What is artificial gravity in space how it form?

Gravity itself cannot be manufactured: it comes from mass, and no spacecraft will ever carry enough. What can be reproduced is the sensation of weight — the steady push a floor gives the soles of the feet. The method is rotation. Turn a vehicle about its axis and anything resting against the outer wall is forced to travel in a circle; the wall supplies that force, and to the occupant it feels exactly like weight, directed outwards. The acceleration produced grows with the radius and with the square of the rate of spin, so a designer can trade a large, slowly turning structure against a small, fast one.

The small, fast option is the one that fits inside a rocket, and it is also the one that makes people ill. In a tight circle the head and feet travel at noticeably different speeds, and every movement of the head meets a sideways Coriolis push that the inner ear reads as a lie. Comfortable rotation implies a structure tens of metres across, assembled in orbit, with the mass, complexity and failure modes that follow. Set against that, weightlessness is itself a research asset, and the International Space Station was built to exploit it rather than cancel it.

Brief spin has been tried in flight: a Gemini crew once tethered their capsule to a target vehicle and set the pair slowly turning, producing a barely perceptible tug. Most current work is on the ground. Volunteers lie head-down in bed for weeks to reproduce the fluid shift and bone loss of orbit, then spend part of each day on a short-arm centrifuge to see whether a daily dose of simulated weight protects them. Small centrifuges aboard the station do the same for cells and plants.