Airbus developing reusable space rocket launcher

June 7, 2015 by Djallal Malti
The Ariane, built by Airbus Defence and Space. Airbus has unveiled plans for a reusable space rocket launcher that should be rea
The Ariane, built by Airbus Defence and Space. Airbus has unveiled plans for a reusable space rocket launcher that should be ready in 2025

European aircraft and aerospace giant Airbus has unveiled plans for a reusable space rocket launcher that should be ready in 2025, which the firm says will be radically different from the concept of rival US firm Space X.

Airbus must overcome significant technical and financial challenges, while the Space X company owned by South African-born billionaire Elon Musk, co-founder of PayPal, is already experimenting with its model.

Since 2010, a team of engineers has been secretly working at an Airbus warehouse at Les Mureaux, just outside Paris, looking for ways to reuse space rocket launchers.

They have a difficult task ahead because they must ensure that reuse ends up costing less than sticking to classic single-use models.

Now, as they give journalists access to their site, it appears their project might end up working.

Airbus has baptised the two phases of its reusable launcher concept Adeline and Space Tugs.

"The main stage launches and operates the rocket in the first phase of its journey. The later stage comes into action in the second part," said Francois Auque, director of Airbus's Defence and Space programme.

Adeline, which stands for ADvanced Expendable Launcher with INnovative engine Economy, is original because it combines space technology with aeronautics, said Herve Gilibert, technical director at Airbus Defence and Space.

An inflatable scale size model of "Adeline", short for Advanced Expendable Launcher with Innovative engine Economy, a
An inflatable scale size model of "Adeline", short for Advanced Expendable Launcher with Innovative engine Economy, a reusable Ariane rocket first-stage engine and avionics package, a project hoping to be operational in 2025-2030
"In order to reuse the main stage, we bring back the most expensive parts and try to make them in a way that they become much cheaper to reuse them than to make new ones," Auque said.

The idea is to recover the propulsion bay and the engine, which account for 80 percent of the launcher's total value, by putting them behind a heat shield that will protect them as they come back to Earth.

Like a plane

Adeline comes in the form of a stabiliser at the base of a launcher, and is outfitted with little wings and a turboprop engine. As with most aircraft, fuel is stored in the wings.

The Space Tugs concept calls for devices that will hover at an altitude of 1,000 kilometres (620 miles), which would be refuelled by new launchers with the help of satellite technology.

The plan is "to stock them up in a 'car park'" for future use, Auque said.

A subscale model of "Adeline", short for Advanced Expendable Launcher with Innovative engine Economy, a reusable Ariane rocket first-stage engine

Once Adelines have completed their mission, they are flown remotely like a drone to a landing strip.

As for how the reusable launchers would work, the principle is to have them take off like normal rocket, but land like a plane, said Auque, who wants to reuse the engine 10 or 20 times.

Gilibert meanwhile claims the Airbus project is superior because it is being designed to withstand more reuse than Space X's version.

Space X's project is also different because its launcher is being built to land on a vessel at sea.

Airbus estimates its module will require two tonnes of fuel to be brought back to Earth—half the amount its rival will need.

In terms of financing, the company is aiming for a 30 percent gain on the launcher's operating costs—estimated at $70 million (63 million euros) for the upcoming Ariane 6.2 model that is equipped with a dual rocket booster.

Explore further: Airbus, Safran do launcher deal to compete with SpaceX

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jan_j_rais
5 / 5 (1) Jun 07, 2015
SpaceX launcher is NOT being build to land at sea. It's just how they test it.
Eikka
3.3 / 5 (3) Jun 07, 2015
The idea is to recover the propulsion bay and the engine, which account for 80 percent of the launcher's total value,


This is what I pointed out with the SpaceX rocket as well. It's pointless to waste fuel and payload capacity into getting the whole thing back in one piece. SpaceX would save a lot more if they installed parachutes and used the empty fuel tank as a crash cushion, because they could then launch more payload per mission.

SpaceX launcher is NOT being build to land at sea. It's just how they test it.


