Super-Strypi/SPARK/LEONIDAS first flight-4th November

[Streetwind]

Right then, since the Super Strypi is unfortunately deceased, let's go a little off topic... (and I'll focus largely on US launches here)

Space Launch Report is a great website that tallies up launch successes and failures of almost every orbital and suborbital rocket. Both by year, and in one comprehensive all-time launch report that gives some useful data on what actually happened in the 50's. Vehicles that flew at the time were, for example, the Atlas-Mercury, which achieved a combined 7 successes in 10 tries across suborbital and orbital launches between 1957 and 1963. The Atlas booster itself, in its primary role as an ICBM, reported a similar average 73% reliability over 247 launches from 1957 to 1975. The Jupiter rockets flew 42 times from 1957 to 1962 and realized a 70% success rate as well... you can find data on many other legacy rockets.

(Disclaimer: the all-time report is only updated once a year and as such doesn't have any of this year's launches factored in yet.)

Meanwhile in the present, the Falcon 9 flew successfully 18 times before the failure; that makes it 94% reliable across all the missions it has flown so far. (Or 89%, if you want to define the loss of a secondary payload as a mission failure, despite the primary mission succeeding... and the fact that the secondary payload could have been saved if the primary customer had authorized a requested upper stage engine restart.) The Atlas V realized 58 successes out of 59 attempts, 49 of which are consecutive (and counting). The Delta II only failed twice in 153 launches, and holds the world record for successful consecutive launches with 98 and counting (though it's not guaranteed that it will launch again). The Delta 4 has a perfect 100% success rate in its medium configuration, and just one single failure in its heavy configuration.

Doesn't quite sound like the 50's after all, now does it?

That the Antares failed, well, the writing on the wall was there. Not only was everyone well aware that these engines were half a century old and stored in less than optimal conditions, but Orbital also had an engine blow up in the test stand half a year prior to the failure for what turned out to be the exact same thing that killed the Antares. Orbital gambled with 60's-era technology and lost. It was very good 60's era technology, sure, and the chance to lose wasn't that big. But ultimately there is a noticable difference between then and today, machines age, and sometimes Murphy's Law comes knocking on the door.

On the Russian side, the Progress vehicle that failed rode on the new Soyuz 2-1a booster that only flew five times in total before that incident. The Soyuz-U booster it used before (and uses again now) has a 97% reliability rating over 770+ flights. The human-rated Soyuz variant that carries ISS crews has a 100% success rate.

Proton, on that one I'll agree with you. It used to be quite reliable, but there were significant internal problems at Krunichev in the last couple years, and the vehicle suffered greatly from it.

Hope that adequately supports my standpoint in this discussion

Edited November 4, 2015 by Streetwind

[Red Iron Crown]

^^ Don't forget Vanguard, which flew in the '50s as well and failed 8 times out of 11 launches. We still get failures now, but it's not like the '50s at all.

[DunaRocketeer]

I stand corrected

[lajoswinkler]

I bet the stream wasn't advertised a lot because the team presumed the chances of this happening were pretty decent. It's a passively controlled (spin and aerodynamics) glorified amateur rocket, really. Kind of like trying to reinvent a wheel.

[Streetwind]

They knew it was likely going to fail because the motor was flawed, not because it had no active controls.

Besides, isn't relying on a known and proven control scheme the literal opposite of "trying to reinvent the wheel"?

[Kryten]

Of course, last time somebody tried to fly a spin-stabilised orbital LV it took four failures and as many years before they could get out to work. Seems the technique doesn't easily scale.

[lajoswinkler]

They knew it was likely going to fail because the motor was flawed, not because it had no active controls.

Besides, isn't relying on a known and proven control scheme the literal opposite of "trying to reinvent the wheel"?

This is not really something best used outside small sounding rockets and amateur rockets. Super Strypi is too fat.

[PB666]

https://directory.eoportal.org/web/eoportal/satellite-missions/o/ors-4

Should've had more struts...............Or something.

Edited November 5, 2015 by PB666

[Streetwind]

For additional info, check the existing thread here on the forums: http://forum.kerbalspaceprogram.com/threads/137804

[PB666]

merge pls

[Vanamonde]

Merged.

[Kryten]

An article on lessons learned from the Super Strypi failure has been published, including preliminary results from the failure investigation (P. 13). 

Quote

Spin stabilization worked as designed from initial rail launcher separation through maximum dynamic pressure and at least one significant wind shear.  Roll rate was nominal through the first 47 seconds, except for initial spin-up nearly twice as fast as expected through the first 10 seconds of flight then returned to as predicted.  However, spin stabilization also doomed the mission as the first stage motor proved insufficiently robust.  In summary, use of spin stabilization in the Super Strypi design is unproven and ability to successfully implement on future launches is beyond current analysis capabilities.  Any future launches will require a design change to the first stage motor and possibly to second and third stage motors.   
[...]The most likely cause of the launch vehicle anomaly was breach of the first stage motor case due to slag build up in the aft end of the first stage motor from vehicle rotation leading to increased insulation erosion. 

Edited August 9, 2016 by Kryten