Can it do it?

[Guest]

I'm here for a Christmas party (also my birthday, incidentally).

Assuming an isp of 310 and a payload of 25 grams, with optimal construction, can it make orbit? it's about 8~9 meters long.

Edited December 16, 2017 by regex

[James Kerman]

Space Beer!!!!

Quote

 in October 2014, six vials of brewer’s yeast traveled above Earth’s atmosphere from Spaceport America on an SL-9 rocket. Reaching a maximum height of 77.3 miles above Earth, the payload containing the yeast touched back down and was immediately transported to Ninkasi’s lab to begin propagation and brewing. 

http://www.ninkasibrewing.com/news/blogs/press-blog/2017/10/26/ninkasi-brewing-company-launches-third-edition-ground-control-space-traveled-yeast/?ageVerified=defaultValue

[Gaarst]

It looks a lot like the SS-520-4, a modified Japanese sounding rocket that failed to reach orbit last January. Disregarding the failure, a rocket this size should be capable of making orbit (it would be the lightest to ever do so).

310s Isp is on the very high end of vacuum optimised solid stages though, I'm not sure how reliable that figure would be.

 

Also, happy birthday.

Edited December 16, 2017 by Gaarst

[Ultimate Steve]

24 minutes ago, Gaarst said:

It looks a lot like the SS-520-4, a modified Japanese sounding rocket that failed to reach orbit last January. Disregarding the failure, a rocket this size should be capable of making orbit (it would be the lightest to ever do so).

310s Isp is on the very high end of vacuum optimised solid stages though, I'm not sure how reliable that figure would be.

 

Also, happy birthday.

I heard they Japanese are doing another attempt with that rocket sometime in this December (although it will probably be pushed to January).

[Guest]

39 minutes ago, James Kerman said:

Space Beer!!!!

http://www.ninkasibrewing.com/news/blogs/press-blog/2017/10/26/ninkasi-brewing-company-launches-third-edition-ground-control-space-traveled-yeast/?ageVerified=defaultValue

Good Christmas I had no idea they've gone for additional batches!

E: Also, up that payload, need at least a quarter kilo.

Edited December 16, 2017 by regex

[tater]

2 hours ago, regex said:

I'm here for a Christmas party (also my birthday, incidentally).

Assuming an isp of 310 and a payload of 25 grams, with optimal construction, can it make orbit? it's about 8~9 meters long.

Happy $@!$@#! Birthday!

[Nightside]

You say that thing is full of beer? You’ll have to shake it pretty hard to get it to liftoff!

[Guest]

1 hour ago, Nightside said:

You say that thing is full of beer? You’ll have to shake it pretty hard to get it to liftoff!

Nah man, yeast!

[kerbiloid]

Community Resource Pack definitley requires new fuel resource.
Maybe even several (dark beer, light beer, etc.)

(And a Brewery station module).

Edited December 16, 2017 by kerbiloid

[tater]

Answering the non-birthday question, if the thing is 10cm in diameter, and 9m long, it can hold perhaps 400 kg of propellant (I'm guessing solid prop density is something like 1.4g/cm³). If the dry mass is under 19kg, it can actually make orbit possibly (9300 m/s, total).

[magnemoe]

It looks like this rocket is single stage+ payload, think new Shepard. you want +3 stages on an pure solid fuel rocket to reach orbit. You might well want 5 with the last for circulation. 
You want lots of stages on solid fuel rockets because they have poor ISP and pretty high dry mass while on the other hand the engines are simple and cheap, it also let you get away with stuff like spin stabilization only on lower stages. 

[PB666]

2 hours ago, tater said:

Answering the non-birthday question, if the thing is 10cm in diameter, and 9m long, it can hold perhaps 400 kg of propellant (I'm guessing solid prop density is something like 1.4g/cm³). If the dry mass is under 19kg, it can actually make orbit possibly (9300 m/s, total).

side drag is a major problem for short thin rockets.

Edit, as Magnmoe says, this rocket will not reach orbit, in fact it probably would not reach 1/3rd of the mechanical energy required to reach orbit.

Edited December 16, 2017 by PB666

[wumpus]

6 hours ago, magnemoe said:

It looks like this rocket is single stage+ payload, think new Shepard. you want +3 stages on an pure solid fuel rocket to reach orbit. You might well want 5 with the last for circulation. 
You want lots of stages on solid fuel rockets because they have poor ISP and pretty high dry mass while on the other hand the engines are simple and cheap, it also let you get away with stuff like spin stabilization only on lower stages. 

I think the Japanese have launched a rocket to orbit with 5 solid stages.  It might have a chance if the last two stages have carbon casings for the solid (they can be extremely small given a 25g payload).  The 25g payload is what makes it all possible, you wind up with an infinite mass ratio, you shouldn't have any issues after getting above aero losses.  I wonder if they are considering air/mountain/balloon launching?

[Guest]

5 hours ago, wumpus said:

I wonder if they are considering air/mountain/balloon launching?

It's just a prop, they sent the yeast up on a proper commercial carrier.

I would consider it for the purposes of the thought exercise though.

