Status Report: Dawn on Track and on Schedule

Officials at NASA announce that the Dawn spacecraft is currently doing alright, with all mission parameters at their optimal values. The probe, which is currently on its way to the dwarf planet Ceres, and the gigantic asteroid Vesta – both in the Inner Asteroid Belt beyond the orbit of Mars – is on time and on track with its scheduled flight path. NASA experts say that they see no reason as to why the robotic explorer would not reach its target. Dawn is one of the few spacecrafts today to be propelled by an ion engine, which delivers a gentle and continuous thrust, SpaceRef reports.

But the Dawn mission is also revolutionary from another point of view as well. It is the first spacecraft to attempt to enter orbit around a body in the Inner Asteroid Belt, not once, but two times. No other probe has ever tried to get on Ceres' orbit for example, let alone enter, then exit, and then enter Vesta's orbit. “ For that matter, this is the first mission ever undertaken to orbit /any/ two solar system targets. [The mission] would be quite impossible without ion propulsion. But with its light touch on the accelerator, taking nearly 4 years to travel from Earth past Mars to Vesta and more than 2.5 years from Vesta to Ceres, how will it enter orbit around Vesta, how will it break back out of orbit, and how will it enter orbit around Ceres?” say experts at the NASA Jet Propulsion Laboratory, in Pasadena, California.

The probe will approach the surface of Ceres, its first target, in gentle, spiral-like motions, as it does not benefit from the advantages of a larger propulsion system to slow it down. It will then perform a wide variety of close-up scientific observations of dwarf planet, which will hopefully help astronomers gain new insight into its origins and traits. Once it leaves Ceres, Dawn will spend 36 months en route to Vesta, where it will perform the exact same maneuvers and conduct similar investigations.

“Dawn is 1.62 AU (243 million kilometers or 151 million miles) from Earth, or 1.61 times as far as the Moon and 650 times as far as the Sun. Radio signals, traveling at the universal limit of the speed of light, take 27 minutes to make the round trip,” the JPL team adds. “As if maintaining the spacecraft's health and powered flight and developing detailed plans for Vesta weren't enough to keep Dawn's engineers happy, they also are continuing work on a new version of the software for the primary computer, scheduled to be transmitted to the spacecraft in June. The mission also will mark 3 milestones that month, and it may not be a surprise if your correspondent marks them in the next log,” the experts conclude.