At the time, NASA actively considered Mars Sample Return (MSR) as a post-Viking mission. Agency interest flagged as it became clear that no such mission would receive funding, so publication of the 1978 design study, titled Orbiting Quarantine Facility: The Antaeus Report, was delayed until 1981.
The Summer Fellows noted that the three biology experiments on the Viking landers had found neither organic carbon nor clear evidence of ongoing metabolic processes in the soil they tested on Mars. Furthermore, the Viking cameras had observed no obvious signs of life at the two rather dull Viking landing sites.
Nevertheless, the Summer Fellows argued, "the limitations of automated analysis" and the fact that "the landers sampled visually only a small fraction of one percent of the planet's surface" meant that there could be "no real certainty" about whether Mars was lifeless. This, they argued, meant that, "in the event that samples of Martian soil are returned to Earth for study, special precautions ought to be taken. . .the samples should be considered to be potentially hazardous to terrestrial organisms until it has been conclusively shown that they are not."
Their report listed three options for attempting to ensure that samples would not accidentally release martian organisms on Earth. The MSR spacecraft might sterilize the sample en route from Mars to Earth, perhaps by heating it. Alternately, the unsterilized sample might be quarantined in a "maximum containment" facility on Earth or in Earth orbit, outside our planet's biosphere.
The Summer Fellows noted that each of these three options would have advantages and disadvantages; sterilizing the sample, for example, might ensure that no martian organisms could reach Earth, but would likely also damage the sample, diminishing its scientific utility. The scientists explained that the Antaeus study emphasized the third option because it had not been studied in detail previously.
The Summer Fellows explained the significance of the name they had selected for their Orbiting Quarantine Facility (OQF) project. Antaeus was a giant in Greek mythology who forced passing travelers to wrestle with him and killed them when he won. The Earth was the source of Antaeus' power, so the hero Hercules was able to defeat the murderous giant by holding him above the ground. "Like Antaeus," they explained, a martian organism "might thrive on contact with the terrestrial biosphere. By keeping the pathogen contained and distant, the proposed [OQF] would safeguard the Earth from possible contamination."
Five 4.1-meter-diameter cylindrical modules based on European Space Agency Spacelab module hardware would form the Antaeus OQF. The Summer Fellows assumed that the modules and many of the other components needed to assemble and operate the OQF would become available during the 1980s as the Space Shuttle Program evolved into a Space Station Program.
OQF assembly in 296-kilometer-high circular Earth orbit would need two years. It would begin with the launch of drum-shaped Docking and Logistics Modules together in a Space Shuttle Orbiter's payload bay.
The 2.3-ton Docking Module, the OQF's core, would measure 4.3 meters long. It would include six 1.3-meter-diameter ports with docking units derived from the U.S. version of the 1975 Apollo-Soyuz "neuter" design. Outward-splayed guide "petals" and a system of shock absorbers and latches would enable identical docking units to link together.
|The Antaeus Orbital Quarantine Facility. Image credit: NASA|
The 4.3-meter-long Logistics Module would weigh 4.5 tons loaded with a one-month supply of air, water, food, and other supplies. After a crew took up residence on board the OQF, a Shuttle Orbiter would arrive each month with a fresh Logistics Module. Using twin robot arms mounted in the Orbiter payload bay, the Shuttle crew would remove the spent Logistics Module for return to Earth and berth the fresh one in its place.
The second OQF assembly flight would see the Shuttle crew link the 13.6-ton Power Module to the Docking Module's aft port. The Power Module would then deploy two steerable solar arrays capable of generating between 25 and 35 kilowatts of electricity. Spinning momentum wheels would provide OQF attitude control and small thrusters would fire periodically to counter atmospheric drag, which would otherwise over time cause the quarantine station to reenter. The Power Module would also provide OQF thermal control and communications.
The OQF's five-person crew would live in the 12.4-meter-long, 13.6-ton Habitation Module, which would arrive on the third assembly flight. The OQF's "command console," five crew sleep compartments, and workshop, sickbay, galley, exercise, and waste management/hygiene compartments would be arranged on either side of a central aisle. The Hab Module would provide life support for all the OQF's modules except the Laboratory Module.
