Let Me Play Among The Stars (A Space Program Plan Quest)
- Thread starter 4WheelSword
- Start date
- Original Alt. History
C0P5: Petit Jacque et al
4WheelSword
The original N-body Problem
- Pronouns
- It/She/They
"You'll have to excuse me," she said with a mollifying tone, looking down the length of the conference table, "I've met so many new faces this past week."
She'd had a large room emptied of files and paperwork as a high priority, sourcing a long table from a local carpenter in a rush. It was important to have this space, for two reasons. First, she wanted to be able to sit down and meet the senior staff all at the same time in the same place. Second, she could take a seat at the head of the table and immediately command the respect of the room. She was working alongside a lot of very intelligent men and women and, while she was no slouch, she knew that more than one of them would consider her just a Hollywood airhead. She was determined to prove them wrong.
"Arne Andersson. I'm in engineering, Miss Bräuner, developmental technologies." he answered, "If we are intending to fly a rocket vertically for scientific purposes I do not know why we do not simply use the Petit Jacque." he finished, his thick Swedish accent making his French sound unusual.
The Petit Jacque, a rocket designed for the Armée de l'Air in 1944, is a contingency weapon intended to deter armoured advances from any nation that might have threatened French territories in Europe or overseas. With a fifty kilogram conventional explosive warhead and a potential maximum speed of 450m/s from a standing launch, it was expected to be incredibly effective in immobilising and destroying tanks from both ground and air launches. They have been made available to PEAC; without their warheads, of course.
| Petit Jacque | Mass Ratio | Mass Flow | Isp | Thrust | Mass | Cost |
| Tier 1 | 150/1 | 0.12M/s | 190s | 30.2kN | 2.2M | 0.64C |
Control | Reliability | Stability | ||||
-2 | 0 | -2 | ||||
| Early Aperture (0.4M), Centre-bore tank (1.6M), 50kg Conventional Warhead |
- Mass Ratio is the fuel per 1M of tank
- Mass Flow is the amount of fuel mass passed through the engine bell per second.
- ISP is the specific impulse of the fuel
- Thrust is measured in kiloNewtons
- M is mass and is 250kg per 1M
"Because, frankly," A small woman piped up from the end of the table,pushing her glasses up her nose and leaning forwards to make sure she was heard. "The Petit Jacque is underpowered for our needs. It is very fast, but not for very long at all. If we want to begin achieving results we need sustained acceleration. A weapon will not suit us." she turned her attention to the head of the conference table, "Apolline Touissant, madame director, research and implementation. I think we must design our own flight vehicles and not rely on military technology."
"Leaving aside questions of technology sources, what are our options in terms of liquid fuelled motors?" Bräuner asked.
"We can source as much pure Ethanol as we like and Kronogård has storage for chilled liquid oxygen. I know the Soviets and the Americans have been experimenting with less stable fuel mixtures but currently alcohol is our most reliable option."
Hedwig fought back the urge to roll her eyes. Some of the people recruited into PEAC were geniuses and others were extremely very conservative when it came to experimentation. Perhaps she would have to go down to the research department herself and really set the cat amongst the pigeons. It would be nice to roll up her shirt sleeves after so long dealing with a more political purview.
"Miss Bräuner?" Dan leaned over, talking quietly in a fakery of a whisper, "The mission we discussed?"
Hedwig nodded, straightening herself in her chair. She slid a small set of notes out of a folder in front of her. It was the work of only a few hours brainstorming with Mr O'Leary, but it was an objective, something for everyone to put their minds to. Perhaps it would even generate some inter-departmental cohesion.
"PEAC needs a mission, and currently the ECN doesn't seem to know what to do with us. I once assumed they chose Dublin for its logistical connections but I'm beginning to think they just wanted us as far from Paris as they could get us."
She smiled and the round of polite chuckles was enough to convince her she'd managed the right tone.
"So we set our own objectives. Now we could design a weapon or a… utility vehicle, something the ECN can actually use, but without the institutional knowledge of how to design them, how to build them, I think we would be setting ourselves up to fail. So we promise nothing except that we will create something that can fly."
