Countdown to new smallsat launchers

[Robotbeat]

Meh, there's also gasoline, propylene, ethylene, ethane, propane, and methane to name a few. I wouldn't limit it to just kerosene. I like that Vector is doing propylene (or was last time I checked). Higher Isp than RP-1, but much better density than methane.

[Robotbeat]

Y'all realize that the R7 rocket family, which is BY FAR the world's most launched rocket (with 3 different launch sites) with over 1800 launches uses peroxide for the turbopumps, right?

Peroxide isn't that hard to get and isn't that hard to train people for. Same with LOx.

R7 was designed for and operated by Red Army. Like torpedoes have had no problems burning peroxide either. Note that there are launch vehicles burning UDMH as well in more than one place, also hence apparently not that hard to get and train for.

Somewhat different constraints and rules for a new entrant trying to operate under modern regulatory environment and commercial supply chain.

And yet R7 continues to be operated and even recently expanded to use be the Europeans at their South American launch site.

Peroxide is not nearly as toxic as hydrazine. People literally gargle 3% hydrogen peroxide. A reputable company can buy it by the ton, and lower grade stuff isn't actually THAT hard to get nowadays.

Please, stop with the peroxide hyperbole. There ain't no such thing as a "nice" oxidizer, but peroxide is easily one of the nicest 3.

[Katana]

Meh, there's also gasoline, propylene, ethylene, ethane, propane, and methane to name a few. I wouldn't limit it to just kerosene. I like that Vector is doing propylene (or was last time I checked). Higher Isp than RP-1, but much better density than methane.

Apart from isp and density, propellants have more  properties:

Mix ratio, boiling temperature/ vapor pressure, critical temperature and pressure, thermal stability (decomposition, polymerize, coke and corrosion), and so on. Those properties may affect cooling , pumping , pressurization, and ground equipment design.

Choose existing combinations allows scaling of historical engines , while new combinations need more time and cost to trial and error for unique pitfalls.

From the system design perspective, "don't reinvent the wheel", or "premature optimization is the root of all evil".

[Robotbeat]

Of course Isp and density aren't the only options. Kerosene has problems with coking, for instance. And it leaves a residue. And it can't autogenously pressurize, either.

But if you're building a new rocket with new engines, you ARE essentially reinventing the wheel already. So you might as well try do do a better job. And the flip side of "don't reinvent the wheel" is, if you're not doing anything different, how the heck do you propose to outcompete everyone else?

It's not actually THAT hard to use a new propellant combo. Garvey Space (now Vector) did even flight tests with propylene, and they had like no money. I actually think the "heritage" for using kerosene isn't actually very helpful unless you're using a heritage engine.

Using a new propellant combo makes more sense than doing something hokey like an aerospike, IMHO.

[Robotbeat]

It's worth noting that XCOR has tested rocket engines with kerosene, methane, isopropyl alcohol, and hydrogen as fuels. Each has its advantage.

Alcohol is a really good choice for reusable suborbital stuff since thermally it allows you to keep the chamber so cool you can make the thing out of aluminum which is cheap, very lightweight, and easy to work with. The V2 used ethyl alcohol as fuel, as did the first Redstone rocket.

Might be good as a reusable first stage for a small sat launcher, too.

[Danderman]

Just for kicks, which New Space Launch companies are using hydrogen peroxide as an oxidizer, and which are using high performance solids?

[Robotbeat]

copenhagen Suborbital used peroxide for their gas generator on their turbopump.

[Robotbeat]

Just for kicks, which New Space Launch companies are using hydrogen peroxide as an oxidizer, and which are using high performance solids?

The first post of this thread has this answer.

Lin Industrial
Tranquility Aerospace
Nammo
SpaceLS

...all plan peroxide.

[Robotbeat]

By the way, the first post incorrectly states that Garvey (GSC, now Vector Space Systems) will use kerolox. They definitely are using Propylene/LOx. They've tested engines already and have flown a small rocket using propylene, too.

[Gliderflyer]

It's worth noting that XCOR has tested rocket engines with kerosene, methane, isopropyl alcohol, and hydrogen as fuels.

We have also used nitrous oxide (as an oxidizer), ethane, propane, and a proprietary storable bipropellant combination. Personally, I am a fan of kerosene and LOX. Both are easy to get and easy to handle. I also think that kerosene coking issues are exaggerated. We have used it in reusable engines for years without issue.

[Robotbeat]

Nice informative reply!

Hope you're still making progress on Lynx after your contractor screwed up. Very neat vehicle, and it'd be cool to see it used for nanosat launch (especially if you ever can fly Lynx uncrewed...).

