NASA’s Dawn Spacecraft Faces Glitches Ahead Of Mission At Dwarf Planet Ceres
NASA's Dawn spacecraft that orbits dwarf planet Ceres has developed a technical glitch. The mission was preparing to study the mysterious Occator crater on the dwarf planet by positioning itself directly between the crater and the Sun. During the event, one of the spacecraft's two remaining reaction wheels stopped working.
The spacecraft has now lost three of its four reaction wheels. However, according to Space.com, such failures have not excessively impacted the probe, which has been orbiting the 950-kilometer-wide Ceres since March 2015. In fact, the Dawn mission team members are used to controlling the spacecraft’s orientation with its hydrazine thrusters instead of the reaction wheels. "This experienced group of space explorers knows how to do it without the reaction wheels," Dawn chief engineer and mission director Marc Rayman stated.
As per Zee News, NASA has said that the malfunction that took place on April 23 will not have a negative impact on the rest of the extended probe at Ceres. The space agency also added that observations made for the crater from the spacecraft’s current position may bring new insights about the bright material in the crater’s center. Dawn controls its orientation in the frictionless, zero-gravity of space by electrically altering the speed at which the gyroscope-like wheels spin.
The malfunction was discovered during a scheduled communications session by NASA on April 24. Subsequently, the problem was diagnosed and the mission was returned to its standard flight configuration. The technical glitch took place on April 22 after Dawn finished its 5-hour segment of ion thrusting to adjust its orbit, but before the shorter maneuver scheduled for April 23 to April 24. The spacecraft will, however, be able to perform its opposition measurements.
Incidentally, Dawn completed its main mission in June 2016 and is now in an extended probe. The spacecraft has been observing Ceres for over two years now. Prior to this, it was orbiting the giant asteroid Vesta and relaying important images and data back to Earth. The probe was launched in 2007.