Mission | Experimental Rocket | Tier | Budget |
Objective | Launch a rocket with an experimental payload that can reach fifty kilometres (50km) altitude. | 0 | ? |
Requirements | A Basic Science payload. At least 1200m/s Delta/v. |
As the program grows, more actions will become available per turn. Currently you have 1 action per turn with which to try to complete your mission.
Engineering
[ ] Design an Engine - Developing a new rocket motor from scratch isn't an easy task, but with the expertise of PEAC and a little luck you'll have a functional system before too long.
[ ] Design a Solid Rocket - Solid rocket motors are a well understood and established technology and designing a bespoke system will be good for PEAC's future endeavours.
[ ] Design a Payload - Whatever type of rocket is used, there will need to be a scientific payload on top of it. Research is the future, after all.
10ebbor10
DON'T PANIC
- Location
- Present
Stats said:
This is a boondoggle that never saw real combat or harsh testing, isn't it.
With those stats, it seems like you'd be lucky if it even impacted near an enemy tank.
The problem is that they're not simple.
Not yet, anyway.
The technology for large, castable solid fuel rockets was only developped under the pressure of wanting to use them as nuclear weapon delivery vehicles.
Right now, as soon as you go beyond the sizes needed for RPG's or take-off boosting rockets, you'll start dealing with a tonne of issues, such as the propellant collapsing under it's own weight, not bonding to the casing, or just improper mixing resulting in bad combustion.
IIRC, they're still made of asphalt at this point.
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[X] Design a Solid Rocket
- Location
- Wörms, the half continent
[X] Design a Payload - Whatever type of rocket is used, there will need to be a scientific payload on top of it. Research is the future, after all.
We probably can, if we like, strap five rockets together, reach 50km with a decent payload. The one we have can already reach a decent height carrying 50kg. It's not great rocketry, but it'll work. But to fulfil our current objective, we need something to turn it from a demonstrator and into an actual sounding rocket.
We probably can, if we like, strap five rockets together, reach 50km with a decent payload. The one we have can already reach a decent height carrying 50kg. It's not great rocketry, but it'll work. But to fulfil our current objective, we need something to turn it from a demonstrator and into an actual sounding rocket.
I don't know all that much about early rocketry, aside from the fact that things tended to go wrong. However, I do know statistics, and strapping five rockets together will increase the chances of things going wrong to the fifth power. As such:
[X] Design an Engine
- Pronouns
- He/She/They
[X] Design an Engine - Developing a new rocket motor from scratch isn't an easy task, but with the expertise of PEAC and a little luck you'll have a functional system before too long.
- Location
- United States
[X] Design an Engine - Developing a new rocket motor from scratch isn't an easy task, but with the expertise of PEAC and a little luck you'll have a functional system before too long.
[X] Design a Solid Rocket
We're not trying to reach space, a 1940s solid-fuelled motor is acceptable for our needs. We don't need fancy castings, the primitive propellants of 1940s military rockets can give us the required delta-v if we bundle enough together. Also, purely optimal choices are boring, let's do something different.
We're not trying to reach space, a 1940s solid-fuelled motor is acceptable for our needs. We don't need fancy castings, the primitive propellants of 1940s military rockets can give us the required delta-v if we bundle enough together. Also, purely optimal choices are boring, let's do something different.
- Location
- Someone else's head
[X] Design an Engine - Developing a new rocket motor from scratch isn't an easy task, but with the expertise of PEAC and a little luck you'll have a functional system before too long.
4WheelSword
The original N-body Problem
- Pronouns
- It/She/They
It's probably about as accurate as an early Tiny Tim (which is what it is - it's the 'Little John' but in French). But yes, it came far too late for the early 1940's brushfire wars and it's too early for
PEAC will focus their January efforts on a Liquid Fuelled Engine.
Update soon.
