Hubble 3Rd Servicing Mission
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1 ,-/... + R ---'-, 9r.. 1 7n #f7I.-t-•r0421 «t' 11% #R' f• 1 3 , e P. -tillttxell_ r- -- 1 <1 - F.I., EL// \179 *LA i,t#../. *1 \-/ L/ \-/1- - 4 - r-/1 ' . 1 4 - .·*/ 3 ta . Bil--I- ' tti I61 A -'' 3- \5/ Tbis October four spacewalki,gg astronauts will prepare tbe Hubble Space Telescopefor its next decade of observations. by Robert Naeye Like a fine wine, the Hubble Space Telescope keeps getting better with age. How can this be, you might be wondering, when the telescope is constantly exposed to the debilitating effects of 400° F (220° C) temperature swings, high doses of radiation, and a constant rain of micrometeorites? The answer is simple. Hubble was specifically designed to be serviced by space shuttle astronauts, who breathed new life into the telescope during two previous 350-mile-high house calls. In December 1993, four spacewalking astronauts brought the telescope back from the brink of disaster when they installed optics to correct for Hubble's flawed primary mirror. In February 1997, astronauts installed two new scientific instruments: the infrared camera NICMOS and an imaging spectrograph called STIS. If all goes according to schedule, the next Hubble servicing mission willlaunch on October 14, 1999. On that day, an international seven-man crew will rocket into space aboard the space shuttle Discovery. Four spacewalkers, three of whom are astrophysicists, will replace the telescope's failing gyroscopes, install a new computer, < and perform several other repairs and upgrades. This third servicing mission won't E © 2015 Kalmbach Publishing Co. This material may not be reproduced in any 54 ASTRONOMYform without permissionNOVEMBER from the publisher. 1999 www.Astronomy.com 1- 44 5 .4 ./ ./ ...9.' #94 4 = 4,V . s » - r#<•• 4-4 .4 .. .1/I'll.&,41 . - ...4 ...:*,""••.-2.,i'.."•I: . ...4..·..6.-12,4...7,>...•,i....•. I .' .fir ' 2:. ' 6....... ..'-... ...... - . aeS''I /:i't'.,2 . - t........../... .... 042·042. '.9, S - . ; 41... 1.- 1 ·,. '-•4 -· Al . 1.« • f.•I .'•' 2.. ... .* .':..... .... "'·- ··W'•• ..' ..P...•* .., , "..ff +,..1. 't:.« ... " , .If. involve radical surgery, but it will make the telescope more was a 10 to 20 percent probability that the next gyro failure reliable while paving the way for new science instruments in would occur as early as June or July 1999, one year prior to the future (see"The Future of Hubble,» page 58). the scheduled launch of Servicing Mission 3. The possibility of a one-year downtime was unacceptable." A Rescue Mission On February 19, Campbell's office asked NASA headquar- The October 1999 servicing mission was moved up eight ters if it could divide Servicing Mission 3 in two and months by necessity, not choice. NASA had planned an schedule a shuttle mission as soon as possible to replace the ambitious Servicing Mission 3 for June 2000, with six sched- gyros. On March 10, NASA complied: Servicing Mission 3 uled space walks ( known as EVAs in NASA-speak, for was split into missions 3A and 38. Because the gyros needed Extra-Vehicular Activities). Besides inserting new gyros and to be replaced as soon as possible, and the Advanced Camera, the new computer, the astronauts would install the state-of- NICMOS refrigerator, and solar arrays wouldn't be ready for the-art Advanced Camera for Surveys, a refrigerator to revive nearly a year, the 3A mission was slated for October 1999, the failed NICMOS camera, and powerful new solar arrays. while the more ambitious 3B mission was tentatively sched- For the astronauts, this was to be by far the most challenging uled for June 2001 (Campbell says there's a good chance it of all the Hubble servicing missions. will be moved up to December 2000). But NASKs plans unraveled earlier this year. Two of the telescope's six gyros had already failed, and on January 24, The EVA Ballet 1999, a third gyro began to hiccup. Hubble can't point accu- Servicing Mission 3A, designated STS-103 by the shuttle rately enough at targets to do science unless three or more program, has a veteran crew of seven astronauts who collec- gyros are functioning properly. If one more failed, Hubble tively have 18 prior space shuttle missions to their credit. would be sitting idly in space, wasting tens of millions of tax- Former US. Air Force pilot Curtis Brown, Jn will command payer dollars. the mission. Brown, who will do the bulk of the flying, was "When the third gyro failed, we estimated odds of also the commander of John Glenn's 1998 shuttle flight. Scott between 1-in-3 and 1-in-2 that Hubble would lose another Kelly, who flew F-14s and F-18s for the US. Navy before join- gyro prior to June 2000;' says Hubble project director John ing the astronaut corps, will serve as pilot; he is the only H. Campbell of NASA's Goddard Space Flight Centen "There rookie on STS-103. European Space Agency (ESA) astronaut HUBBLE HOUSE CALL :it . t· · '¢K==·t,/35*fijt-•B-'**·..2,·:. '. '2. ... .