The most important task once the mission was completed was to make backup copies of all of the tapes. If any original tape got destroyed before copies could be made it could result in a missing chunk in the map of the world.

Michael Kobrick, the program scientist said "We're really going to baby these things, obviously, because they're our crown jewels."

Shuttle Endeavour landed on February 22nd at 6:22 pm. After the astronauts exited the vehicle and the shuttle's hazardous systems were safed the next priority was to offload the large canvas bags containing the 206 flight tapes.

Brian J. Swift was responsible for setting up the duplication system for the U.S. C-Band tapes. He said "JPL took possession of the tapes the night the shuttle landed. We were there until about 2 am going through all of the tapes and inventorying them."

SRTM-Analyzing - Brian Swift, Ronnie Punsalan, Mathew Yeates, with the Jet Propulsion Lab, and Ronnie Punsalan watch while data from the Shuttle Radar Topography Mission (SRTM) is analyzed.

The flight recorders are fairly old units, saving data on high density ID1 cartridges. They were used because they were certified to work in space, extremely reliable, and could record in multiple modes. So part of the task was to transfer the tapes to more modern AIT-2 digital tape cartridges.

The AIT drives could only record data at 6 Mbytes per second, much slower than the 22.5 Mbytes/sec inflight recording rate. So duplications took place at one sixth of the data collection speed. Even with two shifts it took over two months to duplicate all of the data. Two sets of duplicates were made for each flight tape. The duplicates were shipped from the Kennedy Space Center in Florida to JPL in California in daily batches with each set of tapes traveling separately, just in case any of the shipments got lost or damaged.

Reading the flight data cartridges went quite well. Swift said "We were very pleased with results reading the data off the flight tapes. All the data came off very cleanly, the flight recorders performed very well. Looking at the quality metrics off the tapes it appears there was no or very little degradation in the recording quality over the course of the flight." According to Swift there were some minor problems with the tape drives used to write out the duplicated tapes. He said "We had some I/O errors writing the data out to the AIT tapes. When this occurred we'd put in a new set of tapes and rewrite the data. We ended up replacing some of the AIT drives."

SRTM-Reviewing - Mathew Yeates(left), Ronnie Punsalan(right), with the Jet Propulsion Lab, stand by while data from the Shuttle Radar Topography Mission (SRTM) is duplicated.

While the tapes were duplicated engineers removed the SRTM payload from the shuttle's cargo bay and prepared it for shipment back to JPL. It will be kept in storage for a while just in case there's a desire to fly the SRTM hardware again on a future shuttle mission. If not it's quite possible the hardware will be canabilized and used for unrelated space projects, just as SRTM used leftover hardware from other spacecraft.

Duplicating tapes is not exactly the most glamorous activity and Swift's glad he didn't have to do the entire job. He said "I would not have wanted to be one of these fine folks doing this job. You're trapped in this room with hideous acoustics for the entire day. Every couple of hours you swap tapes out and start up the operation. In the time in between you're required to be there just in case something goes wrong. It's not a very pleasant job, we really appreciate the job the operators did, very diligent work."

The tape duplications were finished on May 8th. After all of the duplicates were shipped to JPL the original flight cartridges were shipped in three batches, arriving in California on May 11, 12, and 15.

The original flight cartridges will be stored in an unusual place. JPL is fairly close to Hollywood California where several companies specialize in storing original movies and magnetic tapes in climate-controlled conditions. So the SRTM original flight tapes will be archived at Producers Film Center along with Hollywood's classic movies and television shows!

SRTM-Vault - Ronnie Punsalan, with the Jet Propulsion Lab, places a SRTM data cartridge in a vault for safe storage.

Credit for all photos, Philip Chien Earth News from the NASA Kennedy Space Center

Note, the author is a full-time aerospace writer covering the space shuttle and other aspects of the space program with over 15 years of experience.

Please contact the SpatialNews Editor for additional details.

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