Radian Crewed SSO Spaceplane

[Ronsmytheiii]

From Businessweek’s Mark Harris

https://twitter.com/meharris/status/1333451938189361160?s=21

Basic points:

Radian just closed $20 million series A
Developing rocket-sled launched SSTO five person spaceplane
Uses kerolox engines, have already conducted a firing near Seattle
Edit: Radian estimates cost per seat $5 million initially


Story is linked, but paywalled: https://www.businessinsider.com/space-startup-radian-seeks-funding-for-catapult-based-spaceplane-2020-11

[FutureSpaceTourist]

https://twitter.com/robotbeat/status/1333460655664472066

More info on Radian Aerospace (Gary Hudson of Rotary Rocket and DC-X is involved). The patent discussed in the article: patents.google.com/patent/US20200…

twitter.com/meharris/statu…

Patent attached

[Eerie]

OK, kerolox SSTO rocket plane. Fuel ratio of 95%.

Was there some material science breakthrough? Can you build spaceships of hard light?

[FutureSpaceTourist]

From Businessweek’s Mark Harris

twitter.com/meharris/status/1333451938189361160

Basic points:

Radian just closed $20 million series A
Developing catapult launched SSTO five person spaceplane
Uses kerolox engines, have already conducted a firing near Seattle

More points:

Radian Aerospace believes its so-far-unnamed spaceplane could reach orbit as soon as 2025
Radian hopes to be launching on a daily basis by 2031, serving commercial and government customers
"It will take about $450 million to get to our first flight."

[Ronsmytheiii]

OK, kerolox SSTO rocket plane. Fuel ratio of 95%.

Was there some material science breakthrough? Can you build spaceships of hard light?

I mistakenly called it a catapult, but it is actually a "rocket sled" that is initiallly used to bring it up to speed before launch. so perhaps not a strict SSTO?

[Eerie]

OK, kerolox SSTO rocket plane. Fuel ratio of 95%.

Was there some material science breakthrough? Can you build spaceships of hard light?

I mistakenly called it a catapult, but it is actually a "rocket sled" that is initiallly used to bring it up to speed before launch. so perhaps not a strict SSTO?

The sled brings it to plane take-off speed. So nothing, basically.

[Markstark]

Hope they succeed!

[Eerie]

Hope they succeed!

Well, they stand a better chance than Spinlaunch.

[freddo411]

SSTO with Kero/LOX?   With wings and landing gear and a heat shield?

I will criticize others when they say something is impossible (because there are many things that are possible that haven't been built yet).    But I'm very, very confident when i say:

This is not going to happen.

[Craftyatom]

Patent attached

A few notable details I gleaned from a quick skim through the patent:
The Launch Sled
-Acts as a TEL, with propellant feed lines and physical supports attached to the vehicle
-Has its own engines, which fire in addition to the vehicle's engines
-May feed propellant into the vehicle to replace that burned by the vehicle's engines during the takeoff run (quick disconnect before takeoff)
-May rotate the vehicle from an initial low-drag configuration to a nose-up takeoff configuration
-Has a braking system that can bring the whole vehicle to a halt in case of emergency (the takeoff run is one long engine checkout)
-Provides some initial velocity, but more importantly, reduces the demands on (and thus mass of) the landing gear, since the vehicle is only on its gear when its tanks are empty for landing
The Vehicle
-Designed for crew and low-mass cargo, "about 5-10000 pounds to LEO" (2.3-4.5 mT), claims the F9 is overpowered for these applications
-Fuel is JET-A, oxidizer is LOX
-Main engines have a "Tripped Area Ratio"/"Tripped Flow", which changes from about 33:1 to about 60:1 in-flight, allowing good sea-level and vacuum performance (no details on how exactly this would be implemented)
-Separate set of OMS engines above the main engines, potentially pressure-fed LOX/CNG gas-gas thrusters (I know who might be developing one of those)
-In addition to the shuttle's abort modes (ATO, AOA, Downrange, and RTLS), the entire cabin can detach and perform a powered abort (picture attached), using "bipropellant thrusters" and fuel tanks in the nose, plus chutes for recovery.  Intact abort modes would require venting fuel before landing due to the low-rated gear.
-Material selection hasn't been made yet, but short-lists composites, Aluminum, Titanium, and Stainless Steel.  Heat shield material also not selected yet, but TUFROC given as example.

Opinions: the sled QD will be a huge pain, the crew cabin will be overweight, and the materials really need to be narrowed down before the design solidifies.  That said, I think (without having modeled anything yet) that their mass to orbit numbers aren't impossible, as long as you consider the crew section (the nose of the plane and its abort systems) a part of that mass, and assume that their tripped flow engine works out.

[ZChris13]

"Tripped area ratio" sounds like a dual bell nozzle to me.

SSTO with Kero/LOX?   With wings and landing gear and a heat shield?

I will criticize others when they say something is impossible (because there are many things that are possible that haven't been built yet).    But I'm very, very confident when i say:

This is not going to happen.

It's easier to get higher mass ratios with denser propellants, at least this has a better chance of happening than any hydrogen SSTO.

[libra]

OK, kerolox SSTO rocket plane. Fuel ratio of 95%.

