This past week, we saw the successful test flights of both Boeing's Starliner and SpaceX's Starship. Despite seemingly going right, small issues occurred that show how difficult and punishing space flight can be.
Unveiled in 2010, Boeing's Starliner is one of two space vehicles, the other being SpaceX's Crew Dragon, funded by NASA to ferry astronauts to the International Space Station. These are replacements for the Space Shuttle, which was originally envisioned to be a cheap, reusable, and reliable space vehicle, that could go up every couple of weeks.
In reality, the Shuttle was very expensive and complicated. After every re-entry, the heatshield, which protects the inside and rest of the capsule as it re-enters the atmosphere, needed to be painstakingly replaced. It would take months to do this, with each tile going in a specific location, taking months of human effort.
This week's launch of Boeing's Starliner was their sixth attempt at the fourth test launch. The first test was in December 2019, and the capsule successfully launched. However, a software malfunction threw off the internal clock and timing, meaning the capsule didn't do the right maneuvers at the right time, and couldn't reach the space station.
After about 18 months of fixes, in August 2021, Starliner had its second test. Only this time, it never even got off the ground, with problems being detected with valves before launch.
After eight months of further fixes, Starliner's third test was in May 2022. It was mostly successful, but required more work.
This fourth and latest test was originally scheduled for early May. However, a delay due to the rocket, and then delays with a leak of helium from the capsule pushed it back multiple times into this week, when it successfully flew with people for the first time.
Despite the successful launch, the helium leak, which is the fuel system for thrusters, which allows the capsule to steer in space, was leaking again.
It is hard to get it all right, all the time.
A day after Starliner's launch, Starship had its fourth test. Starship is about 9 metres taller than the Saturn V which carried astronauts to the Moon and can carry nearly twice as much weight. Starship is comprised of two parts. The Starship refers to both the entire system, and specifically, the space vehicle that is the top part (where people will eventually go in). The bottom is the Heavy Booster - the main engine comprised of 33 separate engines.
On Starship's first test, it went up about 30 kilometers, before having a malfunction and exploding in spectacular fashion. About 6 months later, the second test went much higher, and Starship and booster separated. However, both suffered anomalies and exploded. Another 6 months, and the third launch had Starship reach orbit. Upon re-entry, it didn't orientate itself perfectly, and broke-up upon re-entry.
This week's test reached orbit, separated, and came back down in the right orientation as it would have if landing. However, during the re-entry, the intense heat and friction slowly burned away at parts, nearly dissolving them.
While it was successful, it really showed just how hard space flight is and even when everything seemingly goes right, small critical things can still go wrong.
- Brad Tucker is an astrophysicist and cosmologist at Mount Stromlo Observatory, and theNational Centre for the Public Awareness of Science at ANU
