Sunday, September 6, 2009

Space Program Public Support

Two related stories from 9-3-09 AIAA “Daily Launch”, about the future (if any?) of NASA. Bold italic subscripts added by me to relate to comments below.

Augustine Committee Report To Present "Tough Choices" To Administration.

US News and World Report (9/2, Lylte) reports, "Space exploration is at a crossroads," with NASA's scheduled retirement of the space shuttle next year. "Under severe financial constraints, President Obama must decide whether to continue on the current course" of creating a new launch system (1) "and infuse the space program with billions of dollars, or scale back the efforts and risk losing the leadership role the United States holds in space exploration." As the Augustine committee "gets ready to deliver its report to the White House and release it publicly later this month, the White House is finding out just how tough the choices will be," and "the White House and Congress will have to answer some thorny questions," such as if the shuttle or ISS programs should be extended, and if sending people into space should be a commercial, not governmental, task (2). As the charge to the "committee was to work mostly within the current budget," it the report "will most likely present an option that will try to excite the public imagination without a major infusion of cash," such as "a 'deep space' plan for flying out of Earth's orbit but not landing (3) on major planets or large moons."

Orion Could Be Used For Asteroid Missions. (9/2, Covault) reports, "A manned asteroid mission using two Orion spacecraft, docked nose-to-nose (4) to form a 50-ton deep space vehicle, is being studied by Lockheed Martin Space Systems as an alternative to resumption of US lunar landing missions." adds that using Orion "for asteroid missions and other deep space sites would maximize utilization of the Orion system if lunar landings are deleted as a near term goal." While "the official NASA line has been solidly 'all moon' for the last several years," despite "more realistic assessments" showing it "is not feasible, NASA more recently became "more open about an asteroid mission capability for Orion after space scientists and planners meeting before formation of the committee began to criticize the lunar goal as too fragile." Meanwhile, "a Lockheed Martin video "shown in early August at a propulsion conference in Denver sponsored by the American Institute of Aeronautics and Astronautics" had "the twin Orion configuration closely orbiting an asteroid while space suited astronauts explore its surface." The video was "part of a presentation delivered by former astronaut Brian Duffy, now Lockheed Martin vice president and program manager for the Altair lunar module part of the Orion lunar landing infrastructure," that "also cited satellite servicing that could be performed by astronauts from an Orion configuration, equipped with a shuttle-type manipulator arm deployed from its service module."

My comments:

Point (1) – They’re all missing the point of the Ares launch system. Under "Constellation" architecture, both the Saturn-1-like Ares-1 and the Saturn-5-like Ares-5 are required. Men ride up in the Orion capsule on the Ares-1. The Ares-5 may not even be man-rated, it is just a heavy lifter, far outclassing anything available or under development. Going into deep space (meaning out of Earth orbit) manned is beyond anything but a Saturn-5 class rocket. Period. We’re locked in: either finish the job or overtly decide to abdicate all capability for manned exploration and utilization missions.

Point (2) – They’re all failing to learn from history. The most successful colonial powers half a millennium ago had it closer to right. Government is better suited for exploration and for advanced technology leaps. Enterprise is better suited to utilization and colony development, using the results of the government efforts. We Americans have NEVER, EVER done it that way. We should. It works.

Point (3) – There’s no point to emasculating an exploration mission by not landing. It is being there that captures peoples’ imagination, not ogling-from-a-distance.

Point (4) – This proposal addresses an actual (but unstated, and probably not understood) need (information recovery for effective asteroid defense) but lacks at least three critical features for success (meaning survival of the crew):

Living space: Even with the full Ares rocket family behind it, these asteroid missions will typically have 6 month to two-year flight times. Two capsule volumes are not enough living space for a time like that. They need to dock these capsules to a reprise of “Skylab” made from an Ares-5 upper stage.

Radiation protection: Thin aluminum shells provide no protection from lethal solar storms. A steel plate shelter packed inside a utility water tank would. Orion capsules can never be modified to provide this, but a “Skylab”-like habitation module could include it.

Artificial Gravity: This is required for missions exceeding about one year, as has been known since the Russian “Salyut” space station series a quarter century ago. The only available physics for this is centrifugal force. We already know what spin rates are tolerable, but we do not know how much gee is enough. No centrifuge or spinning craft design is possible with Orion alone, but it is easily incorporated into a “Skylab”-type design.

Flight times: Although not critical at all for the first few (minimally-demanding) manned missions, later more demanding missions will require that we fly much faster. This will require very energetic (specific impulses above 5000 sec) and very powerful (vehicle accelerations above 0.1 gee) propulsion. Nothing is available, although there are a couple of old ideas that could be resurrected. The final form(s) will undoubtedly be nuclear in nature, but not with solid reactor cores. This kind of stuff is too dangerous to develop and test on Earth. Propulsion development tests cannot be done hanging weightless in space, where every test is a flight test. So, there is a real reason to return to the moon after all: put a nuclear propulsion development station there, so the technology will be ready when we need it.

My conclusion: The sooner we face these inconvenient truths and deal with them, the sooner we can put our space program efforts back onto a rational basis that everyone can understand, and the sooner we will capture the public’s imagination, and its sustained support, once again.

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