Final Rest

NASA's release of the Columbia Crew Survival Investigation Report answers the lingering questions in my mind regarding the final moments of the Columbia disaster and what the astronauts must have experienced. Some of the questions arise from morbid curiosity while others are the product of a desire to build better crew survival systems into future spacecraft.

The report paints a picture of a rapidly-snowballing disaster. Control was lost and the orbiter began breaking up less than a minute after Columbia's last radio contact with Mission Control. With the hydraulics lost in the left wing, Columbia pitched into a nose-high attitude prior to ballistic flight and breakup. The crew module depressurized through a fairly small rupture, and the crew would have been unconscious prior to the point where the module completely disintegrated. Depending on how long crew consciousness was maintained, they may have felt the violent tumbling of the crew module as it began a multi-axis rotation after separating from the orbiter.

By concluding this investigation with a lengthy and detailed report, NASA has laid the groundwork for enhancing crew survivability during a re-entry accident. For starters, the parachutes should be rigged to deploy automatically (although, in the shuttle's case, they'd only be used during a subsonic, level glide.) NASA should also quantify the current performance envelope for bailing out while wearing the current ACES suit. Of course, there's no substitute for making the shuttle, Orion, and other spacecraft so safe that the escape system will be irrelevant.

That Other Anniversary

Every space enthusiast seems to have some way of commemorating July 20th, the anniversary of when humans first walked on the surface of the moon. But few seem to mark that other anniversary: December 14, 1972, when humans last walked on the moon. For all of the jubilation on Apollo's success in landing a man on the moon before the decade was out, there is very little introspection on why Apollo gave us a tease of a space-faring future that has yet to come to fruition.

The success of Apollo can be credited to a well-run program packed with technical and management genius, flush with cash from a cold-war defense buildup. Conversely, the end of Apollo can be attributed to a decline in national will to continue the lunar effort, making it impossible to justify the human risk and national expenditures that were required to continue sending humans to the moon. Even after the risk was reduced and the development costs were sunk, a majority of Americans didn't want to keep cranking out Saturn rockets and launching them to further our understanding of our moon.

As NASA again embarks on the Apollo adventure, the questions of how we will sustain the lunar program have not been adequately addressed. If the cold war wasn't justification enough for a nationally-funded effort at sustained lunar missions, what is? I doubt that the use of NASA as a government jobs program can justify it alone. With regards to keeping people on the government payroll, sustained lunar missions don't have much advantage over, say, a sustained earth-orbital program such as the shuttle.

It's difficult to see Project Constellation sustaining itself beyond a few sortie missions, if it even achieves the lunar goal to begin with. Humans will only sustain a presence on the moon if a profit motive exists to do so. It doesn't matter if we're talking about the United States, Russia, China, or any other spacefaring world power. If the economic justification does not exist, the lunar landings will be an unsustainable stunt. Until a profitable reason to put humans on the moon exists, a sustained human presence on the moon will have to wait.

DynaSoar Extinction

No single name curdles the blood of space enthusiasts like that of Jeffrey Bell. The University of Hawaii professor and "recovering pro-space activist" often lends a cynical commentary that douses water on the dreams of NASA-lovers and NewSpacers alike. While I can't say that I always agree with Dr. Bell, he crafts a rational argument and often serves to inject a dose of harsh reality into the kool-aid drinkers who deal effective setbacks to space programs by peddling unrealistic fantasies.

In his new piece, Jeffrey Bell strikes back at the “Cult of the DynaSoar,” the aviation enthusiasts who lament the cancellation of the Air Force spaceplane program of the 50’s and 60’s. I will admit that I would probably be labeled as a member of the DynaSoar cult, based on my past polemics about how we needed the X-20, or something like it, to blaze the trail for the operational Space Shuttle. Part of it stems from a desire I share with Dr. Bell, the belief that a small-scale spaceplane demo would have steered decision-makers away from many ill-fated design choices during the Space Shuttle program. Another part of it stemmed from my lack of appreciation for how ineffective the DynaSoar thermal management system was. I didn’t read about the silicon coatings or the liquid hydrogen tank that was essential to keep the cabin cool until Jeff Bell brought attention to them.

Admittedly, DynaSoar was clearly an extreme example of undisciplined requirements creep leading to the death of an acquisition program. Conceived as a suborbital bomber, it evolved through four stages into an orbital spaceplane. The personnel who set goals for the DynaSoar program must have been unaware of the materials science realities of the time. It was a shining example of how a bad acquisition program is run.

If DynaSoar would have served as an example of how not to build a reusable spacecraft, and if the Space Shuttle has served as an example of how not to build a reusable spacecraft, then what approaches are left to try? The shuttle’s thermal protection system is effective but fragile. DynaSoar’s thermal protection system was impractical but robust. But Shuttle and DynaSoar are both examples of what would be called “dense” reentry vehicles. Perhaps the solution is to design a vehicle that carries its propellant tanks to orbit, ensuring that it will have a low wing loading (and low heat loading) when it hits the atmosphere. It would be able to get away with a robust metallic thermal protection system because it would be so “fluffy” that heating would be reduced. That was one of many goals in the X-33 program. And because I brought up X-33, that will undoubtedly be the subject of Jeff Bell’s next polemic.