The Interplanetary Network (IPN) is a group of spacecraft equipped with gamma-ray burst detectors used to localize gamma-ray bursts (GRB) and soft gamma repeaters (SGRs, or magnetars). The astronomical locations of GRBs are determined by the comparison of the arrival times of the event at the locations of the detectors used on different space missions. The precision is proportional to the distance of spacecraft separations, so that the localizational accuracy of a network with baselines of thousands of light-seconds can be equal or superior to that of any other technique. The primary disadvantage of the IPN method, however, is the 1-day to 1.5-day delay in the acquisition of data from all the spacecraft in the network. Interplanetary GRB networks have been in existence since 1977, contributing to the studies of various astrophysical gamma-ray transients, most notably GRBs and SGRs (soft gamma repeaters). The IPN3 began operations in 1990, with the launch of the Ulysses spacecraft. It was joined by the Compton Gamma Ray Observatory in 1991. Pioneer Venus Orbiter, Mars Observer, and the Italian X-ray astronomy satellite BeppoSAX were part of the network while they were operating. Twenty-six experiments or missions have joined the network so far. Today, the main spacecrafts contributing their data are Konus-WIND, Mars Odyssey, INTEGRAL, RHESSI, Swift, Agile, BepiColombo, and Fermi. XMM-Newton and MAXI are kept to record the cosmic ray and SGR but not used for triangulation because of the different energy range. The IPNGRB database table is derived from a list provided by Kevin Hurley <khurley@ssl.berkeley.edu>, based on the IPN3. The initial list also includes particles and solar events as well as unconfirmed SGRs and GRBs. The IPNGRB database includes only the observations of confirmed cosmic gamma-ray bursts and SGR since the launch of the Ulysses spacecraft. It is updated every time a new list is provided to the HEASARC. This HEASARC catalog is derived from the master list of IPN3 events provided by Kevin Hurley. He also provided a FORTRAN program that generates the list of selected events. The output of this program is run at GSFC and ingested into the HEASARC database system. Information on the IPN3 system is available at <a href="http://ipn3.ssl.berkeley.edu/">http://ipn3.ssl.berkeley.edu/</a>;. <p> Information on the IPN can be found at <a href="http://heasarc.gsfc.nasa.gov/docs/heasarc/missions/ipn.html">http://heasarc.gsfc.nasa.gov/docs/heasarc/missions/ipn.html</a>;. <p> In December 2021 Kevin Hurley passed away. He was one of the initiator of the IPN and its evolution. The last table provided is dated August 2021. This is a service provided by NASA HEASARC .
