Complex sentence: The IRAS mission performed an unbiased, sensitive all-sky survey at 12,25,60 and 100 µm during 1983, and after the mission ended, IPAC started the Infrared Science Archive (IRSA) to make the data available to anyone who needed it.
Split into simpler sentences: The IRAS mission performed an unbiased, sensitive all-sky survey at 12,25,60 and 100 µm during 1983. After the mission ended, IPAC started the Infrared Science Archive (IRSA) to make the data available to anyone who needed it.