C1T1 January 1950 - Designing an Engine
4WheelSword
The original N-body Problem
- Pronouns
- It/She/They
The drafting office of PEAC is a windowless room in the basement of the main building, two floors below Hedwig Bräuner's office. It's dim, lit by too few fluorescent tubes mounted on the roof and a handful of armatured lamps illuminating individual desks. A few men and women are scattered around, working quietly with pencil and ruler or tapping out calculations on loud mechanical devices.
"Miss Bräuner, hello," Arne Andersson stands, excusing himself from a seat beside one of the draughtsmen, "welcome to my little kingdom."
He seems genuinely pleased to see her, tired eyes sparkling as he places a cigarette between thin lips and lights it.
"I'm afraid this is all my Kingdom, Mr Andersson, and you are all my subjects," She replies, accepting one of the long cigarettes for herself and leaning forwards to touch its tip to his lighter's flame.
"My fiefdom, then," he says with a quiet chuckle, "Or a part of it. The machine shops are a lot less calm. I assumed this would be a better place to meet to discuss plans."
"I appreciate the quiet. What did you want to discuss?"
"Ah! Yes, now, we've been looking into a home-grown rocket engine. We've not got much of a basis to work on - the French and my own Swedes have mostly been interested in solid rockets, but the Americans have their rocket plane, the Bell, and before the collapse the Germans were working on something massive." he shrugs, seemingly indifferent to the idea.
"You don't think it would have worked?" Hedwig asks,
"We are all limited by materials science, Miss Bräuner, I doubt they could have had a useful design of the scale I've heard whispered without it repeatedly exploding. Let me demonstrate;"
Leading her over to one of the desks he motions the woman sitting at it away and moves rulers and tools aside. On the paper is a - she checks the scale - a very small rocket engine. It is a mess of pipes and coiled tubes leading to a cylindrical detonation chamber with a flat, ugly nozzle at the base. It is drawn to be a metre tall and barely thirty centimetres wide at full scale.
"This has an expected chamber pressure of seven hundred pounds. It's not the limit of our capability but it's already a significant engineering problem to produce something lightweight enough to fly and heavy enough to not tear itself apart." he taps his pencil on the combustion chamber.
"This is the largest we could manage?"
"No, this is a conservative proposal. I didn't want to come to you with an engine that would eat our entire budget. We've been working on something a little more bold though." he turns slightly, looking around the room. "Michael? Bring me what you've been working on."
A slight man with a pinched face and square glasses walks over with another plan tucked under his arm. Once it's laid out it's obvious this is a similar but much larger design.
"We weren't sure if you would appreciate our presenting an engine that is likely to cost us almost a million dollars per unit, or whether we could manage a four thousand pound chamber pressure." Arne says with another thin smile, "Of course this is very much 'how big and how small' but given that we're working from nothing it seemed optimal to put time into the possibilities."
"Oh please, I'm hardly going to complain about reasonable optimism. Do you have the facilities you need to build a test model?"
"We might need to buy in some plumbing supplies, but the machine shop is ready to begin work. We just need the go ahead."
The Go Ahead relies on the Director's word. What do you say?
[ ] Proceed with the XRE-1
[ ] Proceed with the XRE-2
[ ] These are good, but what if we did it like this? - Design a different engine using the rules
Welcome to the first design part of the quest. You'll want access to the design rules. There aren't a lot of options right now because it's the early days. Feel free to ask questions and you should have comment access on the document!
"Miss Bräuner, hello," Arne Andersson stands, excusing himself from a seat beside one of the draughtsmen, "welcome to my little kingdom."
He seems genuinely pleased to see her, tired eyes sparkling as he places a cigarette between thin lips and lights it.
"I'm afraid this is all my Kingdom, Mr Andersson, and you are all my subjects," She replies, accepting one of the long cigarettes for herself and leaning forwards to touch its tip to his lighter's flame.
"My fiefdom, then," he says with a quiet chuckle, "Or a part of it. The machine shops are a lot less calm. I assumed this would be a better place to meet to discuss plans."
"I appreciate the quiet. What did you want to discuss?"
