Deep Space 1 Is Launched Summary

  • Last updated on November 10, 2022

Part of NASA’s New Millennium Program, Deep Space 1 was launched from Cape Canaveral on October 24, 1998, and tested twelve high-risk technologies in space. In an extremely successful extended mission, it encountered Comet 19P/Borrelly and returned the best images and scientific data ever received from a comet up to that time. During its hyperextended mission, Deep Space 1 conducted further technology tests. The spacecraft was retired on December 18, 2001.

Summary of Event

In 1995, the New Millennium Program (NMP) was created by the National Aeronautics and Space Administration (NASA) through the joint effort of its Office of Space Science and Office of Earth Science. The principal concern of the NMP is to test high-risk technologies onboard space missions with the aim of validating such technologies in order to facilitate their use on future missions, to reduce the expense of test situations in real missions, and to contribute to technological developments for use on Earth. Project managers view even the failure of any test technology, including loss of the vehicle, as yielding useful results for subsequent developments. National Aeronautics and Space Administration;Deep Space 1 mission[Deep Space One mission] Deep Space 1 (spacecraft)[Deep Space One] New Millennium Program National Aeronautics and Space Administration;New Millennium Program Astronomy;comets [kw]Deep Space 1 Is Launched (Oct. 24, 1998) [kw]Launched, Deep Space 1 Is (Oct. 24, 1998) National Aeronautics and Space Administration;Deep Space 1 mission[Deep Space One mission] Deep Space 1 (spacecraft)[Deep Space One] New Millennium Program National Aeronautics and Space Administration;New Millennium Program Astronomy;comets [g]North America;Oct. 24, 1998: Deep Space 1 Is Launched[10180] [g]United States;Oct. 24, 1998: Deep Space 1 Is Launched[10180] [c]Spaceflight and aviation;Oct. 24, 1998: Deep Space 1 Is Launched[10180] [c]Astronomy;Oct. 24, 1998: Deep Space 1 Is Launched[10180] [c]Science and technology;Oct. 24, 1998: Deep Space 1 Is Launched[10180] Rayman, Marc D. Weiler, Edward Ledbetter, Ken Li, Fuk Lehman, David Varghese, Philip Livesay, Leslie Nelson, Robert

Deep Space 1 is notable for its many pioneering firsts. Launched on a Delta 7326-9.5 rocket from the Cape Canaveral Air Force Station in Florida on October 24, 1998, Deep Space 1 was the first NMP mission and the first launch of NASA’s Med-Lite booster program. Additionally, Deep Space 1 is noted for its use of solar electric propulsion in an ion propulsion system (IPS) as its principal propulsion method, which enabled long-term preservation of the relatively small amount of hydrazine (31.1 kilograms at launch) used to fuel the reaction control system (RCS).

Its successful primary, extended, and hyperextended missions have earned Deep Space 1 high praise and contributed significantly to concurrent and later missions. The total cost ($149.7 million), although considered a restrictive amount even during the mission, can be viewed as funding not only this mission but also missions of the future.

The following were onboard technologies tested during Deep Space 1’s primary mission (October 24, 1998-September, 1999): solar electric propulsion, used as an IPS; solar concentrator arrays; autonomous onboard optical navigation (AutoNav); autonomous beacon monitor operations; autonomous remote agent; miniature integrated camera and imaging spectrometers (MICAS); miniature integrated ion and electron spectrometers, or plasma experiment for planetary exploration (PEPE); small deep-space transponder; Ka-band solid-state power amplifier; low-power electronics; power actuation and switching modules; and multifunctional structure.

Testing was completed on all of the technologies—with the exception of the AutoNav system—by the end of June, 1999, just forty-seven months after the initial work on Deep Space 1 began. Deep Space 1’s primary mission was accomplished during September, 1999. In addition to the IPS diagnostic sensors (IDS), of crucial importance to the success of Deep Space 1’s extended mission to Comet Borrelly Comet Borrelly were MICAS and PEPE. The successful testing of new onboard technologies evolved into implementation of their capabilities during an extraordinary diagnostic and recovery operation in preparation for encountering Comet Borrelly.

Before that encounter, however, the final test during the primary mission was Deep Space 1’s flyby of asteroid 9969, or Braille. Braille (asteroid) Anticipating and then executing this event required the spacecraft’s autonomous crafting and implementation of trajectory-correction maneuvers (TCMs), in order for it to approach Braille, with ground-based imaging assistance relying on MICAS images to locate the asteroid.

The imaging and surveillance of Braille were accomplished with MICAS, PEPE, and IDS, a remarkable interplanetary meeting with an object approximately 2 kilometers in diameter. Subsequent to this event, Deep Space 1 returned high-quality MICAS imaging of Mars that indicated the previously unidentified mineral composition of the planet.

A Delta II rocket propels Deep Space 1 into the sky after liftoff from Cape Canaveral on October 24, 1998.

