Post by Andrei Tchentchik on Jul 8, 2019 17:30:49 GMT 2
(.#238).- The Rosetta probe blinded by the comet's hair.
The Rosetta probe blinded by the comet's hair.
By Tristan Vey - Updated on 04/03/2015 at 16:13
An image taken during the last flyby close to 14 km from the comet last Saturday.
During its last close flyby of Comet Churyumov-Guerassimenko, the European probe was disoriented by the dust ejected by the frozen core. She has confused them with distant stars that allow her to orientate herself.
The more time passes, the more difficult the navigation of the Rosetta probe, orbiting the comet Churyumov-Guerassimenko. The ball of ice and dust vaporizes faster and faster as it gets closer to the sun. Rosetta must navigate a cloud of illuminated particles, the cometary hair, increasingly dense.
During its last close flyover, at 14km altitude last Saturday, the probe thus confused hundreds of these bright points with distant stars, disrupting its navigation system. The probe was not directly endangered, but its trajectory was sufficiently disturbed so that its antenna does not point more precisely towards the Earth during some distressing moments.
Security mode enabled
The various manipulations to correct the problem were delayed in effect plunging Sunday the probe in safe mode ("safe mode"). In this situation, the probe immediately takes steps to ensure its physical integrity. In this case, it was up to 400 km from the comet and extinguished all its scientific instruments to preserve them.
On Monday, engineers from the European control center in Darmstadt, Germany, managed to regain control of the spacecraft and bring it back Wednesday to an altitude more suitable for scientific observations, about 140 km. These changes in trajectory have also forced scientists to review their observation schedule.
In the end, more fear than harm. The previous brief flyby, mid-February, had also been a source of anxiety for the flight crew because of a similar star-pointing problem. Rosetta did not need to go into safety mode, however, to save the engineers from unpleasant stress.
F I N .
The Rosetta probe blinded by the comet's hair.
By Tristan Vey - Updated on 04/03/2015 at 16:13
An image taken during the last flyby close to 14 km from the comet last Saturday.
During its last close flyby of Comet Churyumov-Guerassimenko, the European probe was disoriented by the dust ejected by the frozen core. She has confused them with distant stars that allow her to orientate herself.
The more time passes, the more difficult the navigation of the Rosetta probe, orbiting the comet Churyumov-Guerassimenko. The ball of ice and dust vaporizes faster and faster as it gets closer to the sun. Rosetta must navigate a cloud of illuminated particles, the cometary hair, increasingly dense.
During its last close flyover, at 14km altitude last Saturday, the probe thus confused hundreds of these bright points with distant stars, disrupting its navigation system. The probe was not directly endangered, but its trajectory was sufficiently disturbed so that its antenna does not point more precisely towards the Earth during some distressing moments.
Security mode enabled
The various manipulations to correct the problem were delayed in effect plunging Sunday the probe in safe mode ("safe mode"). In this situation, the probe immediately takes steps to ensure its physical integrity. In this case, it was up to 400 km from the comet and extinguished all its scientific instruments to preserve them.
On Monday, engineers from the European control center in Darmstadt, Germany, managed to regain control of the spacecraft and bring it back Wednesday to an altitude more suitable for scientific observations, about 140 km. These changes in trajectory have also forced scientists to review their observation schedule.
In the end, more fear than harm. The previous brief flyby, mid-February, had also been a source of anxiety for the flight crew because of a similar star-pointing problem. Rosetta did not need to go into safety mode, however, to save the engineers from unpleasant stress.
F I N .
