Frozen Death of an International Solar Mission
“The data and science output of this mission truly deserves to be named after the legendary explorer in Greek mythology,” said Arik Posner, Ulysses program scientist, NASA Headquarters, Washington. “My compliments go out to the international team of scientists and engineers who built a spaceship and instrument payload that is highly sensitive, yet durable enough that it withstood the most extreme conditions in the solar system, including a polar passage of the giant planet Jupiter.”
In the next couple of months it appears as if the European Space Agency Ulysses and NASA joint mission will cease to operate because of the harsh cold environment of space, slowly freezing the probe to death. It has lasted longer than its original mission of five years that began in 1990, developing a memorable history of 17 years for space observations of the sun and solar system. To date, the slow dying probe is still transmitting useful data on solar winds until it eventually expires.
The Ulysses was the first mission sent out by NASA to survey the space environment, focusing on the environment above and below the sun’s poles. The data that has been sent back has helped the latest technology to view the stars and its effects of today. This invaluable science data was sent back to Earth on a continuous basis, with science findings and mission discoveries that were unprecedented.
When looking the NASA’s history, the first great finds of the Ulysses mission included “direct measurements of interstellar dust particles and interstellar helium atoms in the solar system, and the discovery that the magnetic field leaving the sun is balanced across latitudes.” But now it seems as if a weakening has occurred over the plutonium power source in the probe, causing fuel to freeze as the probe circles the sun as far as Jupiter. Powered by the decay of a radioactive isotope, this power has been slowly decreasing over the years.
NASA engineers had attempted an emergency plan to heat up the fuel in the probe in January, but it did not work. Unfortunately, it moved the death up of the Ulysses by several months. The NASA/ESA project team temporarily shut off the spacecraft’s X-band transmitter, which was supposed to release 60 watts of power that would be channeled to the science instruments and its heater. Once the data was transmitted to Earth, the transmitter was to be turned back on, extending the duration of the Ulysses for another two years.
Unfortunately, the power supply to the radio transmitter did not turn back on as planned. As this would have been the only way to continue the mission, when this happened the mission was considered as done. Presently, the alternate S-band transmitter is the only thing operating Ulysses enough to send smaller quantities of scientific data to Earth. “We will squeeze the very last drops of science out of it that we can,” Marsden said. “Ulysses is a terrific old workhorse. It has produced great science and lasted much longer than we ever thought it would.”
This entry was posted on Friday, February 22nd, 2008 at 3:22 pm and is filed under Public Relations, Space Agency News. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