(NASA/Kennedy Space Center)

Following the Mars encounter, on November 11, 1999, during Deep Space 1’s extended mission (September, 1999-September, 2001), its stellar reference unit (SRU) stopped operating. The loss of this crucial navigational component responsible for delivering attitude data prompted an extraordinary rescue effort in two phases. Phase one was a diagnostic process to determine the SRU’s condition and whether it was recoverable. When this proved impossible, in phase two, the management team developed a new system that knitted together the MICAS and AutoNav technologies. In this system, the attitude control system (ACS) would identify, or acquire, a star in the target attitude. Working with MICAS, a mosaic was generated for use by AutoNav, to assist in locking onto the star as a directional aid. The software to accomplish this new configuration of navigation was uploaded on June 8, 2000, in time for the planned encounter with Borrelly on its thirteenth appearance in the solar system.

This celebrated encounter took place on September 22, 2001, at the beginning of Deep Space 1’s hyperextended mission (September, 2001-December 18, 2001). MICAS, PEPE, and IDS were instrumental in recording observable and quantifiable data. Despite Deep Space 1’s lack of protective shielding, it not only survived passing through Borrelly’s coma but it successfully transmitted the data from the encounter to Earth, where visual images relayed an asymmetrical nucleus of approximately 8 kilometers in length, with varying degrees of ruggedness, but without definitive evidence of impact sites.

Because the TCMs that directed Deep Space 1’s encounter with Borrelly were conducted with the IPS rather than by depleting the hydrazine, a minimal amount of hydrazine remained after this event, which was sufficient to support the hyperextended mission. Testing at this stage was again conducted on all of the hardware technologies, except for the small deep-space transponder, which continued to operate but was not tested. Of particular interest was the investigation of long-term space travel on the technologies, some of which had not been operated during the extended mission.

Deep Space 1 received its last command on December 18, 2001, and went into a safe shutdown mode. The following year, a need arose for the retrieval of Ka-band downlink information to illuminate a reading of turbulent weather, information that Deep Space 1 might have been able to provide. Unfortunately, no response was received to signals sent to Deep Space 1 on March 2 and March 6, 2002.


Even before the end of Deep Space 1’s mission, its operations and test results—particularly from its encounter with Borrelly and the use of AutoNav—were being implemented on other projects. These included Stardust, which was launched on February 7, 1999, and encountered Comet Wild 2 Comet Wild 2 (also known as 81P/Wild) on January 2, 2004, capturing comet and interstellar dust to be returned to Earth. Analysis of such material was expected to lead to a more complete understanding of the composition and behavior of comets as well as insights into the development of the solar system and the evolution of life.

Data from Deep Space 1’s mission also influenced the operations of Deep Impact, launched on January 12, 2005, with the primary objective of capturing and analyzing the orchestrated release of an impactor into Comet Tempel 1. The flyby spacecraft recorded the impact and its effect with optical imaging and infrared spectral mapping, evoking a better understanding of the comet’s composition and response to interstellar impact. Deep Space 1’s successful primary mission and hyperextended mission validated twelve new high-risk technologies that now are not only employed in other missions but also contribute to evolving technology to further future missions and Earth-based applications and knowledge. National Aeronautics and Space Administration;Deep Space 1 mission[Deep Space One mission] Deep Space 1 (spacecraft)[Deep Space One] New Millennium Program National Aeronautics and Space Administration;New Millennium Program Astronomy;comets

Further Reading
  • citation-type="booksimple"

    xlink:type="simple">Rayman, Marc D. “The Deep Space 1 Extended Mission: Challenges in Preparing for an Encounter with Comet Borrelly.” Acta Astronautica 51, nos. 1-9 (2002): 507-516. Details preparations to accommodate the failure of Deep Space 1’s SRU, outlining the use instead of MICAS, and of methods for preserving hydrazine.
  • citation-type="booksimple"

    xlink:type="simple">_______. “The Successful Conclusion of the Deep Space 1 Mission: Important Results Without a Flashy Title.” Space Technology 23, nos. 2-3 (2003): 185-198. Provides a useful overview of Deep Space 1’s primary mission, with extensive commentary on preparations for and the encounter with 19P/Borrelly; implications for future missions; and a graphic rendering of the mission’s trajectory.
  • citation-type="booksimple"

    xlink:type="simple">Rayman, Marc D., and Philip Varghese. “The Deep Space 1 Extended Mission.” Acta Astronautica 48, nos. 5-12 (2001): 693-705. Details Deep Space 1’s encounter with asteroid Braille and its visual survey of Mars, and discusses the diagnosis of the failed stellar reference unit and adoption of the miniature integrated camera and imaging spectrometers to complete the extended mission.
  • citation-type="booksimple"

    xlink:type="simple">Rayman, Marc D., Philip Varghese, David H. Lehman, and Leslie L. Livesay. “Results from the Deep Space 1 Technology Validation Mission.” Acta Astronautica 47 (2000): 475-488. Provides an overview of NASA’s New Millennium Program, details the twelve technologies tested during the primary mission, and includes a graphic of the primary-mission trajectory.

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