They can't land it on land because it has to be launched east over the sea to prevent debris dropping over people if the launch fails. To fly it all the way back to the launchpad under rocket power would require reversing the ballistic trajectory, which would consume all of the fuel and all of the payload capacity, so they have no option but to drop it down in water.

lutoit
not rated yet Jun 07, 2015
The cost of the propellant added by Spacex is unsignificant respect the total cost of the rocket.

Spacex proved They can land on a solid surface without problem.

Spacex guys have to launch their missiles from California or NM and land both the stages on solid terrain without fuel expensive manouvres.
gkam
1 / 5 (1) Jun 07, 2015
At least these will be unmanned. Too many risks to include people. Our rocket-powered aircraft in the service were very sensitive to control. Yeager lost one of our NF-104 Space Trainers from sloppy flying.

These will be interesting tests.
zoljah
not rated yet Jun 07, 2015

They can't land it on land because it has to be launched east over the sea to prevent debris dropping over people if the launch fails. To fly it all the way back to the launchpad under rocket power would require reversing the ballistic trajectory, which would consume all of the fuel and all of the payload capacity, so they have no option but to drop it down in water.


bitte,
expand your way of thinking on that case.
sugmullun
2.5 / 5 (2) Jun 07, 2015
By the time this flies...if it flies... SpaceX will probably have made it's first landing on Mars.
coryatjohn
not rated yet Jun 07, 2015
I think comparing a concept that won't fly until 2020 to what SpaceX is doing today is hardly a worthy comparison. One can only imagine what SpaceX will be doing in 10 years. Besides, if the concept Airbus is taking has merit, you can bet that SpaceX engineers will give it a try and have it flying in 1/3 the time for 1/10th the cost.
Eikka
5 / 5 (1) Jun 08, 2015
The cost of the propellant added by Spacex is unsignificant respect the total cost of the rocket.


There's an exponential relationship between payload and fuel in rockets, where a small amount of excess weight ends up consuming a large amount of fuel. The small amount of fuel used for the return trip acts as if it were payload on the way up, and reduces directly from the amount they can lift to orbit.

The SpaceX rocket's first stage has to separate at mach 6 to have enough fuel for return, instead of mach 10 which it would reach without, which means the subsequent rocket stages get left with 2/3 less kinetic energy at the time of separation.

It's a very significant loss.


Spacex proved They can land on a solid surface without problem.


In perfect weather.

Spacex guys have to launch their missiles from California


They can't because rockets are launched due east, and the debris would fall on populated areas.
Eikka
5 / 5 (1) Jun 08, 2015
Only the Russians launch space rockets over land - over Kazakhstan and Mongolia. They consequently get all sorts of stuff like leftovers of poisonous hypergolic fuels raining down on the steppes.

That's one of the reasons why they're shutting the Baikonur site down and moving over to Vostochny in the far eastern part of Russia, just north of the Chinese border.
Eikka
5 / 5 (1) Jun 08, 2015
One can only imagine what SpaceX will be doing in 10 years.


It's far less difficult to imagine what SpaceX will be doing in 5 years, since it's 2015 already. 2020 isn't the far future.

They're not going to turn their whole show around in that short timeframe even if it proves that the Airbus concept works better, because SpaceX doesn't actually have the engineering background - they're borrowing old NASA's designs for their rockets and building on top of that.

They're cheap and competetive now because all the R&D was done in the 50's and paid by the public.

Besides, if the concept Airbus is taking has merit, you can bet that SpaceX engineers will give it a try and have it flying in 1/3 the time for 1/10th the cost.


In order to do the same thing in just so many years, they'd have to essentially hire Boeing or Orbital ATK - their rival - to design it for them, because SpaceX doesn't have the expertise itself.

Eikka
5 / 5 (1) Jun 08, 2015
expand your way of thinking on that case.


There's nothing to expand. They simply aren't allowed to launch over land, and they can't get back to the launchpad without losing nearly all the payload capacity, so they have to drop down at sea. To reach orbits such as the ISS, you have to launch eastward, and so your only choice is to launch from the east coast.

http://www.scient...florida/
You mention that it had to be on the east coast so the launch would climb over the ocean. Why do launches have to go east rather than, say, west from California?
When you launch headed east, you gain the rotation of the Earth in terms of acceleration. And so you don't have to have quite as powerful a rocket.


