space mission space mission known known planned space developed nasa conjunction contractor main goals mission hunt earth sized planets zones nearby stars sun postponed times finally cancelled addition hunting planets helped construct map way galaxy important tasks included collecting data help stellar masses specific types stars assisting determination spatial distribution dark matter effect measure mass stars spacecraft optical accomplish scientific goals technique collects light multiple mirrors case combined interference pattern precisely measured initial contracts awarded totaling million work project required scientists engineers specific new technology november completed originally scheduled launch aboard evolved launch vehicle result continued budget cuts launch date pushed times nasa set preliminary launch date federal budget documents confirmed launch date expected earlier february engineers working program moved areas projects nasa directed project resources engineering risk reduction preliminary budget nasa included zero dollars december congress restored funding fiscal year bill president later signed time congress directed nasa mission forward development phase project continued risk reduction work waiting findings recommendations astronomy survey performed determine project future august report released recommend nasa continue development prompted nasa astronomy physics director issue letter september project manager informing nasa sponsorship mission directing project phase activities immediately soon practical accordingly activities closed end calendar year mission operated earth trailing orbit drifted away earth rate year end planned mission reached distance million earth taken approximately years sun continuously spacecraft allowing avoid target stars sun occur earth orbit launched performed scientific research years planet hunting powerful planet hunting space built technique spacecraft able detect earth sized planets perform search nearby earth like planets looking parent star apparent motion planet spacecraft accomplish task accuracy thickness viewed distance earth moon titled deep search planet hunting program intended search approximately nearby stars terrestrial planets like earth venus zone liquid water exist revolution year planet star deep search demanding terms accuracy program use capability spacecraft measurements flexible search strategy tunes mass sensitivity star desired level planet search value earth fraction stars carrying earth analog planets estimated time launches strategy planet search deeper search lower mass sensitivity zone smaller number targets earth common shallower search larger number targets earth example assuming mission time allocated planet search survey stars planets earth mass scaled stars planets earth masses scaled stars planets earth masses scaled aside searching earth sized planets scheduled perform dubbed broad survey broad survey looked approximately stars help determine abundance neptune mass larger planets star types earth sector way planet finding mission search mass planets young stars survey helped scientists understand solar system formation including occurrence hot portion planet hunt designed study systems mass planets system reached long term planet hunting techniques star radial velocity measure regular tiny motions induced planets strong atmospheric activity youthful star techniques pioneered able execute primary planet finding missions mission planet finding component set serve important complement future missions designed image measure terrestrial perform important task missions capable determining planet masses task envisioned perform future missions include providing characteristics planets knowledge missions estimate optimal times projected star planet separation angles observe terrestrial planets detected stellar mass key aspect future mission determining upper lower limits star masses today scientists understand limits small large star objects small lack internal pressure initiate fusion causes star shine objects known brown represent lower end stellar mass scale stars large unstable explode mission provide measurements extremes stellar mass evolution able measure mass star galaxy billion instead population census technique able output accurate masses representative examples nearly star type including brown hot white red giant stars elusive black holes current space including nasa space accurately measure mass types stars estimates range stellar mass mass sun excess times mass sun entire study focused star systems stars coupled mutual attraction mapping measurements stellar positions course mission permitted precisely measure distances stars way allowed create galaxy answer questions shape size currently know little shape size galaxy relative know difficult observe entire way inside good analogy trying observe marching band member band observing easier humans outside team planned use help determine shape size galaxy distribution mass motion stars measurements way stars yield data understand topics fundamental parameters limit disk mass potential mass galaxy large fundamental parameters aimed answering key questions size shape rotation rate way team hoped accurately determine distance sun center second topic limit attempted determine mass disk project topic disk mass potential topic designed measurements distances disk stars proper motions results topic study combined results fundamental parameters portion study determine solar system position velocity galaxy final topic dealt dark matter distribution way data create dimensional model mass distribution galaxy radius use different tests determine potential large dark matter dark matter matter universe seen effect stars scientists know approximately matter universe dark matter spatial distribution dark matter universe largely unknown help scientists determine answer question integral mission strongest evidence dark matter comes motion rotate faster visible matter suggests gravity ordinary matter hold galaxy scientists galaxy held huge quantities dark matter similarly clusters appear visible matter balance high speed motions component measuring stellar motions way measure internal average motion neighboring near measurements kind measurements conjunction currently available data provide total mass measurements individual numbers enable scientists