National Aeronautics and Space Administration

How Much X-Ray and Gamma-ray Data Are in the HEASARC's Archive?

Last Update: 2012 April 4

As of Early 2012, there were about 38 Terabytes (TB = 1 billion kB) of X-ray and gamma-ray data in the HEASARC's archive, compared to 1.8 TB at the start of 2000 and 0.3 TB at the start of 1995. Recent growth has been mostly due to the increasing size of the Swift (now 11 TB), INTEGRAL (now 8 TB), Suzaku (now 3.8 TB) and XMM-Newton (now 3.6 TB) archives. Other HEASARC missions which are currently being archived include Fermi (now 2.0 TB), Chandra (now 1.3 TB) and RXTE (now 2.1 TB).

For more detailed statistics, including a breakdown of the data holdings by mission, check out the HEASARC Usage Statistics webpage.

Figure 1: Growth of the HEASARC High-Energy Data Archive and Annual Volume Downloaded by Users.

    Start       Archive Size        Archive Growth Rate    No of Active HEA
   of Year          TB                     TB              HEASARC Missions

     1993          0.001                  0.001                 4 Launch of ASCA
     1994          0.014                  0.013                 4
     1995          0.30                   0.29                  5 Launch of RXTE

     1996          0.45                   0.15                  6 Launch of SAX
     1997          0.55                   0.10                  6
     1998          0.96                   0.41                  6
     1999          1.37                   0.41                  7 Launch of Chandra & XMM; End of ROSAT
     2000          1.84                   0.47                  5 End of CGRO & ASCA

     2001          2.13                   0.29                  5 Launch of HETE2; End of EUVE
     2002          2.52                   0.39                  5 Launch of Integral; End of SAX
     2003          2.85                   0.33                  5 
     2004          3.12                   0.27                  6 Launch of Swift
     2005          4.84                   1.72                  7 Launch of Suzaku

     2006          8.27                   3.43                  7 
     2007         11.90                   3.63                  6 End of HETE2
     2008         17.09                   5.19                  7 Launch of Fermi
     2009         19.88                   2.79                  7
     2010         25.79                   5.91                  7

     2011         30.66                   4.87                  7
     2012         37.90                   7.24                  6 End of RXTE

Web page author and maintainer: Stephen A. Drake