Radian announces plans to build one of the holy grails of spaceflight

"We all understand how difficult this is."

Read the whole story

 

[Statistical]

I can't see the market demand for this concept. What am I missing?

There would be a huge market for routine, low-cost access to space on such a vehicle. The story mentions this toward the end, but we are headed toward an era of more commerce and human activity in LEO. As but one example, being able to bring back 10,000 pounds of microgravity manufactured materials probably would close the business case for companies thinking about space manufacturing.

The big question with Radian One is not the market, but the technology. I suspect there are issues they won't be able to solve, but if they can, then I have zero doubts there will be many, many customers.

My biggest doubt is the "low-cost" argument. The space shuttle was "reusable". It was not low cost - turnaround was crazy expensive. Naturally, being a government project, you can't extrapolate to all private enterprise being *that* bad, but I'm really interested to see if, for example, they claim materials science advances in exterior that will allow reuse without much servicing cost (ablation materials, have they improved that much??).

A "technically speaking" SSTO that still takes weeks/months to turn around and costs 1/4 as much as a new vehicle wouldn't move the needle on demand even if it was a monumental technical achievement. Landing rockets has literally moved the needle, hell, we're not even using the same measuring instrument anymore.

Well there may be scaling issues with scaling down something like Starship. A SSTO Spaceplane targeting a 100t to LEO payload I agree is unlikely to compete with Starship.

However a smaller vehicle maybe. All that assumes they can actually get to orbit and back with a SSTO spaceplane at any price.

Your example doing it at 1/4 the price of expendable launch vehicles would absolutely carve a niche.

 

[alastairmayer]

The only advantage I can think of for a "space plane" is if they have enough fuel overhead to get away from major populated areas before making a bunch of noise. Even then, it still probably makes more sense to have ocean platforms that people just fly/boat out to to take a proper rocket. Taking a pair of wings with you to space just doesn't buy you much other than more landing and take off options, and you pay in fuel and complexity.

Personally, I don't think wings make much sense on orbital craft, at least not at this stage of space development when the barrier is extreme eye watering cost, rather than inconvenient launch locations. On the other hand, I could see the logic in a non-orbital "space plane" that can skip out of the atmosphere for a quick trip to the other side of the world. A sub-orbital space plane that can carry a proper plane's worth of people might be something in the near future. With the drastically reduced tolerances and fuel you need for sub-orbital flight it might even have an economic niche it can live with.

The trade studies I've seen (back in the 90s) for HTOHL vs VTOVL suggest the mass tradeoff for wings + landing gear about the same as for extra landing fuel + landing gear. What really doesn't make sense is VTOHL, like X-33 wanted to do.

 

[mhalpern]

I'm a bit surprised to see bell nozzle engines on the render, rather than aerospikes.

I'm not sure if that makes this concept more possible (because of the difficulty of running an aerospike engine without melting the spike) or less (because of the usefulness for an SSTO of having an engine which is optimized for both sea-level and vacuum).

double bell is also possible.

 

[LordOfTheMorning]

I can't see the market demand for this concept. What am I missing?

I'm imagining something like taking off and going to orbit for space tourism or further deep space missions. Also the taking off and landing part from any airfield on earth

 

[mhalpern]

Why is a single stage space plane a "holy grail" of space flight?

Rockets already take us to orbit with a single stage, and can carry more mass, and are reusable, at least in some cases.

What? Name one.

SSTO has never been achieved. Some designs were close-ish and maybe could be modified to be SSTO with no payload but no SSTO design has ever flown to orbit not even experimentally or expendable. Now it is debatable if SSTO is actually superior to TSTO (on Earth) but we certainly don't have SSTO orbital launch vehicles.

The Long March 5B is a single stage to orbit. Not exactly reusable though!

no it's not it's a 1.5 stage to orbit, it has boosters.

 

[Statistical]

Why is a single stage space plane a "holy grail" of space flight?

Rockets already take us to orbit with a single stage, and can carry more mass, and are reusable, at least in some cases.

What? Name one.

SSTO has never been achieved. Some designs were close-ish and maybe could be modified to be SSTO with no payload but no SSTO design has ever flown to orbit not even experimentally or expendable. Now it is debatable if SSTO is actually superior to TSTO (on Earth) but we certainly don't have SSTO orbital launch vehicles.

