Help Shape the Future of Space Exploration

Join The Planetary Society Now  arrow.png

Join our eNewsletter for updates & action alerts

    Please leave this field empty

Headshot of Emily Lakdawalla

Dawn, now with 33% more Vesta

Posted by Emily Lakdawalla

28-09-2009 15:27 CDT


I just posted Marc Rayman's latest Dawn Journal, and it contained some surprising and welcome news that I wanted to make sure you didn't miss: A "seemingly modest improvement in solar array power" over what was budgeted for in the original mission profile results in Dawn's ion engine performance being "even better than engineers had been counting on. The probe will be able to reach Vesta about 6 weeks earlier than had previously been planned. Moreover, the newfound capability will enable the craft to travel from Vesta to Ceres more quickly, so the deadline for leaving the first world to reach the second on schedule in 2015 is about 6 weeks later. Together, these changes allow the explorer to increase its planned 9-month stay at Vesta to 12 months."

This is fantastic news -- many congratulations to the Dawn team for the outstanding performance of their spacecraft! I expect that what amounts to a mission extension before Dawn even arrives at Vesta won't change the originally planned set of science observations. What it should permit is for the team to respond to the usual sort of mission anomalies that can leave gaps in global data sets, and maybe it'll let them perform more detailed, targeted observations of spots on Vesta of unique interest (much as MESSENGER is just about to perform targeted observations at spots on Mercury identified in data from its previous flyby).

Here's the previous version of Dawn's mission trajectory:

Dawn's mission trajectory as of December 2008

NASA / JPL / courtesy Marc Rayman

Dawn's mission trajectory as of December 2008
And here's the new trajectory, updated using the new predicts for Dawn's engine performance. You can see how Dawn will spend substantially more of Vesta's "year" in orbit there.
Dawn's trajectory as of September 2009

NASA / JPL / courtesy Marc Rayman

Dawn's trajectory as of September 2009

See other posts from September 2009


Or read more blog entries about:


Leave a Comment:

You must be logged in to submit a comment. Log in now.
Facebook Twitter Email RSS AddThis

Blog Search

Help Us Go Farther

The Planetary Fund

Help us accelerate progress in our four core enterprises: Robotic Space Exploration, Human Space Exploration, Planetary Defense, and The Search for Life.


Featured Images

Structures in the Keeler gap
Daphnis in the Keeler Gap
Mars 2020 rover artist's concept
Cyclone Global Navigation Satellite System (CYGNSS)
More Images

Featured Video

We Are The Planetary Society

Watch Now

Space in Images

Pretty pictures and
awe-inspiring science.

See More

Join The Planetary Society

Let’s explore the cosmos together!

Become a Member

Connect With Us

Facebook, Twitter, YouTube and more…
Continue the conversation with our online community!