Which leaves Marsden's design team stuck with the unenviable decision of choosing between tradeoffs. 
Fusion: Locally built, fuel easy to get but hard to store, requires large external power source for startup.
Fission: Externally purchased, fuel not easy to get and dangerous to store, but lasts a LOT longer between fill-ups and doesn't require an external power source to start.
--
Sucrose Octanitrate.
Proof positive that with sufficient motivation, you can make anything explode.
Fusion: Locally built, fuel easy to get but hard to store, requires large external power source for startup.
Fission: Externally purchased, fuel not easy to get and dangerous to store, but lasts a LOT longer between fill-ups and doesn't require an external power source to start.
--
Sucrose Octanitrate.
Proof positive that with sufficient motivation, you can make anything explode.