The Long March 5B is a single stage to orbit. Not exactly reusable though!

The LM 5 has boosters so it is a 1.5 stage to orbit design much like the STS was.

 

[blackhawk887]

"powered by three liquid-fueled engines."

any word on the propellant? The historical choice would be hydrolox. The only other one I could see is methalox.

Almost certainly LH2/LOX. With HTHL there are very hard initial mass constraints, and that is where LH2 shines.

 

[amarant]

Why is a single stage space plane a "holy grail" of space flight?

Rockets already take us to orbit with a single stage, and can carry more mass, and are reusable, at least in some cases.

Is the difference that planes can take off from any airfield, as opposed to needing dedicated and specialised launch pads?

The bolded part is wrong. Note that even SpaceX's Falcon 9 throws away its second stage every launch, only the first stage and fairings are reused.

But is first stage separation always below orbit? I get that it happens before the desired orbit is achieved, or else why the second stage, but I was under the impression rockets at least sometimes achieve LEO before separating? Or how are higher Delta-v orbits achieved? Just a bigger second stage? That kinda makes sense actually...

I guess I should've put this disclaimer earlier, but I don't really know anything about spaceflight beyond what I learn here on ars (SLS is pork!)

This is why I ask questions here, I get to learn more

 

[mhalpern]

I can't see the market demand for this concept. What am I missing?

Fully reusable launch vehicle capable of putting 2.5t in orbit?

That has a market (If the price per launch is cheap).

Same with fully reusable launch vehicle capable of taking 5 astronauts to a space station.

The need for it to be SSTO instead of TSTO is a design choice, but the market they are aiming for is cheap access to space with a medium size payload.

Presumably, a fully-reusable vehicle's operating cost will be largely impacted by propellant cost. Necessarily a SSTO will use more than a TSTO since you don't get to benefit from staging. Therefore, the SSTO's refurb cost has to be substantially lower than the TSTO's to be competitive. You're going to need more thrust at takeoff than a TSTO (since again, no staging) so I'm not seeing how one materially makes the engines less demanding of maintenance.

worse if you go into air breathing, more complicated engines, FOD risk, and impure oxidizer.

 

[fenris_uy]

Why is a single stage space plane a "holy grail" of space flight?

Rockets already take us to orbit with a single stage, and can carry more mass, and are reusable, at least in some cases.

What? Name one.

SSTO has never been achieved. Some designs were close-ish and maybe could be modified to be SSTO with no payload but no SSTO design has ever flown to orbit not even experimentally or expendable. Now it is debatable if SSTO is actually superior to TSTO (on Earth) but we certainly don't have SSTO orbital launch vehicles.

The Long March 5B is a single stage to orbit, depending on how you define the strap on boosters. Not exactly reusable though!

Except that it isn't. The boosters are the first stage, even if they don't name it like that.

 

[blackhawk887]

The only advantage I can think of for a "space plane" is if they have enough fuel overhead to get away from major populated areas before making a bunch of noise. Even then, it still probably makes more sense to have ocean platforms that people just fly/boat out to to take a proper rocket. Taking a pair of wings with you to space just doesn't buy you much other than more landing and take off options, and you pay in fuel and complexity.

Personally, I don't think wings make much sense on orbital craft, at least not at this stage of space development when the barrier is extreme eye watering cost, rather than inconvenient launch locations. On the other hand, I could see the logic in a non-orbital "space plane" that can skip out of the atmosphere for a quick trip to the other side of the world. A sub-orbital space plane that can carry a proper plane's worth of people might be something in the near future. With the drastically reduced tolerances and fuel you need for sub-orbital flight it might even have an economic niche it can live with.

The trade studies I've seen (back in the 90s) for HTOHL vs VTOVL suggest the mass tradeoff for wings + landing gear about the same as for extra landing fuel + landing gear. What really doesn't make sense is VTOHL, like X-33 wanted to do.

With vertical takeoff you can simply brute force the problem. It doesn't really matter if it's 1000 tons or 3000 tons on the pad.

