New Horizons Passing Pluto

By: Jonathan Lowe
Next week humanity will complete our initial survey of the solar system when the New Horizons spacecraft flies about 7800 miles above Pluto’s surface at a relative velocity of over 32,000 mph! This will be the climax of the 9.5 year mission so far, which was designed, developed and operated for NASA by the Johns Hopkins University Applied Physics Lab in Laurel, MD. With a light-time-delay of over 4.5 hours each way all planning and commanding will have taken place days ahead of time and we’ll be waiting days and months to receive the science data from the flyby. The video below shows a notional depiction of the trajectory and observation sequence during the flyby. It also shows the orbits of Pluto’s moons in a Pluto-centered reference frame -- meaning if you were on Pluto, this is how they would appear to move around you.

New Horizons Passing Pluto from Analytical Graphics, Inc. on Vimeo.

These don’t look like your typical circular orbits!  This is because Pluto’s moons are so big relative to it that each body exerts a very noticeable tug on every other body. In fact, it’s more accurate to say that Pluto’s moons do not orbit Pluto, but rather Pluto and it’s moons all orbit a common center of mass (called a barycenter) almost 900km above the surface of Pluto! If you draw all the orbits relative to this barycenter, then they do look circular like this:

New Horizons Passing Pluto with barycentric orbits from Analytical Graphics, Inc. on Vimeo.

From the beginning, AGI has been along for the ride with STK being an integral part of the mission design and operations. Our amazing customers at JHU APL have used STK for various critical functions including: ·       Trajectory design and operational maneuver planning using Astrogator, extended with custom force model plugins ·       Mission operations, analysis and reporting, using imported SPICE files for provided by JPL to model the bodies in Pluto’s local neighborhood ·       Custom imagery on the 3D globes of Pluto and its moons using up-to-date imagery from the mission ·       Instrument operations planning, including individual imaging frames very similar to the work done by JHU APL for the MESSENGER mission ·       Situational awareness and visualization in the Mission Operations Center, making excellent and innovative use of the Movie Timeline Tool and also on the mission webpage’s "Where Is New Horizons?" section Even after the last bit of data from Tuesday’s event is downloaded, New Horizons’ mission still isn’t over! Its RTG will provide power and heat for a number of years and NASA is considering an extended mission starting in 2017. The next main target of Kuiper Belt Objects hasn’t been finalized, but New Horizons has plenty of exploring left to do. Congratulations to JHU APL on the accomplishments so far and godspeed New Horizons!
Posted: 7/10/2015 5:34:33 PM