Abstract & PDF links for HIGHER THAN ADVERTISED MARTIAN AIR PRESSURE.

BASIC REPORT for HIGHER THAN ADVERTISED MARTIAN AIR PRESSURE by David A. Roffman and Barry S. Roffman. Updated April 29, 2013 with MSL weather results.

Click HERE for a presentation of HIGHER THAN ADVERTISED MARTIAN AIR PRESSURE, Critique of NASA's Martian Pressure Position (Updated May 14, 2013).

PowerPoint Summary of HIGHER THAN ADVERTISED MARTIAN AIR PRESSURE - Part 1 by David. Roffman. Posted September 9, 2012.

 HIGHER THAN ADVERTISED MARTIAN AIR PRESSURE

By David A. Roffman (DavidARoffman.GMail.Com)

and Barry S. Roffman (BarrySRoffman@GMail.Com)

ABSTRACT FOR PART 1: The enigma of dust devils/storms on Mars (with a near-vacuum pressure rated at 6.1 mbar at areoid) is cause to question accuracy of accepted pressure values. The Basic Report includes reviews of NASA-archived historical documents, analysis of technical papers, personal interviews of pressure transducer designers, and a brief discussion of an in depth audit of Viking pressure and temperature data (see Annexes A through F for detailed audit results). Five landers attempted to directly measure pressure – two Vikings, Pathfinder, Phoenix and MSL Curiosity. Accepted pressures are based on their data and radio occultation/spectroscopy by orbiters. Viking transducers were only rated at 18 mbar (Pathfinder and Phoenix at 12 mbar, MSL at 11.5 mbar). Both Vikings and MSL showed consistent daily pressure spikes at the same times. They are highly correlated with how gas pressure in a sealed container would vary with Absolute temperature. Pressure fluctuations are linked to heating by radioisotope thermoelectric generators (RTGs) or other heat-generating electronic operating cycles. When the heaters were most needed there was less than a 2% difference for predicted and reported pressures. The formula employed assumes a clogged air access tube/dust filter.

       Radio occultation-derived pressures are discussed, as are Pathfinder, Phoenix and MSL wind speed measurement failures. Phoenix pressure transducer design problems are highlighted with respect to confusion about dust filter location, and lack of information about nearby heat sources due to International Traffic and Arms Regulations. Further pressure questions arise from high densities encountered during aerobraking operations (particularly over the South Pole). Spectroscopy for pressure did not work over ice there. NASA could not replicate dust devils at 10 mbar without employing wind speeds 11+ times greater than associated with Martian dust devils. Sand dunes observed from HIRISE, and rapidly filled MER Spirit tracks indicated sand movement that would require wind speeds of 80 mph at the assumed low pressures. These winds were not seen at either Viking, indicating higher pressures than recorded. Spiral clouds with ~10 km-wide eye walls are seen on and over Arsia Mons where pressure was thought to be ~1 mbar. Future transducers require wider pressure range sensitivity and a way to replace dust filters and keep air access tubes clear. 

PowerPoint Summary of HIGHER THAN ADVERTISED MARTIAN AIR PRESSURE - PART 2 by Barry S. Roffman.  Posted August 18 2011.

ABSTRACT FOR PART 2 by Barry S. Roffman (November 6, 2012): After a cursory review of the Viking Project Data it became apparent that an extensive audit was imperative. The Viking Project Data did not seem to explain weather phenomena (spiral clouds over Arsia Mons, dust devils, etc.) clearly seen on Mars. A general discussion of the problems is offered in the Basic Report by David Roffman. The data audit results are presented in seven Annexes. The Viking Project data divides every Martian day into 25 time-bins (hours), each ~59 minutes long. Annex A (Viking 1 sols 1 to 350) and Annex B (Viking 2 sols 156 to 361) emphasize how pressures change during morning time-bins that correspond to 0630 to 0830. A simple formula, Pressure predicted = (6.51 mbar*255.77 K)/Temperature K measured, was often correct for 0730. Annex C examines how often the pressure sensor did not work (stuck or no pressures) between Viking 2 sols 639 and 799. Annex D examines the percent differences between hourly predictions and reported pressures for Viking 1 from sols 1 to 350. Annex E focuses on predictions and reported pressures for the 0.3 (0730) and .34 (0830) time-bins. Annex F maps out the best and worst prediction times each day, clearly proving the influence of the RTG heaters on hourly pressure reports. Annex G shows what went wrong in the transducer selection and testing process. These Annexes provide hard evidence that the Tavis pressure transducers used for the Vikings (and Pathfinder) likely jammed with dust during the landing process. The meaning of this is that it is doubtful that they ever measured ambient pressure conditions of Mars.  There is evidence that all subsequent attempts to measure pressure were colored by the reported Viking results. Problems with Phoenix pressures based on a Vaisala transducer are discussed in the Basic Report. Annex I discusses the the initial pressure results in from the MSL with a focus on its sols 15 to 87 (Ls 158.8 to 199.8) which occurred between August 22 and November 3, 2012.

BASIC REPORT for HIGHER THAN ADVERTISED MARTIAN AIR PRESSURE by David A. Roffman and Barry S. Roffman. Updated April 29, 2013 with MSL weather results.

ABSTRACT of the Audit of the Viking Project Pressure Data and ANNEX A TO HIGHER THAN ADVERTISED MARTIAN AIR PRESSURE. Viking 1 Morning Pressure and Temperature Changes. Posted October 24, 2012.

PowerPoint Summary of HIGHER THAN ADVERTISED MARTIAN AIR PRESSURE - Part 1 by David. Roffman. Posted September 9, 2012. 

PowerPoint Summary of HIGHER THAN ADVERTISED MARTIAN AIR PRESSURE - PART 2 by Barry S. Roffman.  Posted August 18, 2011.

POWERPOINT for HIGHER THAN ADVERTISED MARTIAN AIR PRESSURE, Part 3: MSL Weather Blunders and Their Implications.