"Ah! Yes, now, we've been looking into a home-grown rocket engine. We've not got much of a basis to work on - the French and my own Swedes have mostly been interested in solid rockets, but the Americans have their rocket plane, the Bell, and before the collapse the Germans were working on something massive." he shrugs, seemingly indifferent to the idea.
"You don't think it would have worked?" Hedwig asks,
"We are all limited by materials science, Miss Bräuner, I doubt they could have had a useful design of the scale I've heard whispered without it repeatedly exploding. Let me demonstrate;"
Leading her over to one of the desks he motions the woman sitting at it away and moves rulers and tools aside. On the paper is a - she checks the scale - a very small rocket engine. It is a mess of pipes and coiled tubes leading to a cylindrical detonation chamber with a flat, ugly nozzle at the base. It is drawn to be a metre tall and barely thirty centimetres wide at full scale.
| XRE-1 | Mass Ratio | Mass Flow | Isp | Thrust | Mass | Cost |
| Engine | 250/1 | 161s | 3.454kN | 0.088M | 0.182C | |
| Motor | 0.0125 | 169s | 0.05M | 0.088C | ||
| Nozzle | 161s | 0.038M | 0.094C | |||
Control | Reliability | Stability | ||||
-2 | -2 | 0 | ||||
| Primitive cycle, Dual-split injector (70%), Basic nozzle, Alc(25%)/LOX fuel |
"This has an expected chamber pressure of seven hundred pounds. It's not the limit of our capability but it's already a significant engineering problem to produce something lightweight enough to fly and heavy enough to not tear itself apart." he taps his pencil on the combustion chamber.
"This is the largest we could manage?"
"No, this is a conservative proposal. I didn't want to come to you with an engine that would eat our entire budget. We've been working on something a little more bold though." he turns slightly, looking around the room. "Michael? Bring me what you've been working on."
A slight man with a pinched face and square glasses walks over with another plan tucked under his arm. Once it's laid out it's obvious this is a similar but much larger design.
| XRE-2 | Mass Ratio | Mass Flow | Isp | Thrust | Mass | Cost |
| Engine | 250/1 | 161s | 17.27kN | 0.438M | 0.907C | |
| Motor | 0.0625 | 169s | 0.25M | 0.438C | ||
| Nozzle | 161s | 0.188M | 0.469C | |||
Control | Reliability | Stability | ||||
-2 | -2 | 0 | ||||
| Primitive cycle, Dual-split injector (70%), Basic nozzle, Alc(25%)/LOX fuel |
"We weren't sure if you would appreciate our presenting an engine that is likely to cost us almost a million dollars per unit, or whether we could manage a four thousand pound chamber pressure." Arne says with another thin smile, "Of course this is very much 'how big and how small' but given that we're working from nothing it seemed optimal to put time into the possibilities."
"Oh please, I'm hardly going to complain about reasonable optimism. Do you have the facilities you need to build a test model?"
"We might need to buy in some plumbing supplies, but the machine shop is ready to begin work. We just need the go ahead."
The Go Ahead relies on the Director's word. What do you say?
[ ] Proceed with the XRE-1
[ ] Proceed with the XRE-2
[ ] These are good, but what if we did it like this? - Design a different engine using the rules
Welcome to the first design part of the quest. You'll want access to the design rules. There aren't a lot of options right now because it's the early days. Feel free to ask questions and you should have comment access on the document!
- Location
- Wörms, the half continent
XRE-2 is basically just a version of XRE-1 that's five times as large, and with a marginal weight premium. Costs also seem to scale linearly, which is nice. Don't really have another comment at the moment.
thinking xre-1? and improvements gleaned from the tests can be put into future, more powerful versions that dont have characters worrying about their capacity to provide parts that work ("whether we could manage a four thousand pound chamber pressure")
- Pronouns
- She/Her
[X] Proceed with the XRE-2
Given the expense, I think we'll want to try to salvage the motor. Engine pod recovery?
Given the expense, I think we'll want to try to salvage the motor. Engine pod recovery?
Dare you doubt the power of a big dumb booster with absurd part tolerances because all of it is an inch thicker than necessary and made out of solid steel?!