On April 24, 1990, the Hubble Space Telescope was launched into low Earth orbit by the Space Shuttle Discovery. On April 25, it was deployed from the shuttle in a slow and purposeful dance orchestrated by the astronauts and the shuttle’s Remote Manipulator System arm. Two weeks later, it started to send back scientific data.
As we observe the 30th anniversary of Hubble’s exploration of our universe, take a virtual peek at the displays the National Air and Space Museum has provided visitors over the past few decades of Hubble’s life. We do this sadly aware of the fact that the Museum is closed to the public for the foreseeable future and we are unable to celebrate Hubble’s incredible work in person.
Since the late 1970s, soon after the Space Telescope project was approved and funded by Congress, the Museum started collecting objects: concept models, drawings, reports, etc. By the early 1980s we had 1/5th scale high definition models of both the telescope’s optical assembly and the spacecraft itself on display, expecting Hubble to launch soon. The Space Shuttle Challenger disaster in 1986 changed all that.
We corrected the labels relating to the mission and help our visitors understand the problems, but then the day finally came, and we were anxiously awaiting data, and most of all images. They started arriving in late May 1990 and did show improvements over Earth-based telescopes and previous space telescopes, but quite soon, it was clear that something was terribly wrong with the telescope. It would not focus point-like objects like stars into tiny brilliant dots. The photos it returned were a little hazy – a little, but enough to be very worried. It was soon discovered that there was an aberration on the space telescope’s primary mirror.
Throughout that summer and fall, astronomers still found observing with Hubble to be highly useful and exciting. They observed all sorts of cosmic curiosities with Hubble, clarifying the structure of an explosive shock front racing away from a supernova that burst forth in 1987 and exploring in detail the spectral and photometric features of a wide range of phenomena, refining our understanding of the composition of the early universe and delving into what we now know are black holes. The media and the public, as well as our Museum, were, however, faced with the challenge of explaining what went wrong with the Hubble mirror, and, of course, seeking answers to how NASA was going to fix it.
After the first servicing mission to Hubble in December 1993 by astronauts aboard Space Shuttle Endeavour, where instruments were traded in and out to correct the optical flaw, the world soon reveled in the flood of spectacular images and spectral data giving new insights into the existence of black holes, into the lives of massive stars, and into the fine structure of the atmospheres of giant planets like Jupiter and Saturn.
The first and subsequent servicing missions to Hubble had, of course, been planned into the program. They were always intended to be ways to fix faults but mainly to upgrade the instruments with better detectors and faster electronics as these technologies were then rapidly advancing. Hubble was, indeed, of all the “Great Observatories” of its generation, designed to be fixed. And it turned out to be the only one that desperately needed fixing.
One side benefit of this servicing mission concept was that as instruments were replaced, they were not just thrown into space to become space debris. They were returned to Earth for evaluation and study, and yes, for display. We have been one of the major beneficiaries of this decision. Once NASA finishes its own engineering checkout and declares something no longer needed by the mission, it is declared “excess property” and goes through a formal General Services Administration process to make them available to other agencies, related government interests, and then, finally, to be sold. The Smithsonian has been fortunate to hold a favored position through a formal transfer agreement, and so over the years we’ve been building our collection of NASA materials, from spacecraft to spacesuits to all things Hubble.
We now have some two-hundred objects relating to Hubble in our collection, ranging from postage stamps and mission patches, to special tools that were used in servicing Hubble, to the major instruments that were returned to Earth, as well as objects that played roles in developing the mission, but never flew.
To celebrate the 30th anniversary of Hubble’s launch, join me for a virtual stroll through the halls of the Museum to have a look at some of the major Hubble components that have been on display and will continue to be on display when the Museum reopens.
The Hubble Primary Back-Up Mirror
With the Hubble Space Telescope in orbit in the early 90s, NASA looked for ways to repurpose what was called the “Back-Up Mirror.” Identical in design to what is flying in space, this mirror, a lightweight grid-like cellular structure covered by glass plates all fused together, was manufactured by Corning and ground, polished, and figured by the Kodak Precision Optics Division. It remained in storage and was never overcoated with reflective aluminum like the flown mirror was. When the flaw in the flight mirror was discovered, NASA decided it would be too expensive and risky to bring the whole telescope home and switch out the mirror, so the backup mirror was excess property. NASA queried observatories around the world to see if they might be able to use it. But as it was made for “zero-g” operation, it proved impractical to repurpose. So we got it here at the Museum. These photos show how it arrived courtesy of Kodak, was brought into the Museum, mated to its transport cradle, and finally exhibited in Explore the Universe, which opened in 2001.
