Atom Wave: Hubble Telescope Reprise

Atom Wave

Monday, January 15, 2007

Hubble Telescope Reprise

NASA Schedules Flight to Update Hubble Space Telescope

Back in 2004, NASA was considering the possibility of either scrapping the Hubble Space Telescope or sending a risky untested robotic mission to refurbish the beast in the wake of the Columbia disaster. As you might know, I advocated the construction and launch of a replacement Hubble in, as it would be the UK magazine Astronomy Now in October of that year. The original unedited version is below. Today the New York Times reported that NASA is finalizing plans to launch a shuttle to the telescope in 2008 to rebuild it. While I am undeniably joyful of the news, it is still a mistake. When it costs nearly half a billion to simply get one shuttle into orbit, that money would still be better spent building a upgraded replacement and sending it up on a much cheaper expendable. In any matter, I still give a tip of my hat to NASA for their decision of the skies.

Hubble Telescope Robot Rescue Mission

Within the next three years, NASA is planning to launch a robotic rescue mission to the Hubble Space Telescope. With the shuttle mission SM-4 grounded last January, the only option left to service the Hubble is a highly ambitious, risky, and expensive robotic mission scheduled to lift off in late 2007. If executed, this mission will be a mistake in that it will incorporate experimental technology which may not work and will endanger the already fragile Hubble Telescope, plus it will waste more money in a already high cost ineffective program. If NASA is intent on extending the Hubble Program, then it should launch an upgraded Hubble to fill in the void until the James Webb Telescope becomes operational by 2012 or so.

The proposed mission that is currently under study at the Goddard Center is designed to be composed of two parts, service and sustain. The mission would begin with a launch of the spacecraft from the Cape in late 2007 aboard a heavy-lift Atlas 5 or Delta 4 booster. After a two to twelve day voyage, the robot would mate with the Hubble in orbit and then the servicing mission would begin and last about 30 days. The first stage of the mission would be to connect the telescope to a new set of batteries via an umbilical to the spacecraft, which would further be wired to the solar arrays. This would be followed by the installation of the new Wide Field Camera with replacement gyros attached and the installation of the new Cosmic Origins Spectrograph. Once the upgrade is complete, the robot along with the old instruments is ejected to decay in the atmosphere. A deorbit rocket would be left on the Hubble to bring it down at the end of its life. While the plan is ingenious, nothing resembling it has ever been done in practice. If history is any guide, than we can expect most experimental technologies to fail because the engineers simply have no previous experience with it. The execution of this mission would be a gamble at best.

Besides the risks of the mission, the expected costs should be a showstopper. In terms of cost effectiveness, the Hubble Space Telescope has already been a horrible bust in respect to what has been scientifically accomplished to the funds expended. The Hubble Telescope was explicitly built to be serviced by the Space Shuttle, which is no small expense when the cost per flight of the Shuttle is nearly half of a billion dollars. Aside from the enormous cost of servicing the Hubble is the practicality of the affair. Since the Hubble was designed to be launched by the Shuttle, it missed its targeted opportunity to be deployed in the early 1980's in part due to the Challenger Disaster. When the Hubble Telescope finally reached orbit in 1990, its optics were already a decade out of date. The three Shuttle missions to the telescope over the past 14 years have upgraded the machine, but its basic technology is still in excess of 24 years old. Now the proposed robotic mission is expected to cost upwards of a billion dollars, which at that price is well within the cost of a replacement Hubble Telescope. Riccardo Giacconi, former director of the Space Telescope Science Institute, once said that seven similar space telescopes could have been built and launched on expendable rockets for the amount of money which has been spent so far on just one.


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