I have published that correcting magnesium( Mg.) deficiencies may prolong life. In U.S.A. estimated 60 % have significant reductions of Mg. often unrecognized, since 99% is intracellular. Mg. required for synthesis of telomeres: repetitive nucleotide sequences at ends of chromosomes, protecting them from deterioration. The enzyme telomerase, Mg.- dependent, is involved in DNA repair. There are significant deficits with space flight (SF) of serum Mg (<0.0001) and invariably elevated adrenaline with vicious cycles between the two; this combined with dust inhalation, brought into habitats on space suits and > 40 % reductions of a vessel dilator: Mg –dependent atrial natriuretic peptide in 7-12 SF days, triggering cardiovascular complications. With access to data of only 4 of 12 Apollo astronauts: Irwin, Apollo 15, with brief heart rhythm disturbance, triggering syncope, severe dyspnea with classical angina during reentry, stress test( ST)-cyanosis of fingernail beds on landing day and next day ST- extraordinary blood pressure (BP) > 275/125) in 3 minutes ; both Scott and Irwin showed ST- deterioration of cardiac function; after Apollo 14, Shepard’s ST- BP dropped from 210/85 to 185/70; after Apollo 11, Armstrong showed marked elevation of ST- diastolic B.P. in comparison with a resting B.P. of 110/85 one month before, to 160/135 at the end of his mission, consistent with ischemic left ventricular dysfunction. Since, with microgravity, an accelerated aging process is 10 times faster than on Earth, research on the International Space Station would be easier and cheaper. Four months old Sprague-Dawley, female rats with a life span on Earth of 3 years would be used. First there would be determination of the ideal Calcium / Mg. intake ratio in microgravity whereas on Earth it is 2:1. They would be treadmill- exercised, and exposed to urban dust 4 hours/ day. White blood cell telomerase and telomere lengths would be measured with age-matched controls on Earth. Studies would require 6 months. In those rats, not surviving, organ vascular cell telomere lengths and telomerase would be determined.