But with horizontal takeoff that kind of mass does really bad things to wing area and runway length.

 

[NoNeeeed]

As far as I understand, anyone going into orbit on a rocket needs to be in pretty good shape, and to be trained to deal with it. Would something like this, if someone actually got it to work, be a sufficently more gentle experience for "ordinary" people?

Going up in a dragon is probably fine for most people. zero-g motion sickness is probably the biggest potential problem. The free-fall and g loads aren't that different than experienced during skydiving, and most reasonably healthy adults can do that.

The technical training is probably mostly unnecessary these days, since the autonomous systems do all the work during nominal flight, and during the parts where remote control isn't possible, human overrides aren't likely to make a bad situation any better.

Thanks, that's interesting. The stereotypical depiction of rocket launch in films always makes it look like such a grueling experience, but I guess that's just for dramatic effect.

The more I learn about living in space, the more just understanding how to use the toilet sounds like the most difficult thing to deal with

 

[snowysaskatoon]

Wow, it's almost like I have heard this before. Many past times. I think bezos and branson should invest a LOT of money in this, they deserve it. And I'd love to see all that all unfold.

 

[Zylon]

We need to build...a space elevator!

I think we should try a space escalator first. That way, it's still usable if the motor breaks down, as long as you aren't too lazy to climb all of those steps...

 

[stdaro]

The more I learn about living in space, the more just understanding how to use the toilet sounds like the most difficult thing to deal with

Oh yea, definitely. If you can get past the 'stuff coming out the top end' phase, the 'stuff coming out the bottom end' doesn't sound like fun at all.

 

[Statistical]

Why is a single stage space plane a "holy grail" of space flight?

Rockets already take us to orbit with a single stage, and can carry more mass, and are reusable, at least in some cases.

Is the difference that planes can take off from any airfield, as opposed to needing dedicated and specialised launch pads?

The bolded part is wrong. Note that even SpaceX's Falcon 9 throws away its second stage every launch, only the first stage and fairings are reused.

But is first stage separation always below orbit? I get that it happens before the desired orbit is achieved, or else why the second stage, but I was under the impression rockets at least sometimes achieve LEO before separating? Or how are higher Delta-v orbits achieved? Just a bigger second stage? That kinda makes sense actually...

I guess I should've put this disclaimer earlier, but I don't really know anything about spaceflight beyond what I learn here on ars (SLS is pork!)

This is why I ask questions here, I get to learn more

Questions are always fine.

In all current and previous rockets the first stage throws the upper stage on a suborbital trajectory. It is the second stage (or in some cases second plus third) which achieve orbital velocity.

If the second stage on a Falcon 9 (or any orbital launch vehicle developed to date) didn't fire for some reason it would just make a nice parabolic arc and crash back to Earth.

If you like exploratory type video games well worth playing Kerbal Space Program. It won't make you a rocket engineer but it does help illustrate orbital mechanics, mass fractions, and the tyranny of the rocket equation. Even the base game without reality mods will show the concepts nicely it is just the values which are off.

 

[odikweos]

I can't see the market demand for this concept. What am I missing?

There would be a huge market for routine, low-cost access to space on such a vehicle. The story mentions this toward the end, but we are headed toward an era of more commerce and human activity in LEO. As but one example, being able to bring back 10,000 pounds of microgravity manufactured materials probably would close the business case for companies thinking about space manufacturing.

The big question with Radian One is not the market, but the technology. I suspect there are issues they won't be able to solve, but if they can, then I have zero doubts there will be many, many customers.

My biggest doubt is the "low-cost" argument. The space shuttle was "reusable". It was not low cost - turnaround was crazy expensive. Naturally, being a government project, you can't extrapolate to all private enterprise being *that* bad, but I'm really interested to see if, for example, they claim materials science advances in exterior that will allow reuse without much servicing cost (ablation materials, have they improved that much??).

A "technically speaking" SSTO that still takes weeks/months to turn around and costs 1/4 as much as a new vehicle wouldn't move the needle on demand even if it was a monumental technical achievement. Landing rockets has literally moved the needle, hell, we're not even using the same measuring instrument anymore.

Well there may be scaling issues with scaling down something like Starship. A SSTO Spaceplane targeting a 100t to LEO payload I agree is unlikely to compete with Starship.

