Inter-data center transfers of mission archives by CD-ROM:are also continuing:
copies of the ASCA archive (59 CD-ROMs per copy, totaling about 35 GB of data)
were sent to the U. Leicester LEDAS, the BeppoSAX Data Center, and the NSSDC
in the last year, equivalent to ~9 GB per month.
One extrapolation of our future data transfer rate (ftp + http) is to assume that our
data attractiveness to the community stays at its current value of ~13% per month, i.e.,
the total amount transferred in 8 months is equal to the archive size: this implies the
following future transfer rates:
Date ftp+http rate ftp+http rate
per month per day
May 2002 365 GB 12 GB
May 2003 432 14
May 2004 608 20
May 2005 810 27
The rates for 2004 and beyond will, in fact, probably be much higher than this due to the
special demands for Swift data, and may actually exceed 100 GB per day by then.
The (theoretical) capacity of the HEASARC's servers is ~ 1000 GB per day (~ 10 MB per second),
So, in principal, this should not strongly impact performance. In fact, though, network limitations
might be a factor before this limit is reached. The HEASARC System Manager is actively
Studying this issue.
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