It seems that the Dawn spacecraft won't be going anywhere after NASA planners rejected a project to have the probe visit another asteroid.
Dawn successfully completed its probe of the dwarf planet Ceres on Thursday, June 30, but mission scientists still wanted to utilize its remaining fuel to check out a nearby asteroid.
While the team declined to name the asteroid initially, it was revealed through an update posted on the Dawn mission's website that the intended target was supposed to be a 150-kilometer (93-mile) wide asteroid known as 145 Adeona. This was later confirmed by NASA.
If the proposal for Dawn's third act had been approved, it would have the spacecraft spiral out of Ceres' orbit this month. It would then orbit the Sun for a few years before heading toward 145 Adeona by May 2019.
Members of NASA's Planetary Mission Senior Review Panel, however, decided that the Dawn spacecraft would be more suited to continue its probe of Ceres instead.
Jim Green, director for planetary science at NASA, said the space agency believes it would be more beneficial to have Dawn push through with its long-term observation of Ceres than to have it make the trip to 145 Adeona.
Proposed Flyby Of 145 Adeona
According to Carol Raymond, one of the lead scientists involved in the Dawn mission, the planned flyby of asteroid 145 Adeona was proposed during a meeting of members of the Small Bodies Assessment Group (SBAG) on Tuesday, June 28.
Mission scientists believed that having the Dawn spacecraft visit another asteroid would be of more interest to the team than just to have remained at Ceres.
Raymond pointed out that the space probe had already completed all of its primary objectives at the dwarf planet earlier this year.
"I think we've gotten so much already that the incremental amount of knowledge that we would gain would be maybe not as great as one would have thought," Raymond said.
It is possible to have the Dawn mission be extended to another asteroid because project scientists were able to conserve the probe's hydrazine supply, which is used to power up its thrusters.
This fuel-conservation strategy was begun back in 2012, when Dawn was still orbiting the Vesta asteroid. The spacecraft encountered problems with its reaction control wheels, which would have led Dawn to exhaust all of its hydrazine supply even before it was able to make its orbit of Ceres.
Raymond said Dawn's remaining fuel is enough to have it operate at Ceres' orbit until 2017. This timetable could still be adjusted if ever the space probe encounters further issues with its reaction wheels, causing it to use its thrusters further.
The proposed extended mission of the Dawn spacecraft to asteroid 145 Adeona may have ended in disappointment, but another space probe was given the go signal to continue its exploration of space.
NASA has green-lighted plans to have the New Horizons' spacecraft, which just finished its mission to the Pluto system, to journey to a distant object in the Kuiper Belt designated as 2014 MU69. New Horizons is expected to reach its new target by Jan. 1, 2019.