[HMXHMX]

It's worth noting that XCOR has tested rocket engines with kerosene, methane, isopropyl alcohol, and hydrogen as fuels.

We have also used nitrous oxide (as an oxidizer), ethane, propane, and a proprietary storable bipropellant combination. Personally, I am a fan of kerosene and LOX. Both are easy to get and easy to handle. I also think that kerosene coking issues are exaggerated. We have used it in reusable engines for years without issue.

Presumably you've been operating at the same o/f point we did at Rotary, about 2.7.  That dramatically lowered the coking problem.  But my biggest coking concern would be for gas generators which need to operate fuel-rich to lower gas outlet temperatures.  If there is a reuse issue, that's where it will appear.

[Robotbeat]

...hmmm... So for a turbopump running on peroxide (like R7/Soyuz) or an electric turbopump like Rocketlabs, coming isn't much of a problem. (Though those two are no reusing their rockets).

(And I'm calling an electric turbopump an electric turbopump, because a pump can still be turbomachinery even if it doesn't extract energy with a turbine... And the Latin word turbo means vortex or whirlwind... I.e. Spinny fluid thing, so yeah, I say it's an electric turbopump).

[Steven Pietrobon]

Just for kicks, which New Space Launch companies are using hydrogen peroxide as an oxidizer, and which are using high performance solids?

Gilmour Space Technologies here in Australia is using a hybrid motor with HTP.

https://www.facebook.com/gstpropulsion/?fref=nf

[john smith 19]

But if you're building a new rocket with new engines, you ARE essentially reinventing the wheel already. So you might as well try do do a better job. And the flip side of "don't reinvent the wheel" is, if you're not doing anything different, how the heck do you propose to outcompete everyone else?

What a very good question.

[john smith 19]

Just for kicks, which New Space Launch companies are using hydrogen peroxide as an oxidizer, and which are using high performance solids?

Gilmour Space Technologies here in Australia is using a hybrid motor with HTP.

https://www.facebook.com/gstpropulsion/?fref=nf

All solid designs have made orbit (Scout was pretty impressive on this score) and I've always wondered with better build methods and fuels if HTP or LOX could match the Isp of a fully solid stage.

[Steven Pietrobon]

All solid designs have made orbit (Scout was pretty impressive on this score) and I've always wondered with better build methods and fuels if HTP or LOX could match the Isp of a fully solid stage.

Generally, LOX/RP-1 and HTP/RP-1 have better Isp than solids. However, only HTP/RP-1 has a better impulse density than solids. See my paper "High density liquid rocket boosters for the Space Shuttle".

http://www.sworld.com.au/steven/pub/lrb.pdf

[john smith 19]

Generally, LOX/RP-1 and HTP/RP-1 have better Isp than solids. However, only HTP/RP-1 has a better impulse density than solids. See my paper "High density liquid rocket boosters for the Space Shuttle".

http://www.sworld.com.au/steven/pub/lrb.pdf

I was posing the question in reference to the HTP Hybrid you mentioned Gilmour are working on.
I recall AMROC felt they had a good shot at making orbit with a TSTO hybrid but that was with LOX. HTP sidesteps the issues with cryogenics and offers a pump drive medium as well as the possibility of a composite casing. 

All good but IIRC their Isp was 10s of secs below solids.

As a side interest I've always wondered if a modern hybrid design (LOX or HTP) could the Shuttle SRB Isp without the safety issues.  IIRC NASA said they could by switching to something like candle wax whose surface vaporized better, but I've no idea what happened to it.

[Katana]

But if you're building a new rocket with new engines, you ARE essentially reinventing the wheel already. So you might as well try do do a better job. And the flip side of "don't reinvent the wheel" is, if you're not doing anything different, how the heck do you propose to outcompete everyone else?

What a very good question.

And the common incentive of failed exotic rockets before SpaceX ?

[Katana]

Generally, LOX/RP-1 and HTP/RP-1 have better Isp than solids. However, only HTP/RP-1 has a better impulse density than solids. See my paper "High density liquid rocket boosters for the Space Shuttle".

http://www.sworld.com.au/steven/pub/lrb.pdf

I was posing the question in reference to the HTP Hybrid you mentioned Gilmour are working on.
I recall AMROC felt they had a good shot at making orbit with a TSTO hybrid but that was with LOX. HTP sidesteps the issues with cryogenics and offers a pump drive medium as well as the possibility of a composite casing. 

All good but IIRC their Isp was 10s of secs below solids.

As a side interest I've always wondered if a modern hybrid design (LOX or HTP) could the Shuttle SRB Isp without the safety issues.  IIRC NASA said they could by switching to something like candle wax whose surface vaporized better, but I've no idea what happened to it.

Compare it to the struggle of SpaceShip2.