I’ve already posted this over on Arcturus, but Lex asked that I share it here also. I’m noticing several interesting lessons in my favorite topics — project management (especially risk management) and public perception of large scientific endeavors.
As Randall Parker himself once noted in an e-mail to me, a Mars mission need not, indeed probably should not, consist of one spacecraft using one type of propulsion for interplanetary transfer: send the hardware and consumables on ahead by some relatively conventional means, following a Hohmann transfer ellipse (long; do a search on “Hohmann”), whose typical time-of-flight is 8½ months (calculation). Then use your exotic propulsion system — magnetic, nuclear, whatever — to get the people there fast, in a much smaller spacecraft, arriving at the same time; in project planning, we call this a “finish-to-finish dependency.”
This manages several risks. By category, as found in §220.127.116.11 of the PMBOK (2000 edition), they are:
- Technical/quality/performance – Much lower for the “slow boat” carrying the habitat and supplies, due to its use of more familiar technologies. For the crew module, managed by virtue of needing to remain operational for only a fraction of the time a more conventional spacecraft would require. Technically, the propulsion method in question may be regarded as an “active” version of Solar Windsurfing, and is potentially fantastically efficient by comparison with any chemical or even nuclear rocket.
- Organizational – Possibly mitigated by dividing the project between a “slow boat” and a crew module.
The great lesson of the CAIB Report, however, was that NASA’s organizational risks have not been well-managed historically. I believe that these have largely resulted from conflicting requirements imposed by Congress, which in turn derive from American political culture as a whole. Not an easy thing to fix; but Strauss and Howe offer hope in the form of a more effective alignment of generational talents, to emerge over the next couple of decades. I hasten to add that my preferred solution, like that of most of my readers, would be a mechanism that avoids public funding and its attendant political wrangling as much as humanly possible. This in turn presumes adequate economic incentive to put people on Mars, though I note that such an incentive could consist of someone with a great deal of money simply wanting to do it. Mars has had a powerful hold on the public imagination at least since the opposition of 1877.
- External – There’s nothing like space travel for external risks, though the public’s conception of these (as indicated by many of the comments to Randall’s post) is, shall we say, less than congruent with the reality. Radiation is not much of a problem, nor are meteoroids. Microgravity is a problem, and it would be far better to expose the crew to 3 months of it than 9 months.
A significantly greater external risk is that microbial life may yet be discovered on Mars. This could put the entire planet off limits for an extended period.
- I note that the category of project management risks itself still remains, and indeed might be an even greater concern than otherwise, as the Mars mission now becomes, in effect, two separate projects whose ultimate objectives must nonetheless be coordinated. I note that the bifurcated nature of the Chunnel project was a major factor in its high cost overruns.
My point, as usual, is: don’t confuse a proposal for, or even the existence of, an intriguing technology with the actual work of employing it effectively. Organizational and project-management risks have sunk many a project that was technically feasible.