Replacing Hubble with Hubble 2.0
Taken from SpaceNews.
WASHINGTON — SpaceX’s Crew Dragon spacecraft is performing well enough on orbit to give NASA confidence that the mission can last until August, an agency official said June 9.
I write in response to the recent op-ed piece by Donald F. Robertson regarding a possible servicing mission to extend the life of the Hubble Space Telescope.
As a card-carrying “Hubble hugger” who has done a large fraction of my scientific work for over 20 years using Hubble data, who has helped design and build the Cosmic Origins Spectrograph instrument that was installed onboard Hubble during the 2009 servicing mission, who has managed NASA’s astrophysics portfolio during the most recent science community-based decadal planning effort in 2009-2010, and who has spent significant time and energy considering what to do when Hubble reaches the end of its lifetime, I will discuss reasons why the servicing mission idea may not be in the best interests of the astronomical science community or the taxpaying public, and describe an alternative to servicing Hubble — namely, build Hubble 2.0.
To be clear, I am pleased about Mr. Robertson’s interest in the topic. I and many of my colleagues recognize that the loss of Hubble will create a large gap in our space ultraviolet and visible light capabilities for astronomy. But we part ways when considering how to react to this eventuality.
While Mr. Robertson reports mostly on the engineering challenges, I bring the additional perspectives of a scientist and portfolio manager — this is not merely a matter of how, but also what, why and how to pay for it. The technical approaches are interesting to speculate about, but the scenarios that rely on future spacecraft with orders of magnitude less carrying capacity than the space shuttle appear to me to understate the scale, complexities, costs and effectiveness of another Hubble servicing mission.
Conducting another servicing mission to Hubble flies in the face of the National Research Council’s recommendations in the so-called decadal surveys in astronomy and astrophysics. This in itself is the reason why NASA’s astrophysics program is not pursuing any sort of Hubble servicing options within its highly constrained budget.
The 2001 decadal survey (“Astronomy and Astrophysics in the New Millennium”) stated, “The committee endorses the current plans that call for [Hubble] to continue operation until the end of the decade, with reduced operating costs after completion of the final servicing mission.” The timetable for these events was delayed after the final servicing mission — Servicing Mission (SM) 4 — was canceled, reinstated, then finally performed in May 2009. (As Mr. Robertson noted, NASA counts four maintenance missions rather than five because mission three was split into two flights.)
Subsequently, the 2010 decadal survey (“New Worlds, New Horizons in Astronomy and Astrophysics”) stated, “Following the fourth servicing mission, the Hubble Space Telescope (HST) is now more capable than ever before and is enabling spectacular science, including observation at ultraviolet wavelengths. No more servicing missions are planned, and NASA intends to deorbit HST robotically at the end of the decade. The committee endorses this decision.”