Sunday, 23 April 2017

Happy 50th, Soyuz!

23 April 1967, 50 years ago today, the first crewed Soyuz spacecraft launched. Three days ago, the latest crewed Soyuz spacecraft launched and docked with the ISS. We've been flying to space in this same design for a full 50 years now, and more of them have been built than any other type of spacecraft by a huge margin - it's the VW Beetle of human spaceflight. Uncrewed test launches of Soyuzes had begun in November 1966, so by that measure, Soyuz already passed its 50th anniversary last year. But I'm more inclined to measure crewed spacecraft by when they're actually inhabited in space.

The closest any other crewed spacecraft comes to that longevity is the DOS space station core module (reaching its 46th crew-carrying anniversary this June), which featured in most of the Salyut space stations and the Mir space station, and is currently part of the ISS. Soyuz and DOS were designed to work together, so it's appropriate but remarkable that they're still doing so today. You'll see in the visual history below how much the two vessel types have been connected.

By coincidence, today is also the 46th anniversary of Soyuz 10's unsuccessful docking attempt with Salyut 1, the first Soyuz-DOS meetup in orbit. Later this year we'll see the 60th anniversary of the R-7 family of rockets, the oldest orbital launcher there is, variants of which have launched all crewed Soyuzes and most uncrewed Soyuzes, plus all sorts of other things.

The longest serving US spacecraft, the Space Shuttle Orbiter, lasted 30 years, and the 5 of those that were built got into space 134 times, accruing a total spaceflight time of just under 1 331 days. Flying only once each, 132 Soyuzes have gotten their crews into space 132 times so far, adding up to 14 956 days of human spaceflight time, and counting. Nine more Soyuzes are scheduled to launch, keeping them in use until 2020. Adding in all the uncrewed Soyuz and Soyuz-variant launches more than doubles the number of times the Soyuz family has flown; there were no uncrewed Space Shuttle flights. So, it's not the simplest comparison.

The second most numerous spacecraft design was the Apollo CSM, of which a mere 15 were launched into space with humans on board.

And while the latest version of Soyuz is definitely modernised and digital, it's also still clearly very close to its original 1960s form; consider below the full evolution of the Soyuz:
(Click to embiggen.)
Top row: Crewed variants of Soyuz.
Bottom row, left group: Major uncrewed variants of Soyuz.
Bottom row, right group: Crewed variants of Tiangong.
(Image credit mostly goes to historicspacecraft.com, with a couple bits from elsewhere and/or modified by me.)

Note that I've included more than just the crewed versions. Soyuz has been around so long, it's been mutated into a few different forms - most import of all is undeniably the Progress cargo vessel. I've also included China's larger Tiangong spacecraft, which was intentionally based on the Soyuz layout, and operates in a very similar way. It is arguably part of the Soyuz family.

One weird thing going through all of the Soyuz missions brings up is how openly sexist the Soviet and Russian space programs have been. Hundreds of people have travelled on Soyuzes, but only 3 of them were Russian women (less than 1 per decade!), and no Soyuz has ever had a woman commander. There are plenty of stories floating about of nasty sexism in Soviet/Russian spaceflight, and they even chose to put it in some of their public relations videos. One case leapt out at me from the Soyuz TMA-11 near-disaster, discussed towards the end of this post. The Roscosmos general director at the time publicly blamed the fact that the vessel concerned had too many women onboard (one American, one South Korean), and said he'd work to prevent this from happening again. You don't joke about crap like that, but I suspect he wasn't kidding.

Because Soyuz has been around for so long, it's hard to discuss absolutely every flight and every crew. At the same time, one of its virtues has been how uneventful and routine most of its operations have become. I think the best way to celebrate this 50th anniversary is a simple visual history of some of the major Soyuz moments. Even condensed this way, it's still a lot.

1966-11-26 (no image available): Kosmos 133, the first uncrewed Soyuz test vehicle, launches. It malfunctioned in orbit and was intentionally destroyed before it could crash. Two further uncrewed test launches followed, both with serious systems failures.