The First Wide Field/Planetary Camera (WFPC-1)
NASA’s plan to fix Hubble centered on placing a set of small correcting mirrors into the beam of the primary mirror. This would correct the light for all the instruments except for the Wide Field/Planetary Camera (WFPC), which required a larger field of view. The WFPC was therefore removed, and we acquired key elements of its optical system which are on display in Explore the Universe.
The Structural-Dynamic Test Vehicle (SDTV)
Well before Hubble was launched, the Museum was searching for objects that were critical to its construction and testing. In the mid-1980s, curators learned that a full-scale low-definition structural mock-up might be available from Lockheed Missile and Space Company, the prime contractor for the spacecraft. We acquired it in 1987 and restored it for display starting in 1989. In 1996, with support from Lockheed, Hubble subcontractors, and NASA’s Goddard Space Flight Center, it was temporarily removed from display and upgraded with thermal blankets and accessories to represent the actual spacecraft as being deployed from Hubble. It was reinstalled in 1997 together with labelling on the first two servicing missions.
The Faint Object Spectrograph (FOS)
The second servicing mission to Hubble took place in February 1997, performed by astronauts aboard the Space Shuttle Discovery. They also brought back the Faint Object Spectrograph (FOS), which had spent a very successful seven years performing a host of tasks, including the first full assessment of the existence of a supermassive black hole in the core of a giant galaxy in Virgo, and a careful reconnaissance of the nature of a crash of a comet, Shoemaker-Levy 9, into Jupiter’s atmosphere. The Museum acquired the FOS in the late 1990s, put it on temporary display in Space Hall next to the SDTV, and it is now displayed in Explore the Universe as the tool that provided the first solid evidence for supermassive black holes.
COSTAR (Corrective Optics Space Telescope Axial Replacement) and the Second Wide-Field Planetary Camera (WFPC2)
As the servicing missions continued, replacing worn components and upgrading the instruments and electronics, fewer and fewer of Hubble’s instruments needed COSTAR (Corrective Optics Space Telescope Axial Replacement) because their replacements came with built-in optical corrections. In addition, by the early 2000s, detector and data handling technologies had advanced so much that it made good sense to retire WFPC2 and replace it with a far more precise, more sensitive, and far broader banded imaging system, allowing for higher resolution imagery from the ultraviolet through the near infrared portions of the spectrum.
So in what became the fifth and final servicing mission in May 2009, WFPC2 and COSTAR were retired and after full checkout and postflight assessment, they found their way to the Museum. WFPC2 in particular was scrutinized for the effects of its over 15 years in space. As earlier servicing missions reported, its large white radiator was pock-marked with over 600 tiny dents evidently from collisions with debris in space. The question was: were they natural bodies, or human space junk? The answer we know today: they were both. And it could have been worse if NASA had not decided to bring back the instruments it replaced on its servicing missions!
WFPC2 was one of the prime imagers aboard Hubble. From 1993 through 2009, it was used to create literally thousands of high-definition images providing a scientific data flow that will last for decades in NASA’s archives. These archives contain data on moons and planets in our solar system, stars, planetary systems in formation, star forming regions, galaxies — just about every class of celestial object. Early on, always sensitive about the public interest, NASA created the “Hubble Heritage Team” at the Hubble’s Space Telescope Science Institute in Baltimore. This multitalented group of astronomers and visual artists mined the flood of data from Hubble’s instruments like WFPC and WFPC2, and later the Advanced Camera for Surveys (ACS), the Near Infrared Camera and Multi-Object Spectrometer (NICMOS), and now the Wide Field Camera 3 (WFC3). Their mining massaged the data, retaining scientific integrity, while colorfully highlighting their dramatic structures. Their techniques and strategies produced some of the most memorable images of the space age.
What did Hubble show us? In a new blog, Dr. Elizabeth Kessler provides an interpretive glimpse of some of these images in the historic context of seeking the sublime in nature.