[Zeiss Ikon]

If you could launch a rocket in that class from an SR-71 flying at near maximum altitude and speed, it might have a chance of reaching a once-around orbit (Pe would dip back into atmosphere, without some means to circularize).  Then again, a once-around is all the Japanese brewery wants from this; they're after "space traveled" yeast to brew with.  Assuming the SR-71 flies at 1.1 km/s above 97% of the atmosphere (published operational altitude appr. 22 km), you're 13% of the way to orbit and have almost no air drag to deal with.  You essentially just need a dV of about 6.9 to 7.2 km/s in your vehicle.  Additionally, you can launch with a nozzle optimized for .03 bar and get much better Isp than launching with a sea level nozzle.

Too bad the SR-71s are all in museums, now.

[GoSlash27]

I would be shocked if *any* solid fuel rocket could make orbit in a single stage. You're talking like a 24:1 wet/ dry mass ratio; 96% of the total mass would need to be propellant.

Best,
-Slashy

Edited December 18, 2017 by GoSlash27

[magnemoe]

9 minutes ago, Zeiss Ikon said:

If you could launch a rocket in that class from an SR-71 flying at near maximum altitude and speed, it might have a chance of reaching a once-around orbit (Pe would dip back into atmosphere, without some means to circularize).  Then again, a once-around is all the Japanese brewery wants from this; they're after "space traveled" yeast to brew with.  Assuming the SR-71 flies at 1.1 km/s above 97% of the atmosphere (published operational altitude appr. 22 km), you're 13% of the way to orbit and have almost no air drag to deal with.  You essentially just need a dV of about 6.9 to 7.2 km/s in your vehicle.  Additionally, you can launch with a nozzle optimized for .03 bar and get much better Isp than launching with a sea level nozzle.

Too bad the SR-71s are all in museums, now.

You have an russian figher jet who is almost as fast and it has hardpoints and you can rent it
It was some experiments showing that an 1 ton rocket should be orbit capable with an fast figher jet as first stage. 

[Guest]

4 hours ago, Zeiss Ikon said:

Then again, a once-around is all the Japanese brewery wants from this; they're after "space traveled" yeast to brew with.

Oregonian. Eugene, Oregon, to be specific. They've done two batches of beer with "space-travelled" yeast and are on to the third, apparently, and now Budweiser is going to try the gimmick with "space-travelled" hops, apparently. Freeze-dried, maybe? 

[Streetwind]

On 16.12.2017 at 3:45 PM, tater said:

Answering the non-birthday question, if the thing is 10cm in diameter, and 9m long, it can hold perhaps 400 kg of propellant (I'm guessing solid prop density is something like 1.4g/cm³). If the dry mass is under 19kg, it can actually make orbit possibly (9300 m/s, total).

If this thing is 9 meters long, it is thicker than 10 cm. Significantly so.

I made the simplification "8 meters body, 1 meter nosecone", then held up a piece of paper to the image and marked off 8 equal segments along the body with a sharpie. That gave me a rough measuring stick to eyeball the diameter. I would peg it around 40 cm. Maybe 45, at most. But definitely less than 50.

[wumpus]

12 hours ago, Zeiss Ikon said:

If you could launch a rocket in that class from an SR-71 flying at near maximum altitude and speed, it might have a chance of reaching a once-around orbit (Pe would dip back into atmosphere, without some means to circularize).  Then again, a once-around is all the Japanese brewery wants from this; they're after "space traveled" yeast to brew with.  Assuming the SR-71 flies at 1.1 km/s above 97% of the atmosphere (published operational altitude appr. 22 km), you're 13% of the way to orbit and have almost no air drag to deal with.  You essentially just need a dV of about 6.9 to 7.2 km/s in your vehicle.  Additionally, you can launch with a nozzle optimized for .03 bar and get much better Isp than launching with a sea level nozzle.

Too bad the SR-71s are all in museums, now.

One of the SR-71 fatalities was due to launching a drone/missile, and the whole (launching) project was canceled immediately afterwards by Johnson.  Presumably such launches are inherently dangerous.

11 hours ago, GoSlash27 said:

I would be shocked if *any* solid fuel rocket could make orbit in a single stage. You're talking like a 24:1 wet/ dry mass ratio; 96% of the total mass would need to be propellant.

Best,
-Slashy

25g of payload screams "as many stages as you want".  Also that last stage can be both small and use just a few grams of carbon fiber to contain the solid motor.  I'd also recommend launching off a mountain (the Chinese might have an advantage at their high altitude launch facility) to cut down the aero losses.

[Zeiss Ikon]

10 hours ago, wumpus said:

One of the SR-71 fatalities was due to launching a drone/missile, and the whole (launching) project was canceled immediately afterwards by Johnson.  Presumably such launches are inherently dangerous.

