A Timeline of Boeing's Starliner Problems as NASA Eyes Mid-August Launch

NASA said the upcoming launch of Boeing's Starliner space capsule could happen as early as mid-August, following delays over the past couple of weeks.

The capsule is due to launch on an uncrewed test-flight mission to the International Space Station (ISS) that will also serve as a cargo delivery.

The launch should have taken place days ago, but engineers encountered a problem with the spacecraft's valves that meant they didn't open correctly shortly before a scheduled launch on August 3. As a result, Starliner had to be taken off the launchpad and returned to its hangar.

The valves are crucial. They connect to the spacecraft's thrusters, which enable it to move around in space and also to make a quick escape from its rocket if there is an issue at launch.

In a mission update posted on Monday, NASA said it was working with Boeing to restore functionality to the valves and that seven out of 13 had been successfully opened. Work is ongoing to get the others open, too.

The space agency said: "If all valve functionality can be restored and root cause identified, NASA will work with Boeing to determine a path to flight for the important uncrewed mission to the space station.

"NASA, Boeing and ULA are assessing the potential for several launch opportunities with the earliest available in mid-August."

Below is a timeline for Boeing's Starliner progress and hiccups so far.

First Orbital Launch, December 2019

Starliner launched on its first mission in late 2019. The capsule, which didn't have astronauts on board, was due to make a rendezvous with the ISS in a flight intended to showcase its capabilities.

Starliner launched successfully aboard an Altas V rocket on Friday, December 20, that year, but quickly encountered an issue with an on-board timing system.

As a result, the capsule got itself into the wrong orbit, which meant it could not meet up with the space station. The mission was cut short and, after orbiting the Earth for a while, Starliner made a successful re-entry and landing back on Earth a couple of days after the launch.

NASA accepted Boeing's proposal to attempt the mission again at a later date.

Second Launch, First Delay

Boeing's second attempt to link Starliner with the ISS was initially scheduled for July 30 this year.

However, with just one day to go before launch, the ISS experienced a problem with Nauka, a Russian module that accidentally fired its thrusters and pushed the space station off-kilter.

NASA and Boeing decided to push the launch back to the following week to give the ISS crews time to prepare the station for Starliner's arrival.

Second Launch, Second Delay

After the Nauka delay, Starliner was prepared once more for an anticipated launch date of August 3.

On the day, just hours before launch, Boeing engineers "detected unexpected valve position indications in the propulsion system," according to a statement from the company, and the launch was pushed back to August 4.

The issue was not fixed in time and the launch was canceled. The spacecraft was returned to its hangar for further examination, and NASA is releasing regular updates.

Boeing Starliner
The Starliner capsule seen atop an Atlas V rocket in the days leading up to its first test mission in December, 2019, at Cape Canaveral Air Force Station in Florida. A launch date of mid-August 2021 for the capsule's second mission is possible. Joel Kowsky/NASA / Getty