The post Rand links to below brings up some issues that have been floating around in the amateur rocketry community for some time. There are some people within the community who claim that there is no realistic problem, but they are simply wrong. If amateur rocket scientists are to have any relevance to opening the high frontiers they will develop weapons relevant technologies. The simple and obvious reason for this is that rockets are a transportation technology, and as such they can be used to transport harmful payloads just as aircraft, boats, and trucks can.

Compounding this problem is the fact that the ideal method for developing new technologies or bringing established technologies within reach of amateurs is to leverage the power of information technology to facilitate collaboration between widely separated individuals and groups. This is something that Michael Mealling of RocketForge has been working on for some time now. The Arocket mailing list is another collaborative tool (and Michael has been extremely helpful in providing tools to the Arocket community such as the Arocket Wiki).

I’ve been working on an igniter for some time which is part of a collaborative project with other folks on Arocket (see the Arocket Igniter Wiki on RocketForge for an idea of what we’ve been up to). One of the nice things about a high reliability bipropellant igniter is that it’s not very weapons-relevant since weaponeers tend to prefer either solids or hypergolics. The ARocket Igniter is explicitly intended as an exploration of the feasibility of open development for rocketry. John Carmack has shown that open discussion of R&D efforts can help cut development time and bring out good ideas. It would be very sad if we lost this tool due to terrorism concerns.

The only way forward I can see which both leverages the Open Development model and minimizes the terrorism proliferation risk is to work primarily on systems aimed at manned flight. Obviously a terrorist would love to have access to a manned RLV, but the bad guys can do cost-benefit analysis just as well as anyone else. If the effort required to build a vehicle is high relative to the cost of an alternative attack with equivalent results then the alternative will be preferred. The difficulty associated with construction of a manned vehicle also increases risk exposure from the terrorist standpoint – the more time spent in development, particularly development of a vehicle with a large number of “suspicious” components, the higher the chance of being discovered and the investment being lost. The bad guys face a resource deployment problem that any businessman can relate to – given the available set of resources, how should they be allocated in order to most effectively achieve the desired results? It is within this framework that amateurs must work to ensure that our discussions of rocketry technologies take place in an unfavorable region of the terrorist’s resource allocation trade space.

Within the context of this trade space I think that unmanned solids fired straight up with primitive guidance are just about the worst thing amateurs could work on. I won’t go into details other than to refer to Jay Manifold’s post, and to note that the enemy understands public relations. The target would not be surveillance satellites. It would be ISS, STS, or a Soyuz (almost certainly the former). A manned vehicle would have a much higher chance of success, but also a vastly larger development program, with negative (from the enemy’s point of view) impacts on the chances of discovery, as well as large opportunity costs.

Apart from choosing the right problem, the only thing I can see that amateurs can do to be relevant to opening the high frontier is to support an active research and development program in ballistic missile defense. If there is a credible defensive option then the hazard created by easier access to rocketry technologies is much less. This doesn’t help the ISS attack scenario, but it reduces concerns due to other factors.

A note on comments: I very much want feedback on this issue, as it directly affects my own choice of future path. However: do not discuss technical details of weaponizing amateur class rockets, modes of attack, or any other technical details which might lower the bar for the bad guys. As a calibration point – Jay’s post is a little past the line I am comfortable with, as he discusses some technical details of warhead design and suggests a possible attack scenario. I will delete or edit comments which I think cross the line.