Pressure Vessels to Infinity and Beyond

Welcome to All Sensors “Put the Pressure on Us” blog. This blog brings out pressure sensor aspects in a variety of applications inspired by headlines, consumer and industry requirements, market research, government activities, and you.

Pressure Vessels to Infinity and Beyond

Well, maybe not quite that far. As noted in an earlier Put the Pressure on Us blog, a pressure vessel is a storage tank or vessel that has been designed to operate at pressures above 15 psig. The Office of Safety and Mission Assurance Division of National Aeronautics and Space Administration (NASA) reports that there are approximately 10,000 ground-based Pressure Vessels and Systems (PVS) across the agency.

However, there are out of this world applications, too. One example is the pressure vessel built for the crew compartment of the Orion spacecraft. In this pressure vessel, flight crews will live and operate the spacecraft on flights from the Earth to cislunar (within the Moon’s orbit) space and back. While the vacuum of space exists outside of the vessel, an earthlike 15 psia pressure must be monitored and controlled inside to support the crew.

In contrast, an unpressurized lunar rover is being pursued as part of NASA’s project to land the first woman and the next man on the Moon by 2024. In this case, the astronauts’ suit will regulate the pressure the aliens from earth will need to survive.

The crew module pressure vessel for NASA’s first crewed Orion spacecraft. Source: NASAspaceflight.com

The crew module pressure vessel for NASA’s first crewed Orion spacecraft. Source: NASAspaceflight.com

Do you have a pressure sensing question? Let us know and we’ll address it in an upcoming blog.
Email us at info@allsensors.com

Out of this World Pressures

Welcome to All Sensors “Put the Pressure on Us” blog. This blog brings out pressure sensor aspects in a variety of applications inspired by headlines, consumer and industry requirements, market research, government activities and you. In this blog we’ll be discussing pressure outside of our blue planet.

Out of this World Pressures

The earth’s average atmospheric pressure is 1 bar (101.3kPa, 29.92 mm Hg or 14.69 psi). Temperature and altitude are among the factors that cause variations. At a specific location, the air pressure can vary about 10%. Leave this planet, where we have the weight of a life-producing atmosphere of oxygen and nitrogen exerting pressure on us and the situation is quite different.

In outer space, the pressure is 1.322 × 10-11 Pa – essentially zero, since there is very little air and hardly any water.

Our nearest neighbor, the moon, has a surface pressure at night of 3 x 10-15 bar (or 3 x10-10 Pa). In contrast, Mars has a layer of gases surrounding it composed mostly of carbon dioxide. As a result, the atmospheric pressure on the Martian surface averages average  750 Pa (0.109 psi) or about 1/100 of the Earth’s. At any given location on Mars, the air pressure can vary by as much as 50%.

Earth’s pressure variations at a given location seem small compared to these other locations. Measuring earth’s pressure variations is also quite easy and commonly performed with a 100 kPa absolute pressure sensor.

Post36

The size difference between Earth and Mars is minor compared to the atmospheric pressure difference. Image courtesy of NASA.

What do you think/Comments?
Do you have a pressure sensing question? Let me know and I’ll address it in an upcoming blog.
-Han Mai, Senior Marketing Specialist, All Sensors Corporation (hmai@allsensors.com)