.