The stunning images taken by the Hubble Space Telescope (HST) (Figure 1) over the past two decades, using a variety of optical instruments and sensors, have transformed our view, literally and figuratively, of the cosmos. But the Hubble’s story is also one of project conception, engineering persistence, joy, misery, embarrassment, improvisation, rehearsal, and eventual redemption.
As the Hubble telescope nears the end of its life and NASA prepares to launch its much-delayed successor, the James Webb Space Telescope (JWST) in 2021, a look at the Hubble’s history reveals many lessons, both technical and non-technical. It’s an amazing and complicated story of what can happen when “big science” meets budget and bureaucratic reality, as well as how major technical mistakes can slip through the system.[Note that these spectacular images are “false color”; they have been colorized based on optical/IR spectrum and wavelength. If this was not done, you’d see a whitish glow for visible-light objects, and nothing at all for IR-emitting objects!]
The concept of what eventually became the Hubble Space Telescope (Figure 2), was first proposed by astronomer Lyman Spitzer in 1946, where he provided details of benefits of orbiting observatory which would not suffer from atmospheric disturbances which are inherent with ground-based units, even those at higher altitudes such as those based in Chile or Hawaii. But it took until 1969 (24 years later), for the National Academy of Sciences to give its formal approval for what was called the Large Space Telescope project, it was formally named the Hubble Space Telescope in 1983.
Delays and cost add up
Congress approved initial funding for the project in 1977 (nearly a decade after the NAS approval). Among the reasons for the delay were the usual budget limits (the Space Shuttle project was also underway), of course, as well as feelings in Congress that there were enough telescopes already, as it had also recently funded various ground-based optical and radio telescopes. Many legislators couldn’t see why yet another telescope was needed, even if it promised far superior results and more “science.” The initial HST budget was a relatively modest $500 million, not including launch and on-going operating expenses.
Still, even after initial funding was approved, it was a very long journey to get Hubble into orbit. Hubble was finally deployed by Shuttle Discovery in April 1990, twenty-three years after initial funding was approved. The delays were the result of a toxic combination of budget issues, personal politics, bureaucracy, and of course, technical issues:
- Budget: the original estimate was way, way too low (partially due to misjudging of the technical issues, and also the desire to “pitch it” at a more-acceptable cost), so NASA had to go back for extra funding every few years, with a final cost of $5 billion, roughly ten times original number. Actually, it is impossible to truly gauge the cost because so much of the launch, deployment, operation, repair, and maintenance expenses were borne by (and buried in) the Space Shuttle program.
- Personalities and politics: while there were many extremely competent and even brilliant scientists and engineers involved, there were also many careers and egos, resulting in on-going conflicts as to who would run which parts of the program, who would responsibilities and control for various aspects, and many corporate-like “politics.” Beyond the personalities, there were also institutional issues of which university, research center, or consortium would-be leader of the overall project and which ones would “own” various subsections, related to prestige, money, and reputation of the participants.
- Bureaucracy: since this was a huge and highly visible project with many individuals, academic institutions, research centers, and NASA centers, there were constant “turf battles” between the NASA side and the non-NASA sides with shifting alliances, demands, objections, counterproposals, and compromises. Complicating this, Hubble was actually more than an optical telescope – admittedly the glamorous, public-interest part of the project – as it would also have about half a dozen specialized scientific instruments such as UV-spectrum analyzers. Therefore, which instruments would be chosen and who would design, manage, and have ownership of each was a political battle as much as a scientific one.
- Finally, the technical issues: although these are to be expected in a project as complicated and sophisticated as Hubble, they still were more challenging than expected. One of the major ones (which now seems like it should have been trivial, but that’s from our perspective of the advances in technology) was at the imager at the core of the project. In contrast to what we have available now, the solid-state, digital-imaging sensors that were available during the Hubble design phase were relatively low performance with respect to their sensitivity, resolution, and size; CCD and CMOS imagers with suitable specifications were simply not available.
It may be hard to believe now, but there was serious consideration of using a conventional film-based camera and have Hubble eject the film periodically for Earth-based retrieval. This complicated procedure had been perfected after many problems and used successfully in American “Corona” spy satellites in the 1960s and 1970s (see References). With this approach, of course, Hubble would run out of film; also, film cameras have all sorts of strange problems in the vacuum and particle stream of space, as the Corona project found out.
Even if a suitable digital image sensor was available, the communications links for transmitting the digitized images back to Earth were painfully slow, and downloading a single image would take hours. Ironically, the good news is that better sensor and communication technologies were developed during the delays in the project, and while these reduced those problems, they also required more design and validation effort and time, and so created even more delays.
Part 2 looks at the well-known as well as lesser problems of the Hubble Space Telescope.
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Related Content and References:
Hubble Space Telescope:
- Robert Zimmerman, “The universe in a mirror: the saga of the Hubble Telescope and the visionaries who built it”
- NASA: ST-161, Endeavor and First Hubble Space Telescope Servicing Mission
- NASA: The Hubble Space Telescope Servicing Mission
- NASA: A Brief History of the Hubble Space Telescope
- Astronomy Magazine, NASA extends Hubble Space Telescope science operations contract, June 24, 2016
- CNET News, Overachieving Hubble mission gets five more years, June 26, 2016
- Physics Today, Saving Hubble: A conversation with the director, June 12, 2012
Corona Spy Satellite Program
Dwayne A. Day, John. Logsdon, & Brian Latell, “Eye in the Sky: The Story of the Corona Spy Satellites”
James Webb Space Telescope:
Books on Major NASA Projects:
- (about Mars Rovers Spirit and Opportunity, 2004) Steven W. Squyres, “Roving Mars: spirit, opportunity, and the exploration of the red planet”
- (about Voyager 1 and 2, 1977) Stephen J. Pyne, “Voyager: seeking newer worlds in the third great age of discovery”
- (about the Mars Rover, 2012) Adam Steltzner, with co-writer William Patrick, “The Right Kind of Crazy”
- (about the Apollo Moon Mission) Charles Murray and Catherine Bly Cox, “Apollo: The Race to the Moon”