Sky & Telescope March 1984 [antikvár]

Astronomy from SateWite CAustetsRobert Stachnik, Harvard-Smithsonian Center for Astrophysics, and Antoine Labeyrie, CERGA, FranceAS THE SPACE TELESCOPE cornes arc second (see the boxed discussion on fondes, d\iecX\y reXaXed Xo XYve axtçptax J\ closer to reality, various investigators the next page).diameter cfi XYve sXat, c\van%es as tcvvc-are beginning to consider what will be the The simplest system of Xh\s type \s Xhe rots' séparation Naties. K modem gcound-next major step in optical instrumentation. so-called M\che\son steUar mterferometer. based \ers\on of Xb\s ex^pedmeuXis wwi op-Evidence is accumulating that giant space lt consists of two \\ght-co\\ect\ng éVements erat\nL successfuWy aX \be Cent d'^Audes telescopes, made up from a number of and a precisely \ocated detector. \n Xhe el de KecbetcbesX Kstoco-separate mirrors on independent satellites, classical experiments carned out eatWet nom\ques tÇS&QM tveai Gxasse, ^xaxvee are a realistic prospect that can potentially this century by Albert k. Miche\son, Pran- ^see pa^e of Xbe kpu\, YföL, \ss\ieY provide research tools of extraordinary cis G. Pease, and John A. Anderson, two \-ofX\n% a >A\cbe\soxv 'mXexfexomeXex xxvX' power.mirrors separated by up to 20 feet (.and, space, away fxom aXmospbetvc XwxbvAervcIn the coming decades, it may be possi- with a later devke, 50 feet) re\ayed WfcYvt Ys an attractive notion. ^wX deN\sxn% ble to place in orbit the elements of an ex- from tbe same star to a common focus at exXteme\y \ax%e and u^\d support sXxnc pandable optical array with a "düute" ap- the Mount WWson \00-\ncb te\escope. reç\u\red fox ^xecxse ^osxtioxvxn% of tive erture kilometers across. Such a device lf the opt\ca\ paths traced out by tbe ca\ component* a danntin^ obsXa&\ could be more than just a light bucket; op- two \ight tays are the same to V\tb\n tbon^b botb \be Brcopeaxv Srçfcce erating as a "coherent" (phase-preserving) a few microns, a pattern of \nterference ÇESiCiconadexedimaging system, it could achieve diffrac- frmges \s obsetved by tbe detectot (?ee tbe accompY\sb tbe option tvs tion-limited resolution of millionths of an box on page 201). Tbe contrast of tbe \d connection of tive \x%\vVco\\