Gilmour Space Technologies

[ringsider]

First orbital launch delayed to 2022.

Based on what we have so far and the design switch, add several years to that.

[john smith 19]

RL are succesful because they stayed focus on getting to orbit and stayed course on their LV design. With reliable LV and solid customer base they can now afford to play around with more radical ideas eg reuse, even new engines and fuels.

Gilmour don't have this luxury they need fly ASAP with whatever well tested engine they have. Redesigns can come later when they have solid customer base. The small LV market well only support a few players and late comers well find it very difficult market to enter against proven LV providers.

Indeed.

An expendable launch vehicle is only as good as its reputation, which is as good as its launch history.

If payloads are about the same which one would you buy, the one with 12 successful launches or the one that's launched once?

That said there are  a lot of things any LV mfg company has to get right, or at least not get so wrong that they cannot recover from it. 

Propellant choice is a pretty fundamental design decision with knock on effects throughout the design. AFAIK all the successful players chose a set and stuck with them.

Time will tell if this is a brilliant pivot to a cheaper, more readily sourced propellant, an unwise diversion of resources which takes time to fix, or the beginning of the end. 

[CameronD]

Propellant choice is a pretty fundamental design decision with knock on effects throughout the design. AFAIK all the successful players chose a set and stuck with them.

Time will tell if this is a brilliant pivot to a cheaper, more readily sourced propellant, an unwise diversion of resources which takes time to fix, or the beginning of the end. 

Given this recent 'announcement':

Interview with Adam Gilmour.
..................
* Launch site for both vehicles is Whaler's Bay, here in South Australia.

which is a huge change from their original plan of launching in outback Queensland, perhaps the change is driven partly by whatever propellants might be readily available in SA?

After all, Gilmour Space are in the business of making rockets, not rocket fuel.

[Steven Pietrobon]

Interview with Adam Gilmour.
..................
* Launch site for both vehicles is Whaler's Bay, here in South Australia.

which is a huge change from their original plan of launching in outback Queensland, perhaps the change is driven partly by whatever propellants might be readily available in SA?

I don't think the decision has anything to do with the propellant. Most small satellites want to go into polar orbits, which is best done from Southern Launch's site here in SA.

[Steven Pietrobon]

Gilmour signed an MoU with the Australian Space Agency. Saying they did an engine test around 9 December. Channel 9 saying first launch in 2021, but I think that's for the first suborbital flight test. Currently have 45 employees. Would like to increase that to 80 in the next 1 to 1.5 years. Plan to have 50 engine tests in the next year.

https://twitter.com/9NewsGoldCoast/status/1204647109913243648

[Steven Pietrobon]

Christmas 2019 update. New information is that

* Moved into a new static test facility in December
* Teamed up with Titomic, Victoria in October to explore use of new 3D printed materials
* Team is now 45 strong
* Moved to a larger facility on the Gold Coast
* CEO Adam Gilmour won the 2019 Advance Award in Advanced Manufacturing
* Adam appointed to the Australian Space Agency's Space Industry Leaders Forum

[Comga]

I've had confirmation from Gilmour that they are changing to LOX. Here's a reply I sent to them explaining why I think this is a really bad idea.

Number 1 reason why changing from HTP to LOX is a bad idea.
*Schedule* Gilmour has a working motor that can do the job. Changing to a different propellant combination means a complete redesign of the motor along with all the required testing to make sure its working. That adds at least one year (and probably longer) to Gilmour's schedule. Listen to Elon Musk "If the schedule is long it's wrong, if it's tight it's right.”

(Snip)

This post deserves more than one “Like”
Clear, analytical, and quantitative. Even authoritative IMO
Such a minuscule performance improvement can’t be worth a fraction of cost in added time.
“Better is the enemy of Good”

[john smith 19]

This post deserves more than one “Like”
Clear, analytical, and quantitative. Even authoritative IMO
Such a minuscule performance improvement can’t be worth a fraction of cost in added time.
“Better is the enemy of Good”

There might be a couple of other reasons.

It's a rule of thumb in the rocket industry that propellant is a trivial part of the cost of launch. Musk said that filling the tanks on an F9 is about $120-150k. Not very much at all.

But how does that change (as a proportion of cost) when the LV shrinks?

I'm not sure but you've got a lot less structure wrapping a significant amount of a pretty expensive liquid.

I don't know if they buy in HTP or make it from commercial grade which would make a difference (you get into the equivalent question of "Separative Work Units" that you get in uranium enrichment in terms of costing)

The other option would be that their design is not running as well as they expected on HTP. But AFAIK they have said their engine tests have been successful.

