Concorde launched micro sat.

[slomobile]

So there is this air pressure/vacuum cannon. It could be made much larger.
Concorde can fly 2,179 km/h and 18.3km high. It has hydraulic systems to reconfigure the nose. Pressurized fuselage. Cruises at altitudes where air pressure is quite low. Fuselage internal length 39.32 m. Fuselage internal height 1.96 m. Enough to fit a single sea level Raptor engine.
Presumably, a Concorde could be purchased relatively cheaply compared to building a new orbital rocket and modified for an unmanned mission.

At 60,000 feet, 93% of the atmosphere is below you. The air pressure is just 7% of what it is at sea level. The air density, or the weight of the air, is just 9.5% of what it weighs at sea level. The average temperature is -75 F (-60 C).
Article Source: http://EzineArticles.com/6878487

Lets say its possible to launch a micro satellite and rocket out the nose at 3000km/h before we light the fuse.

How much methane and O2 would it take to get to LEO(Low Earth Orbit)?
Would that volume of fuel and oxidizer fit inside a Concorde fuselage?


Sources:
https://en.wikipedia.org/wiki/Concorde
https://ezinearticles.com/?HALE-UAV-at-60,000-Ft-(20,000-M)---Flying-in-the-Stratosphere&id=6878487

 

[JBee]

Not sure what your intention is to discuss, but there are some assumptions you make that are not quite right, so shedding some light on them will likely help come to more representative ideas.

From what I understand there hasn't been a concord flight for 20 years or so (2003) and a part from the airframes in museums they have all been decommissioned? Remember Concord first flew in 1969, so reusing 50 year old airfames is not cost effective due to maintenance/repair costs, which is why btw they got decommissioned in the first place.

Second thing is if you open up the nose on anything flying at 2200 kmh (not 3000kmh) it will suffer a rapid random disassembly from the aerodynamic pressure, which would be like watching the Concord being pealed off the rocket booster like a banana peel, that you propose to have inside. If it doesn't take out the rocket onboard, it will most definitely be a single use Concord

You could try sliding it out the back, but even there I doubt it would work as you would have to seriously reinforce the cabin fuselage pressure vessel that holds the wings, tail and motors together. Let alone the shift backwards of the rocket will change the Concord center of gravity backwards, and would result in a uncontrolled positive pitch up and disassembly midflight.

To get to 20km altitude, which is higher than Concorde can go, it only takes 2 minutes for a rocket going straight up. Once there aerodynamic drag is greatly reduced, at which point having wings doesn't help much, because they gradually decrease in lift generation the higher you go. Then in space they are useless because there is not matter to interact with, and by then the rocket is only interested in going faster in a vacuum to reach orbital velocity.

Overall the repurposing Concorde idea would not work for what you want to do on various levels.

As for trying to launch a micro satellite, you need to be aware that the main fuel consumption of a rocket is NOT to reach a high altitude an space, but rather to accelerate the satellite to orbital velocity.

So if you want to launch something into orbit, what you really need to do is head for space, once you get there you go sideways to get faster to stay up.

That is also why there is a big difference between being high enough to be in space, like Blue Origin and Virgin Space do their "flights" (or weather balloons can nearly get to), and being in orbit like SpaceX. Being orbital means you have reached orbital velocity, meaning you are travelling fast enough to perpetually (nearly - think of earth orbit around sun) fall around the earth and not lose altitude and crash back to earth.

As you can see in the diagram above, velocity is what keeps you up in space. Don't go fast enough, you come back down after a short period, go fast enough you keep going, and go to fast you leave orbit and head somewhere else in the solar system.

Technically, if the earth did not have a atmosphere, like the moon, you could actually reach orbital velocity a lot closer to the surface. On the moon you can actually shoot yourself in the back with a decent gun/cannon, with the projectile circumnavigating the moon.

In regards to fuel consumption, and how much methane you need etc that is actually not that easy to answer because of the amount of variables (you know like rocket science ), but remember, you will use more fuel to launch enough fuel to get to orbit, than actually have in payload or vehicle. That is to say you need more fuel to launch more fuel too. That's why rockets are really just flying fuel tanks with rocket engines, with just enough rigidity to keep together on ascent, they even use the fuel pressure to keep together!



