Astronauts will no longer be able to urinate on bus that picks them up for launch

Russia has unveiled a new space suit but the design may have to be changed to continue a decades-old tradition – making a stop to pee on the way to the launch.

The Sokol-M prototype suit was designed as a replacement for suits worn during launches to the International Space Station (ISS) on Soyuz spacecraft.

The Soyuz, in use since the 1960s, is to be phased out and replaced in the next few years with a new Russian ship called the Federation.

The maker of the suits, the aerospace firm Zvezda, says they will be made of new materials and adaptable to different body sizes.

But the new design makes it impossible to carry out one particular ritual launched by the first man in space, Yuri Gagarin, who had to relieve himself on the back wheel of the bus that was taking him to the launch pad in 1961.

The stop has been replicated at every launch from the Baikonur launch pad and, many male cosmonauts and astronauts pee on the tyre for good luck – something that would be impossible in the new suit, according to its maker.

Female astronauts are not obligated to participate but some have brought vials of their urine to splash on the wheel instead.

“I’m not sure how they will be able to (carry on the tradition), since we haven’t designed the fly,” said the Zvezda director, Sergei Pozdnyakov, quoted by Russian agencies. “We have the design specifications. They don’t state that it’s necessary to pee on the wheel. The design specifications would need to be adapted.”

The orange Sokol-M suit has one diagonal zipper, rather than the currently used white Sokol-K, which has a V-shaped opening pointing to the crotch.

The new suit is lighter due to the zipper and all seams are airtight, so there is no longer a need for the internal rubberised layer known as “the bladder”, which is difficult to get in and out of.

All members of the ISS crew have to wear bespoke Sokol-K suits, since they must be worn on the Soyuz spacecraft that brings cosmonauts and astronauts to orbit.

The suits are designed to be comfortable while reclining in the deep Soyuz chairs, but are heavy and contribute to a noticeable stoop when walking up to the rocket.

Soyuz launches are full of rituals in which cosmonauts plant trees at Baikonur, get haircuts, watch the classic Soviet film White Sun of the Desert and have an Orthodox priest sprinkle holy water on them.