Personally I'd say it's not worth the effort now they have got to test firing their engine. A working engine on the stand is worth two on the CAD screen.    Unless results were very poor I'd focus on building the vehicle and getting to a first (paying) launch customer.

Obviously they have decided to take the schedule hit and move to LOX instead. I'll wish them well and hope it works out for them. 

[Steven Pietrobon]

Assuming eight 70 kN motors at a lift-off thrust of 1.2g gives a vehicle mass of 47.6 t. Assume 90% of that is propellant and a mixture ratio of 7.1 oxidiser to fuel, gives a HTP mass of 37.5 t. This website lists 90% HTP for $400/t (24 t minimum order)

https://www.alibaba.com/product-detail/Hydrogen-Peroxide-H2O2-50-90-Best_1986377402.html?spm=a2700.7724857.normalList.12.327b7b1eRMY4pk&s=p

That gives a propellant cost of only $15,000, which would be 0.3% of a $5M launch price.

[john smith 19]

Assuming eight 70 kN motors at a lift-off thrust of 1.2g gives a vehicle mass of 47.6 t. Assume 90% of that is propellant and a mixture ratio of 7.1 oxidiser to fuel, gives a HTP mass of 37.5 t. This website lists 90% HTP for $400/t (24 t minimum order)

https://www.alibaba.com/product-detail/Hydrogen-Peroxide-H2O2-50-90-Best_1986377402.html?spm=a2700.7724857.normalList.12.327b7b1eRMY4pk&s=p

That gives a propellant cost of only $15,000, which would be 0.3% of a $5M launch price.

Still less than 1/2of 1%.

And a possible improvement of 1% in performance by switching to LOX.

I know margins on small LV's are tight but Gilmour knew this from day one.

It seems an odd time to make such a fundamental change. One other idea occurs to me, but it seems a very long shot.

Are they getting their engine from another company?

That would mean all the engineering problems are sorted already and they just have to drop it in, maintaining their schedule.  I have heard no reference to them using a third party engine and that would worsen the economics, unless what they save on the cost of HTP is so great they can afford to buy in a LOX engine.

While almost anything is possible this does not sound plausible.

There design decision baffles me. 

[Steven Pietrobon]

Are they getting their engine from another company?

I don't believe so. One of the advantages of their hybrid technology using 3D printed ABS plastic fuel was very good combustion stability. I'm pretty sure they would like to continue that technology with LOX, although there might be a risk in switching from HTP due to the very different mixture ratios (7.1 for HTP compared to 2.6 for LOX). Also, who would they buy the motor from?

There design decision baffles me. 

You're not the only one. Here's their Advisory Board:

Pamela Melroy (former NASA astronaut)
Dava Newman (former NASA deputy administrator)
Rick Baker (co-founder of Blackbird Ventures)
Martin Duursma (partner of Main Sequence Ventures)

So we have two people with a heavy NASA background and two people with a heavy venture capital funding background, but not in aerospace. Well, maybe its not so surprising that decisions that cost more and take longer to do are being made!

[john smith 19]

You're not the only one. Here's their Advisory Board:

Pamela Melroy (former NASA astronaut)
Dava Newman (former NASA deputy administrator)
Rick Baker (co-founder of Blackbird Ventures)
Martin Duursma (partner of Main Sequence Ventures)

So we have two people with a heavy NASA background and two people with a heavy venture capital funding background, but not in aerospace. Well, maybe its not so surprising that decisions that cost more and take longer to do are being made!

So reassuring to people who don't know anything about space launch. For people who do, not so much

Melroy was Director of Field Operations for the FAA Office of Commercial Space Transportation, which would seem quite relevant.

Trouble is they don't seem to have any experience of start ups and what you can (and can't) do on an available (constrained) budget. 

BTW my LOX price from memory was $0.16/lb. That gives $352/tonne. IE it's about 12% cheaper (HTP prices seem to have come way  down since I last checked them, which is good).  That's about an $1800 saving per launch.

That doesn't sound like it's worth the engineer time, stand time or fabrication time to switch to LOX and get it working, or to afford to buy in a new engine.

Still baffled.

[edzieba]

Beyond raw oxidiser costs, there's also supply and handling.
LOX is - while not a household good - a readily available product in very large volumes with plenty of off-the-shelf handling equipment, skilled staff who know how to handle it, and regulatory backing to handling procedures.
HTP - especially if you're in the 99%/99.9% range desired for long-term stability rather than the 'garden variety' 90% - is not quite so standard. Handling equipment is available but bespoke, experience with handling it in bulk is rather rare, provision is more complex than "just ring up one of the many producers who would be able to ship it same day", and local officials are more likely to yell "you want to move a hundred tons of what?!". Peroxide may not be the demon it's often made out to be, but it's still no joke.

