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Gravity Probe B

Testing Einstein's Universe

Program Info


GP-B in a Nutshell Info Brochure

GP-B in a Nutshell Information Sheet

A 2-page (one-sheet, front & back) overview summarizing the GP-B experiment, its history, scientific purpose, technology, flight mission and spinoffs.

Executive Summary, Preface & Spacecraft Info

Final Report—Preface, Executive Summary & Spacecraft Information

A 28-page excerpt from the GP-B Post-Flight Analysis, Final Report to NASA that provides a more complete summary of all aspects of the GP-B experiment and flight mission.

GP-B Post-Flight Analysis Final Report

GP-B Post-Flight Analysis—Final Report to NASA, March 2007

A 616-page report covering all aspects of the GP-B flight mission. This report comprises 16 chapters covering the history scientific objectives, management of the program, mission operations, technologies developed, performance of all systems on-board the spacecraft, data analysis procedures, preliminary experimental results as of March 2007, and lessons learned. In addition, six appendices include spacecraft information, a complete chronicle of status updates posted on the GP-B Web site from launch through the completion of the flight mission, a complete list of anomalies and observations logged during the mission, lines of code in the various software systems on-board the spacecraft and a glossary of terms.

GP-B Science Results—NASA Final Report, December 2008

On October 6-10, 2008, five members of our GP-B team presented papers on various aspects of the GP-B data analysis at the International Space Science Institute (ISSI) workshop in Bern, Switzerland on “The Nature of Gravity: Confronting Theory and Experiment in Space.”

GP-B Post-Flight Analysis Final Report

The five papers summarize the interim results of the GP-B experiment, as also reported to our GP-B external Science Advisory Committee (SAC) at their 18th meeting on August 29, 2008. Following the ISSI meeting, the papers were submitted for publication in the international, refereed journal, Space Science Reviews.  They will be reprinted in a hardcover book in the Space Sciences Series of the ISSI, both to be published by Springer later this year.

These papers, along with an introductory preface, comprise the contents of an 80-page science results report that was submitted to NASA in December 2008, This report was the final deliverable on our NASA contract, which expired on September 30, 2008.

GP-B/NASA Fact Sheet

NASA GP-B Fact Sheet

A 6-page standard NASA mission fact sheet summarizing the GP-B experiment and mission, as of 2005. The fact sheet includes a table containing information about the spacecraft and its orbit.

Posters & Slide Show Presentations

GP-B in a Nutshell Poster

GP-B 8-Panel Overview Poster

A 40 x 60 inch, eight-panel poster that provides a visual overview of the GP-B experiment and flight mission. Reduced 11 x 17 inch (tabloid size) and 8.5 x 11 inch (letter size) versions are also available.

GP-B Photo Collage Poster

GP-B Photo-Collage Poster

A 32 x 48 inch poster featuring a collage of photos, drawings and graphs summarizing the GP-B experiment and mission.

GP-B in a Nutshell Slide Show

GP-B in a Nutshell Slide Show (9 Slides)

The same visual overview information from the GP-B in a Nutshell Poster displayed as a series of Microsoft PowerPoint slides and formatted in both PowerPoint and Adobe Acrobat PDF versions. In addition to the eight overview slides, the presentation contains a ninth title slide.

KACST Presentation-102508

Francis Everitt's KACST Presentation (46 Slides)

Slides from a presentation by GP-B Principal Investigator, Francis Everitt, to KACST on October 25, 2008. Both Microsoft PowerPoint slides and a PDF copy are available for downloading.

Frequently Asked Questions (FAQs)

Answers to the questions that we are most frequently asked about GP-B.

GP-B Time Line

A time line of the GP-B program time line, beginning with the roots and history of Einstein's general theory of relativity in the 1800's, some historical milestones in the lives of the three GP-B founders (Leonard Schiff, William Fairbank, and Robert Cannon), the genesis of GP-B in 1959-60, and milestones in the history of the GP-B program and flight mission, which concluded in September 2005.

Photo of an assembled paper model of the GP-B spacecraft.

Paper Model of the GP-B Spacecraft

In 2004, Stanford graduate student and GP-B graphic designer, Katherine Stephenson, created a 1/20 scale paper model of the GP-B spacecraft that you can download as a PDF file, print out, and assemble.

Glossary of Terms Used in the GP-B Mission

A short glossary of terms used throughout this Web site.

A list of Web site links covering a variety of topics related to the GPB project.