1967-04-23: Soyuz 1 launches, with a single pilot, Vladimir Komarov. Space Race pressure had rushed a premature launch, and the flight was a complete disaster, with several technical failures forcing an early landing. But the parachute failed too, and Komarov simply fell straight from orbit to the ground, the first fatal spaceflight.
1968-10-30: Soyuz 3 lands safely, the first successful crewed Soyuz landing. Soyuz 3 had met up with the uncrewed Soyuz 2 in orbit, but failed to dock with it. Soyuz was the first Soviet spacecraft designed for orbital docking, so many of its early flights were focused around docking experiments.
1969-01-16: Soyuz 4 and Soyuz 5 dock in orbit, allowing the first crew transfer from one spacecraft to another, and therefore also the first time that cosmonauts had landed in a different vessel from the one they launched in. They had to spacewalk along the outside of the spacecraft to get from one to the other, as there was no internal hatch between the two yet.
1971-04-23: Soyuz 10 attempts to dock with Salyut 1, the first ever space station, but fails to completely do so. Then they had trouble getting completely loose from the station's docking equipment again, but eventually got home.
1971-06-30: Ground crews perform CPR on the already dead crew of Soyuz 11, shortly after it landed. Soyuz 11 successfully docked with Salyut 1, making it the first occupied space station in history. The crew of Georgy Dobrovolsky, Vladislav Volkov and Viktor Patsayev spent 22 successful days working on the station, but after they undocked Soyuz 11 to go home again, their spacecraft began to rapidly depressurize, asphyxiating the crew in seconds. They are the only humans to have died in space, and while there have been further Soyuz accidents, this was the last fatal one.

1974-07-03: Soyuz 14 launches, docking with the Salyut 3 space station, probably the only crewed spacecraft to be armed.

1975-01-12: Soyuz 17 docks with the Salyut 4 space station for a month. A little over 3 months later, Soyuz 18 docks with Salyut 4 (pictured), making it the first Salyut to receive more than one crew. They were followed in November that year by Soyuz 20, which I believe was the only conventional* Soyuz ever with a fully non-human crew: Tortoises and fruit flies were kept inside as part of a biology research project, while the Soyuz was given a long-duration (90 day) engineering test by remote control. Since the non-human animals never entered Salyut 4, it's a matter of precise definition whether they were its 3rd group of visitors or not.

(*By conventional, I mean the Earth-orbit crew ferry sort of Soyuz, normally used by human crews. In 1968 there were two variant Soyuzes of the Zond lunar program that also carried non-human animals. Zond 5 successfully carried tortoises, wine flies and meal worms around the Moon and safely landed back on Earth. Zond 6 also flew around the Moon with similar passengers, but on return to Earth, it suddenly depressurized, killing everything inside, and then also suffered a prachute failure. If Zond 6 hadn't failed, and if Apollo 8 hadn't beaten them to it, the next Soyuz 7K-L1 might have been allowed to launch humans around the Moon. There may have been animals on one or more Progresses too, but I haven't dug that up yet.)

1975-04-05: The crew of what is now officially only called Soyuz 7K-T #39, but also variously known as Soyuz 18a, Soyuz 18-1, or the 5 April Anomaly, and what had orginally been launched as Soyuz 18 (for a few minutes, anyway). Due to a mechanical failure and subsequent launch abort, just after it reached space, this accidentally became the only crewed suborbital Soyuz launch. The re-entry module landed on a snowy slope and rolled down it for a while, but the crew survived.

