What's your favorite rocket engine?

[Grand Ship Builder]

21 hours ago, Geschosskopf said:

And thanks to @Grand Ship Builder for bringing this to my attention.  I'd never heard of it before.  Love aerospikes, though

You're welcome! 

 

 ARCA Aerospace is relatively unknown in the Aerospace industry, with giants like SpaceX getting lots of attention, so that's why you probably haven't heard of them before.

[Geschosskopf]

2 hours ago, Grand Ship Builder said:

 ARCA Aerospace is relatively unknown in the Aerospace industry, with giants like SpaceX getting lots of attention, so that's why you probably haven't heard of them before.

Well, it seems ARCA is no longer a thing.  The CEO, Dumitru Popescu, just got arrested upon his return to the States on charges of fraud, embezzlement, and forgery. 

http://www.lcsun-news.com/story/news/crime/2017/11/13/arca-ceo-dumitru-popescu-charged-fraud-embezzlement/859103001/

 

The question remains as to whether the whole project was a scam never intended to fly, or whether mistakes were made in pursuit of a legit project.  The company has been around for over a decade and made only 2 launches, plus a number of aborted projects.  EDIT:  They seem to have been involved with testing the ExoMars Schiaparelli landing stuff.  Given how that mission ended, ARCA came under scrutiny, although I don't see them mentioned in the ESA's post mortem.

Edited November 26, 2017 by Geschosskopf

[StrandedonEarth]

The F-1, of course, because, well....

[Grand Ship Builder]

35 minutes ago, Geschosskopf said:

Well, it seems ARCA is no longer a thing.  The CEO, Dumitru Popescu, just got arrested upon his return to the States on charges of fraud, embezzlement, and forgery. 

http://www.lcsun-news.com/story/news/crime/2017/11/13/arca-ceo-dumitru-popescu-charged-fraud-embezzlement/859103001/

 

The question remains as to whether the whole project was a scam never intended to fly, or whether mistakes were made in pursuit of a legit project.  The company has been around for over a decade and made only 2 launches, plus a number of aborted projects.  I think their major achievement is making the parachute for ESA's ExoMars mission, which is currently en route.

I think ARCA would still run. You could always get a new CEO and as far as we know, ARCA isn't like Mars One.

[Geschosskopf]

5 hours ago, Grand Ship Builder said:

I think ARCA would still run. You could always get a new CEO and as far as we know, ARCA isn't like Mars One.

I dunno.  There are apparently a fair number of folks who think ARCA scammed a lot of folks in Romania, fled to the US, and continued the same business model.  I managed to find an ARCA press release saying that work was continuing at the factory but they haven't updated their vlog in a long time so I really wonder.  Still, haven't found anything about the company's assets being seized or frozen, so we'll see.  However, things don't look good.

Edited November 26, 2017 by Geschosskopf

[UmbralRaptor]

RL10 because it's an underappreciated workhorse. High Isp, and used on upper stages on some version virtually all US launchers.

 

But HiPEP deserves an honorable mention. Double the Isp of VASIMR at equal or better energy efficiency, and bench tests ran for at least 1000 hours (vs maybe 15 seconds).

[DDE]

@Geschosskopf @Grand Ship Builder As some people point out, if it promises you hoverboards, it's probably gonna crash and burn.

And ARCA started as a hoverboard company.

[Geschosskopf]

57 minutes ago, DDE said:

@Geschosskopf @Grand Ship Builder As some people point out, if it promises you hoverboards, it's probably gonna crash and burn.

And ARCA started as a hoverboard company.

Actually, they started as a rocket company about 1999 and have done most of their speculative, inconclusive puttering about with rocket stuff ever since.  The hoverboard (for ~$15K, one could be yours!) was very recent in the company's sketchy history, like only 3 years ago.

That said, however, I definitely agree with your suspicions.  For being nearly 20 years old, ARCA has launched only 2 rockets, the results of which fell far short of pre-launch hype and neither of which used the technology they keep claiming they're really going to use in production versions.  They keep saying their production engines will burn kerolox or H2O2 + kerosene but AFAIK, the only engines they've ever started were either big model rocket solid engines or simple H2O2 decomposition "water rockets".  In fact, this aerospike engine they were supposedly going to launch this fall is/was also just an H2O2 decomposition "water rocket".  Spray 70% (not even 90%) H2O2 onto a catalyst inside the tailcone, then vent the resulting steam out venturis along the sides of the aerospike-looking tailcone.  The temperatures are so low that no special materials are required, which makes you wonder if the resulting steam pressure is enough get airborne, let alone validate the aerospike concept anyway.

