No, it is not possible for an object to slowly rise into space at a constant velocity lower than orbital velocity. This is because of the presence of gravity and the nature of orbital mechanics.
To understand why, let's consider the basic principles of orbital motion. When an object is in orbit around a planet or any other celestial body, it needs to achieve a certain orbital velocity to counteract the gravitational pull and maintain a stable orbit. This orbital velocity is determined by the gravitational force between the object and the celestial body it is orbiting.
If an object is traveling at a velocity lower than the required orbital velocity, gravity will eventually cause it to decelerate and fall back towards the celestial body. The gravitational force will continually act to pull the object back, preventing it from escaping into space.
In order for an object to reach and maintain a stable orbit, it must achieve the specific orbital velocity corresponding to its orbital altitude. This velocity allows the object to continuously "fall" towards the celestial body while simultaneously maintaining a tangential velocity that matches the curvature of its orbit, resulting in a stable, elliptical path.
Therefore, an object cannot slowly rise into space at a constant velocity lower than orbital velocity because gravity will eventually cause it to decelerate and fall back to the celestial body. Achieving and maintaining a stable orbit requires the object to reach the necessary orbital velocity to balance the gravitational force.