However a smaller vehicle maybe. All that assumes they can actually get to orbit and back with a SSTO spaceplane at any price.

Your example doing it at 1/4 the price of expendable launch vehicles would absolutely carve a niche.

Assuming you're right about the price argument, it still doesn't change the game. The reason I, at least, get excited about SSTOs is the potential to 10x lower price to LEO per person. That seems unlikely unless the turnaround cost goes to 1/100 of a vehicle or less (rough shouting distance of airliner maintenance).

 

[mhalpern]

"powered by three liquid-fueled engines."

any word on the propellant? The historical choice would be hydrolox. The only other one I could see is methalox.

Almost certainly LH2/LOX. With HTHL there are very hard initial mass constraints, and that is where LH2 shines.

you also have very hard propellant mass ratio requirements, where LH2 is horrible, you might be able to get away with a smaller TWR, but unless we go into exotic oxidizer, I don't see how you get the right combination of ISP and mass ratio with chemical propulsion for SSTO.

 

[blackhawk887]

I can't see the market demand for this concept. What am I missing?

There would be a huge market for routine, low-cost access to space on such a vehicle. The story mentions this toward the end, but we are headed toward an era of more commerce and human activity in LEO. As but one example, being able to bring back 10,000 pounds of microgravity manufactured materials probably would close the business case for companies thinking about space manufacturing.

The big question with Radian One is not the market, but the technology. I suspect there are issues they won't be able to solve, but if they can, then I have zero doubts there will be many, many customers.

My biggest doubt is the "low-cost" argument. The space shuttle was "reusable". It was not low cost - turnaround was crazy expensive. Naturally, being a government project, you can't extrapolate to all private enterprise being *that* bad, but I'm really interested to see if, for example, they claim materials science advances in exterior that will allow reuse without much servicing cost (ablation materials, have they improved that much??).

A "technically speaking" SSTO that still takes weeks/months to turn around and costs 1/4 as much as a new vehicle wouldn't move the needle on demand even if it was a monumental technical achievement. Landing rockets has literally moved the needle, hell, we're not even using the same measuring instrument anymore.

Well there may be scaling issues with scaling down something like Starship. A SSTO Spaceplane targeting a 100t to LEO payload I agree is unlikely to compete with Starship.

However a smaller vehicle maybe. All that assumes they can actually get to orbit and back with a SSTO spaceplane at any price.

Your example doing it at 1/4 the price of expendable launch vehicles would absolutely carve a niche.

Starship is so overly large that even if you lost some efficiency by scaling it down, you should still have a viable vehicle. Dropping the gross mass from 5000 t to 1000 t might drop payload from 100-150 t to only 10-15 t. But 10-15 t with full rapid reuse would have a pretty good market - that's about where F9 is with ASDS landings, and is where this spaceplane is targeting. It would be good for launching constellations and crew missions to LEO and beyond.

 

[NoNeeeed]

The more I learn about living in space, the more just understanding how to use the toilet sounds like the most difficult thing to deal with

Oh yea, definitely. If you can get past the 'stuff coming out the top end' phase, the 'stuff coming out the bottom end' doesn't sound like fun at all.

Yeah, finding out that they have special "pooping gloves" really took some of the mystique and romance out of the idea of being an astronaut...

 

[arcite]

Fifth Element did it first.

 

[fenncruz]

Physics and the rocket equation says this is almost impossible.

But the starry eyed dreamer that still manages to push its way out past the sarcasm and cynicism once in a while is screaming "I want my Pan-Am SSTO to orbit before I do it as postumous ashes!"

When have the laws of physics ever stopped a venture capitalist?

 

[Sabrewings]

We need to build...a space elevator!

I think we should try a space escalator first. That way, it's still usable if the motor breaks down, as long as you aren't too lazy to climb all of those steps...

An escalator can never break: it can only become stairs. You should never see an Escalator Temporarily Out Of Order sign, just Escalator Temporarily Stairs. Sorry for the convenience.

 

[Statistical]

I can't see the market demand for this concept. What am I missing?

