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Blue “Hubble”: The Manned Orbiting Laboratory as a planetary telescope

A 2005 Hubble image of Pluto and its moons Hydra (right) and Nix (second from right). (credit: NASA)

Although it’s been two years since the first large drop of documents about the Manned Orbiting Laboratory (MOL) and its KH-10 DORIAN camera, surprising revelations about the system keep on appearing. In a recently answered Freedom of Information Act (FOIA) request about contractor-generated material on MOL, the National Reconnaissance Office (NRO) released a document that had only been referred to in the previous drops: “Contributions of Man in the MOL Program.” The entire MOL program is explained quite effectively in this document, aside from one mission area that is still redacted. Research aficionados of the MOL program will find nothing inside that is earth-shattering, but it’s a palatable introduction to the 356-page Carl Berger tome on the History of MOL.

One mission area mentioned inside the document, as well as throughout the NRO MOL Collection, is the use of hardware for “planetary astronomy.” In open-source literature, the MOL had previously been compared to a manned spy satellite, but the concept of actually using it as a manned space telescope seemed far-fetched. The cover story for MOL included ambiguous phrases such as: “The laboratory itself will conduct military experiments involving manned use of equipment and instrumentation in orbit and, if desired by NASA, for scientific and civilian purposes.”

But, according to the number of times “planetary astronomy” shows up in keyword searches within the MOL collection, this was a thoroughly studied mission area.

How can we do that exactly?

The problem with research-focused cover stories, such as the one for the Discoverer program, is they run thin after a while. With Discoverer, the program had a lot of launches, but only a few manifested with “mechanical mice” and “biomedical payloads.” With the run-up to the first manned Mercury flights, the biomedical cover story would have logically culminated in launching a primate inside Discoverer XXIII. The Discoverer cover was running thin by 1961, forcing Joseph Charyk, Director of the NRO, to enact the security strategy named RAINCOAT. This plan prohibited any publicity releases on military space activities and programs, dissociated missions from launches, and discontinued project nicknames in favor of arbitrarily-selected program numbers. Its successor plan, UMBRELLA, was even more restrictive. Without knowledge of what was being sent up, the space agencies would be hard pressed to explain where the received products came from.

Dually applicable is the concern with three space programs: the intelligence (NRO), military (US Air Force), and the civil (NASA). How do you take pictures with a covert spy satellite, then provide them to civilian agencies to use? A study performed 1966, and a subsequent steering committee named Project ARGO, attempted to evaluate classified satellite photography of the Earth use for civilian agencies. An offshoot question, not fully answered by released NRO documents, is “How can we disseminate astronomy images if taken by a classified satellite system?”

Vice Director of the MOL Program, Major General Harry L. Evans, summed up this quandary, in effect pushing off a solution until “later”:

“Policy issues relative to the use of both the [DORIAN camera] instrument and its product are important but can be defined and solved with more certainty once technical applications for astronomical and planetary observations have been established.”

While MOL tied into the study of military man in space, the idea that the optics would be aimed at the outer planets may have originally fed into the cover story. Studies done by the Aerospace Corporation, however, gave hard data behind the idea and surmised that it was feasible, if not wholly desirable. Buried deep inside “Contributions of Man in the MOL Program,” the Astronomy-focused paragraph starts out with an ominous “Although not of particular interest to the Defense Department…”

“…the MOL Project Office and NASA have investigated the possibilities of using the MOL system to accomplish visible-spectrum photography of the planets or other celestial objectes [sic] of comparable brightness. The results of these investigations indicate, depending on the particular planet in question, MOL photographic resolutions 2 to 8 times better than achievable with ground-based telescopes.”


Planet MOL Ground-Based
Photo Res. (LP/MM) Angular Res. (Sec) Surface Res. (Mi) Surface Res. (Mi)
Mercury 120 0.13 52 400
Venus 120 0.13 39 300
Mars 106 0.15 35 230
Jupiter 64 0.25 440 1800
Saturn 59 0.27 980 3600
Uranus 56 0.28 2200 7800
Neptune 54 0.29 3400 12000
Pluto 32 0.50 8200

The conclusion reached in the Aerospace report was optimistically blunt: “Planetary Photography from the MOL vehicle can significantly improve knowledge of surface features of the planets.” (Emphasis added)

“Look at how they shine!”

The most surprising inclusion in the table above is the planet Pluto. First discovered in 1930 by Clyde Tombaugh, images of Pluto have been historically scarce and obviously not high in detail due to the distance from Earth to the outer reaches of the solar system.

In the weeks before the July 2015 Pluto flyby by the New Horizons spacecraft, an article at PetaPixel (“This is How Our Photos of Pluto Have Improved over the Years”) compared a collection of Pluto images from 1994 to 2015. Understandably, the images get better as the years increase, with shuttle servicing missions upgrading the equipment aboard the Hubble Space Telescope.

A 1966 paper attached to a DORIAN-focused memo, “Use of a High Resolution Orbiting Telescope for Astronomical Observations by Direct Photography in Visible Light,” shows early directed interest in the outer planets:

“The outer planets (Uranus, Neptune and Pluto) are less well known, but very deserving of high resolution observations. The diameter of Pluto lies below the limit of measurements by ground-based telescopes, and should be examined visually if possible. Surface features of Uranus and Neptune are inconspicuous and little known. The low surface brightness of these remote bodies would, however, require longer exposures than would be needed for Mars or Venus.”

Just a footnote in MOL’s history

After the cancellation of MOL in 1969, some equipment did end up supporting planetary astronomy. Dwayne Day has traced the destination of DORIAN optical blanks (see “Mirrors in the dark”, The Space Review, May 11, 2009, and “Through the looking glass”, The Space Review, August 22, 2016) to the University of Arizona’s astronomy program. NASA began viewing the heavens from orbit with their Orbiting Astronomical Observatory program, with four missions launched, though only two would operate successfully. And the first of the Great Observatories, the Hubble Space Telescope, was launched in 1990, providing astronomers the best images of Pluto until the New Horizons flyby.

Given the unlikelihood of many BYEMAN or RUFF-cleared astronomers, I wonder who the Air Force, NRO, or NASA assumed would actually be looking at the DORIAN-provided photos of the outer planets, had MOL been launched.


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