Radian Aerospace

[StrandedonEarth]

Zooming  out from  under the radar comes Radian Aerospace, working the HTOL angle. No mention of power plants, perhaps they’re using SABRE tech?  (Or is it RAPIER, I get those mixed up…)

 

[Beccab]

26 minutes ago, StrandedonEarth said:

Zooming  out from  under the radar comes Radian Aerospace, working the HTOL angle. No mention of power plants, perhaps they’re using SABRE tech?  (Or is it RAPIER, I get those mixed up…)

 

 

[JoeSchmuckatelli]

Why is the guy from Duluth standing next to the rocket? 

 

[Scotius]

Very ambitious goal for a brand new startup.

I wish them well, but I will withhold enthusiasm until they show some real, reasonable hardware.

[wumpus]

Kerolox SSTO.  No it isn't a scam, they have tweets and everything!

[StrandedonEarth]

8 minutes ago, wumpus said:

Kerolox SSTO.  No it isn't a scam, they have tweets and everything!

The only thing going for it is the rocket-sled-assisted takeoff. Then maybe if they take off from Denver, that’s another minor boost. Then they just have to hitch it to Santa’s reindeer…

[JoeSchmuckatelli]

12 minutes ago, StrandedonEarth said:

Then they just have to hitch it to Santa’s reindeer…

The pattern is open for the next several months... so why not?

[StrandedonEarth]

Naturally, someone is already measuring it for a coffin…

Wouldn’t be a surprising ending 

[JoeSchmuckatelli]

Gary Hudson? 

[AtomicTech]

Nan- Nani!?

It's not supposed to be possible!

I've recently fallen hopelessly in love with the X-33, so I'm really excited to see where this company goes!

Fingers crossed that this goes somewhere...

Edited January 20, 2022 by AtomicTech

[wumpus]

On 1/19/2022 at 2:08 PM, StrandedonEarth said:

The only thing going for it is the rocket-sled-assisted takeoff. Then maybe if they take off from Denver, that’s another minor boost. Then they just have to hitch it to Santa’s reindeer…

It is an interesting concept and allows for some other possibilities.  Adding SCRAMJETS might put it in the realm of physically possible, and a rocket sled takeoff might make it feasible to light such things.  The Pratt &  Witney SJX61 engine might not exactly be "off the shelf", but it does have a designation, official testing, and they might be willing to sell more.  Slightly more likely than hitching to reindeer, but not much.

[Shpaget]

Many have promised SSTO, none have delivered.

[Beccab]

On 1/20/2022 at 9:33 PM, JoeSchmuckatelli said:

Gary Hudson? 

The Rotary Rocket guy

[ZenAtWork]

I can't believe it never occurred to us before! Just FLY to space! Boy I bet NASA's faces are red! Just imagine! All we'd need is a rocket powered sled that can sustain around 30 G's for a few hundred km, and we're right there! Duh! How could have overlooked this for so long!?

Whats that you say? "It liquify the passengers?" I'm sure the worked that out.

"Rocket equation?" Ah, but it's a rocket SLED!  
 

"No atmosphere to generate lift past a certain point?" Psssh! They just have launch of the EDGE of the earth! Plenty of space to get up to speed!

Why, I bet men this smart will someday walk on the sun!

Edited February 5, 2022 by ZenAtWork
Typo corrections

[sevenperforce]

Radian has an update:

Wow! They have finally gotten enough capital to pay for a NEW RENDER!

[Shpaget]

Specifications

CREW 2-5

UPMASS up to 2,270 kg

DOWNMASS up to 4,540 kg

 

PAYLOAD BAY DIMENSIONS

LENGTH 5.2 m

WIDTH 3.8 m (fwd) 5.6 m (aft)

HEIGHT 2.7 m (fwd) 4.0 m (aft)

VOLUME ~93 m3

*SPECIFICATIONS SUBJECT TO CHANGE

 

Yeah, $5 they'll change.

 

Anyway, 90 on demand capability, but "Deliver anything under 2270 kg  anywhere on Earth in under an hour".

