On Monday, a small capsule launched from their test bench at the White Sands Missile Range, New Mexico, reaching speeds in excess of 600 miles per hour in just a few seconds. The spacecraft was Boeing's Starliner Crew Capsule, which will bring NASA astronauts to the International Space Station from next year. Later this week, SpaceX will also conduct a test of its Crew Dragon capsule, a second attempt after a catastrophic explosion earlier this year ended a similar test run.
These tests are intended to demonstrate the capsule's ability to cope with a suborbital emergency. If something goes seriously wrong while the astronauts are sitting on a rocket, the capsules should take them to safety. The passing of these tests is an important milestone as the two companies are the first NASA astronauts to launch into space. But getting an astronaut safely off the pad does not count for much if you can not bring him back to earth as safely. And for that you need a lot of big parachutes that are guaranteed to work every time ̵
In the Starliner test on Monday, only two of the three parachutes of the capsule were in use. Technically, the capsule needs only two to land safely on the ground, and Boeing considered the test successful. However, parachutes have boring aerospace companies and their partial use on Monday suggests that they continue to pose a significant technical challenge. SpaceX had a similar incident earlier this year, as all parachutes could not be used during a drop test.
"Parachutes remain a challenge for both providers," an aerospace safety advisory panel reported on Boeing's and SpaceX's commercial crew programs this year. "Both vendors have experienced technical challenges, albeit different ones, in terms of deployment and performance of their parachute systems."
Each company is undergoing a different certification process for its commercial crew program, but ultimately parachutes face the same basic challenges. They must withstand extreme forces when they slow a 10-ton vehicle from over 160 km / h to speed. To make matters worse, these loads constantly shift when the parachute inflates – if at all. Throw a little more randomness into the wind and you have an incredibly complex technical problem.
Before launching this week, Boeing had successfully tested its parachutes by dropping a Starliner test vehicle five times from a balloon. On Monday, when the Starliner capsule had reached its peak, it released the parachutes that were used to pull out the much larger main parachutes. The canopies of the main slides are wide enough to accommodate three school buses throughout. According to Boeing, it's still being investigated why the third parachute was not opened.
"It's too early to see why all three main parachutes have not been triggered. However, two out of three successful triggers are acceptable for the test parameters and crew safety, "said Boeing spokesman Todd Blecher in a statement.
The parachutes used in Boeing's Starliner are a downsized version of older parachute designs Developed by NASA almost 20 years ago as part of the Constellation program, this pressure of the Bush era on the moon was broken, the Orion capsule was redesigned and equipped with a new parachute system.As the design of the parachute system of Boeing Similar to NASA, the company had to do fewer tests to prove the safety of the system compared to SpaceX, but despite extensive testing of the slides, a Boeing spokesman said there is still a lot of work to be done to make sure that the Astronauts safely return to Earth.
In particular, engineers are worried about About "asymmetric loads". Different parts of a parachute experience Different loads when the shaft inflates. This means that it is important to reinforce the areas that are most heavily used. However, this increases the weight of the system, which limits the carrying capacity of the capsule. The engineers therefore try to limit the reinforcement only to the areas that are absolutely necessary by modeling the use of the chute under different conditions.