There would be a huge market for routine, low-cost access to space on such a vehicle. The story mentions this toward the end, but we are headed toward an era of more commerce and human activity in LEO. As but one example, being able to bring back 10,000 pounds of microgravity manufactured materials probably would close the business case for companies thinking about space manufacturing.

The big question with Radian One is not the market, but the technology. I suspect there are issues they won't be able to solve, but if they can, then I have zero doubts there will be many, many customers.

My biggest doubt is the "low-cost" argument. The space shuttle was "reusable". It was not low cost - turnaround was crazy expensive. Naturally, being a government project, you can't extrapolate to all private enterprise being *that* bad, but I'm really interested to see if, for example, they claim materials science advances in exterior that will allow reuse without much servicing cost (ablation materials, have they improved that much??).

A "technically speaking" SSTO that still takes weeks/months to turn around and costs 1/4 as much as a new vehicle wouldn't move the needle on demand even if it was a monumental technical achievement. Landing rockets has literally moved the needle, hell, we're not even using the same measuring instrument anymore.

Well there may be scaling issues with scaling down something like Starship. A SSTO Spaceplane targeting a 100t to LEO payload I agree is unlikely to compete with Starship.

However a smaller vehicle maybe. All that assumes they can actually get to orbit and back with a SSTO spaceplane at any price.

Your example doing it at 1/4 the price of expendable launch vehicles would absolutely carve a niche.

Starship is so overly large that even if you lost some efficiency by scaling it down, you should still have a viable vehicle. Dropping the gross mass from 5000 t to 1000 t might drop payload from 100-150 t to only 10-15 t. But 10-15 t with full rapid reuse would have a pretty good market - that's about where F9 is with ASDS landings, and is where this spaceplane is targeting. It would be good for launching constellations and crew missions to LEO and beyond.

They are targeting a lot smaller than that. Not sure how to translate 5 persons to mass but 5,000 lbs is 2.3t. If one meatbag plus chair plus lifesupport = 1,000 lbs that means roughly ~5 tons to orbit is the performance goal.

Still it is a bit academic. I think there largest problem is doing it at any pricepoint. If they could get 5 people (and no cargo) to orbit and back fully reusable with a spaceplane at a cost of even $100M per launch I would be genuinely impressed.

If you can do it at any cost it can be done then second third, fifth generation vehicles could potentially improve the cost (or it just dies as a technical marvel).

 

[mhalpern]

The only advantage I can think of for a "space plane" is if they have enough fuel overhead to get away from major populated areas before making a bunch of noise. Even then, it still probably makes more sense to have ocean platforms that people just fly/boat out to to take a proper rocket. Taking a pair of wings with you to space just doesn't buy you much other than more landing and take off options, and you pay in fuel and complexity.

Personally, I don't think wings make much sense on orbital craft, at least not at this stage of space development when the barrier is extreme eye watering cost, rather than inconvenient launch locations. On the other hand, I could see the logic in a non-orbital "space plane" that can skip out of the atmosphere for a quick trip to the other side of the world. A sub-orbital space plane that can carry a proper plane's worth of people might be something in the near future. With the drastically reduced tolerances and fuel you need for sub-orbital flight it might even have an economic niche it can live with.

The trade studies I've seen (back in the 90s) for HTOHL vs VTOVL suggest the mass tradeoff for wings + landing gear about the same as for extra landing fuel + landing gear. What really doesn't make sense is VTOHL, like X-33 wanted to do.

With vertical takeoff you can simply brute force the problem. It doesn't really matter if it's 1000 tons or 3000 tons on the pad.

But with horizontal takeoff that kind of mass does really bad things to wing area and runway length.

with Vertical take off, if you can't get the math to work out for single stage you can stack it on top of a booster

 

[real mikeb_60]

The only advantage I can think of for a "space plane" is if they have enough fuel overhead to get away from major populated areas before making a bunch of noise. Even then, it still probably makes more sense to have ocean platforms that people just fly/boat out to to take a proper rocket. Taking a pair of wings with you to space just doesn't buy you much other than more landing and take off options, and you pay in fuel and complexity.