Edited April 2, 2024 by Shpaget

[AckSed]

Haven't heard of these people. It does seem similar to proposals I've read in the old sci.space.* USENET archives. And Gary Hudson made me prick my ears up. Ridiculous as it might seem, the Roton could have worked, its payload just couldn't grow beyond what the customer wanted, and, already on a shoestring, they ran out of money. The story of the rise and fall is told in USENET posts by the man himself: https://yarchive.net/space/launchers/roton.html

Quote

From: [email protected] (GCHudson)
Newsgroups: sci.space.policy
Subject: Re: Rotary Rocket: what happened?
Date: 30 Jun 2000 15:21:13 GMT

*snip*

The essence of building a commercial space transportation company is finance,
not engineering.  The basic mission remained largely unchanged, even if there
were technical alterations.  Fail to acommodate to your customer's/investor's
wishes and you absolutely won't succeed, either in finding funding (which we
did pretty well, but even so not well enough) or finding launches.  You'll end
up with a technically pure venture which will go nowhere.  Or like NASA, doing
mostly technology sandbox stuff.

I'm assuming he was contracted to design the engine, not to advise on the business. Back to the spaceplane.

Thing is, the key metric of any SSTO is propellant mass fraction, or 'how much is fuel, versus how much is structure?' You want structure to be a low fraction and fuel to be particularly high. If you have a spaceplane and use 'wet wings' for the kerosene, the thinking goes, then the 'dead' weight of the wings becomes part of the fuel tanks and the mass penalty of having them is offset enough to have a workable mass-fraction. You also want a combination of dense propellants and relatively high ISP. Kerelox is perfectly servicable in this regard.

Small launchers are particularly sensitive to mass; I recall Peter Beck saying Electron's mission to launch CAPSTONE was so near the limits of what it could do that the mass of which NASA logo sticker to use was significant. The larger you get the more mass your structure gains, but tank mass grows at a lower rate than tank volume... which increases your propellant mass fraction. This is the hope and dream behind every oversized reusable SSTO dreamed up since before the space program began.

Do I think they have an engineering case? There's a flicker of hope there, but they need to be eagle-eyed to any mass increase. a business case? Much less confident yet.

[Minmus Taster]

2 and a half tons to orbit for something this large? Yeah I'm not so sure about this. Still a very cool idea.

[AckSed]

Found the missive; it's on how in NASA's 1993 Access to Space initiative, one working group concentrated on a hydrolox SSTO with wet wings.

All hardware and structure and avionics and all that being equivalent, a kerelox vertical-takeoff, horizontal landing SSTO would have been a whopping 35% lighter, even with bulky, heavy NK-33 and RD-58 Russian engines: https://yarchive.net/space/rocket/fuels/hydrogen_deltav.html

(Mitchell Burnside Clapp was one of the founders of Pioneer Rocketplane with Robert Zubrin... which also ran out of funding. 70s through to early 2000s, "US private space pioneer" was a byword for 'losing your shirt'. :-/ )

The why is interesting. For one, the structures (tank and pressurisation systems) are much simpler, more mature and need less pressure overall. For another, because you have dense propellants and lower ISP: you burn them faster and have more thrust; you grow lighter near the end of your ascent; you end up accelerating faster; and you need slightly less delta-V to reach their reference 51-degree ISS orbit. It's not much - 8,870 m/s versus 9,135 m/s - but if making a SSTO rocketplane, you take what you can get.

Their improved kerelox plane was essentially the same proportions as the Boeing RASV: https://www.secretprojects.co.uk/threads/usaf-nasa-rlv-programs-from-the-past-amsci-science-dawn-have-region-etc.315/

We know a bit more about winglets these days, so lacking a central rudder might not be a deal-breaker.

Can sled launch make HT work? I don't know. Consensus is that it grants about 100-500 m/s to the initial takeoff, but the shallower ascent wipes out that advantage.

[Exoscientist]

  Former Air Force officer Livingston Holder is the chief technology officer and co-founder of Radian Aerospace. He gave a lecture on the design of their spaceplane here:

Livingston Holder, Radian Aerospace - It’s Good to Know How Things Work | Iteration22
https://m.youtube.com/watch?v=exeZnrQt8YE

I enjoyed the lecture. He discusses why their sled-launched spaceplane is technically and financially feasible.

 However, the horizontal launch method they propose has the disadvantage of needing heavy wings to support the fully-fueled weight of the spaceplane. In contrast a vertical launch method would use wings that only had to support the dry mass of the craft on return, resulting in much lighter wing weight. I advise Radian to do the trades to find which is the optimal method.