Now if you wanted to make a spaceplane then you can actually use the air/oxygen available whilst you climb through the atmosphere as more than half of your fuel source, instead of carrying an oxidizer with in rocket tanks. Raptor on Starship is around 3.8 parts LOX to 1 part CH4, so you could have a LOX tank probably half the size in comparison, because at higher altitudes where the air is to thin, you will still need thrust to maneuver, so you have to take LOX with too. This is fairly complicated to though, as your engines will have to go through various modes depending on altitude and velocity. SABRE is well on their way at achieving this:

As you can see still really a flying fuel tank with limited payload (5) but it does look cool.
The wings are also handy for landing, the idea is to use dedicated long runways for launch and recovery, there was some talk about using standard runways, but I doubt that will eventuate in the short term.

Then of course there is Starship...yeah that's something else and makes much more sense as a solution for a inter-planetary spaceship. It can launch hundreds of satellites at a time at a cost around $100 per kg. That is just crazy cheap in comparison to Falcon at $23,000kg.

 

[slomobile]

there are some assumptions you make that are not quite right

I want to identify those and correct my assumptions, but I cannot pick them out from your reply. Actually, many of the facts you state are the reasons for this idea in the first place.

The intent of this thought experiment is to explore an alternate type of reusable first stage. Like any new type of reusable stage, there is a chance something will go wrong making it non reusable. If that happens, better to lose a piece of equipment which was purchased near scrap value, and when recovered in pieces, can be resold for scrap value, plus a bit of markup on some pieces as mementos. If it works, we have proved a new concept which can be applied toward designing a proper dedicated in flight launch system.

This concept is far too risky to spend billions testing a proof of concept from scratch. But a few million in boneyard parts and a few million more in engineering? Maybe. So I'm just doing some bar napkin speculation here for free. Given SpaceX embraces failure as a compulsory step, I figured it was more likely to happen in the SpaceX era than the old NASA era.

This is a way to stretch out the first 2 minutes of rocket flight, which is extremely high power, high energy, and unfamiliar to most engineers. Into something of longer duration, moderate power, equivalent energy, and familiar to most engineers and lay people alike.

It reduces delta V for the rocket by placing V0 at 3000km/h rather than 0km/h.
It eliminates the turn to horizontal because it launches that way.
It uses wings and jet engines in the part of the atmosphere where those things work.
Jettisons them in a way that adds velocity to the rocket.
Lights the rocket in an atmosphere much closer to vacuum.

A vacuum optimized rocket engine would work much better at 60,000ft than at sea level. I selected the sea level Raptor variant above because the vacuum optimized Raptor engine bell is slightly too big for the fuselage. That is the maximum amount of thought I put into engine selection. Raptor was a name I knew, picked out of a hat, then checked the diameter on Wikipedia.

Of course "rapid random disassembly from the aerodynamic pressure" when launching a rocket through the nose of a supersonic aircraft is the most likely outcome. I've completely solved that problem in the most efficient way.

Being only a hypothetical problem, I've instructed poll participants to ignore it.

Trying to solve it in reality could involve a few different approaches.
1. Treat each Concorde as disposable. This is probably the most realistic approach for a first test. Plus, wouldn't you just love to film that?
Light the rocket within the fuselage, like a bullet in the chamber of a gun. High pressure exhaust gasses escaping out the front ahead of the rocket create a temporary buffer where the differing speeds of sound aren't quite as profound. The peeling away of the Concorde would be a desirable effect. Reinforcing some areas, while selectively weakening others could help limit the randomness of the disassembly.

2. If this is a proof of concept for a reusable vehicle, we better test some reusability features before we run out of old birds. The entire nose needs to be rebuilt. No cockpit required, it will be remotely piloted. I'm thinking the nose would be composed of many "petals" similar to the "turkey feathers" that make up the afterburner orifice on military jets. As the rocket leaves the fuselage, the nose orifice is opening at the same time to minimize the surface area which is penetrating the sound barrier. Following the exiting rocket, a cone shaped plug will also mostly exit the fuselage, but not beyond the turkey feathers. This forms a new nose, plugging up the orifice. Lets call it the snot rocket. Since we are already scouring the boneyards for Concordes, lets try to scrounge up some turkey feathers as well and see if we can run it off the nose lowering hydraulics on Concorde.

There are many many things wrong with this plan without any doubt. I am just not yet convinced that it is impossible. Because I haven't seen anyone give it more than a cursory analysis, including myself. As detailed and accurate as your response was JBee, I am not yet able to draw the same conclusion you did.

I think its viable until someone points to something impossible, not just very very hard. You know, like rocket science.

However, viability must also make financial sense, not just be technically possible. 100$/kg to orbit is tough to beat. This will not beat that price. This kind of approach is limited to a single small payload. In order for it to make sense, the payload would be something that cannot travel next to several other cube sats on the space bus. This is a single seater.

