A nice solid bit of writing.
Oh, alright then.
The European Space Agency has announced its selection for the rocket design which will replace the mighty Ariane 5 as Europe's workhorse launch system. OK, forget power and people. You want cheap? Here it is. The planned new Ariane 6, which will fly in the early 2020s, is to employ an unusual arrangement of engines and …
A nice solid bit of writing.
Oh, alright then.
Nice and informative article from Mr. Page.
These private-sector space ventures are anything but, Musk's efforts and ambititions are admirable and all, but the reality is massive handouts from the state.
X prize was the precedent, the winning entry was from a massively US defense-subsidised company, and was reliant on tech derived from that. I enjoyed the video at the time, also love the pilot, and the shuttlecock concept, but their team should have been disqualified as totally reliant on the govt.
Liquid fuelled rockets have a much smoother ride to orbit. Solids are rough as hell on people and equipment.
_That_ was (and is) one of the major objections to putting peple on top of Ares (or any other solid-fuelled stack)
That said, solids are a hell of a lot cheaper - none of that pesky LOX to handle. Just be sure your flight spares are packed away securely, as you might need them more often.
(All this assumes we don't hit tipping point with all the junk in LEO making ascent to higher planes difficult. It seems to be getting closer)
The BBC article on this (http://www.bbc.co.uk/news/science-environment-23241158) says that the upper stage is designed to be sent back into the atmosphere specifically to avoid adding to the space junk issue.
I also thought that another issue with SRBs and manned flight was the partial failure problem. i.e. that you have to be sure that none of them light or that all of them light. I think one of the nightmare scenarios for the shuttle was that only one SRB would light and the concern as to whether the pad would survive holding down an SRB for two minutes.
I seem to remember reading about the ability to partly throttle a solid, but can't remember where, and can't remember what the trade-offs are (there are always trade-off when you add a feature!). I'm not directly involved in that side of things, it's only a passing interest.
On the subject of being able to shut-down a solid, they tend to be much, much more reliable, so you don't have to light them up and check all the telemetries to decide to launch or not, like you do with a liquid. Also it is possible to shut one down by firing a cutting cord around the top; the sudden pressure release in the opposite direction stops the acceleration and allows you to contain where the mess ends up a little (although you've still lost the launcher). In this scenario, I don't know if there is any benefit in trying to get the 3rd stage to separate to save the payload, but the 3rd stage is optimised for working in vacuum and with less mass (no cover over the payload), so not sure if the thrust/control would be enough in the atmosphere.
"I seem to remember reading about the ability to partly throttle a solid, but can't remember where, and can't remember what the trade-offs are (there are always trade-off when you add a feature!). I'm not directly involved in that side of things, it's only a passing interest."
You stick a moveable pintle in the throat. IIRC Aerojet did this for a US anti armour missile design competition. The "turndown ratio" as they called it was something like 10 or 20:1, so quite good for a long cruise over the battlefield. ElReg did cover it. Downside is complexity (pintle runs hot and you need an actuator that does not get cooked.
"On the subject of being able to shut-down a solid, they tend to be much, much more reliable, "
They do indeed make excellent weapon systems.
"Also it is possible to shut one down by firing a cutting cord around the top; "
Or Polaris, which cut the bottom end off instead.
Shutdown methods for solids do exist. The issue has been doing it for big solids (which this, shuttle SRB and the monster 160" that NASA wanted as a strapon for the Saturn V) without the shock loads that tend to snap the necks of anyone on board a vehicle attached to the rocket, which is why they deleted a possible method from the Shuttle SRBs and the procedure was "Hang on tight and if you're still alive after burnout go onto step 2".
The liquid fueled upper stage could allow abort to orbit (if a lower stage failure did not tear the stack to bits)
wow - I'd not heard of that method of shutting down an SRB before! From a shuttle crew point of view I'm not entirely sure that cutting the top off a lit SRB and thus presumably sending a fairly unconstrained flame up past your ears (and past the top of the main tank) is an immediately obvious improvement on the situation but I guess (as per JS19's comment) cutting the bottom off to reduce the pressure but keep the exhaust heading into the flame pit could help.
It still all makes me curious as to the general thought processes:
-So, we're going to attach you to this big firework to get you into space...
