Stories
Slash Boxes
Comments

SoylentNews is people

posted by Fnord666 on Monday August 17 2020, @10:11AM   Printer-friendly
from the sunny-with-a-chance-of-clouds dept.

Simulations show lander exhaust could cloud studies of lunar ices:

A new study led by scientists at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, shows that exhaust from a mid-sized lunar lander can quickly spread around the Moon and potentially contaminate scientifically vital ices at the lunar poles.

Computer simulations of water vapor emitted by a 2,650-pound (1,200-kilogram) lander—about a quarter of the dry mass of the Apollo Lunar Module—touching down near the Moon's south pole showed exhaust takes only a few hours to disperse around the entire Moon. From 30% to 40% of the vapor persisted in the lunar atmosphere and surface two months later, and roughly 20% would ultimately freeze out near the poles a few months after that.

Those results, published online Aug. 11 in the Journal of Geophysical Research: Planets, show that researchers' interest in studying the native ices in the Moon's poleward craters—ices that may date back several billion years—will need to be carefully considered during increased efforts to return humans to the Moon.

[...] "The interesting thing about Parvathy's work is that it shows very well that the effect, while small and temporary, is global," said Dana Hurley, a planetary scientist at APL and coauthor on the study.

Space organizations can expect volatile gases to significantly coat the lunar surface at well over 60 miles (100 kilometers) from the landing site.

The residue exhaust does eventually fade away, but Hurley points out that current plans for human lunar exploration mean it will happen more frequently and with much heavier landers.

"The results of this study drive the critical need to conduct the research we want to do about the lunar atmosphere and volatile deposits while they are relatively pristine," Hurley said.

Journal Reference:
Parvathy Prem, Dana M. Hurley, David B. Goldstein, et al. The Evolution of a Spacecraft‐Generated Lunar Exosphere, Journal of Geophysical Research: Planets (DOI: 10.1029/2020JE006464)


Original Submission

 
This discussion has been archived. No new comments can be posted.
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
  • (Score: 4, Insightful) by NotSanguine on Monday August 17 2020, @03:24PM (2 children)

    Just dust off the top layer when you collect your samples. In person, by an astronaut living and working on the Moon.

    And/or use some sort of unmistakable, not-found-in-nature, molecular marker in the material that forms the exhaust so we'll know it when we see/analyze it.

    --
    No, no, you're not thinking; you're just being logical. --Niels Bohr
    Starting Score:    1  point
    Moderation   +2  
       Insightful=2, Total=2
    Extra 'Insightful' Modifier   0  
    Karma-Bonus Modifier   +1  

    Total Score:   4  
  • (Score: 2) by Immerman on Monday August 17 2020, @08:19PM (1 child)

    by Immerman (3985) on Monday August 17 2020, @08:19PM (#1038026)

    Like what?

    Any chemical marker you might add to the fuel will likely be completely destroyed by the high temperatures in the rocket combustion chamber, and even if it survived it wouldn't incorporated in the water or CO2 in the exhaust anyway. Not t mention the damage it could do a reusable engine that's designed to burn as clean as possible.

    Assuming a Starship-style methalox engine, you could theoretically use Oxygen-17 or 18 instead of the common 16 to leave a (relatively) clear indicator of its origin - but that will increase the propellant mass and thus reuduce the rockets performance, as well as making the propellant outlandishly expensive to acquire, dramatically increasing the cost of a flight that will (hopefully) already be dominated by fuel costs.

    • (Score: 2) by NotSanguine on Tuesday August 18 2020, @12:14AM

      Like what?

      A good question.

      Perhaps modified concentrations of oxygen, carbon or hydrogen isotopes. Better yet, some combination thereof which doesn't occur naturally.

      And you don't have to use enormous amounts of various isotopes either. Just enough to make it *different* from what occurs naturally.

      Since the average ratio of deuterium to hydrogen is ~1 to 26 million [wikipedia.org], doubling that amount would create an unusual isotopic ratio, yet increase the mass of the methane reactant an insignificant amount. This could also be done with oxygen and/or carbon isotopes too, also without impacting reactant mass significantly.

      That said, no one is really going to do anything about the "contamination" of the lunar surface by rocket exhaust.

      --
      No, no, you're not thinking; you're just being logical. --Niels Bohr