Seen from that perspective, it could be used to launch private space weapons. I hope it goes without saying that is a use case which I abhor. It didn't occur to me till just now. Kind of makes me wish I hadn't posed the question. But it also reveals a reason to know the answer to "is it viable for terrorists?" If it is, someone ought to be keeping tabs on the locations of these old planes.

 

[Crissa]

I think you should probably look up https://en.wikipedia.org/wiki/Cosmic_Girl_(aircraft)

The problem with the Concorde is that it's fuel inefficient for its weight capacity, speed, and altitude. Which limits its cargo capacity.

I always loved to sketch these things up when I was in high school and university, but... Space X's boosters and belly flops are just more fuel efficient to orbit at this point. Our atmosphere is thick and while that gives us leverage - it reduces the speeds we can attain and speed is the important bit. That's why SpinLaunch and Hyperloop do their acceleration in near vacuum; you need to get to 67000 mph, and big losses from air resistance start at 50. ...While a Concorde needs at least 250 mph to get off the ground.

The wings just don't help. ?

-Crissa
Very Sad Aerospace Engineering Student

 

[JBee]

I think its viable until someone points to something impossible, not just very very hard. You know, like rocket science.

There are 7 Concords on display in UK, 6 in France, 3 in the USA and one in Barbados. Only 20 were ever built of which only 14 ever flew. I don't even think that all of them would be enough to test it to get it to work

But there is not a single flyable Concord around. I remember way back when they stopped flying that the maintenance problem was that the aircraft was riveted together, and the millions of rivets needed to be replaced because of material fatigue.

So without building a new Concord from scratch for x $billions the idea would stop there. There are no donor Concordes and even stealing a non-functional one from museums for a thought experiment wouldn't happen. You need FAA approvals to fly too, which you would never get for it anymore.

Even if you got one nobody would buy a flight on one for their expensive payload, especially if its more expensive than SpaceX now on Falcon, let alone next year (Max two) were they start flying Starship on schedule launches.

As for the technical issues, I'm not sure its worth contemplating them if you can't get a flyable Concorde anyway. BTW the nose petal idea doesn't get rid of the CoG/CoL, structural pressure vessel etc problems, let alone the 2nd stage rocket blast etc. Most 2nd stage aircraft launches are dropped in air before ignition like a missile.

Now if we can ignore using the Concorde airframes because of the above, then we could consider some options that would actually be possible.

If you want wings to make use of the air as a oxidiser and for lift, I'd just go the SABRE engine route. Single reusable launch vehicle that can land and takeoff on a runway. Brilliant. Technically, financially and physically that makes sense in comparison to Falcon, but Starship in another league because they have pushed the mass fraction (3.6%) by making it huge which then works in their favour. There's simply no runways big enough to make that work with wings.

The thing with orbital velocity is that it is already barely possible with a chemical reaction energy alone. You really need another energy source (nuclear is to heavy) that can also produce enough thrust in space (you need some mass to expel).

There are ion drives on satellites that use solar power and magnets to use ionised gas at sub-light speed projectiles, but they only have single digit Newton levels of thrust which won't accelerate fast enough to be useful (think months to reach interplanetary travel velocities), so launching with them from earth is obviously impossible anyway. (BTW there are some ion propulsion aircraft if your interested)

Just to accelerate 1kg from the ground at the equator to orbit (8km/s) requires 32MJ of energy, and methane has 55MJ per kg, but you have to bring 3x as much oxygen with to burn it to get that energy out of the 1kg of methane. For every ton Starship launches it uses 48tons of fuel you also have to launch, plus rocket stages etc. Remember, this is not the energy to lift it to space, this is the energy required to achieve enough velocity (speed) to stay in orbit.

A rocket is really like controlled explosion of a fuel storage container, that stops fuel leaking in directions you don't want, and burns fuel at one leaky end to produce thrust in the other direction which is hopefully where you want to go.

I'm not a big fan either of a brute force approach to high kinetic energy launches, but the numbers look like they will work for Starship, and getting payload mass to orbit also means fuel to orbit, which then means fuel for interplanetary travel. Overall a much more significant development than repurposing an aircraft for a small satellite launch. ?

 

[SparkChaser]

If you recall the Concord suffered a catastrophic failure from running over a strip off metal that fell off another Airplane. The integrity of the airframe and structure was never meant to last the decades that was needed to make them profitable. The route restrictions due to sonic boom and huge fuel consumption made them expensive to operate.
While a huge engineering advance they never developed into more than a niche market. Newer designs are coming and solve many of these problems. I am excited about the Boom test aircraft I have been following.

Boom - Supersonic Passenger Airplanes (boomsupersonic.com)