# Boeing’s Starliner Gears Up for Crucial Return from the International Space Station
Boeing’s **Starliner spacecraft** is poised to undock from the **International Space Station (ISS)** on Friday evening, entering a pivotal stage in its return to Earth. The spacecraft, which has encountered various technical obstacles during its mission, will execute a precisely coordinated series of maneuvers to guarantee a secure departure from the ISS and a successful landing at **White Sands Space Harbor** in New Mexico.
*Boeing’s Starliner spacecraft is set to undock from the International Space Station on Friday evening. (Credit: NASA)*
## A Measured Exit
The undocking procedure is slated to commence at **6:04 pm EDT (22:04 UTC)** on Friday, when the docking hooks linking Starliner to the ISS will disengage. Springs in the docking mechanism will gently propel the spacecraft away from the station, starting its exit. This approach is aimed at ensuring a seamless and secure separation from the ISS, which currently houses a nine-member crew.
Roughly **90 seconds** post-undocking, Starliner will activate its forward-facing thrusters in a sequence of **12 quick pulses** to push the spacecraft further from the ISS. These thruster activations will direct Starliner on a path that arcs over the ISS and behind it, preparing the spacecraft for its forthcoming deorbit burn.
The **deorbit burn** is set for **11:17 pm EDT (03:17 UTC)**, positioning Starliner for reentry into Earth’s atmosphere. Provided everything proceeds as planned, the spacecraft will touch down at White Sands Space Harbor shortly after **midnight EDT**.
## NASA’s Modifications to Starliner’s Flight Path
NASA has implemented several changes to Starliner’s departure protocol to alleviate risks tied to the spacecraft’s **reaction control system (RCS) thrusters**. During Starliner’s approach to the ISS in June, five of the 28 RCS thrusters failed due to overheating, which was later linked to the swelling of **Teflon seals** in the thrusters’ poppet valves. While engineers managed to restore four of the five thrusters, NASA is exercising caution regarding the possibility of additional overheating incidents.
To mitigate the stress on the thrusters and lower the risk of further failures, NASA requested that Boeing adjust Starliner’s exit plan. The revised strategy involves a quicker departure from the ISS, lightening the burden on the thrusters and ensuring that the spacecraft distances itself from the station at a swifter pace than initially intended.
**Steve Stich**, NASA’s commercial crew program manager, noted that the updated departure sequence is intended to “move away from the station with less strain on the thrusters.” The spacecraft will execute a series of brief thruster firings to enter a secure trajectory, minimizing the duration it remains near the ISS.
## Starliner Returns Without Its Crew
Importantly, Starliner will make its return to Earth without its two-person crew, **Butch Wilmore** and **Suni Williams**, who were the first astronauts to pilot the commercial capsule during its crew test flight in June. NASA officials determined last month that it was too dangerous for the astronauts to return on Starliner due to concerns regarding the spacecraft’s thruster reliability. Instead, Wilmore and Williams will stay aboard the ISS until February, when they will fly back to Earth on a **SpaceX Dragon** spacecraft.
The initial flight plan, had the astronauts been on board for the return journey, envisioned a more gradual departure from the ISS. This would have allowed engineers to fully evaluate the spacecraft’s navigation sensors and test its capability to linger near the station for photographic assessments. However, with no crew present, NASA opted for a swifter exit to minimize risk.
## Thruster Issues and Backup Strategies
Starliner’s RCS thrusters are essential for managing the spacecraft’s orientation and path during its return to Earth. Should further thruster failures occur, NASA has contingency plans established to ensure the spacecraft can still safely depart the ISS. The springs that propel Starliner away from the station are built to generate sufficient force to avert any collision risk, even in the event of total thruster failure.
Once Starliner has exited the **approach ellipsoid**, an invisible zone surrounding the ISS that spans **2.5 by 1.25 by 1.25 miles (4 by 2 by 2 kilometers)**, the spacecraft will transition into a more stable segment of its flight. NASA flight director **Anthony Vareha** noted that the spacecraft will “maintain some very benign attitudes” and limit thruster use to conserve fuel while reducing overheating risks.
## The Final Descent and Landing
Following the completion of the deorbit burn, Starliner will re