Personally, I don't think wings make much sense on orbital craft, at least not at this stage of space development when the barrier is extreme eye watering cost, rather than inconvenient launch locations. On the other hand, I could see the logic in a non-orbital "space plane" that can skip out of the atmosphere for a quick trip to the other side of the world. A sub-orbital space plane that can carry a proper plane's worth of people might be something in the near future. With the drastically reduced tolerances and fuel you need for sub-orbital flight it might even have an economic niche it can live with.

Can't remember the name of the book, but there was a scifi novel about a suborbital plane that had a malfunction and ended up in orbit. All the usual crazy people on board freaking out. Not one of the high points of the genre, but the idea was perhaps sound - if you have enough power to do useful suborbital or partial orbit, you might have enough to reach a very low (and perhaps degrading quickly) orbit. Even just high hypersonic needs to get out of most of the atmosphere (and can and will be launched on a conventional rocket at least for expected weapons).

 

[amarant]

Why is a single stage space plane a "holy grail" of space flight?

Rockets already take us to orbit with a single stage, and can carry more mass, and are reusable, at least in some cases.

Is the difference that planes can take off from any airfield, as opposed to needing dedicated and specialised launch pads?

The bolded part is wrong. Note that even SpaceX's Falcon 9 throws away its second stage every launch, only the first stage and fairings are reused.

But is first stage separation always below orbit? I get that it happens before the desired orbit is achieved, or else why the second stage, but I was under the impression rockets at least sometimes achieve LEO before separating? Or how are higher Delta-v orbits achieved? Just a bigger second stage? That kinda makes sense actually...

I guess I should've put this disclaimer earlier, but I don't really know anything about spaceflight beyond what I learn here on ars (SLS is pork!)

This is why I ask questions here, I get to learn more

Questions are always fine.

In all current and previous rockets the first stage throws the upper stage on a suborbital trajectory. It is the second stage (or in some cases second plus third) which achieve orbital velocity.

If the second stage on a Falcon 9 (or any orbital launch vehicle developed to date) didn't fire for some reason it would just make a nice parabolic arc and crash back to Earth.

If you like exploratory type video games well worth playing Kerbal Space Program. It won't make you a rocket engineer but it does help illustrate orbital mechanics. Even the base game without reality mods will show the concepts nicely it is just the values which are off.

Thanks for being such a deep well of knowledge! I've updated my original post to reflect what I've learned today!

I did play ksp a bit a couple of years ago! Iirc I actually achieved something that apparently was cooler than I realized at the time, I'm pretty sure I managed orbit on a single stage at one point! Not reusable, and in a video game, so it doesn't count, but still!

My proudest creation was a 12 stage rocket laid out like a pancake, with each stage being a ring of boosters that would drop off as the ring inside it would ignite! I got soo much payload to orbit with that thing!

But it took all my struts to build it

 

[Heavy Metal]

I can't see the market demand for this concept. What am I missing?

"Yeah, but your engineers were so preoccupied with whether or not they could, they didn't stop to think if they should."

Elon created Raptors and yes, he should have.

 

[BinaryMuppet]

What are the differences in the economics of this versus simply reusing vertical take off and landing rockets like SpaceX? I don’t see how a runway takeoff makes any of this more efficient??? And having your primary engine integrated into the orbital vehicle introduces significant risks.

This feels like moving backwards.

There's certainly less landing options.

 

[lamarcheb]

I wish them the best. What they're proposing, like those before them, is a rocket with wings. Cool. But what would be even cooler is a plane that reaches orbit and goes to space, and then flies like a plane.

 

[BinaryMuppet]

Why is a single stage space plane a "holy grail" of space flight?

Rockets already take us to orbit with a single stage, and can carry more mass, and are reusable, at least in some cases.

Is the difference that planes can take off from any airfield, as opposed to needing dedicated and specialised launch pads?

The bolded part is wrong. Note that even SpaceX's Falcon 9 throws away its second stage every launch, only the first stage and fairings are reused.

But is first stage separation always below orbit? I get that it happens before the desired orbit is achieved, or else why the second stage, but I was under the impression rockets at least sometimes achieve LEO before separating? Or how are higher Delta-v orbits achieved? Just a bigger second stage? That kinda makes sense actually...

I guess I should've put this disclaimer earlier, but I don't really know anything about spaceflight beyond what I learn here on ars (SLS is pork!)

