4

A spongy material is installed to the inside helmets called the Valsalva device (top right in this image) enter image description here allow astronauts to do the Valsalva maneuver to relieve pressure on their eardrums when there is a pressure differential.

Samantha Cristoforetti demonstrating Valsalva device. enter image description here

When do (did) the astronauts generally use this device to relieve the pressure, during ascent, descent, and/or while their spacecraft was in the vacuum of space. If the astronauts used it during ascent or descent was there a common altitude, or a range of altitudes, it was generally used?

Bob516
  • 6,917
  • 3
  • 27
  • 67

1 Answers1

6

As a scuba diver I know when to do a Valsalva maneuver to equalize pressure on my ears: only when descending from surface during a fast pressure increase. While ascending from the deepth my ears never needed help in equalizing pressure. For the anatomy of the ears see Wikipedia.

The astronauts experienced a fast pressure increase only during the very last phase of flight after the hot reentry and before and during parachute flight when the atmospheric pressure outside the capsule rised above the pressure inside and the overpressure valve opened to let air in. If the pressure in the suit was dropping or constant the Valsalva device was not used. If the helmet was open, the astronauts simply closed their nose between two fingers.

The picture of Samantha Cristoforetti was taken on Earth before launch, see the carpet below her. When the suit is closed and pressurized to perform a leak test, a Valsalva maneuver may be neccessary to avoid pain in the ears.

Uwe
  • 48,975
  • 4
  • 121
  • 206
  • I recall doing equalizing the pressure about every 7-10 feet underwater when I did dives, so it's probably not needed more than 2-3 times during descent right? – Magic Octopus Urn Feb 07 '20 at 13:39
  • 1
    I've had to use the Valsalva maneuver when taking off in a plane. From the Mayo Clinic website, "Follow these tips to avoid airplane ear:...Use the Valsalva maneuver during ascent and descent." https://www.mayoclinic.org/diseases-conditions/airplane-ear/symptoms-causes/syc-20351701. Is that a sourced statement about astronauts that they only experience over pressure during descent? – Bob516 Feb 07 '20 at 13:48
  • 1
    @MagicOctopusUrn If you ever did a "dive" in a hyperbaric chamber (I did), you know that the ears needed equalization more often in air than in water. The ears are less sensitive to pressure changes while in water. You may notice that while driving in the mountains. – Uwe Feb 07 '20 at 14:10
  • 3
    In recent US spacesuits, it's the EVA suits that have Valsalva devices. I am not sure that the orange ascent/entry shuttle suits had them. The training manual does not mention them when describing the helmet https://www.nasa.gov/centers/johnson/pdf/383443main_crew_escape_workbook.pdf The Soyuz launch & entry suits do have them. – Organic Marble Feb 07 '20 at 14:18
  • @Bob516 If the eustachian tubes are healthy, not swollen and free from viscous mucus, the Valsalva maneuver is neccessary only during a descent before landing. – Uwe Feb 07 '20 at 14:21
  • I forgot to add a link; the EMU Valsalva device is referenced on page 5-7 of the EMU Systems Workbook https://archive.org/details/EMUSystemsWorkbookJSC19450B/page/n211/mode/2up – Organic Marble Feb 07 '20 at 17:03
  • @uwe really?! That's extremely interesting... I wonder why. – Magic Octopus Urn Feb 08 '20 at 15:33
  • 1
    @MagicOctopusUrn ... the outlet of the Eustachian tubes into the throat has a bit of a "reed valve" configuration. They act as one way valves. Pressure effortlessly exits the middle ear during ascent. There are tiny muscles around the Eustachian exits which contract when swallowing, which tends to temporarily open the orifice. That's why swallowing often lets the ears equalize. – Woody Feb 07 '23 at 05:26