Was there some material science breakthrough? Can you build spaceships of hard light?

I mistakenly called it a catapult, but it is actually a "rocket sled" that is initiallly used to bring it up to speed before launch. so perhaps not a strict SSTO?

The sled brings it to plane take-off speed. So nothing, basically.

All time record for kerolox specific impulse: must be RD-0124, 362 seconds - in vaccuum.

All time record propellant mass fraction: 0.962 - Titan 2 stage 1. Expendable, zero payload without a second stage.

The margins are razor slim or non existing.

Hey, looks like our very own HMXHMX is part of this !

[Zed_Noir]

They should pay royalties to the Gerry Anderson estate. This concept looks like the Fireball XL5 rocketship down to the rocket powered sled and capsule miniship that separates from the rest of the airframe.   

[john smith 19]

OK, kerolox SSTO rocket plane. Fuel ratio of 95%.

Was there some material science breakthrough? Can you build spaceships of hard light?

I mistakenly called it a catapult, but it is actually a "rocket sled" that is initiallly used to bring it up to speed before launch. so perhaps not a strict SSTO?

It's essentially the kerolox version of the Boeing RASV concept without a high pressure staged combustion LH2 engine and for many of the same reasons. 

That patent is the USPTO "Anything that is not patented is patentable (and let the lawyers sort it out)" approach so disliked by other countries. It could be this. It could be that. It could be the other. Blah blah. Vehicle has "stuff" on board which does "things."  Oh really. My mind is blown by the depth of such concepts.

Anyone who's read the RASV docs from NASA (they are here on another thread) will recognize the likenesses.

What baffles me is why they stayed with RP1.
Assisted SSTO (the technical term for this approach)  is so marginal why wouldn't you go for something better than RP1? Sure LH2 makes people twitchy but it's definitely no longer the only other game in town. You're already handling LOX, why not go Methane or better Propyne?

[Gliderflyer]

Face-shutoff pintle with pure film cooling. Interesting choice given those are not known for their efficiency. Chamber shouldn't have much fatigue issues though.

https://patents.google.com/patent/WO2020010098A1/

[john smith 19]

All time record for kerolox specific impulse: must be RD-0124, 362 seconds - in vaccuum.

All time record propellant mass fraction: 0.962 - Titan 2 stage 1. Expendable, zero payload without a second stage.

The margins are razor slim or non existing.

And of course a winged vehicle will not get anywhere close to that.  Check the Virgin Global Challenger. That had a structural mass fraction of something like 25%.

Hey, looks like our very own HMXHMX is part of this !

Which suggests this might not be entirely hopeless.

RASV's takeoff speed was higher than Skylon's.  . While that's  about 2.25% of total orbital velocity (less depending on how much you add on for losses) it's the delta v that is the most expensive in fuel burn to get

Secondly it's already going at an angle, not vertically, which is the direction you want it in to lower ascent losses.

Thirdly those wings (despite their mass) absorb many of those ascent losses, "neutralizing" mass while allowing the engines to focus on accelerating the vehicle.

Is this enough to get the job done? IDK. But it'll be fun watching what happens.

You're right about the margins though. Although it's "not quite" SSTO the usual design rules apply. Every mass unit counts. The landing gear is a real biggie. Likewise the OMS/RCS/internal power (they are fluids. It is a vehicle. This does not make it an IVF system) can benefit from being combined in some ways. 

[matthewkantar]

SSTO with Kero/LOX?   With wings and landing gear and a heat shield?

I will criticize others when they say something is impossible (because there are many things that are possible that haven't been built yet).    But I'm very, very confident when i say:

This is not going to happen.

My bold, PLUS a separable structural cabin that has engines, propellant and chutes!

[john smith 19]

Face-shutoff pintle with pure film cooling. Interesting choice given those are not known for their efficiency. Chamber shouldn't have much fatigue issues though.

Isn't the pintle the only design that supposed to never had an issue with combustion instability? Attractive if you want a hassle free, quick to develop (and quite easily throttled) engine I imagine.

You're point about efficiency does make it an odd choice to include in a patent. With mass growth and efficiency so critical in this application you'd expect them to go for the best they can find.

[Gliderflyer]

Face-shutoff pintle with pure film cooling. Interesting choice given those are not known for their efficiency. Chamber shouldn't have much fatigue issues though.

Isn't the pintle the only design that supposed to never had an issue with combustion instability? Attractive if you want a hassle free, quick to develop (and quite easily throttled) engine I imagine.

You're point about efficiency does make it an odd choice to include in a patent. With mass growth and efficiency so critical in this application you'd expect them to go for the best they can find.

I've heard that about pintles before, but never from someone who worked on one (they tend to laugh at that). Face-shutoff is also annoying to get working from what I've heard, but I think Gary has done it before so he may have a head start.

Film cooling is the strangest choice to me. Armadillo did a similar cooling method, and the Isp hit was large.

[Asteroza]

I think it was HMXHMX who previously stated if he tried again, he would run with a dense propellant like propane or propyne. I think he also said he wanted to do tripropellant as well to adjust fuel density for flight regime. With these guys also exploring 3D printed engines, there way be some additional trickery involved there. The mention of an advanced carbon fiber LOx tank may suggest linerless to reduce weight?