estimate spatial distribution dark matter extension universe development beginnings began month preliminary architecture study march nasa selected conduct study selected contractor project acquired took contract selected lockheed space located california contracts included mission implementation phases announced september worth total million phase mission included initial mission design planning scale implementation mission time nasa announcement launch scheduled mission series missions designed answer questions humans earth august nasa asked project managers consider looking space shuttle instead previously proposed launch vehicle late november nasa announced project scientific team selected group included notable names world planet research including entire group consisted principal investigators mission specialists time nasa announcement launch scheduled mission new technologies new technology meant lead development powerful images earth like planets distant stars determine planets able sustain life nasa started developing future missions build technological legacy technological development phase mission completed november announcement mission technology set nasa reached necessary steps technological development flight control instruments begin designed completion milestone meant new systems developed control knowledge technology systems enable accurate measurements extreme accuracy new technologies developed mission high tech rulers capable making measurements fraction width hydrogen addition rulers developed work network mission team created shock alleviate effects tiny vibrations spacecraft accurate measurements involved combining new rulers shock prove craft detect tiny stars caused earth sized planets fifth technology required demonstration performance wide angle field regard wide angle measurements determine fixed positions stars time measured level performance demonstrated ability grid key development known narrow angle ability apply measurement capability worked wide angle milestone step narrow angle measurements aiming accuracy micro early stages technique allows star positions measured setting grid reference stars instead sets reference frame reference stars target star observed different locations star positions calculated delay measurements separate observations narrow angle field detect terrestrial planets team applied criteria narrow wide angle measurements final requirement beginning work flight controls sure systems developed mission worked final nasa technology goal completed dependent status end april june project completed engineering november completed spacecraft internal design review june engineering successfully completed project phase june case july phase called preliminary design phase phase develops mission concept developed phase prepare project entry implementation phase project requirements defined schedules determined specifications prepared initiate system design development addition project number reviews nasa including phase experiments proposed peer reviewed eventually selected nasa experiment selections based scientific value cost management engineering safety planned launch launch date mission pushed times program outset launch scheduled launch date delayed date held project scientists cited late contractor company designing developing listed launch date website release nasa budget predictions changed time date earlier delay launch date primarily related budget cuts program change represented difference years launch date outlined nasa budget years budget predictions groups predicted dates matching officially predicted launch dates sets date june nasa postponed launch date indefinitely nasa operating plan mission phase spring launch planned evolved launch vehicle likely equivalent budget considered flagship mission nasa known according nasa program coherent series increasingly challenging projects mission building results capabilities preceded nasa searches planets outside solar system program addition includes large originally approved mission given million cap dollars included launch costs years operation contracts preliminary architecture study worth nasa budget outlined plans projects fiscal year missions delayed saw budget cuts nasa budget stipulated phase activity continue new cost schedule plans developed consistent recent funding decisions funding decisions included million cut nasa budget request budget laid projections program year year successive funding cuts compared request numbers starting receive million compared following years cuts million million compared request entered terms phase fringes space mission newsletter called important milestone way launch delays budgetary nature mission received million increase million previous year cuts amounted million program million million estimated cut budget come mission additional million decrease program reduced million supplemented substantial previous year awaiting results astronomy survey february budget cuts outlined budget felt project engineers worked forced find areas work february editorial described situation entirely budget pressures priorities nasa scientific motivation mission strong nasa budget cuts directed project efforts engineering risk reduction february newsletter plans process completed project status april august found public web site form submissions astronomy survey request information documents use launch date reference communicating schedule budget nasa set launch date report released mid- late instruments optical technique pioneered 19th century optical matured decades combines light multiple precise measurements akin accomplished single larger interaction light waves called interference makes possible interference cancel bright stars measure distances angles accurately construction word partially illustrates interfere measure radio electromagnetic spectrum years measure structure distant functions optical composed science collectors separation guide collectors guide sophisticated guide instrument pointing dimension spacecraft operational limiting magnitude goes planet finding accuracy single measurements accuracy global sky grid design consists light collectors strictly speaking mounted opposite ends meter structure observatory able measure small stars detect planets causing earth mass distances light years sun
Space Interferometry Mission