Elon Musk’s SpaceX has been developing an advanced version of the Dragon spacecraft for deorbiting the International Space Station (ISS).
The orbital station is massive, and bringing it down safely requires precision. During a press conference, NASA revealed specifics about the United States Deorbit Vehicle (USDV) — a spacecraft that would dock with the ISS and assist it in safely re-entering Earth’s atmosphere.
On June 26, NASA granted SpaceX a $843 million contract to deorbit the ISS once it is decommissioned in 2030. NASA previously stated that after construction is completed, it will acquire full ownership and operation of the deorbit vehicle.
Deorbit vehicle’s components
Orbital mechanics are extremely complicated, and even small changes can mess things up because of the way things move in space. So far, the station has maintained a perfectly steady orbit around Earth due to the ISS operators’ high-precision planning.
The USDV will be a “souped-up version” of the Dragon spacecraft. As per SpaceNews , it’ll have a bigger trunk packed with engines, propellant tanks, a power generating system, and other components. Notably, it will store six times more propellant and three to four times the power of a standard Dragon.
To ensure a smooth descent, the spacecraft will be armed with 46 Draco thrusters – 30 for the strong duty of decreasing the station’s orbit and 16 for precision altitude control.
The USDV will dock with the ISS just before the final crew departs.
After the USDV’s arrival and a thorough inspection, the mission control will initiate a series of crucial maneuvers, beginning with a controlled fall in which the station’s orbit is allowed to naturally drop. The final crew will depart after the station’s altitude drops from 400 kilometers to 330 kilometers. This orbital decline will last for six months.
After a six-month wait, the USDV will take charge when the ISS falls to an altitude of 180 km. Using its powerful thrusters, it’ll carefully guide the ISS into a controlled re-entry, aiming for a safe zone in the ocean. However, the exact dates have not been disclosed.
Some big pieces will survive re-entry
Most of the piece will burn during the fiery re-entry. Due to ISS’s large size, some pieces, ranging from microwave-sized to car-sized, will likely survive re-entry. NASA has picked a remote, uninhabited region of the South Pacific to reduce risk. The SpaceNews reported that the selected location is an open ocean “in a narrow corridor about 2,000 kilometers long” where the fragments are likely to splash down.
The USDV, which weighs more than 30,000 kilograms, will carry a significant 16,000 kilograms of fuel, to provide the power required to manage the ISS during re-entry.
This means that the USDV is too heavy for a Falcon 9, so NASA will procure a separate, heavy-lift launch vehicle. SpaceX has offered its services, but the competition is open.
But why did NASA select SpaceX? For a few years now, the Dragon capsule has been NASA’s reliable mode of transportation for sending astronauts and goods to the space station.
Flight experience was a major factor. SpaceX’s proven track record with Dragon missions made them a strong candidate. Apart from SpaceX, just one other company, Northrop Grumman, bid, but their plan was more expensive.
SpaceX has a limited amount of time to complete the design and execute a set of tests on the whole capsule, as well as its software and communication systems. Moreover, The USDV needs to be attached to the ISS 18 months before the station comes back down to Earth.
Most Popular
Comments / 0