The Vandenberg Air Force Base in California is designed for launching rockets into polar orbits. They're launching south - again over water.

Eikka
5 / 5 (1) Jun 08, 2015
Besides, the orbits of satellites are not all exactly equatorial. The ISS for example is highly inclined so it would fly over as much of the earth as practical. Different launches have different inclinations, so the rocket gets aimed south-east or north-east and can't have a fixed landing site even if it was down the range. They'd need to use yet more fuel to steer the rocket to it, and get even less payload to orbit.

So what's the only way to make a landing site that catches your rocket regardless of the direction you go?

You put it on a boat.

All the talk about launching and landing on the same spot was just early marketing hype from SpaceX.
Urgelt
5 / 5 (2) Jun 08, 2015
I find it hard to credit that anyone who is truly interested in this subject hasn't bothered to learn that the Space-X reusable launcher concept is *not* being developed for at-sea landings on barges. That's only a test phase; they have said many times that they intend to recover the booster at a spaceport. Which they can't do in the early test phases; it's simply too dangerous until they have a firm grip on the technology involved.
lutoit
1 / 5 (1) Jun 08, 2015
The payload is just few percent ot the total mass of the rocket it is a nothing to do with fuel.
A 100 ton full load rocket with a 5% payload = 10 ton of empty mass rocket + 5 ton payload + 85 ton fuel/lox.

Lets add 5 tons of wings, landing gears and the other stuff for make a landing proof rocket.
You say: OK no payload.
Whereas you have sumply to build a 200 ton rocket.

200 ton full load rocket = 15 ton empty rocket (10 + 5 added for reusable) + 5 ton payload + 180 ton fuel/lox.

Et voilà! You have the same payload by simply consuming the double amount of fuel ... lets say 100K $!

I don't see any stopover for landing in a barge and there are no impediment for Spacex to simply relocate to Hawaii or some better equatorial location.
However if a reliable number of launch will be accounted I'll bet Spacex will launch their rockets from Arizona or Texas.
The debris problem will be coped by the tradeoff of insurance costs/potential damage/reliability of the rocket.
lutoit
1 / 5 (1) Jun 08, 2015
The second stage may be recovered by landing it in Morocco.

I totally agree with you about the nosense for flybacks.

The ESA way for a reusable rocket, imho, appears far worse tha spacex one.
It is a partial recover of the rocket and there are a lot of dead weight like landing gears, turboprop, wings.

Far better the Skylon for a winged SSTO.
Eikka
5 / 5 (2) Jun 09, 2015
That's only a test phase; they have said many times that they intend to recover the booster at a spaceport.


Yes - they intend - but that's something they'll never achieve.

The payload is just few percent ot the total mass of the rocket it is a nothing to do with fuel.


It has everything to do with the fuel. The reason WHY the payload is such a small percentage of the total mass is because it takes exponentially more fuel to orbit the more payload you add.

If you add one pound, you need to add enough fuel to lift that to orbit, and then more fuel to lift that fuel, and then more fuel to lift that fuel...

The reason you don't need infinite fuel is because the rocket sheds mass when it flies. A typical rocket has about 15% fraction for "other than fuel", of which 5% is the payload. The fuel required for return has to fit within the other 10%

SpaceX simply claims they've figured other weight savings to limit the payload loss to 30%
Eikka
4 / 5 (2) Jun 09, 2015
It gets rather complicated to consider second and third stages, so let's look at just the first stage and make a standard comparison. Suppose the rocket is 85% fuel for the acceleration, 10% engines and 5% payload, and it lobs that payload off at say mach 10. The payload is the rest of the rocket which flies to orbit; at this point it's just dead weight.

So, to get that remaining 10% of the mass back to base, you first need to stop it completely, and then accelerate it backwards to mach 10 to fly back before it slams into the lower atmosphere.

