Hubble Rescue Mission: B Y S U S A N M. R E I S S

A Stellar Success On the eve of the New Year, N A S A scientists got the

best news they'd received in a long time. Images sent back from the newly serviced Hubble Space Tele­scope (HST) confirmed that the world's first orbiting tele­scope would fulfill its mission to probe the universe with unprecedented clarity and sensitivity. (See After Image, page 80.)

"The image of galaxy M100 clearly showed that we'd fixed Hubble," says HST project scientist Ed Weiler. "Be­cause we can see individual stars in this galaxy, we wil l be able to measure the Hubble constant and, thus, the age of the universe."

The HST triumph helps N A S A overcome recent im­age problems that have included mismanagement and over-budget, off-schedule projects. "The HST mission shows that N A S A can get something done on time and within budget," says a H i l l staffer involved in the appro­

priations process. Although the Hubble rescue has re­newed Congress's confidence in the agency, NASA 's fu­ture budgets won't turn on this mission. "They will have to work within the same constraints as everyone else," the staffer adds. One of the factors contributing to HST's positive outcome was support from Congress. Sen. Bar­bara Mikulski (D-Md.) led the charge to fund the Hubble fix. Says the Hi l l aide, "We spent so much on Hubble, to get that far [the 1990 deployment] and stop would have been pointless." In all, the Hubble rescue mission cost $51 million. Through 1993, the Hubble project had spent half of its 15-year, $6.5 billion budget. The 1994 budget is $260 million. During the telescope's projected lifetime, NASA wil l spend $800 million to analyze data collected by the instrument.

H U B B L E FIX

L I K E L A N D I N G ON T H E MOON

The complexity of the HST mission has been compared to NASA 's lunar landing missions. Harkening back to those golden days of space flight, the scores of individuals con­nected with the servicing mission proved N A S A could work as a team. "There was extraordinary teamwork and very little infighting between the folks at Goddard Space Flight Center, Johnson Space Center, N A S A headquar­ters, and Kennedy Space Center," says the Hi l l appropria­tions aide. " N A S A focused on a solut ion, tested extensively, and stuck with the benchmarks set."

Extensive training and countless independent reviews also contributed to the successful 11-day servicing mis­sion last December. Time and again, those involved in the Hubble Servicing Mission say the intense training pro­gram set up for the astronauts and the ground crew was integral to the mission's favorable outcome. The astro­nauts, who spent more than 400 hours in water tanks simulating the actual repairs in space, also used virtual reality technology to learn the spatial relationships of the payload bay. Scientists and engineers on the ground took part in simulations of various challenges that might arise during the flight so they could react quickly with solu­tions in real time.

To do Hubble right the second time, N A S A officials reviewed everything—from components to full-scale sys­tems—countless times. "One possible reason everything went so well was the number of reviews," says Robert Shannon, a member of the Hubble Board of Investigation. "The engineers doing the work were themselves doing an excellent job, but the glare of publicity made it impossible

06 OPTICS & PHOTONICS N E W S / M A R C H 1994

for them [the e n g i n e e r s ] to let a n y t h i n g go by unexamined. "

From 1990 through 1993, N A S A spent between $5 mi l ­l ion and $10 mi l l ion on testing and review. The space agency estimates the Hubble mission underwent at least 15 reviews. Five high-level review panels scrutinized HST-related work. These panels included the HST Op­tical Systems Board of Investiga­tion, chaired by Lew A l l en , and the Hubble Independent Optical Review Panel (HIORP), chaired by Duncan Moore. The A l len C o m ­mittee determined the cause of Hubble 's problems, and H I O R P determined the prescription for the corrective optics. A long the way, components were tested by their vendors, including Ball Aerospace and Tinsley Laboratories.

F ind ing the right prescr ip­t ion " took a bit of l uck , " says Moore , now science adv isor to Sen. Jay Rockefel ler (D-W.Va.) . Moore attributes the successful fix to "a l l the people who worked on this project. W e spent an i n ­credible amount of manpower analyz ing the prob lem."

"Learn ing what was wrong wi th Hubble took a lot of hard work , " says Shannon, former d i ­rec to r of the U n i v e r s i t y of Ar izona 's Opt ica l Sciences C e n ­ter. "The [Al len] panel spent a year look ing at the data," he says. In addi t ion, the panel was helped by the fact that 90% of the prob­lem was in one m i r ro r . "The panel gave its best guess to solve the other 10%."

The Hubble telescope, con­ceived by Lyman Spitzer in the 1940s, built dur ing the 1980s, and retrofitted in the 1990s, has re­newed the conf idence of a belea­guered space agency. " N o one wou ld have bet a penny the mis­sion wou ld be 100% and wou ld be c a r r i e d out i n a n o r m a l amount of t ime," says N A S A ' s Weiler. "When N A S A has a clear goa l , adequate—but not fat— budgets, and a real schedule, the agency can per form."

For more information on the recovery mission, see the Novem­ber 1993 special issue of Optics &

Photonics News, " H u b b l e Space Telescope: Engineer ing for Recovery. " Watch upcoming issues of OPN for a de­tailed art icle on the Hubb le fix.

S U S A N M . R E I S S IS Managing Editor of Optics & Photonics News .

OPTICS & PHOTONICS NEWS/MARCH 1994 7