1975-07-17: Soyuz 19 and Apollo 18 dock in orbit, the first international spacecraft docking. They didn't do much up there, but their long-term influence has been enormous.
1976-07-07: Soyuz 21 becomes first spacecraft to dock with the Salyut 5 space station. Soyuz 23 failed to become second to dock there, and on landing accidentally became trapped under the ice of Lake Tengiz, the only crewed Soyuz water landing. It took 9 cold hours to safely get the crew out. Soyuz 24 later made the actual second (and final) successful docking with Salyut 5.
1977-12-11: Following the failure of Soyuz 25 to dock with Salyut 6, Soyuz 26 becomes first to dock with the new space station. In total, 17 Soyuzes successfully docked with Salyut 6, as well as one more failed docking by Soyuz 33. Soyuz T-4 (pictured) was the last to undock from the station, on 1981-05-26. Salyut 6 was the first space station to allow multiple simultaneous dockings, so that Progress supply ships could make deliveries to crews, and multiple crews could board the station at the same time, without having to leave the station unoccupied. This was first demonstrated when Soyuz 27 arrived a week before Soyuz 26 departed. Salyut 6 was also notable for beginning the Interkosmos program of various international guest cosmonauts joining the Soyuz/Salyut crews on a regular basis.
1982-05-15: Soyuz T-5 is first to dock with the Salyut 7 space station. In total, 10 Soyuz spacecraft successfully docked with Salyut 7, with only Soyuz T-8 failing to. Salyut 7 had fewer Soyuzes visit it than Salyut 6, but longer visits meant that Salyut 7 lasted for longer than its predecessor. Soyuz T-14 is pictured docked to it here.
1983-09-26: People watch the critical escape of what is now officially only called Soyuz 7K-ST #16L, but also variously known as Soyuz T-10a or Soyuz T-10-1, and what had been 90 seconds short of launching as the original Soyuz T-10. This Soyuz was the only case of its launch escape system saving a crew, when the launch rocket exploded underneath it. The crew were flung away and landed unharmed, and their spacecraft's orbital module was even recycled for use on Soyuz T-15.
1986-03-13: Soyuz T-15 launches (with its recycled orbital module) and becomes first to dock with the Mir space station. They then left Mir's lights on, flew the Soyuz to Salyut 7 to dock with it for the final time, stole a bunch of useful equipment for Mir, and then flew their Soyuz back to dock with Mir again. This makes Soyuz T-15 the only spacecraft so far to fly back and forth between different space stations.
Following Soyuz T-15, another 29 Soyuzes visited Mir. During the same period, three of the US shuttles made 9 dockings with Mir, the first international dockings since 1975's Soyuz-Apollo meeting. Soyuz TM-30 was the last to undock from Mir, on 2000-06-15. Lots of interesting things happened on Mir, but the fact that there's not much more to add about Soyuz specifically is an indication of how reliable and routine Soyuz operations had become by this point.
2000-11-02: Soyuz TM-31 is the first Soyuz to dock with the International Space Station, carrying the crew known as Expedition 1. Three US shuttles had preceded it since December 1998, making 5 dockings before Soyuz TM-31 arrived. However, that Soyuz visit marks the start of the station's continuous occupation (over 16 years without being empty once), as shuttle visits could only be a couple weeks long before returning to Earth, while Soyuz had been made suitable over the Salyut/Mir years to remain docked at the station for 6 or 7 months at a time.
Today, 2017-04-23, there are two Soyuzes docked at the ISS (Soyuz MS-03 and Soyuz MS-04), and their combined crews are its Expedition 51. The three US shuttles visited the ISS 37 times altogether, while 50 Soyuzes have so far docked there, along with a whole lot of different uncrewed cargo vessels. Since the shuttles retired in 2011, Soyuz has been the only way to get people to and from the ISS (apart from making a deal with China to use Tiangongs, maybe). In the next few years, Crew Dragons and Starliners are due to start bringing crews there too, and possibly also Federatsias.
One worrying but luckily never disastrous malfunction struck both early and late Soyuzes in similar ways during their re-entries. Soyuz 5, back in 1969, and then both Soyuz TMA-10 and Soyuz TMA-11 in 2007/2008, all had their service modules fail to separate from their re-entry modules (step 3 in the diagram), causing them to fall uncontrolled, with their heat shields facing the wrong way. Happily, in all three cases, the heat of re-entry was enough to melt through the last connections to the service module, breaking it free in time for the re-entry module to swing back around to face the correct direction, before the weaker top end of the re-entry module also melted through. Crews suffered injuries and landed well off target, but survived.
Several Soyuz replacements have been proposed over the years, but it looks like Russia is finally really going to switch to a new spacecraft. The larger Federatsia spacecraft is not expected to carry humans until 2024, at the earliest, leaving a four year gap after the last Soyuz lands. Federatsia won't launch on a Soyuz rocket (nor any member of the R-7 rocket family), and it will launch from the new Vostochny Cosmodrome in eastern Russia, rather than the Baikonur Cosmodrome in Kazakhstan that every crewed Soviet/Russian launch to date has started from, so it'll see a lot of changes beyond the spacecraft itself.
What strikes me in all of this is that Soyuz is almost never the hero of the story, especially when it's working properly. Early on, it's not really doing too much very groundbreaking, compared with the drama of the first few years of the Space Race, or the ostentatious Apollo Moon missions. Soyuz was originally conceived for Moon missions too, and then had that taken away. And later on, when Soyuz starts servicing space stations, the stations are most often the center of attention, not their little support craft. The little bit of limelight Soyuz has had since 2011 often comes from (or draws in) angry Americans, raging that they're now forced to hitch rides. They don't seem grateful that old Soyuz is still keeping things moving forwards. But that's the main accomplishment of Soyuz: In a series of tortoise-vs.-hare contests, it's been the sure and steady tortoise.