These are the sorts of things that don't really crop up during initial prototyping, but start becoming obvious when you call up a supplier and get "you want how many tons? We don't have the facilities to produce that in a year! And you want to ship it where?!".

[ringsider]

Beyond raw oxidiser costs, there's also supply and handling.
LOX is - while not a household good - a readily available product in very large volumes with plenty of off-the-shelf handling equipment, skilled staff who know how to handle it, and regulatory backing to handling procedures.
HTP - especially if you're in the 99%/99.9% range desired for long-term stability rather than the 'garden variety' 90% - is not quite so standard. Handling equipment is available but bespoke, experience with handling it in bulk is rather rare, provision is more complex than "just ring up one of the many producers who would be able to ship it same day", and local officials are more likely to yell "you want to move a hundred tons of what?!". Peroxide may not be the demon it's often made out to be, but it's still no joke.

These are the sorts of things that don't really crop up during initial prototyping, but start becoming obvious when you call up a supplier and get "you want how many tons? We don't have the facilities to produce that in a year! And you want to ship it where?!".

Agreed.

Also the high purity and concentration HTP used in aerospace applications (i.e. without stabilizer additives) can be very difficult to work with. There are some very good reason why LOX is preferable.

This paper from Solvay outlines some of the difficulties of getting it in large quantities and handling it safely if you do:-

http://www.student.montefiore.ulg.ac.be/~teney/h2o2propulsion/The%2520safe%2520supply%2520and%2520handling%2520of%2520HTP.doc

HTP is dangerous stuff if/when you get it wrong.

[Steven Pietrobon]

HTP is dangerous stuff if/when you get it wrong.

LOX is equally as dangerous if you get it wrong.

[john smith 19]

HTP is dangerous stuff if/when you get it wrong.

LOX is equally as dangerous if you get it wrong.

Wow.

My first reaction was this was a really well done spoof in the style of these sorts of films.

Of course in fact it's the real deal. Complete with the sort of consequences you can only show in these sorts of films. And the consequences are very serious.

I recall John Carnack saying he'd dipped his unprotected finger in HTP and got tiny "Oxygen blisters" but that was all. I'm sure he'd never try that with any other common (or not so common) oxidizer.

[Steven Pietrobon]

Also, who would they buy the motor from?

Ursa Major?

Their website only has liquid engines.

https://www.ursamajortechnologies.com/engines

[john smith 19]

Also, who would they buy the motor from?

Ursa Major?

Their website only has liquid engines.

https://www.ursamajortechnologies.com/engines

TBH I've never really understood the benefits of ox rich over fuel rich stage combustion or vice versa.

Both put the oxidizer and fuel on either side of a interpropellant seal while raising one of them to a very high temperature.  In both cases that seal absolutely, positively must not fail. I think it's debatable wheather a LOX/hot fuel rich gas or a fuel/hot ox rich gas is a more difficult design problem.

Once you realize what a massive PITA that seal (and its purging) are you realize if you're going to do SC anyway the only logical way is to go full flow, with separate fuel and ox rich preburners to design out the problem.

That would be quite radical and potentially a quite nice enabler of RLV designs, as long as they didn't make any foolish design choices (like ablative cooling for the chamber or nozzle. Fine for weapon systems, not so good for any other environments).

[edzieba]

Also, who would they buy the motor from?

Ursa Major?

Their website only has liquid engines.

https://www.ursamajortechnologies.com/engines

TBH I've never really understood the benefits of ox rich over fuel rich stage combustion or vice versa.

The seal is a red herring.
Fuel rich = extreme coking issues with hydrocarbon fuels. Oxidiser rich = materials challenges with hot oxidisng environment.
For RP-1 (and hypergolics), the coking is so bad that fuel-rich is basically ruled out, making oxidiser-rich the way to go for anything other than Hydrolox even with the materials challenge.

[john smith 19]

The seal is a red herring.
Fuel rich = extreme coking issues with hydrocarbon fuels. Oxidiser rich = materials challenges with hot oxidisng environment.
For RP-1 (and hypergolics), the coking is so bad that fuel-rich is basically ruled out, making oxidiser-rich the way to go for anything other than Hydrolox even with the materials challenge.

As usual it depends on your assumptions. Using Methane as the HC fuel substantially reduces the coking issues, OTOH if you you want to reuse the engine the seal is very far from a red herring. It was a major PITA for SSME. Failure to meet leakage specs in the original design added a 270lb GHe tank to the engine pack (to hold 30lb of GHe) to deal with the increased seal leakage.

That's something you'd want to avoid in a reusable engine.