Stoke Space Technologies

[Action]

Obviously ideally the heat shield can take it all.  But if the peak heat flux is too high, perhaps they figured a reentry burn is a positive trade.  Who knows, we'll see.  I hope of course that they can do without.

Usually the limit on expendable coolant reentry schemes is set by total heat load.  They're generally good at dealing with high peak heating rate - you just turn up the coolant flow to accomodate a higher heating rate.

Too high a total heat load and you wind up having to carry too much coolant.  So they're more suitable to short, sharp reentries.

[Robotbeat]

And using hydrogen gives them more margin for the same mass than they would with any other option.

[edzieba]

ttps://youtu.be/812xKz9pcnU

Nice video. Much more explicit about how they are going to handle the second stage than others on a similar subject.

If they can deliver what they are proposing this will be game changing.

They show what I took as a reentry burn. If it is, it's critical how long it'll be.

I love the heat shield / plug thing.  Motie level engineering.

Deorbit burn which is different from reentry burn and typically lot shorter. Whole idea of active heatshield is to avoid high DV reentry burns.

From my recollection, based on angle and timing, it looked like a reentry burn.

Obviously ideally the heat shield can take it all.  But if the peak heat flux is too high, perhaps they figured a reentry burn is a positive trade.  Who knows, we'll see.  I hope of course that they can do without.

No entry burn. Just a deorbit burn.

[Robotbeat]

Yeah, they’re just bleeding a little hydrogen through the heatshield. It’s not intended to produce a bunch of thrust.

[Action]

The thing that’s novel and interesting about Stoke’s vehicle, at least to me, is that canted heat shield base.  Many proposed capsule-style RLVs have incorporated some sort of deployable decelerator to gain a little lift and corresponding crossrange.  Many have incorporated an offset center of mass to achieve the same thing.  This is the first time I’ve seen Stoke’s idea.

Intuitively, I imagine there’d be some asymmetric thrust from the exhaust expanding against an asymmetric base, and that that would exert a torque on the vehicle.  Maybe I’m wrong.  If I’m not, presumably that’s well-modelled, not too large, maybe useful in some respects, and offsetable by throttling to the extent it’s undesirable.

I get that asymmetric head shields are common – it’s the asymmetric heat shield which is also the expansion surface for a rocket that seems new.  But other people may have references of prior art.  I’d be interested in seeing any.

[chopsticks]

ttps://youtu.be/812xKz9pcnU

Nice video. Much more explicit about how they are going to handle the second stage than others on a similar subject.

If they can deliver what they are proposing this will be game changing.

They show what I took as a reentry burn. If it is, it's critical how long it'll be.

I love the heat shield / plug thing.  Motie level engineering.

Deorbit burn which is different from reentry burn and typically lot shorter. Whole idea of active heatshield is to avoid high DV reentry burns.

From my recollection, based on angle and timing, it looked like a reentry burn.

Obviously ideally the heat shield can take it all.  But if the peak heat flux is too high, perhaps they figured a reentry burn is a positive trade.  Who knows, we'll see.  I hope of course that they can do without.

No, that was almost certainly just a deorbit burn, not a re-entry burn.

[meekGee]

ttps://youtu.be/812xKz9pcnU

Nice video. Much more explicit about how they are going to handle the second stage than others on a similar subject.

If they can deliver what they are proposing this will be game changing.

They show what I took as a reentry burn. If it is, it's critical how long it'll be.

I love the heat shield / plug thing.  Motie level engineering.

Deorbit burn which is different from reentry burn and typically lot shorter. Whole idea of active heatshield is to avoid high DV reentry burns.

From my recollection, based on angle and timing, it looked like a reentry burn.

Obviously ideally the heat shield can take it all.  But if the peak heat flux is too high, perhaps they figured a reentry burn is a positive trade.  Who knows, we'll see.  I hope of course that they can do without.

No, that was almost certainly just a deorbit burn, not a re-entry burn.

Yes, agreed, wasn't reading.  Cool.

[ThePonjaX]

They show what I took as a reentry burn. If it is, it's critical how long it'll be.

True.

I love the heat shield / plug thing.  Motie level engineering.

Only to someone unfamilar with the work of Philip Bono, or plug nozzles generally.

Propellent cooled heat shieds have been talked about for a long time.

Yes , like "retro propulsive landing" was talked before SpaceX. No new ideas here but someone is trying at least to make it work. That's new.

[FutureSpaceTourist]

Stoke have been allocated SLC 14:

https://forum.nasaspaceflight.com/index.php?topic=58427.msg2464474#msg2464474

[FutureSpaceTourist]

https://twitter.com/andylapsa/status/1633290210317590531

Today the Space Force allocated Launch Complex 14 for our dedicated use. This is the same site John Glenn used to become the first American to reach orbit. Needless to say, this is incredibly humbling. We will work tirelessly to make his legacy, our country, and our world proud.

[Lampyridae]

ttps://youtu.be/812xKz9pcnU

Nice video. Much more explicit about how they are going to handle the second stage than others on a similar subject.

If they can deliver what they are proposing this will be game changing.

They show what I took as a reentry burn. If it is, it's critical how long it'll be.

I love the heat shield / plug thing.  Motie level engineering.

If only they had a Langston field for re-entry.

Just looking back at this thread, it's amazing just how quickly rocket startups can get up and running these days. So many failed ones over the years have just had vapourware rockets. (Cough cough Kistler)

[Asteroza]

ttps://youtu.be/812xKz9pcnU

Nice video. Much more explicit about how they are going to handle the second stage than others on a similar subject.