-4 -,·'32.:... ''' -· , ' Install new solid-state /5. ' i Install sheets on .· Replace voltage- recorder Replace . : '.. - forward section :, temperature kit ..:\ , 9&... A. --.4 coinputer .-I..... \ -•-4: 11 ..... .. .. .. if :. \1 94' ' -.9 13*b 7 i \. tfit ill'* \•332.•11.»«'-1 -- e I.... i<4 . 666•,fealt.2•5.-,sl.,• : ..4•Ii. 1 4 9,-Wlee'llililia.,127-7-·-•2,•i"•//H • ...%. 6-·f-imiLY#82,Iix<.Fay' ' ... - 1 9 0 01..- Install sheets on •*b:·:-':.'- t.& ,PR.I//.d middle section A'·41.'-/4.•i.--1*'1•*'Ii.,#-61lllllll s'- 1%-- · ·.· i'-···--.'·-'--"-- · --- · -Awal.li':1- *•....9 1 h I-,f.• I.A... -F-:.'S'' F • •1 91 9.,C.,1 9 429'd. ' 4.4 kip '1. EVA 1 Smith and Grunsfeld -¤ S *Sh, EVA 2 Foale and N icollier 2 :, t.r':..£ . EVA 3 Smith and Grunsfeld -' •8=a• 4 3:j' EVA 4 Foale and Nicollier V - - •.-•- §51•.' CI":de•ine•185 f•to i To learn more about this mission and to read biographies of the crew, visit: www.ksc.nasa.gov/shuttle/missions/sts-103/mission-sts-103.html Z - 56 • ASTRONOMY NOVEMBER 1999 ./ *" t " i / i . : * 4 A036 » ' -, 4" l A 4,4,4 i f -- i 4 0.2/dpi *f ji ts. » From left to right, the crew of STS-103 Hubble Servicing Mission 3A: Michael Foale, Claude Nicollier, Scott Kelly, Curtis Brown, Jean-Francois Clervoy, John Grunsfeld, and Steven Smith. WASAtJSC Jean-Frangois Clervoy of France will operate the shuttle's mission. Like Grunsfeld, Foale and Nicollier both have Canadian-built robotic arm. advanced degrees in astrophysics. A pair of two-man teams will do the EVAs. Steven Smith, Two days after launch, Brown will deftly maneuver a former electrical engineer who performed three space Discovery into position to rendezvous with Hubble. "The . walks during the February 1997 servicing mission, will be main thing we worry about is the fragile solar arrays, says paired with John Grunsfeld, an astrophysicist who studies Brown. "We're flying an orbiter that weighs 230,000 pounds, high-energy objects such as x-ray pulsars and black holes. and we're very precisely maneuvering within tolerances of British native Michael Foale, who spent 134 days on the inches as we slowly move into position so that the robotic Russian space station Mir in 1997, will do EVAs with ESA arm can grab the telescope." astronaut Claude Nicollier of Switzerland. Nicollier operated On the third day of the 10-day mission, Smith and the robotic arm during the December 1993 servicing Grunsfeld will venture outside the shuttle to perform the first of four 6-hour EVAs. The two astronauts will install a kit The skin on Hubble's sunward side is cracking and peeling. The astro- that protects the batteries from overcharging, but their main nauts will place large metal "Band-Aids" over the skin. NASA•JSC chore will be to replace all six gyros. As Smith says, "It's the single most important thing we're doing." Because NASA anticipated that the gyros would eventually ML*$ *0• fail, they were designed to be replaced. But this EVA is hardly a leisurely afternoon stroll in the park. "It means going right ./=. Uei into the bowels of the telescope, right into one of the most 1 .t sensitive regions," says Grunsfeld. Smith and Grunsfeld will -=\4 « -1 1. take turns guiding each other into passageways that are just > .= barely wide enough to accommodate an astronaut in his 036't «- .. I space suit. Standing virtually motionless like statues for three 1 ,» t-•b. 46 half-hour shifts, they will have to disconnect three boxes )*,%% , 4 B. *LE + containing the old gyros and replace them with three new 11 I * t=••. .. /A boxes. "We're told we can't touch anything, except for the . box we're replacing," says Grunsfeld. "You have to remember 4, 4 1,4 that when you take a box out, it might be a $5-million or 16 Fi 1 $10-million box that you're holding, and that you're working VJ . inches away from a $5-billion astronomical resource." 4, .4.1*... + d The next day, it's Foale and Nicollier's turn. They will -..,.'.--" replace Hubble's "ancient" computer, which is based on NOVEMBER 1999 ASTRONOMY 57 1,2. E ./...4- /'143./F\-<-*Fi'M , I •1•4 --•lif., 1 6 -,444 ... i / '42,1, i• 11• 5'44,, '• 7 , -'.01, • r tiffeg•• - - 1 '94 * 01/ ..t' -, i . 11*1 7:».3-4. i.·t i.t. ' /; t: ·... .e....1=. S. ··2*:1' V•'1.•.' S. '4'. E ... Al< L: -*4/#4 + IZA./.\·:\ 3 2 ......i#.1,·.042-' ' ·'.