Editing Space Interferometry Mission (section)

===New technologies===
SIM's new technology was meant to lead to the development of telescopes powerful enough to take images of Earth-like [[extrasolar planets]] orbiting distant stars and to determine whether those planets are [[Planetary habitability|able to sustain life]]. NASA has already started developing future missions that will build on SIM's technological legacy.<ref name=pqmissions>"[http://planetquest.jpl.nasa.gov/missions/missions_index.cfm# Planet Finding Missions: The Big Picture] {{webarchive|url=https://web.archive.org/web/20070428181159/http://planetquest.jpl.nasa.gov/missions/missions_index.cfm |date=28 April 2007 }}", Missions, NASA, PlanetQuest, ''Jet Propulsion Laboratory''. Retrieved 24 April 2007.</ref> The technological development phase of the mission was completed in November 2006 with the announcement that the eight, mission-technology-milestones set by NASA were reached.<ref name=tech/><ref name=goals/> The milestones were necessary steps in the technological development before flight control instruments could begin to be designed. The completion of each milestone meant that new systems had to be developed for [[nanometer]] control as well as [[picometer]] knowledge technology; these systems enable the telescope to make its accurate measurements with extreme accuracy.<ref name=tech>"[http://www.irconnect.com/noc/press/pages/news_releases.mhtml?d=108763 Star- and Planet-Mapping Telescope Mission Ready to Move Forward]", ([[Press Release]]), Northrop Grumman, 14 November 2006. Retrieved 24 April 2007</ref>
[[Image:SIM-Testbed-590.jpg|thumb|left|Engineers at JPL examine components on an optical bench that simulates the precision performance of NASA's future SIM Lite mission.]]
One of the new technologies developed for the mission were high-tech "rulers", capable of making measurements in increments a fraction of the width of a [[hydrogen]] atom. In addition, the rulers were developed to work as a [[Network analysis (electrical circuits)|network]]. The mission team also created "[[shock absorber]]s" to alleviate the effects of tiny vibrations in the spacecraft which would impede accurate measurements. Another of the milestones involved combining the new "rulers" and "shock absorbers" to prove that the Space Interferometry Mission craft could detect the tiny wobbles in stars caused by Earth-sized planets. The fifth of the technology milestones required the demonstration of the Microarcsecond Metrology Testbed at a performance of 3,200&nbsp;picometers over its wide angle field of view. The wide angle measurements were to be used to determine the fixed positions of stars each time they were measured. This level of performance demonstrated SIM Lite's ability to calculate the [[astrometry|astrometric]] grid. Another key development, known as gridless narrow-angle astrometry ([[GNAA]]), was the ability to apply the measurement capability worked out in the wide angle milestone and take it a step further, into narrow-angle measurements. Aiming to give an accuracy of 1 micro-arcsecond to the early stages of the SIM,<ref>High-precision early mission narrow angle science with the Space Interferometry Mission" by Shaklan, S., Milman, M. H., Pan, X., ''JPL Report''Issue Date: 22 August 2002 [http://hdl.handle.net/2014/37180]</ref><ref>{{cite journal |doi=10.1016/j.actaastro.2007.01.036 |title=The SIM PlanetQuest science program |date=2007 |last1=Edberg |first1=S |last2=Traub |first2=W |last3=Unwin |first3=S |last4=Marriv |first4=J |journal=Acta Astronautica |volume=61 |issue=1–6 |pages=52–62 |bibcode = 2007AcAau..61...52E |url=https://trs.jpl.nasa.gov/bitstream/2014/40982/1/06-2967.pdf }}</ref><ref>[http://sim.jpl.nasa.gov/scienceMotivations/diverseAreas/science_shaklan.pdf A New Approach to Micro-arcsecond Astrometry with SIM Allowing Early Mission Narrow Angle Measurements of Compelling Astronomical Targets] {{webarchive|url=https://web.archive.org/web/20110722171456/http://sim.jpl.nasa.gov/scienceMotivations/diverseAreas/science_shaklan.pdf |date=22 July 2011 }}</ref> the technique allows star positions to be measured without first setting up a grid of reference stars; instead, it sets up a reference frame using several reference stars and a target star observed from different locations, and star positions are calculated using delay measurements from separate observations. The narrow angle field was to be used by SIM to detect [[terrestrial planet]]s; the team applied the same criteria to both the narrow and wide angle measurements.<ref name=goals>"[http://planetquest.jpl.nasa.gov/SIM/sim_milestones.cfm The eight technology milestones] {{webarchive|url=https://web.archive.org/web/20070509085545/http://planetquest.jpl.nasa.gov/SIM/sim_milestones.cfm |date=9 May 2007 }}", NASA, SIM PlanetQuest, ''Jet Propulsion Laboratory''. Retrieved 24 April 2007.</ref> The final requirement before beginning work on flight controls was to make sure that all of the systems developed for the mission worked cohesively; this final NASA technology goal was completed last as it was dependent upon the others.