Pluto Google Doodle

Pluto Flyby – 14 July 2015

New Horizons is an interplanetary space probe that was launched on January 19, 2006, as part of NASA’s New Frontiers program. Built by the Applied Physics Laboratory (APL) and the Southwest Research Institute, with a team led by S. Alan Stern, the spacecraft was launched to study Pluto, its moons and the Kuiper Belt, performing flybys of the Pluto system and one or more Kuiper Belt Objects (KBOs).

Pluto Google Doodle
Pluto Google Doodle

New Horizons is the result of many years of work on missions to send a spacecraft to Pluto, starting in 1990 with Pluto 350, with Alan Stern and Fran Bagenal of the “Pluto Underground”, and in 1992 with the Jet Propulsion Laboratory’s Pluto Fast Flyby; the latter inspired by a USPS stamp that branded Pluto as “Not Yet Explored”. The ambitious mission aimed to send a lightweight, cost-effective spacecraft to Pluto, later evolving into a Kuiper Belt Object mission named Pluto Kuiper Express. However, because of underwhelming support from NASA and a growing budget, the project was eventually cancelled altogether in 2000.

Pluto photographed by the LORRI instrument aboard New Horizons on 11 July 2015.
Pluto photographed by the LORRI instrument aboard New Horizons on 11 July 2015.

Following backlash from the cancellation, the New Frontiers program was established for missions that fit in between the big budgets of the Flagship Program and the low budgets of the Discovery Program. The Applied Physics Laboratory, with a team led by Alan Stern and consisting of former Pluto Kuiper Express team members, won a competition to fund their New Horizons project, based on work left off from Pluto Kuiper Express, under the New Frontiers program. However, funding for the mission was not secured until after a financial standoff between the team and then-NASA Administrator Sean O’Keefe. After three years of construction, and several delays at the launch site, New Horizons was launched on January 19, 2006, from Cape Canaveral, directly into an Earth-and-solar-escape trajectory with an Earth-relative speed of about 16.26 kilometers per second (58,536 km/h; 36,373 mph); it set the record for the highest launch speed of a human-made object from Earth.

After a brief encounter with asteroid 132524 APL, New Horizons proceeded to Jupiter, making its closest approach on February 28, 2007 at a distance of 2.3 million kilometers (1.4 million miles). The Jupiter flyby provided a gravity assist that increased New Horizons‍ ’​ speed by 4 km/s (14,000 km/h; 9,000 mph). The encounter was also used as a general test of New Horizons‍ ’​ scientific capabilities, returning data about its atmosphere, moons, and magnetosphere. Most of the post-Jupiter voyage was spent in hibernation mode to preserve on-board systems, except for brief annual checkouts. On December 6, 2014, New Horizons was brought back on-line for the encounter, and instrument check-out began. On January 15, 2015, the New Horizons spacecraft began its approach phase to Pluto, which will result in the first ever flyby of Pluto on July 14, 2015.

There are less than 5 hours until the New Horizons spacecraft flies closest to Pluto on July 14, 2015 11:49:57 UTC (07:49:57 EDT) when it will be 7,800 miles (12,500 kilometers, less than 5.3 Pluto diameters) from the surface.

Goal of the mission

The goal of the mission is to understand the formation of the Pluto system, the Kuiper Belt, and the transformation of the early Solar System. The spacecraft will study the atmospheres, surfaces, interiors and environments of Pluto and its moons. It will also study other objects in the Kuiper Belt. By way of comparison, New Horizons will gather 5,000 times as much data at Pluto than Mariner did at Mars.

Some of the questions the mission will attempt to answer are: What is Pluto’s atmosphere made of and how does it behave? What does its surface look like? Are there large geological structures? How do solar wind particles interact with Pluto’s atmosphere?

Specifically, the mission’s science objectives are to:

  • map the surface composition of Pluto and Charon
  • characterize the geology and morphology of Pluto and Charon
  • characterize the neutral atmosphere of Pluto and its escape rate
  • search for an atmosphere around Charon
  • map surface temperatures on Pluto and Charon
  • search for rings and additional satellites around Pluto
  • conduct similar investigations of one or more Kuiper Belt objects

New Horizons on course for Pluto flyby