Approximately similiar ratios apply for each equal change in velocity, so the returning 10% must consist of about 85% fuel to stop in mid-air, and of the remaining part again 85% must be fuel to accelerate it towards the base. Of the starting mass, only 2.25% remain, of which a part must be fuel again to land it.

To get a rocket, fly up, brake, reverse and land back where it started, all you could return is the paint on its skin.
Eikka
5 / 5 (1) Jun 09, 2015
There's a decimal point error in the previous message:

Of the starting mass, only 0.225% will remain to return back to base.

That's why SpaceX can't even afford the fuel for a full stop at the apogee, much less reversing the ballistic trajectory to get back. They're already tapping into the payload fraction and the ascent fuel, and that's enough - after help from air drag - to get them to a controlled stop hundreds of miles down the range.

Eikka
5 / 5 (2) Jun 09, 2015
I'm guessing that Elon Musk simply ran his mouth well before the engineers came back with the calculations to say that it won't be done, so he can't really back off now without losing face (and investors), so he's holding the idea of returning back to base as a pie in the sky marketing teaser.

The Airbus idea is much more realistic: toss the heaviest cheapest bit, fly the most expensive bit home using virtually no fuel. Much less loss in payload - and it's actually doable.
Eikka
5 / 5 (2) Jun 09, 2015
If you're interested in the theory of the problem, look at the Tsiolkovsky rocket equation. It describes how much mass in fuel you need to perform a certain velocity change with a rocket.

http://en.wikiped...equation

One apparent solution to the issue, which SpaceX is already employing to get them so far, is simply separating at a lower velocity which reduces the necessary mass ratio, but this is only an apparent solution because it leaves the separating second stage with less speed, and therefore -it- needs a larger fuel mass ratio to reach orbit.

The ESA way for a reusable rocket, imho, appears far worse tha spacex one.
It is a partial recover of the rocket and there are a lot of dead weight like landing gears, turboprop, wings.


It's a simple loss of the weight of the machinery, instead of having to lift fuel to lift fuel to lift more fuel.

And who knows, maybe the turboprops can assist on takeoff by being efficient.
javjav
not rated yet Jun 09, 2015
you are missing an important point here. A reusable rocket could use more efficient engines like ATK / shuttle. They are simply too expensive for one use, but not for a reusable rocket. The same apply to lighter materials like titanium and expensive alloys. Still not enough to compensate? just do more launches, as they are cheap for a reusable rocket.
Said that, Airbus proposal make sense, but they should find a way to use the wing engines also during the initial launch ( to reduce number of rocket engines and compensate weight )
lutoit
1 / 5 (1) Jun 09, 2015
The reentry of the second stage doen't need so much fuel.

You don't have to stop a second stage by burning fuel, the friction with upper atmosphere do the job.

If Spacex will be able to decelerate the second stage to mach 10 by friction and parachutes a full reusable is doable.

The payload ratio is irrelevant.

If You have a expendable rocket with a 5% payload and You have the skill to build a reusable rocket with a mere payload of 1% by simply building a five sized reusable rocket You obtain the same nominal payload, by burning five more amounts of propellant/LOX.
Propellant/LOX cost 0.3% - 0.5% of the total cost mission for a expendable rocket so a reusable should cost 1.5% - 2.5% respect a expendable.
Than adding the cost for recover and refit of the stages it is possible to obtain a huge saving in costs.
Eikka
5 / 5 (1) Jun 10, 2015
A reusable rocket could use more efficient engines like ATK / shuttle.


That is true, but the question is about whether the better engines are that much more efficient for cost. Remember, the rocket has already lost a third of its lifting capacity to orbit, so you need to first make that up, and then make up for the cost of the more complex engines.

Then you also have to factor in the probability of a launch failure and total loss of the rocket.

You don't have to stop a second stage by burning fuel, the friction with upper atmosphere do the job.


Yes, but we're talking about the first stage. The second stage isn't even under consideration yet.

The payload ratio is irrelevant.


It's the most relevant thing there is. If you get 30% less stuff to orbit per launch, the cost to orbit increases by 42% and the returned first stage barely covers the difference, which is why you need to launch it 10-12 times to make it economically feasible.