Additionally, I advise they base the core of their vehicle on existing upper stages to save on development costs and technical risk. I discuss using the Falcon 9 upper stage or Centaur upper stage for the purpose here:

Radian Aerospace Spaceplane.
https://exoscientist.blogspot.com/2024/05/radian-aerospace-spaceplane.html

  Robert Clark

[Ultimate Steve]

Steel manning the math. We know they're using kerolox, so I'll assume 360s, which is about what staged combustion kerolox can do in a vacuum, far higher than what their all altitude engine is likely to manage.

They are using a rocket sled for takeoff, from the renders it appears that the sled itself is rocket powered (stretching the definition of single stage imo). Let's assume they can get to mach 1 on the ground (the current land speed record) without major problems, and subtract 340m/s from the Delta-V to orbit.

Total Delta-V to orbit will be variable based on launch site, drag, TWR, and more. The lowest credible number I can find is 8600m/s. That makes our total 8260m/s. An SSTO would run into far more drag than the average rocket.

And let's assume zero for the de-orbit burn.

Adding this all up, you need a mass ratio of about 10.4. The X-33 prototype managed about 3.8, although it was never intended to be orbital. Starship, probably the most capable vehicle actually flying, is theoretically 13, although we don't know how heavy the current one is. Those numbers are without payload.

While it's definitely not impossible for a spaceplane with a crew compartment, payload bay, payload, landing gear, heat shielding, and wings to reach a mass ratio of 10.4, I am definitely skeptical that they can pull it off. And that's like the best case scenario number.

More realistically you're going to be getting 340s and needing 8800m/s or so, although I'd argue that's still optimistic. That puts you up to a mass ratio of 14.

Not impossible, but for a brand new company, with so much else needing to go on the vehicle, I will believe it when I see it, although I hope it will happen!

Kinda wish someone would look at a shcramjet (not scramjet, shcramjet) based SSTO.

Edited May 3, 2024 by Ultimate Steve

[AckSed]

RE: Kerelox ISP: Launcher/Vast's E-2 engine has reached 365s, 9.9 metric tons of thrust, and over three minutes of burntime on the test stand (and has a blue flame). Given the relative size and thrust, this seems like a replacement for the similar RD-58. If they needed an Orbital Manoeuvring Engine to shape up an orbit after their high-thrust engines cut out, that'd be a safe buy.

[Shpaget]

3 hours ago, Ultimate Steve said:

Let's assume they can get to mach 1 on the ground (the current land speed record) without major problems, and subtract 340m/s from the Delta-V to orbit.

Not saying that this is ever going to achieve that much, but the record is Mach 8,5 for rocket sled.

https://www.af.mil/News/Article-Display/Article/139307/test-sets-world-land-speed-record/

 

[AckSed]

It seems Radian is still plugging away at its spaceplane, except now it's methalox and has a 'wet wing' for the LOX, with the heatshield providing some of the structural stiffness. You may be flashing back to Venture Star's composite tanks, but these days there are much better composites and automated fibre-winding for tanks. Here's the slides from their FISO presentation: https://fiso.spiritastro.net/telecon/Holder_7-10-24/Holder_7-10-24.pdf

Side note: of course the United States Air Force is in on this.

[Nuke]

having fixed launch infrastructure requirement invalidates most of the reasoning for doing a space plane in the first place.

i had kind of hoped for a skylon derivative suborbital spaceplane that can loft a second stage out of the atmosphere and fast enough such that the spaceplane can re-enter without a difficult to service heat shield. think of it as a winged falcon/falcon heavy/superheavy or a stratolaunch that goes higher and faster. engines would be a sabre derivative on hydrolox. id do away with payload bay for a piggyback config. aerodynamic design on that may be difficult, especially in the hypersonic regime, but it could save significant weight. separation would occur above the karman line.

staging configs could be a 2-stage fully reusable config with a lifting body orbiter, for crew/light cargo. or a 2 stage disposable rocket for heavy lift to leo. or a 3-stage disposable rocket for geo and interplanetary payloads. would compete with falcon/falcon heavy but would benefit from being able to launch/land to any orbit from any properly equipped runway, thus saving significantly on infrastructure costs. flight profile would allow for powered takeoff and landing, even allowing use of civilian runways provided you can get hydrolox trucked to the airport.