Once you burn fuel to accelerate your spaceship to a certain speed and point it in a direction, you can turn off your engines completely. The spaceship will coast through space at that exact speed indefinitely without using a single drop of fuel.
Why Spacecraft Don’t Need Engine Power to Move
On Earth, a car needs continuous engine power to stay moving at 100 km/h because it fights air resistance and friction from the road. In the vacuum of space, those friction forces don’t exist.
This behavior follows Newton’s First Law of Motion (Inertia): An object in motion stays in motion with the same speed and in the same direction unless acted upon by an external force.
The Voyager 1 probe, launched in 1977, turned off its primary thrusters decades ago. It is currently traveling out of the solar system at roughly 38,000 mph (61,000 km/h) purely on momentum.
When Spacecraft Do Need Fuel or Energy
While you don’t need energy to stay moving, a spaceship still requires energy for three specific actions:
- To Change Speed or Direction: To go faster, slow down, or turn, you must fire rocket thrusters to exert a force.
- To Fight Gravity: If you are in Low Earth Orbit (like the International Space Station at ~400 km altitude), tiny traces of Earth’s upper atmosphere create «atmospheric drag.» Spacecraft in low orbits occasionally fire small thrusters (a «reboost») to avoid falling back into Earth’s atmosphere.
- To Run Onboard Systems: Life support, navigation computers, heat controls, and communications require electrical energy—typically powered by solar panels or nuclear generators (RTGs), separate from rocket fuel.
Summary
- To cruise in a straight line: 0 fuel required.
- To change velocity, steer, or land: Fuel is required.
Question: Is there any progress on anti gravitional lifting equipment?
Gemini: There is no progress on true «anti-gravity» (manipulating, shielding, or canceling gravitational fields) because it remains impossible under known physics. General relativity dictates that mass-energy is always attractive, and experiments (such as CERN’s ALPHA-g project) have confirmed that even antimatter falls downward like ordinary matter.
However, depending on what context you mean by «anti-gravity lifting equipment,» there are significant real-world technologies that achieve «gravity-defying» effects:
1. Medical & Rehabilitation Equipment
If you have heard of «anti-gravity treadmills» or lifting gear in physical therapy:
- Differential Air Pressure (DAP) Systems: Equipment like the AlterG Anti-Gravity Treadmill uses an airtight chamber inflated around the lower body. By pressurizing the air, it lifts the body and reduces a patient’s effective weight by up to 80%, allowing low-impact post-surgery rehabilitation.
2. Industrial «Zero-Gravity» Lifting Systems
In manufacturing and logistics, factory equipment designed to make heavy loads feel weightless is commonly referred to as «zero-gravity» or «anti-gravity» lifters:
- Intelligent Assist Devices (IADs) & Servo-Balancers: These overhead hoists use force sensors and computer-controlled electric motors or pneumatic systems to continuously sense operator input and counteract the weight of heavy components (e.g., engines, steel plates). Operators can move 200 kg loads using just a few grams of fingertip pressure.
3. Alternative Levitation Technologies (Physics)
Where physical forces offset gravitational pull without changing gravity itself:
- Magnetic Levitation (Maglev): Uses high-powered electromagnets or superconductors (quantum locking) to suspend heavy loads, train cars, or industrial bearings completely without friction.
- Acoustic & Electrohydrodynamic Levitation: High-frequency sound waves (acoustic tweezers) or ionized air (ion thrusters/lifters) are used to lift small objects and liquid droplets in laboratory settings.