Firefly Space : Company and Development General Thread

[novak]

Alpha uses LOX/RP-1, but I'm not seeing any frost on the rocket, unlike Electron.

Not going to look like that at launch, will be white with ice, see real launches of Electron.

You seem very confident but stage testing videos of the Firefly Alpha S2 do not generally support this statement.  One carbon composite structure is not necessarily like another.

First =/= second stage. For the second stage theres a clear need to keep the LOX well-insulated for long duration coast (which Firefly apparently plans, but Rocket Lab ditched in favor of a more easily restarted third stage). For the first stage, performance losses to boiloff are negligible, that insulation would just be a waste of dry mass and labor.

There were some older Alpha renders (in the aerospike era IIRC) even showing the second stage painted white for thermal control, while the booster remained black

While the facts cited above are generally correct the conclusion does not necessarily follow.  Composite structures are often highly insulative in and of themselves, and can easily have this kind of behavior without any additional insulation.  Besides, that kind of ice build up is a waste of dry mass. 

Either way hopefully we'll see soon enough what stage 1 looks like chilled in.

Not as soon as I'd hoped but now we've seen.  Composites have a lot of interesting features and challenges.  Very different from metallic structures, and may also be very different from each other.

[Gliderflyer]

Alpha uses LOX/RP-1, but I'm not seeing any frost on the rocket, unlike Electron.

Well you can see the LOX tank from the condensation making that tank slightly darker compared the RP-1 tank,

On a side note:
I've seen a paper a while back I think on researchgate which was about a CFRP tank wrapped in a printed honeycomb cylinder with facesheets. Honeycomb can be impregnated with an insulating gel or foam.

I asked them on twitter a while back, their tanks use sandwich construction. So they probably some form of honeycomb or foam core with composite skins on each side.

It's nice because, in addition to the insulation, you can tailor the composite properties; LOX compatibility for the inside, strength and temperature resistance for the outside. Also makes the structure pretty stiff.

https://twitter.com/Firefly_Space/status/1181287187339300864

[john smith 19]

I asked them on twitter a while back, their tanks use sandwich construction. So they probably some form of honeycomb or foam core with composite skins on each side.

It's nice because, in addition to the insulation, you can tailor the composite properties; LOX compatibility for the inside, strength and temperature resistance for the outside. Also makes the structure pretty stiff.

https://twitter.com/Firefly_Space/status/1181287187339300864

Interesting. Obviously honeycomb construction has always been an option but AFAIK only LM with the X33 every actually tried to use it.

As you note it gives you additional axes of design freedom with being able to choose (potentially) different materials for inner, honeycomb and outer facesheets, as well as their thickness.

The tank end caps are still going to be quite tricky.

[HMXHMX]

I asked them on twitter a while back, their tanks use sandwich construction. So they probably some form of honeycomb or foam core with composite skins on each side.

It's nice because, in addition to the insulation, you can tailor the composite properties; LOX compatibility for the inside, strength and temperature resistance for the outside. Also makes the structure pretty stiff.

https://twitter.com/Firefly_Space/status/1181287187339300864

Interesting. Obviously honeycomb construction has always been an option but AFAIK only LM with the X33 every actually tried to use it.

As you note it gives you additional axes of design freedom with being able to choose (potentially) different materials for inner, honeycomb and outer facesheets, as well as their thickness.

The tank end caps are still going to be quite tricky.

We used it at Rotary on the Jet A fuel tank and I got Scaled to quote a honeycomb-cored composite tank for QuickReach (for the DARPA-AirLaunch FALCON program) but that program ended before we could implement it.

(Edit: added a photo of the Rotary Roton fuel tank fabrication.)

[john smith 19]

We used it at Rotary on the Jet A fuel tank and I got Scaled to quote a honeycomb-cored composite tank for QuickReach (for the DARPA-AirLaunch FALCON program) but that program ended before we could implement it.

(Edit: added a photo of the Rotary Roton fuel tank fabrication.)

I did not know that. I don't have any sort of feel for relative cost in this area. Skin-and-core sounds expensive. How do you wrap a honeycomb around a relatively low radius? The easiest way I can figure to use this sort of construction is actually foam core. That seemed a lot more forgiving, but I'm not sure the property increases you get are worth the mass and complexity. 

Did you use the design freedom of using different thickness skins on inside and outsider?

