Deep Space 1

Deep Space 1 was a pioneering NASA technology demonstration mission managed by the Jet Propulsion Laboratory. Launched in 1998, its primary goal was to test a suite of twelve advanced, high-risk technologies in deep space, most notably an ion thruster for primary propulsion. The mission's successful validation of these systems paved the way for their use on subsequent interplanetary spacecraft, while its extended operations also included flybys of the asteroid 9969 Braille and comet 19P/Borrelly.

Overview

Conceived under NASA's New Millennium Program, the mission was designed to retire risk for future science missions by proving revolutionary technologies in actual flight conditions. The project was led by the Jet Propulsion Laboratory, with the spacecraft bus built by Spectrum Astro. Key objectives included demonstrating autonomous optical navigation, a solar concentrator array, and several miniaturized integrated instrument and spacecraft systems. This philosophy of testing unproven hardware on a dedicated platform was a significant shift from the traditional approach of adding new technologies as secondary payloads on science-focused missions.

Mission profile

The mission launched from Cape Canaveral Space Force Station atop a Delta II rocket on October 24, 1998. After an initial checkout period in an Earth-centric orbit, the spacecraft's NSTAR ion engine was activated for a long-duration burn to begin its primary mission. The flight plan included a flyby of the asteroid 9969 Braille in July 1999. Following the completion of its primary technology validation objectives, NASA approved an extended mission, which culminated in a daring and highly successful flyby of comet 19P/Borrelly in September 2001, returning the best images of a comet nucleus at that time.

Spacecraft design and systems

The spacecraft structure was based on a modular design from Spectrum Astro. Its most prominent feature was the ion thruster, which used xenon propellant and was powered by large, advanced solar arrays. The Remote Agent artificial intelligence software, developed in collaboration with Ames Research Center, demonstrated fully autonomous spacecraft command and control. Other key technologies included the Miniature Integrated Camera Spectrometer, the Plasma Experiment for Planetary Exploration, and the PEPE ion and electron spectrometer. Navigation was primarily achieved through the autonomous Autonav system, which used images of asteroids against the star field to determine the spacecraft's position.

Scientific results and legacy

Although primarily an engineering mission, it returned valuable scientific data. The flyby of 9969 Braille provided spectral data suggesting a composition similar to 4 Vesta. The encounter with 19P/Borrelly was a landmark, revealing a rugged, dry cometary nucleus with distinct terrain features, challenging existing models of comets. The mission's greatest legacy was proving the viability of ion propulsion for deep-space travel, a technology later adopted for the Dawn mission to 4 Vesta and 1 Ceres, and the Hayabusa missions. The success of the Remote Agent software also influenced the development of autonomous systems for later NASA missions.

Mission timeline and status

Key milestones included launch in October 1998, the 9969 Braille flyby in July 1999, and the primary mission end in September 1999. After a survival emergency in November 1999, the team at the Jet Propulsion Laboratory performed a remarkable recovery. The extended mission phase featured the comet 19P/Borrelly flyby in September 2001. Final commands were sent to the spacecraft in December 2001, and it was left in a heliocentric orbit. The mission was formally terminated by NASA in March 2002, having exceeded all its original objectives and fundamentally altering the approach to technology infusion in planetary exploration.

Category:NASA spacecraft Category:Comet missions Category:Asteroid spacecraft Category:Spacecraft launched in 1998