Eikka
5 / 5 (1) Jun 10, 2015
If You have a expendable rocket with a 5% payload and You have the skill to build a reusable rocket with a mere payload of 1% by simply building a five sized reusable rocket You obtain the same nominal payload


Yes, but rockets don't scale up linearily. Getting the 5x rocket up requires more than 5x the rocket, and more than 5x the cost.

And speaking of the second stage, which now needs to perform a larger velocity change to reach orbit because the first stage is slower, the prospect of returning IT for re-use are worse, since the larger velocity change requires a larger fuel-mass ratio, leaving even less for the return journey.

If it doesn't do a braking burn, it will burn up or break down on re-entry into the atmosphere because it has too much speed - nearly orbital velocity - and if it does brake, then it has no room left over for the payload from the fuel.

Eikka
5 / 5 (1) Jun 10, 2015
just do more launches, as they are cheap for a reusable rocket.


One of the selling points of the SpaceX's simple engines is that they're very robust with a low probability of failure. A more complex engine like the Space Shuttle one requires more upkeep to keep the failure probability in check, which is the fundamental issue why the Shuttle program was never cost-efficient. They ignored the risk, and then Challenger happened.

The shuttle fleet were originally designed to launch almost once a week, but ended up launching about once every 5-6 weeks due to the extensive overhauls between flights to keep it safe.

Turns out they couldn't "just do more launches".

SpaceX is also limited in how many times they can launch in a year because of weather considerations. They have to wait until the weather is clear on both the launch and the landing sites, because they can't land the rocket in wind and rain. It's just too unstable for that.
lutoit
1 / 5 (1) Jun 10, 2015
The new Spacex's methane/lox engine will allow a better performing second stage infact, Imho the plan is to recover the second stage with the new engine not the old RP1 engine.

The total loos is a risk involving every flying rocket.

"Yes, but rockets don't scale up linearily. Getting the 5x rocket up requires more than 5x the rocket, and more than 5x the cost."

It is only a example.
Let put : You have to multiply fivefold the number of lauchs!

There are the weather uncertainty, obvious!

Why are You discounting the fact that SpaceX has to launch their rockets from a single pad?
I'll bet SpaceX is evaluating a number of locations around the world, Indonesia, Morocco, Australia, why not Arabia or multiple landing site in the middle or caraibean isles or pacific ones?
jeremy_h
not rated yet Jun 10, 2015
I'll bet SpaceX is evaluating a number of locations around the world

The International Traffic in Arms Regulation (ITAR) actually forbids launching any US-developped rocket outside the US.
This regulation is intended to avoid sensitive US technologies falling in the wrong hand and being used against its creator, and a few other reasons.
Eikka
5 / 5 (1) Jun 10, 2015
Imho the plan is to recover the second stage with the new engine not the old RP1 engine.


At this moment they're only planning to recover the first stage. The second stage recovery isn't on the table at all.

The total loos is a risk involving every flying rocket.


The total loss risk becomes significant when you're flying the same rocket over and over again.

If the risk of failure of a single flight is 2% then the risk of total loss before it reaches 10 launches is actually 18.3%

So even a small failure risk means that a significant number of the rockets will be destroyed before they reach a sufficient number of launches to pay themselves back. The surviving rockets must then survive even more launches to negate the cost.
lutoit
1 / 5 (1) Jun 11, 2015
""The International Traffic in Arms Regulation (ITAR) actually forbids launching any US-developped rocket outside the US.""

When Spacex will reach the first reusable rocket landing there will be a lot of foreign deep pocket competitors cloning the Falcon.

Before the first falcon clone will take off the ITAR will be dismissed.
lutoit
1 / 5 (1) Jun 11, 2015
"At this moment they're only planning to recover the first stage. The second stage recovery isn't on the table at all."

Infact, they have to reuse the first stage first, this move should put the price of the Falcon under 20M$ price tag from over 60M$.
The reusable secon stage should reduce the price to 5M$ from 20M$ enablig another marginal gain.
Spacex appears to be clever guys in planning their strategy.