This is why I ask questions here, I get to learn more

Questions are always fine.

In all current and previous rockets the first stage throws the upper stage on a suborbital trajectory. It is the second stage (or in some cases second plus third) which achieve orbital velocity.

If the second stage on a Falcon 9 (or any orbital launch vehicle developed to date) didn't fire for some reason it would just make a nice parabolic arc and crash back to Earth.

If you like exploratory type video games well worth playing Kerbal Space Program. It won't make you a rocket engineer but it does help illustrate orbital mechanics. Even the base game without reality mods will show the concepts nicely it is just the values which are off.

Thanks for being such a deep well of knowledge! I've updated my original post to reflect what I've learned today!

I did play ksp a bit a couple of years ago! Iirc I actually achieved something that apparently was cooler than I realized at the time, I'm pretty sure I managed orbit on a single stage at one point! Not reusable, and in a video game, so it doesn't count, but still!

My proudest creation was a 12 stage rocket laid out like a pancake, with each stage being a ring of boosters that would drop off as the ring inside it would ignite! I got soo much payload to orbit with that thing!

But it took all my struts to build it

"For science!!"

-Scott Manley

 

[cocoman]

"powered by three liquid-fueled engines."

any word on the propellant? The historical choice would be hydrolox. The only other one I could see is methalox.

I don't see this having a chance in hell with hydrolox, personally.

Why?

If they use airport infrastructure, that would be the best option. Future aircraft designs by Boing and Airbus go in that direction.

Also as it will be flying at lower altitudes, the thrust requirement will be much lower at take off and until it reaches higher altitudes.

On that basis I would say hydrolox looks very good. Could you please explain what am I missing?

 

[SomeAndrian]

I can't see the market demand for this concept. What am I missing?

Getting into orbit cheaper gets the asteroid mining that much closer to reality.

We need asteroid mining technology because it is the same technology that can divert an asteroid on a collision course.

But the market demand would be getting closer to the possibility of asteroid mining

 

[fl4Ksh]

What are the differences in the economics of this versus simply reusing vertical take off and landing rockets like SpaceX? I don’t see how a runway takeoff makes any of this more efficient??? And having your primary engine integrated into the orbital vehicle introduces significant risks.

This feels like moving backwards.

The problem with horizontal takeoff-horizontal landing (HTOHL) SSTO concepts is the mass of the wing. That's why the McDonnell Douglas DC-X/XA SSTO test vehicles were vertical takeoff-vertical landing (VTOVL) designs--wing not needed.

It's a shame that NASA picked Lockheed's lifting body design (vertical takeoff-horizontal landing - VTOHL) design for its X-33 SSTO development program in the late 1990s. The X-33 program was a fast paced (30-month) program with a $1B (1995$, $1.8B in today's money) budget. The McDonnell Douglas X-33 entry, the DC-Y, could have been built and flown on that schedule and with that budget. The DC-X/XA test vehicles were built for about $60M (1995$, $108M in today's money) and flew eight times.

NASA chose the Lockheed design because it was packed with new technology (aerospike engine, lifting body configuration, twin-lobed composite LH2 propellant tank). The DC-Y used a proven composite design inherited from the DC-X/XA vehicles and flight-proven Space Shuttle Main Engines (SSMEs) and was down-scored by NASA because it was too conventional. Unfortunately, NASA and Lockheed bit off more than they could chew with that highly developmental design and the X-33 program was cancelled in 2000 before the vehicle was built.

Side note: My lab spent nearly two years developing and testing thermal protection (heat shield) designs for the X-33 under a separate NASA contract.

 

[mhalpern]

I can't see the market demand for this concept. What am I missing?

There would be a huge market for routine, low-cost access to space on such a vehicle. The story mentions this toward the end, but we are headed toward an era of more commerce and human activity in LEO. As but one example, being able to bring back 10,000 pounds of microgravity manufactured materials probably would close the business case for companies thinking about space manufacturing.

The big question with Radian One is not the market, but the technology. I suspect there are issues they won't be able to solve, but if they can, then I have zero doubts there will be many, many customers.

