NASA's Swift space telescope has already witnessed 9 gamma ray bursts. Launched in November last year, the Swift space telescope had its instruments tunes in the middle of December. Just days later, on December 17th, it witnessed the first GBR.
Swift's mission is to collect data so that scientists can understand exactly what GRBs are. David N. Burrows, head scientist, said: "We hope to understand what's causing them and how these things are interacting with the medium around them."
GBR's can be very short but have an X-ray after-glow. Once the Swift becomes fully automated in two weeks time it will be able to turn to track the after-glow within a minute. Other telescopes need up to 8 hours to swivel to the right position. Source