If they can deliver what they are proposing this will be game changing.

They show what I took as a reentry burn. If it is, it's critical how long it'll be.

I love the heat shield / plug thing.  Motie level engineering.

If only they had a Langston field for re-entry.

Just looking back at this thread, it's amazing just how quickly rocket startups can get up and running these days. So many failed ones over the years have just had vapourware rockets. (Cough cough Kistler)

Newspace stands on the bones of their ancestors.

K-1 might not have flown but it was generating real hardware. The first stage airbag landing tests were not a dog & pony show.

[chopsticks]

Just looking back at this thread, it's amazing just how quickly rocket startups can get up and running these days. So many failed ones over the years have just had vapourware rockets. (Cough cough Kistler)

And that's why I'm hopeful about Stoke. (Don't know anything about Kistler)

It's a bit of a long shot, but they are making real hardware and have a hop test planned soon. And now they have a future launch site. Their architecture seems future-proof and should serve them well if they can pull this off.

[Lampyridae]

ttps://youtu.be/812xKz9pcnU

Nice video. Much more explicit about how they are going to handle the second stage than others on a similar subject.

If they can deliver what they are proposing this will be game changing.

They show what I took as a reentry burn. If it is, it's critical how long it'll be.

I love the heat shield / plug thing.  Motie level engineering.

If only they had a Langston field for re-entry.

Just looking back at this thread, it's amazing just how quickly rocket startups can get up and running these days. So many failed ones over the years have just had vapourware rockets. (Cough cough Kistler)

Newspace stands on the bones of their ancestors.

K-1 might not have flown but it was generating real hardware. The first stage airbag landing tests were not a dog & pony show.

Huh, I thought they'd only got as far as testing the (already existing) engines and when NASA pulled the plug. I'm surprised that they actually got as far as building hardware. News coverage of the time made it seem like they'd gotten hardly anything done.

I'm also surprised that Roton got as far as testing rotary flight, though they were even further from an assembled test vehicle.

[Hug]

Huh, I thought they'd only got as far as testing the (already existing) engines and when NASA pulled the plug. I'm surprised that they actually got as far as building hardware. News coverage of the time made it seem like they'd gotten hardly anything done.

I mean, they had spent $600 million in the 90s (which adjusted for inflation is like $1.1 billion now), some hardware testing was to be expected.

"RpK’s COTS proposal was based, as expected, on the K-1 RLV that Kistler Aerospace had been trying to develop since the 1990s. “We spent $600 million in the late ’90s designing and building this vehicle,” Trafton said, “so a lot is done already.” Trafton’s charts indicated that the K-1 vehicle hardware is “75% complete”, a figure that Kistler Aerospace had been using since before it filed for Chapter 11 bankruptcy protection in 2003.

https://www.thespacereview.com/article/733/1

[Lampyridae]

I mean, they had spent $600 million in the 90s (which adjusted for inflation is like $1.1 billion now), some hardware testing was to be expected.

"RpK’s COTS proposal was based, as expected, on the K-1 RLV that Kistler Aerospace had been trying to develop since the 1990s. “We spent $600 million in the late ’90s designing and building this vehicle,” Trafton said, “so a lot is done already.” Trafton’s charts indicated that the K-1 vehicle hardware is “75% complete”, a figure that Kistler Aerospace had been using since before it filed for Chapter 11 bankruptcy protection in 2003.

https://www.thespacereview.com/article/733/1

Oh I see. So they actually had hardware sitting around in 2003, went bankrupt, then got a COTS contract and did... nothing much? Maybe some hardware tests? Certainly not a fully assembled (let alone integrated) stage.

Anyway, Stoke seems to at least have a hop test coming up, so that's encouraging.

[john smith 19]

Huh, I thought they'd only got as far as testing the (already existing) engines and when NASA pulled the plug. I'm surprised that they actually got as far as building hardware. News coverage of the time made it seem like they'd gotten hardly anything done.

I'm also surprised that Roton got as far as testing rotary flight, though they were even further from an assembled test vehicle.

No they got a lot further than that. IMHO they were the best funded of the startups of that era, I thought they'd had about $900m from Barclay's capital but obviously my memory was playing tricks. 

Their original plan was a near vertical "launch platform" to gain lot of height and some speed then the stg2 to do most of the speed.

Then they hired a load of ex-NASA because (supposedly) the VC's wanted people with experience

They ran it like a NASA programme. IE farmed out engineering, lots of meetings and (fundamentally) the expectation that if they ran out of  money they'd go back to Congress for more.

Turns out this was not good thinking.  They got a chunk more money from NASA to continue but these folk didn't know how to  work to a budget.

Despite having the highest performance Kerelox SC engines on the planet to work with. The NK's from the Russian N1 moon launcher programme.

[FutureSpaceTourist]

https://twitter.com/stoke_space/status/1637136279375863809

Wet dress rehearsal complete. ✔️ #hopper

[chopsticks]

These guys aren't messing around.

[niwax]

These guys aren't messing around.

It's pretty incredible. In my mind, Stoke went from the most credible reuse-era startup to just straight up best managed new rocket. They are doing 2020s era rocketry on Falcon 1 cost control. They probably spend about the same getting to full stage expander hydrolox aerospike tests as Branson did on emergency salvage loans for VO.