[russianhalo117]

We used it at Rotary on the Jet A fuel tank and I got Scaled to quote a honeycomb-cored composite tank for QuickReach (for the DARPA-AirLaunch FALCON program) but that program ended before we could implement it.

(Edit: added a photo of the Rotary Roton fuel tank fabrication.)

I did not know that. I don't have any sort of feel for relative cost in this area. Skin-and-core sounds expensive. How do you wrap a honeycomb around a relatively low radius? The easiest way I can figure to use this sort of construction is actually foam core. That seemed a lot more forgiving, but I'm not sure the property increases you get are worth the mass and complexity. 

Did you use the design freedom of using different thickness skins on inside and outsider?

easiest way these days per research is to 3D print the honeycomb onto either the tank itself or a face sheet. Some satellite manufacturers a toying with this concept. Can do hexa, iso, ortho and other grids via this method.

Firefly uses honeycomb for the entire length of both stages. Benefits densified propellants as well.

[HMXHMX]

We used it at Rotary on the Jet A fuel tank and I got Scaled to quote a honeycomb-cored composite tank for QuickReach (for the DARPA-AirLaunch FALCON program) but that program ended before we could implement it.

(Edit: added a photo of the Rotary Roton fuel tank fabrication.)

I did not know that. I don't have any sort of feel for relative cost in this area. Skin-and-core sounds expensive. How do you wrap a honeycomb around a relatively low radius? The easiest way I can figure to use this sort of construction is actually foam core. That seemed a lot more forgiving, but I'm not sure the property increases you get are worth the mass and complexity. 

Did you use the design freedom of using different thickness skins on inside and outsider?

We used foam on the LOX tank and Nomex core on the fuel tank, and definitely did use differing densities of core materials as well as skin thickness.  The typical cost was about $150/lbm of finished structure using the hand layup prototyping techniques that were available to us – but that was over 20 years ago, and some things are cheaper to do and some things more expensive these days.

[john smith 19]

We used foam on the LOX tank and Nomex core on the fuel tank, and definitely did use differing densities of core materials as well as skin thickness.  The typical cost was about $150/lbm of finished structure using the hand layup prototyping techniques that were available to us – but that was over 20 years ago, and some things are cheaper to do and some things more expensive these days.

Interesting. That's about $253K/t

I don't think people often appreciate that some approaches that would be rejected now were quite a bit cheaper then because of the availability of people with the needed skillsets from other industries employing those techniques.

Not everything becomes cheaper over time. Does anyone still make Boron fiber?

[Phillipsturtles]

Apparently there was a fire at SLC-2 today: https://twitter.com/DavidNagySFgang/status/1316911786298363904

And everything is ok now: https://twitter.com/DavidNagySFgang/status/1316918021177430016

[woods170]

Apparently there was a fire at SLC-2 today: https://twitter.com/DavidNagySFgang/status/1316911786298363904

SLC-2 West is the location of the old Delta II launchpad. The fire broke out in the Mobile Service Tower while demolition was taking place. There is lot of history associated with that MST.

The MST began life as a modified, 1950s jack-up type, mobile oil drilling rig (!) to create a mobile service tower for the Little Joe II rocket at White Sands Missile Range, New Mexico.

Yes, you read that correctly. The SLC-2 West MST originally was constructed at White Sands. And it was a modified oil drilling rig.

It was relocated to Vandenberg AFB in the early 1970s, where it was mounted on a rail system. A new truss structure was added underneath to raise the top to the required height for Delta 3000 series rockets. Extensive external bracing and cladding were added, as well as several fixed platforms. Larger guy cables for the bridge crane were added as well as a much larger counterweight.

The MST was modified again in the 1990s when Delta switched to Delta II. The entire MST was jacked up several meters and once again a new truss structure was added underneath.

The overall result of this is that the SLC-2 West MST was a  momumental kludge of a construction. And a nightmare to maintain. But it worked beautifully.

[edzieba]

Not everything becomes cheaper over time. Does anyone still make Boron fiber?

Yes, generally combined with Carbon fibre into a hybrid composite.

[FutureSpaceTourist]

https://twitter.com/firefly_space/status/1317140215002255361

Please see the below statement regarding the fire which occurred yesterday at Launch Complex 2 at Vandenberg Air Force Base.

[ParabolicSnark]

That fire on SLC-2 is going to be a pile of paperwork for them to handle. I'm wondering if that's going to cause launch permitting issues if Vandenberg doesn't think Firefly is following proper protocol/diligence throughout all their activities.