The D-21 drone was essentially a baby SR-71 mounted on top of the aircraft -- it had a single central engine similar to (albeit smaller than) the J-57 turbo-ramjets that powered the SR-71.  The drone launch was intended to have the D-21 start its engine and bring it to full thrust before decoupling and climbing away from the parent aircraft.  Doing this inside a supersonic shock structure is inherently dangerous, no question -- it'd be like launching a Space Shuttle from the back of a 747 by starting the main engines (we'll assume tankage inside the payload bay), and look how well that worked in Moonraker.  Based on the account I've read, the D-21 was unstable when it decoupled, likely due to shock wave interactions between its nose or wing and the top deck of the SR-71.

Launching essentially a missile, even from a dorsal hardpoint like the one the D-21 used, is far safer.  All you do is put the SR-71 into a mild negative G maneuver, and hit the launch switch, which decouples the rocket and starts a time delay (during which the rocket will pass out of the SR-71's shock wave structure), after which the engine ignites.  There's enough air at 22 km to support the SR-71, so there ought to be enough for the rocket's fins to stabilize it at Mach 3.

If you use a belly hardpoint (no, the SR-71 never had one, but we'd probably have to build a few new ones to make launching from them a going concern), like a conventional missile launcher, it's better still -- the missile falls away from the hardpoint, then ignites, just like a Phoenix or AAMRAM.

My understanding is that there is no Russian aircraft that's "almost as fast" as the SR-71.  The fastest one I'm aware of is roundly 2/3 the Blackbird's top speed, at a couple kilometers lower level flight ceiling.

Edited December 18, 2017 by Zeiss Ikon

[sevenperforce]

40 minutes ago, Zeiss Ikon said:

The D-21 drone was essentially a baby SR-71 mounted on top of the aircraft -- it had a single central engine similar to (albeit smaller than) the J-57 turbo-ramjets that powered the SR-71.  The drone launch was intended to have the D-21 start its engine and bring it to full thrust before decoupling and climbing away from the parent aircraft.  Doing this inside a supersonic shock structure is inherently dangerous, no question -- it'd be like launching a Space Shuttle from the back of a 747 by starting the main engines (we'll assume tankage inside the payload bay), and look how well that worked in Moonraker.  Based on the account I've read, the D-21 was unstable when it decoupled, likely due to shock wave interactions between its nose or wing and the top deck of the SR-71.

Launching essentially a missile, even from a dorsal hardpoint like the one the D-21 used, is far safer.  All you do is put the SR-71 into a mild negative G maneuver, and hit the launch switch, which decouples the rocket and starts a time delay (during which the rocket will pass out of the SR-71's shock wave structure), after which the engine ignites.  There's enough air at 22 km to support the SR-71, so there ought to be enough for the rocket's fins to stabilize it at Mach 3.

If you use a belly hardpoint (no, the SR-71 never had one, but we'd probably have to build a few new ones to make launching from them a going concern), like a conventional missile launcher, it's better still -- the missile falls away from the hardpoint, then ignites, just like a Phoenix or AAMRAM.

My understanding is that there is no Russian aircraft that's "almost as fast" as the SR-71.  The fastest one I'm aware of is roundly 2/3 the Blackbird's top speed, at a couple kilometers lower level flight ceiling.

And let's not forget that an SR-71 had to launch with half-full fuel tanks in order to get airborne, by design, and thus required a top-off refuel by a specially-designed high-airspeed tanker, just to START missions.

[GoSlash27]

11 hours ago, wumpus said:

25g of payload screams "as many stages as you want".

wumpus,
 Granted, but the rocket shown in the OP isn't "as many stages as you want". It's a single stage SRB.

Best,
-Slashy

[GoSlash27]

12 hours ago, wumpus said:

One of the SR-71 fatalities was due to launching a drone/missile, and the whole (launching) project was canceled immediately afterwards by Johnson.  Presumably such launches are inherently dangerous.

 Did they ever launch a D-21 from an SR-71? I was under the impression that they only ever tried that with the A-12 Oxcart (Subtly different from the SR-71). Lower altitude and range, lighter, shorter, single cockpit, higher dash speed, owned by the CIA instead of SAC...
  In addition to the danger of launching a drone from (whatever it was), I remember hearing that it was scrapped because it was entirely pointless. The idea of having the D-21 was that it could penetrate airspace that was impenetrable to the SR-71, but it turned out that there was nowhere on the planet that the SR-71 couldn't go with impunity.

Best,
-Slashy

 

[mikegarrison]

1 hour ago, sevenperforce said:

And let's not forget that an SR-71 had to launch with half-full fuel tanks in order to get airborne, by design, and thus required a top-off refuel by a specially-designed high-airspeed tanker, just to START missions.

I don't recall whether they took off with "half-full" tanks or not. They did lose a lot of fuel during takeoff and climb due to the tanks not being sealed unless they were hot. So they had to tank up in the air almost immediately.

The tankers they used were not "specially designed". They were regular KC-135 tankers. But the fuel was special, so they couldn't use just any old tanker that happened to be in the air. They had to have their own dedicated fleet of tankers with their JP-7 fuel, plus tankers with regular fuel to tanker their tankers. Normally tankers can use their own tankered fuel as a reserve capacity, but not when the tanker flies on kerosene but the tank is full of JP-7. https://en.wikipedia.org/wiki/JP-7