Edited November 26, 2017 by Geschosskopf

[MaxwellsDemon]

On 10/31/2017 at 8:57 AM, Racescort666 said:

Kerosene engine: NK-33 all the way. 

I think it's fascinating that the NK-33 and NK-43 are still worthy of a serious look (the Antares AJ26 accident notwithstanding).   Don't know if I have a "favorite" rocket engine per se, but those and the J-2 impress/interest me.

Edited November 29, 2017 by MaxwellsDemon
doubled post

[T-10a]

One of my favourites is the RD-701. It's such a weird engine, it uses LH2/RP-1/LOX from ignition, and when it reaches space it switches to just pure LH2/LOX mode to circularise. Pity it never flew.

[DDE]

15 minutes ago, T-10a said:

One of my favourites is the RD-701. It's such a weird engine, it uses LH2/RP-1/LOX from ignition, and when it reaches space it switches to just pure LH2/LOX mode to circularise. Pity it never flew.

Apparently Energomash and KBKhA did a lot of work on other triprops. I even saw reference to an RD-0120 not-SSME being converted for triprop use - the 0120TD and the later the 0750.

[T-10a]

Interesting. I might try to make those two into configs for SSTU engines to model those for KSP antics, it's such a weird way of fuelling a rocket.

[DDE]

2 hours ago, T-10a said:

Interesting. I might try to make those two into configs for SSTU engines to model those for KSP antics, it's such a weird way of fuelling a rocket.

I actually thought whether it’d be possible to base that on whatever module the Rapier uses for its own resource switching.

The weirdness... if you played with Nertea’s hydrolox motors, you’d probably understand. Hydrogen tankage sizes are no joke.

[53miner53]

The RS-25. Because De Laval SSTO engine. 

[DDE]

4 hours ago, 53miner53 said:

The RS-25. Because De Laval SSTO engine. 

Falcon 9 called...

[Canopus]

6 minutes ago, DDE said:

Falcon 9 called...

The engines on the Falcon don‘t burn from ground to orbit and even though both stages use the same engines, they are optimised for high thrust on the first, and vacuum operation on the second stage.

[DDE]

12 hours ago, Canopus said:

The engines on the Falcon don‘t burn from ground to orbit and even though both stages use the same engines, they are optimised for high thrust on the first, and vacuum operation on the second stage.

Yet the first stage is SSTO-capable, albeit with meagre payload.

I’m not sure the same can be said about a booster-less Shuttle.

[Grand Ship Builder]

Update video on ARCA fraud allegations:

 

[ChrisSpace]

On 8 November 2017 at 9:18 AM, ChrisSpace said:

Chemical propulsion: Horridly low Isp.

Solid-Core Nuclear-, Solar- or Antimatter-thermal rocket, LANTR, Vapour-Core or Liquid-Core NTR: Isp is a bit low, but I like the idea.

Metallic Hydrogen, Antimatter Gas Core engine, high-TWR He3-D Fusion, Epstein Drive, Inertially confined Proton-Proton Fusion or Antimatter-Catalysed Microfission Hydrogen-Boron Fusion: High-thrust and High-Isp. My personal choices.

Gas-core, Plasma-core or detailed Beam-core Antimatter designs, Antimatter "Bottle" engine, Positron Ablative, Laser-thermal, Metastable Helium, Magnetoplasmadynamic, Pulsed Plasmoid, VASIMR, Colloid, Hall Effect, Ion, Arcjet, Microwave Electrothermal, Resistojet, Wakefield E-Beam, most types of Fusion, Closed-Cycle Gas Core NTR, Fission-fragment, Fission Sail, Antimatter-driven Sail, Mini-mag Orion, n-Li6 micro fission, PuFF, most types of Antimatter-Catalysed micro fission or micro fusion, Photon, Magnetic or Electric sail, Mass Driver or Photon Beam engine: TWR too low to lift off Earth, at least not with enough propellant to reach LEO with any payload.

Coaxial Gas Core NTR, Open-Cycle Gas Core NTR, NSWR, Nuclear Pulse Propulsion or Medusa: Throws radioactive death everywhere.

Also, here's some starting points for anyone who wants to learn more about these:

http://www.projectrho.com/public_html/rocket/enginelist.php