[russianhalo117]

That fire on SLC-2 is going to be a pile of paperwork for them to handle. I'm wondering if that's going to cause launch permitting issues if Vandenberg doesn't think Firefly is following proper protocol/diligence throughout all their activities.

Do you read bro??
It is an unaffiliated contractor not hired by Firefly. Like CCAFS, VAFB oversees such activities. In the SLC-2 facilities turnover agreement managed by VAFB Firefly did not want to assume responsibility for costly legacy hardware it did not need since it was going to a clean pad design. ULA worked with VAFB to remove their retired DII structures for Firefly. Schedules for all parties are coordinated in advance.

[AirmanPika]

I was literally passing by there the same day at lunch time (12ish?). They have been breaking down the towers for a while now (the fixed tower is gone as of Oct 2 or earlier). I can't see the fire having any impact on the launch facilities since they are so far apart. The mobile tower could collapse and still have zero impact.

Pics from same day but before fire.

[AirmanPika]

So I drove by today...too foggy to take a pic but honestly you wouldn't know there was a fire on the tower without being told. Of course since it's getting taken down anyway its kinda silly one would care.

[FutureSpaceTourist]

Firefly Aerospace Announces New Customer Agreements, Completes Stage 1 Acceptance Testing Ahead of First Alpha Launch

NEWS PROVIDED BY
Firefly Aerospace, Inc.
Oct 20, 2020, 09:20 ET
     
CEDAR PARK, Texas, Oct. 20, 2020 /PRNewswire/ -- Firefly Aerospace, Inc., a leading provider of economical and dependable launch vehicles, spacecraft, and in-space services, today announced the successful acceptance test of the first stage of its Alpha launch vehicle for its inaugural flight later this year, and the execution of new customer agreements.

Firefly has signed a Launch Services Agreement (LSA) with Spire Global (Spire) for the launch of Lemur spacecraft on the Alpha launch vehicle. The LSA will provide for the launch of Spire spacecraft on multiple Alpha missions over the contract period. Firefly has also executed an LSA with Geometric Space Corporation for the full payload capacity of an Alpha launch vehicle.

Robert Sproles, Senior Director, Constellation Planning and Operations at Spire said, "The addition of Firefly Alpha to the Spire launch program further diversifies options to populate and replenish our world leading nanosatellite constellation. We are looking forward to flying many successful missions with Firefly."

Samuel Reid, CEO of Geometric Space Corporation said, "With a 1,000 kg payload capacity to low Earth orbit, Firefly Alpha provides a unique capability in the small launch vehicle market.  Geometric Space looks forward to working in conjunction with Firefly and our customers to provide an integrated launch experience on Alpha."

In addition to the customer agreements, Firefly also provided information on recently achieved Alpha milestones.  The Alpha Flight 1 Stage 1 performed a 35 second static fire, including a full suite of thrust vector control maneuvers. Subsequently, a 15 second final trim test was performed, and the stage will now ship to Firefly's launch complex at Vandenberg Air Force Base (VAFB).

Concurrently, the Alpha Flight 1 payload fairing successfully completed a separation test. The payload fairing separation system was designed and manufactured by Firefly. The system is operationally recyclable, allowing for multiple tests of the flight unit.

Firefly is also nearing completion of its Launch Control Center, Integration Hangar, and launch pad, including assembly of the Transporter Erector Launcher (TEL) at historic Space Launch Complex 2 West (SLC-2W) at VAFB. Firefly's TEL, built by Firefly's design and fabrication teams in Texas and California, is being integrated and will soon commence ground system activation.

"The successful first stage acceptance testing is the latest in a series of hardware, facilities and test milestones occurring weekly as we approach the inaugural Alpha launch later this year," said Dr. Tom Markusic, Firefly Aerospace CEO. "Our continued technical successes correspond to increasing confidence and demand from our customers. We welcome Spire and Geometric Space to the Firefly customer family and look forward to delivering their payloads on Alpha, the most capable and economical small launch vehicle on the market."

The Alpha launch vehicle, which stands 95 feet tall with the capability to deliver 1 metric ton to Low Earth Orbit (LEO) and 630 kilograms to Sun Synchronous Orbit (SSO), is designed to fulfill the needs of the burgeoning small satellite market. Combining the highest payload performance with the lowest cost per kilogram to orbit in its class, Alpha provides launch options for both full vehicle and rideshare missions.

