Wow- anyone catch today’s launch failure out of Baikonur? I love how the press is liberally using words like “ballistic “ and “breakup” to spice up the story. Seems like the launch abort system worked exactly as designed and the crew were in comparitavely little danger. (Of fourse, there’s always a danger in spaceflight). The Soyuz’s record is pretty stout considering how long it’s been flying.
I saw that! I know these things happen in spaceflight, but I thought it was pretty shocking. I'm just glad they made it out okay.
I'd heard about it but hadn't quite understood when the failure occurred. Found a video that captures it: This starts with them boarding the spacecraft and then into the launch with some gaps. Advance to 3:41 to the point in flight just before the escape tower jettisons the capsule. So it was only 2 minutes after launch that a booster error occurred, sending the craft off course. The video shows some breakup in the transmission but it looks like the occupants of the capsule were getting buffeted around (not sure if part of that was the escape tower in action or a rough ride from the faulty booster). Such a great demonstration of the fail-safe mechanism doing its job. What's a little unnerving is the timing. The narration was following a timed script. "Escape tower jettisoned" would have meant the escape tower was no longer on top of the rocket. And that means the capsule would no longer have any means of escape. So it sounds like the escape tower was ignited in less than 30 seconds prior to the detection of trouble. I mean just think of it... if they jettisoned the escape tower and THEN detected the booster problem... they'd be in mortal danger.
Fascinating. Thanks for the video link, @Asbo Zaprudder. Had no idea about the Soyuz launch abort system and it's an interesting design, especially with the dual sets of rockets (tower and shroud).
Wonder what their thinking was with the seperate orbit and descent modules verus the American Command modules which performed both functions and allowed for a simpler escape system.
Probably more about specialization and fuel types. For descent, the imperative for the Soviets was to avoid toxic fuels, in case of ingress into the cabin. So the descent module uses a peroxide based fuel. The only trouble with that, is the fuel has a shorter lifespan. If you wait too long, you end up with water and oxygen that is no longer useful. I prefer the philosophy of making a better capsule with a cabin that is perfectly insulated from the fuel system. It works very well. There was only one case of ingress, which was on an older design. And it created only a momentary issue for the human occupants.
Soviet designs are usually overdesigned, heavy and built to be maintained by simple tools, there's a story about an Aeroflot aircraft being delayed, the pilot told the passengers there was a fan blade at the front of the engine which was a little crooked, in the west this means the aircraft will be sent to maintenance and you need another aircraft to haul the passengers, not in the USSR, a mechanic walked towards the engine which, climbed into the engine housing, found the crooked blade and whacked it back into shape with a large hammer, he hopped out of the engine, gave a thumbs up and walked off, the pilot then started that engine, gave it full throttle for a few seconds, seemed to be pleased and just flew off without a hitch.. I think this accident was a fluke, there have been so many of them used over there years and only a few incidents, I think it is doing quite well..
A small reentry module minimises the mass required for heat shielding and the parachute system. The orbital module can be relatively large as it doesn't have to reenter so the total habitable volume of 7.5 cubic metres is larger than the Apollo command module's 6.2 cubic metres. The total mass of the Soyuz reentry and orbital modules is 4.3 tonnes compared to the 5.8 tonne mass of the Apollo command module so the service module has less mass that it needs to accelerate during orbital manoeuvres.
Possibly, but they have had some quality control issues of late. The failures of Proton have almost cancelled it. They flew fewer Proton launch vehicles this year, their commercial workhorse, than any time since the mid 60's. Their designs are sound and they can no doubt figure what caused it and put in methods to prevent it. The very good thing is, no one was killed and the abort sequence worked. The bad thing is, at some point the remaining three crew aboard ISS are going to have to come down, and if Soyuz is significantly delayed the station will have to be abandoned for the first time in almost 2 decades, which would be a shame. Dragon and Starliner aren't quite ready to handle crew rotation duties yet. This probably could not have happened at worse time.
Apollo had the same system of service, descent and specialist modules, it's just that the latter was stowed in the S-IVB adapter for retrieval in orbit (and of course Soyuz has only ever flown with the OM, whereas Apollo had the docking module rather than the LM on ASTP, with other alternatives proposed for Apollo-X before that became Skylab). A General Electric RFP for Apollo had an orbit module launched on top of the CM, as per Soyuz. http://www.astronautix.com/a/apollod-2.html
umm not quite. The U.S descent module was the LEM used for moon landings and the Command Module was used for launch and re-entry. The Soyuz descent module is used to return the crew to Earth. https://en.wikipedia.org/wiki/Soyuz_(spacecraft)#Descent_module
Whether you call it a descent module or a command module, the middle bit is the one with a heat shield and parachutes that carries a crew.
The LEM is a separate spacecraft and has no bearing on Apollo CM/SM stack. It just came up for the ride on the same Saturn V. It could have been brought up seperately in a 2 launch system. It wasn't used on all the Apollo flights, it wasn't used on any of the Skylab or ASTP flights LEM is not a "Descent module" it's a single stage to lunar orbit vehicle and lander. There really isn't any equivalent to the LEM as nothing like it has been built since.
yeah I did some further reading and realized I got confused over the Russian naming and methodology. thought they travelled up seated in the orbital module and transferred to the descent module for the return.
From what I've heard descent module is really crowded. they had to expand it a little bit when they started ISS flights as the restrictions on cosmonaut candidate size were smaller then than they were for ESA, JAXA and NASA. The also have custom seat liners tailored to each person going up and back. When you transfer from one Soyuz to the next you take your seat liner with you. Be funny if airlines did that (oh god, I just gave them an idea)
An early Soyuz kit made the same mistake, putting crew couches in the OM. There was a Soviet analogue to the LEM, the LK, but it never carried a crew (there were couple of automated solo test flights in Earth orbit in the early 70s): a full size version was in the Cosmonautics exhibition at the London science museum a few years ago.
looks like the problem was caused by a sensor failure that led to further issues resulting in the abort. There are a few more soyuz rocket flights upcoming, and with the cause identified, that might lead to crewed Soyuz launch in December, which in turn will keep ISS from running without a crew in early 2019.