The Lab Module, delivered during the fourth and final OQF assembly flight, would measure 6.9 meters long and, like the Hab and Power Modules, would weigh 13.6 tons. Not surprisingly, the Ames Faculty Fellows devoted an entire chapter of the Antaeus report to the Lab.
Spacelab pressurized modules included a central corridor running their entire length. Experiment equipment lined their walls. The Spacelab-based OQF Lab Module, on the other hand, would have a central experiment area running most of its length with corridors along its walls. Most of the experiment area would be located within glass-walled "high-hazard" "Class III" biological containment cabinets similar to those at the Centers for Disease Control in Atlanta, Georgia.
The Summer Fellows provided no obvious aids for crew positioning. In the illustration of the Lab module above, scientists are shown floating without handgrips or feet or body restraints. Given the delicate and sensitive nature of the work they were meant to perform, this would probably turn out to be a significant omission.
The Lab Module would include an independent life support system with "high efficiency particle accumulator" (HEPA) filters. Experimenters would enter and exit the Lab Module through a decontamination area, where they would don and doff respirator masks and protective clothing. If a mishap contaminated the Lab Module, the module could be detached from the OQF and boosted to a long-lived 8000-kilometer circular orbit using a Laboratory Abort Propulsion Kit delivered by a Shuttle Orbiter.
Following the two-year assembly period, a rehearsal crew would board the OQF to test its systems and try out the Mars sample analysis protocol using biological samples from Earth. The Summer Fellows set aside up to two years for these practice activities. At about the time the rehearsal crew boarded the OQF, a robotic MSR spacecraft would depart Earth on a one-year journey to Mars.
Two years later and four years after the start of OQF assembly, a small Mars Sample Return Vehicle (MSRV) containing one kilogram of martian surface material and atmosphere samples would fire rocket motors to enable Earth's gravity to capture it into a high orbit. The sample would ride within a sample canister, the exterior of which would have been sterilized during Mars-Earth transfer. Meanwhile, a Shuttle Orbiter would deliver to the OQF the first five-person sample-analysis crew. It would comprise a commander (a career astronaut with engineering training) and four scientists with clinical research experience (a medical doctor, a geobiologist, a biochemist, and a biologist).
A Shuttle-launched remote-controlled Space Tug would collect the sample canister from high-Earth orbit and deliver it to a special "docking cone" on top of the Lab Module. This is not shown in the illustration of the completed OQF; in its place, one finds a cylindrical "Sample Acquisition Port." The canister would then enter the experiment area through a small airlock.
The first sample analysis crew would cut open the canister using "a mechanism similar to a can opener." They would immediately place 900 grams of the sample into "pristine storage." Over the next 60 days, they would execute an analysis protocol that would expend 100 grams of the sample. Twelve grams each would be devoted to microbiological culturing and challenge cultures containing living cells from more than 100 Earth species; six grams each to metabolic tests and microscopic inspection for living cells and fossils; 10 grams to chemical analysis; and 54 grams to "second-order" follow-up tests.
If the 60-day analysis protocol yielded no signs of life in the test sample, a Shuttle Orbiter would carry the 900-gram pristine sample from the OQF to Earth's surface for distribution to laboratories around the world. Based on highly optimistic 1970s NASA estimates of Shuttle, Spacelab, and Station costs, the Summer Fellows placed the total cost of OQF assembly and operations for this "minimum scenario" at only $1.66 billion.
If, on the other hand, OQF scientists detected life in the Mars sample, then analysis on board the OQF could be extended for up to six and a half years. Throughout that period, Shuttle Orbiters would continue to deliver a steady stream of monthly Logistics Modules; they would also change out OQF crews at unspecified intervals. In all, about 80 Logistics Modules would reach the OQF by the time its mission ended. The cost of this "maximum scenario" might total $2.2 billion, the Ames Summer Faculty Fellows optimistically estimated.
Orbiting Quarantine Facility: The Antaeus Report, D. DeVincenzi and J. Bagby, editors, NASA, 1981
Clyde Tombaugh's Vision of Mars (1959)
Peeling Away the Layers of Mars (1966)
What Shuttle Should Have Been: NASA's October 1977 Space Shuttle Flight Manifest
Making Rocket Propellants from Martian Air (1978)
Astronaut Sally Ride's Mission to Mars (1987)