Deimos Synchrotron Light Source


A launch loop can send the components of massive scientific instruments to Deimos (or Phobos), to help scientists evaluate samples lifted from Mars for potential biomolecule evaluation. Humans must not contaminate Mars, but mission planning and sample return to Earth takes years, while a typical !PhD thesis may require dozens of sequential sample evaluations in a few years. Even if the experimenter is on Earth and the "lab assistants" are robots near Mars, the sample cycle should be days, not decades.

The largest biological sample evaluation machine on Earth is the National Synchrotron Light Source (fact sheet) at Brookhaven Labs in New York. This 250 meter diameter ring circulates 500mA of 3 GeV electrons, feeding 60 beamlines (24 in use) that produce (among other things) spectrally pure X-rays for nanometer-resolution crystallography. This can produce exquisitely accurate 3D maps of the atoms in a protein, for example. Though crystallography measures crystals made of thousands of identical molecules, future techniques may resolve smaller samples using similar high energy machines.

The NSLS-II magnets were massive and numerous, built on girders for stiff support in Earth gravity. Magnets for "DSLS" (Deimos Synchrotron Light Source) might require the same amount of magnet material, coils, power, etc., But Deimos gravity is 0.3 milligees, so the girders can be 1000 times less massive. I cannot find dimensions for the magnets; estimate that the volume of magnets and windings is one meter square times 800 meters circumference, and the density is 8 tonnes per cubic meter; the mass of the ring might be 6400 tonnes. Estimate that the entire facility (plus experimental stations) masses 30,000 tonnes. That's a LOT to ship to Deimos.

Space fanboys often assume that we will turn non-beneficiated meteoric rock and sand into machines; many space fanboys have never built anything more complicated than a sandwich. NSLS was built and tested by thousands of specialists at hundreds of organizations worldwide, enabled by a planetary technological civilization. This will not be replicated in space by uninformed claims and hand-waving, not even robotic hand-waving. So, an Earth-full of specialists will design and build the components of DSLS, with the additional design constraint that they must launched at three gees and assembled by hundreds of technicians and thousands of agile robots in harsh conditions hundreds of millions of kilometers away. Damage a magnet, and a replacement spare will take years to deliver.

DSLS will be a prodigeous effort, but launch loops will help make it possible.

DSLS (last edited 2019-01-20 22:44:16 by KeithLofstrom)