The total loss depend only by the reliability of the rocket not the number of launch.
Obviously, a companyy launching thousands rockets will gain Huge experience and knowledge whereas a company launching a single rocket not, with the same risck of total loss.
A company with a rocket never launched will mantain its standing record of 100% reliability.
lutoit
1 / 5 (1) Jun 11, 2015
"One of the selling points of the SpaceX's simple engines is that they're very robust with a low probability of failure. A more complex engine like the Space Shuttle one requires more upkeep to keep the failure probability in check, which is the fundamental issue why the Shuttle program was never cost-efficient. They ignored the risk, and then Challenger happened."

Spacex will not use SRB or sidemounted EFT, nor LH and SpaceX will not usa a winged spacecraft like ESA is trying to do nowadays.
A dead end.

The only way to do a winged spaceship il Skylon.
Eikka
5 / 5 (1) Jun 11, 2015
The total loss depend only by the reliability of the rocket not the number of launch.


You don't seem to have any idea of how probability works.

The probability that the rocket fails increases with every subsequent lauch until at some point it is practically guaranteed to fail, no matter how reliable the rocket is.

Careful maintenance reduces the odds that the rocket fails, but won't eliminate it. Eventually it must break down, so you can't keep re-using the rocket forever, and you can't even use it until it fails because it wouldn't be attractive to your customers to know that one of the rockets will break down with their expensive cargo.

jeremy_h
5 / 5 (1) Jun 11, 2015
Before the first falcon clone will take off the ITAR will be dismissed.

Clones (or copies) won't change anything.
Any technology used for space (commercial, NASA-related, or defense) typically is ITAR controlled because it is integrated with launch vehicles which automatically come under the ITAR (Category IV).
Clones of military night-vision devices exists, but they are still ITAR-regulated (Category XII).

When Spacex will reach the first reusable rocket landing

If they manage to do it.
At least the Airbus concept can take advantage of aerobraking to reduce its fuel requirement for landing (even negate it), something a rocket can't (they usually crash rather than land softly) so a rocket will need to double its deltaV to return to its launching pad.
For a deltaV of 3.4 km/s, the normal rocket's lower stage must be 63% fuel, on the other hand a SpaceX lower stage must be 86% fuel, decreasing significantly the payload (using LH2 fuel, CH4 will be even higher).
lutoit
1 / 5 (1) Jun 12, 2015
Jeremy the clones I'm speaking about are from foreign states/corporations.

For example China reversed the stealth tech or another wxample Brasil lauch its satellites with China vector.

There will be no problem to reverse engineering a Falcon, methane/lox is not new tech, a TSTO is not anew tech, automated landing softaware and a couple of landin legs are not based on exotic tech.
China, India, Russia, Brasil are plenty of money, smart people and willingness, knowledged and experienced workers can travel wherever they find a better paycheck.

It is onlly a matter of 'when'.

Itar will be dismissed or US will be let behind.

Again: there is no difference in how You try to make a first stage reusable, add fuel, wings, landing gears, heat shields, parachutes or whatever You want.
A reusable stage will exprience a loss of payload.
Airbus concept is a couple of heavy supersonic wings that must stand max aerodynamic load, landing gears, turbofan with fuel and avionics.
lutoit
1 / 5 (1) Jun 12, 2015
Eikka, You are speaking about: 'the fact that there will be a failure'

Failure is day bay day business in rocket industry.

The risk is factored in to the launch price, the company able to run a big number of launchs will have simply a better experience a better reliance and a fraction of fixed costs.

I don't know if the falcon stage will be reusable for 2, 5, 10, 50 launchs, obiusly specific components have different life cicle.
If a falcon stage is able to stand 10 launch on the paper and there is a 1% failure per launch, the median life cicle of the stage will be for 9 launchs.
The real numbers will dictate than the success or not.
lutoit
1 / 5 (1) Jun 12, 2015
Jeremy: .. At least the Airbus concept can take advantage of aerobraking ...

A rocket stage can do a aerobraking reentry but never existed a reason to do it.

