is PSLV and LVM3 reusable like Spacex's Starship?

The Polar Satellite Launch Vehicle (PSLV) and LVM3 developed by the Indian Space Research Organisation (ISRO) is not designed to be fully reusable in the same way as SpaceX's Starship or Falcon.

While SpaceX's Starship is designed to be a fully reusable spacecraft, including both the spacecraft itself and its booster, the PSLV follows a more traditional expendable launch vehicle design. This means that the components of the PSLV, including its stages and boosters, are not intended to be recovered and reused after launch.

What happens to the rocket/booster after launch

The PSLV is a highly reliable and cost-effective launch vehicle, but it operates on a more conventional model of single-use stages. After each launch, the stages of the PSLV are discarded and do not return to Earth for refurbishment and reuse.

The specific altitude at which the first stage of the Polar Satellite Launch Vehicle (PSLV) is discarded and whether it falls into the ocean depends on the mission profile and the intended orbit for the payload.

1. Stage Separation: The PSLV is a four-stage launch vehicle. The first stage, known as the "PS1" or "Core Stage," is the largest and provides the initial thrust during liftoff. The first stage consists of solid rocket boosters.

2. Burnout and Separation: Once the first stage's solid rocket motors burn out and are depleted of propellant, the first stage is jettisoned from the rest of the rocket. This typically occurs at an altitude of around 60 to 80 kilometers (37 to 50 miles) above Earth's surface.

3. Descent and Impact: After separation, the first stage follows a ballistic trajectory and descends back to Earth. If the launch takes place from ISRO's spaceport in Sriharikota, India, the discarded stage usually falls into the Bay of Bengal. The stage is designed to reenter Earth's atmosphere in a controlled manner to minimize the risk to populated areas.

4. Safety Precautions: ISRO takes safety precautions to ensure that the falling debris poses minimal risk to ships or aircraft in the area. This may involve closing airspace and maritime areas during launch windows.

How starship and falcon rockets are reusable

Starship is designed with a fully reusable architecture, which includes both the spacecraft itself (the upper stage) and the first stage booster, known as "Super Heavy."

Here's how reusability works in the context of Starship:

1. Reusable Fuel and Engines:

   • Starship is powered by Raptor engines, which use liquid methane (CH4) as fuel and liquid oxygen (LOX) as the oxidizer. These propellants are environmentally friendly and can be produced on Mars, aligning with SpaceX's long-term goal of interplanetary travel and colonization.
   • The use of liquid methane and liquid oxygen as propellants allows for efficient combustion and higher performance engines.

2. Full Reusability:

   • Both the Starship spacecraft and the Super Heavy booster are designed to be fully reusable. This means that after launch, both stages are intended to return to Earth, land vertically, and be refurbished for reuse in future missions.
   • Reusability is a key element of SpaceX's strategy to significantly reduce the cost of space access and make space travel more sustainable.

3. Refueling in Space:

   • The Starship spacecraft is also designed with the capability to be refueled in space. This feature is essential for longer missions, such as interplanetary travel to Mars, where the spacecraft would need to carry additional propellant for the journey.
   • By refueling in space, Starship can carry out extended missions without having to carry all the necessary propellant from Earth.