As Space Shuttle Discovery lifted off this morning -- setting a record for the most women simultaneously in space -- three other women on the ground looked to break some ground of their own. An Arizona State U. Biodesign Institute research trio launched a first-of-its-kind experiment aboard Discovery that will offer insight into how cells react to infectious disease under the low-gravity conditions of space.
The experiment aims to better define the infectious disease process and the progression of diseases like cancer and immune system disorders, but it will also provide key data that could benefit crews aboard prolonged space missions. Crews exposed to prolonged conditions of microgravity are particularly susceptible to infection because of reduced immune system function during spaceflight.
We know that cells react differently to low-gravity environments, but this experiment is the first to expose human cells to infectious pathogens in spaceflight. The 13-day experiment will turn the food-borne bacteria Salmonella typhimurium loose on a culture of intestinal cell, measuring the responses of both the bacteria and the human cells to microgravity as well as too each other.
Bacteria like Salmonella are particularly adept at responding to environmental conditions and tweaking their virulence to best circumvent cellular defenses, so the research could shed some serious light on bacterial virulence and the mechanisms pathogens employ to adapt so well to their surroundings.
As for the three women aboard Discovery, they joined the one woman already orbiting Earth aboard the ISS to round out a record-setting foursome that marks the most women ever to ride the outskirts of the atmosphere simultaneously.
"Microgravity" misleads people into thinking that the gravity in orbit is almost zero. This is a common (and completely wrong) misconception. Misnomers are bad, m'kay? Please quit perpetuating them. "Simulated microgravity" is the closet thing you can say that's accurate. "Orbital freefall" sounds way cooler, but doesn't convey the idea that this experiment requires equal and opposite forces resulting in seemless low-gravity setting.
"seemless" should have been "seemingly." Sorry...
Here are some links for you regarding what microgravity and how microgravity is defined:
Microgravity is a state in which gravity is reduced to almost negligible levels, such as during space flight
You might find this useful as well:
There's two different point of view on this:
1. Newtonion mechanics aka classical physics: In this point of view, there's no such thing as micro gravity, since the loss of weight is due to the inertial motion of the orbiting object, aka the shuttle. If gravity was removed, you wouldn't be in orbit! You would go in a straight line with constant velocity unless acted upon by an external force. (velocity implies speed and direction) You're in orbit because gravity in this case is your centripedal force keeping you in orbit, it provides an acceleration that alters your velocity constantly. (remember that uniform circular motion implies centripetal acceleration and no tangential acceleration, meaning even if your "speed" was constant, there's still acceleration, therefore your velocity is NOT constant) Also another misnomer, there's no such thing as a "centrifugal" force, the force you feel that people call "centrifugal" force, the outward force, is not a force at all, rather the inertial motion of the object due to the first law: object in motion stays in motion with constant velocity unless acted upon by an external force.
2. General Relativity aka modern physics:
From this point of view, the object's local reference frame would indeed be in micro gravity. But not for the reasons most people think. The loss of gravitional field in your local frame, the free falling observer, is due to your motion, not because you're are far enough away from any mass (or energy). The same applies if you're free falling in an elevator, or in a parabolic trajectory of an airplane. The only gravity you would have is due to something known as tidal forces, which on Earth is very tiny, hence the term micro gravity. So from this point of view, you are indeed in micro gravity from the reference frame of the falling observer.
"setting a record for the most women simultaneously in space". Awesome news! When will they come up with one that set the record for all women???
In this context, free fall is a more accurate term than microgravity.