"Our Alpha launch vehicle fills a major market gap with its ability to deliver four times the current maximum payload of other small satellite launch vehicles. This successful stage 1 test, combined with previous successful stage 2 testing, fully validates the design and manufacture of the Alpha launch vehicle and positions Firefly as the future leader in the one metric ton small launcher class." Markusic added. "I had the good fortune to participate in the development of SpaceX Falcon 1 and Falcon 9, over a decade ago.  The current version of Alpha, along with our planned block upgrade to 1,300 kg to LEO, returns long-needed Falcon 1 class mission options to the smallsat market."

https://www.prnewswire.com/news-releases/firefly-aerospace-announces-new-customer-agreements-completes-stage-1-acceptance-testing-ahead-of-first-alpha-launch-301155360.html

[TrevorMonty]

They are planning on upgrade from 1000kg-1300kg. This maybe switch to 5 engine booster or extract more power from existing Reavers.
With 5th engine they have option of using it for rentry burn and do mid air recovery, also extra performance can help offset recovery losses. End result is 1000kg RLV or 1300kg ELV.

[moddedLimes]

We used it at Rotary on the Jet A fuel tank and I got Scaled to quote a honeycomb-cored composite tank for QuickReach (for the DARPA-AirLaunch FALCON program) but that program ended before we could implement it.

(Edit: added a photo of the Rotary Roton fuel tank fabrication.)

I did not know that. I don't have any sort of feel for relative cost in this area. Skin-and-core sounds expensive. How do you wrap a honeycomb around a relatively low radius? The easiest way I can figure to use this sort of construction is actually foam core. That seemed a lot more forgiving, but I'm not sure the property increases you get are worth the mass and complexity. 

Did you use the design freedom of using different thickness skins on inside and outsider?

We used foam on the LOX tank and Nomex core on the fuel tank, and definitely did use differing densities of core materials as well as skin thickness.  The typical cost was about $150/lbm of finished structure using the hand layup prototyping techniques that were available to us – but that was over 20 years ago, and some things are cheaper to do and some things more expensive these days.

looks like there is a new article up from composites world at least from this tweet https://twitter.com/CompositesWrld/status/1318567874701778946?s=19

https://www.compositesworld.com/articles/the-alpha-launch-vehicle-designing-performance-in-cost-out

[JEF_300]

I didn't see anyone else point this out, but they've updated the page on their site talking about Firefly Beta: https://firefly.com/launch-beta/

Firefly Beta is an evolutionary design based on Firefly Alpha technology. Beta is a 2-stage launch vehicle capable of delivering 8,000 kg to a 200 km (125 mile) Low Earth Orbit and has the capability of achieving Geosynchronous Transfer Orbits. The Beta vehicle utilizes technologies such as all carbon composite tanks, heritage LOx/RP-1 liquid fueled engines and builds on other elements of the existing Alpha architecture. Firefly Beta will have lowest cost per kg to orbit of all launch vehicles in the 8,000 kg and under class.

Propulsion: Stage 1
ENGINE
5X Reaver 2
PROPELLANT
LOX/RP-1
PROPELLANT FEED
Turbopump
COMBUSTORS
5
THRUST (VAC)
4,261 kN 957,910 lbf
ISP (VAC)
334 sec

Propulsion: Stage 2
ENGINE
1x Reaver 1 Vac
PROPELLANT
LOX/RP-1
PROPELLANT FEED
Turbopump
COMBUSTORS
1
THRUST (VAC)
194 kN 43,613 lbf
ISP (VAC)
325 sec

Dimensions
STAGE 1 DIAMETER
3.7 m 12 ft
STAGE 2 DIAMETER
3.7 m 12 ft
PAYLOAD FAIRING DIAMETER
4.7 m 15.3 ft
OVERALL LENGTH
46.7 m 151.8 ft

It looks like they've decided to build a new engine themselves rather than using the AR1. Otherwise, it's generally what you'd expect.

Edit: Of note, the fairing has a diameter of 4.7m, which should be plenty big enough to fit a Cygnus or vehicle of equivalent size.

Edit Again: Also, that Reaver 2 engine will have a thrust of (4,261/5=) ~852 kN, so it's fairly similar to the modern Merlin. But they claim a vacuum isp of 334, which is around 20s better than the Merlin. That's a significant enough increase in isp to suggest to me that it may be a staged combustion engine.