My biggest doubt is the "low-cost" argument. The space shuttle was "reusable". It was not low cost - turnaround was crazy expensive. Naturally, being a government project, you can't extrapolate to all private enterprise being *that* bad, but I'm really interested to see if, for example, they claim materials science advances in exterior that will allow reuse without much servicing cost (ablation materials, have they improved that much??).

A "technically speaking" SSTO that still takes weeks/months to turn around and costs 1/4 as much as a new vehicle wouldn't move the needle on demand even if it was a monumental technical achievement. Landing rockets has literally moved the needle, hell, we're not even using the same measuring instrument anymore.

Well there may be scaling issues with scaling down something like Starship. A SSTO Spaceplane targeting a 100t to LEO payload I agree is unlikely to compete with Starship.

However a smaller vehicle maybe. All that assumes they can actually get to orbit and back with a SSTO spaceplane at any price.

Your example doing it at 1/4 the price of expendable launch vehicles would absolutely carve a niche.

Starship is so overly large that even if you lost some efficiency by scaling it down, you should still have a viable vehicle. Dropping the gross mass from 5000 t to 1000 t might drop payload from 100-150 t to only 10-15 t. But 10-15 t with full rapid reuse would have a pretty good market - that's about where F9 is with ASDS landings, and is where this spaceplane is targeting. It would be good for launching constellations and crew missions to LEO and beyond.

They are targeting a lot smaller than that. Not sure how to translate 5 persons to mass but 5,000 lbs is 2.3t. If one meatbag plus chair plus lifesupport = 1,000 lbs that means roughly ~5 tons to orbit is the performance goal.

Still it is a bit academic. I think there largest problem is doing it at any pricepoint. If they could get 5 people (and no cargo) to orbit and back fully reusable with a spaceplane at a cost of even $100M per launch I would be genuinely impressed.

If you can do it at any cost it can be done then second third, fifth generation vehicles could potentially improve the cost (or it just dies as a technical marvel).

The way I see it, the only scenario in which an SSTO has an economic advantage is if we first assume there is a minimum viable size for an economically reusable orbital vehicle, thus a minimum viable size for a fully reusable TSTO, AND enough of a market below that point for partially reusable rockets that the SSTO MIGHT be able to beat in price.

 

[niwax]

This sort of reusability combined with a runway takeoff means the vehicle could be transported wherever is needed in order to take off. That means no more limits to a specific location. Obviously it's very early but this is hardly a minor thing, should they achieve it. It means much less expensive access to orbit for a large number of purposes. That includes tourism, I'm sure, but if they can make this work, it opens a lot more options, as I understand it, for smaller clients.

Other than handling a thousand tons of cryogenic propellant and a "launchpad" (runway) capable of handling rocket engines? GSE doesn't become easier just because you put half of it in a flimsy aluminium body with people on board and the other half next to a vulnerable airport full of civilians.

The fundamental cost of a rocket launch is a + b, where a = minimal launch pad with purpose-built fuel handling infrastructure and crew and b = purpose-built tanks, engines, navigation and just enough fuel to get less than 5% of takeoff mass to orbit.

The cost of anything more complicated such as a spaceplane is a + b + c, and I have yet to see a single good reason why c should ever be negative.

 

[toastie]

I recall the day that that NASA selected Lockheed Martin's paper X-33 over a demonstrated working DC-X for the RLV program, and everyone in my Physics department was shocked. We all knew that the LM X-33 designed relied too much on undeveloped technology, LM had a bad history of running seriously over budget and not delivering on time, and that we predicted that X-33 would never fly, while DC-X had already demonstrated that vertical take off and landing was possible and didn't really require great new developments of technology. Needless to say, X-33 was a failure, and US spaceflight development was set back another 10 years.

So, Radian wants to take us back to a place we were 25 years ago, while SpaceX and the other RLV companies have moved on. I wish them good luck and success, but I just don't see an aircraft style SSTO vehicle nearly as necessary as it once seemed to be.

 

[Drkrieger]

I can't see the market demand for this concept. What am I missing?

Satellite repair and maintenance, de-orbit decommissioned satellites, pickup cargo from drone vessels (from Moon/Mars/etc.), tourism, scientific operations and experimentation, space junk cleanup... the list goes on