SpaceX invented nothing new.
The mindset is relevant.

By thinking to a reusable stage SpaceX guys made their rockets with multiple engines, able to survive to a engine failure, They switched to methane for a long life cicle, They started with a step by step approach for first stage recovery only.

In my opinion SpaceX is evaluating a second stage reentry based on heat shields, aerobraking, inflatable.
jeremy_h
not rated yet Jun 12, 2015
ITAR will be dismissed or US will be left behind

Then, tell me why the US is still number one in defense and aerospace exports ?
All these items are ITAR-controlled but the US is still at the top.
http://www.sipri....industry
The fact is if you want to use SpaceX launchers, then you send your cargo to SpaceX, it's not SpaceX coming to you, so why the US would be left behind if they operate inside their borders only?
It's true that a few deals have not been brokered because of ITAR, but the fact is that the US is recognized internationally to be the leader in aerospace and defense and so countries will still use their service because of this aura, with or without ITAR.

A reusable stage will exprience a loss of payload

But the trick is to find the ideal option, the one that gives you maximum payload for the minimum amount of fuel, and as far as I'm concerned, SpaceX is not meeting this criterion.
lutoit
1 / 5 (1) Jun 12, 2015
SpaceX is meeting the criterion infact they delivered a payload to orbit with their Falcon already.
The failure of the landing on the barge doen't change the fact they proved a reusable first stage.

About ITAR: don't miss the point.

If a soil landing in necessary (I doubt) and if ITAR is preventing SpaceX from landing the stages on solid soil simply Spacex or future competitors will operate in Brasil or north Africa with a clear competitive advantage, than or ITAR will allow solid soil landing for reusable or the launch business will move fron US to another country.
lutoit
1 / 5 (1) Jun 12, 2015
The turboprop of Airbus concept may operate at low speed, a turboprop lift-assist launch is limited to the first seconds of the launch than the propellers has to be folded.
Calculating the total economy of the rocket should account for the increased aerodynamic drag, it is difficult to say if there is a gain in performance.
jeremy_h
not rated yet Jun 12, 2015
if ITAR is preventing SpaceX from landing the stages on solid soil

It seems you didn't actually understand what ITAR does.
It simply forbids the operation of US-developped rocket outside the US but you can still launch or land a rocket in the national borders.

SpaceX is meeting the criterion

Yes, all rockets meets the criterion as I stated it, of course. What I meant was they don't meet it as greatly as the Skylon, for example.

should account for the increased aerodynamic drag

I think Airbus guys have already done that by stating it will require 2 tonnes of fuel.
SoylentGrin
not rated yet Jun 12, 2015
...nevermind...
Eikka
not rated yet Jun 13, 2015
If a falcon stage is able to stand 10 launch on the paper and there is a 1% failure per launch, the median life cicle of the stage will be for 9 launchs.
The real numbers will dictate than the success or not.


That's my point exactly.

If it takes 9 launches just to break even in cost, then with a 1% failure rate, half the rockets never get to the number of launches that would make them cheaper than just launching expendable rockets.

Although 1% is a very very high failure rate. The company won't get any customers if the customers know that they have a 50/50 chance of failure on a certain re-launch of a certain rocket because it's already been launched 8 times before. They don't want to play Russian roulette.

1% failure rate would be permissible for an expendable rocket, because each launch has an independent probability of failure, whereas the re-launched rocket is like stepping onboard a 70-year-old Tupolev and crossing your fingers.
lutoit
1 / 5 (1) Jun 14, 2015
Jeremy, I'm stating that SpaceX may land the stages on land by launching the rockets from california, New Mexico or Arizona avoiding the needs of flybacks.

I'm speaking about the takeoff drag.
lutoit
1 / 5 (1) Jun 14, 2015
Eikka the stages are refitted, it is not true that they will be like a tupolev.

The day by day running of launchs will set how many launchs can stand a stage, or the costs of refit.
Maybe a stage will reusable for 5 or 10 or 50, I suppose that the number will be low than if will increase, and the refit costs will follow.

SpaceX already has big customers and they will increase when there are a >20M$ available.

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