Spaceflight Now: Breaking News

New craft watching universe for violent explosions

Posted: February 11, 2001

An artist's concept of HETE-2. Photo: NASA-GSFC
NASA's High-Energy Transient Explorer 2 spacecraft was officially declared operational this month, beginning a mission of possibly up to four years to detect massive cosmic explosions.

After its launch on October 9, aboard an air-launched Pegasus rocket, HETE-2 was put through its paces throughout the last four months. Tests have verified that the craft is healthy and ready to undertake the challenges involved in rapidly identifying cosmic gamma ray bursts, which some scientists say could be the most powerful explosions in the Universe.

However, NASA officials say that not all of the fine-tuning of the satellite is complete, but they assure the scientific community that these tests yet to be performed will not impact HETE-2's ability to carry out its mission.

HETE-2 will detect and identify gamma ray bursts more quickly than any other spacecraft to date. Once one of these bursts, or GRB's, is located, the craft will transmit data regarding the GRB to ground stations along its equator-hugging orbit. From there, the information will be sent to the satellite's control center at MIT. Upon the arrival of the message at MIT, the data is transferred to NASA's Goddard Space Flight Center in Maryland, where the information will be given out to interested ground observers who wish to further study the GRB. This process only takes a matter of minutes to complete, allowing observers to see a GRB while it is still occurring.

An artist's concept of gamma ray bursts with HETE-2 watching. Photo: NASA-GSFC
So far, one HETE-2 instrument has already found at least six confirmed GRB's. The French gamma ray telescope, called FREGATE, has also detected eight other likely GRB's, but these are yet to be confirmed.

One of the confirmed sightings activated the transmitting systems aboard the satellite and successfully demonstrated the viability of the HETE-2 concept.

Those transmitting systems may get another run for their money later this month when the HETE-2 project team will try to provide high so-called "up-time" levels for GRB identification during the days surrounding the next new moon on February 23. Project officials say they hope to continue this rationale during most lunar dark periods in the craft's lifetime.