-How do you get it going?
-Big pyrotechnic thing up the middle of it set off with an explosive detonator...
-How do you stop it falling over?
-How do you undo them at the right time?
-We don't. They explode...
-Err, OK. What happens if you need to stop the big firework?
-Ah, that's easy - we've wrapped more explosive round the top and/or bottom of it to chop the ends off...
Not so much rocket science as officially approved pyromania!
Ariane5 is liquid fueled because the bottom half is a French SLBM
A clever way to get industry and other governments to fund development of your military toys
Concerning manned launches, one of the major safety concerns for solids is the debris cloud in the event of a catastrophic failure. The solid fuel may may scatter and continue to burn across a wide area, and incinerate the parachute of any capsule descending through it following an abort.
You can see such a cloud in this footage of a Titan IV failure in the 90's.
This risk was highlight as a major concern for Ares 1, and had not been resolved when the launched was cancelled. The shuttle of course had no launch escape system.
I also notice that BBC article says they're aiming to get Ariane 6 "down to" $90m/launch in order to remain "competitive".
Falcon 9 is advertised at $54m/launch for broadly similar payloads and capabilities. You can even split the cost with secondary & tertiary payload customers. I'm not sure when being undercut by 40% became "competitive".
And you've got proven redundancy on Falcon in case of an engine-out (okay, so on CRS-1 the secondary payload still didn't make it but that was because it was sharing a CRS mission and NASA wouldn't authorise a second burn due to ISS proximity. A 2-satellite launch would probably get authority on the second burn and get both payloads to orbit).
I also wonder how Arianespace are spending that much money when they're only using 4 solids and a LOX? As opposed to 10 relatively complex liquid motors on Falcon 9!? Is 1 LOX motor undoing all the cost savings of using cheaper solids? I think not...
Anyway, thumbs up to Musk and SpaceX for giving the industry a giant boot up the backside to raise their game.
> Ariane5 is liquid fueled because the bottom half is a French SLBM
You get this pretty ass-backwards.
"the concern as to whether the pad would survive holding down an SRB for two minutes"
Ooh! An easy one! It wouldn't. Once the SRB lit it was going somewhere, the question was how much else of the stack went with it. If both lit at the same time then everything was fine, if only one lit then the external tank was going to rip in half. The hold down bolts were triggered by the same signal that fired the SRBs anyway.
There were a couple of cases where the explosive nuts on hold down bolts failed to fire. Either the bolt would stretch and snap (it was actually designed to do that) or the whole thing would pull through the skirt of the SRB.
Ariane 5 liquid fuel is LOX and LH2. Those are CERTAINLY too high-maintenance for use in a Ballistic Missle.
"A clever way to get industry and other governments to fund development of your military toys"
Absolutely. The Japanese do this. Their H-II vehicle uses strap-on solid rocket boosters, maintaining an expertise base in solid rocketry, which could presumably be repurposed to weapons development in extremely short order.
Europe actually already does this too. The Vega rocket, while small, uses a similar "all"-solid setup, with the rocket motors being produced in Italy, similarly maintaining Italian expertise in solid rocketry, which again could be repurposed.
I though that SpaceX's costs were roughly on a par with those of Ariane? Anyway it's a bit of a nonsense to pretend that SpaceX is so much more private and efficient than EADS: it has a nice reliable contract from NASA for the work. The important thing is moving from the traditional cost plus arrangement. But if it ever gets involved in DARPA work then the usual rules are likely to apply: cost explosion, secrecy and silliness.
Also Arianes' cost estimates are based on actually doing this for decades, SpaceXs are marketing projections of what they hope to achieve.
Both lying like weasels of course but with different standard deviations
They are nowadays generally seen as an option more suitable to government operations where a lot of performance is wanted and quick launch and cost are not the primary issues
I think that "cost not an issue" window may be shrinking as real-world economics snap back.
What's that? A brand-new governmental printshop? Oh carry on...
Incredible. Rather than try to take the lead in developing new space technlogies such as reusable launchers they apparently decided to give up and try to make some money by launching GEO sats on a yet to be designed piece of artillery.
Quite the opposite vision as what the EU's new semconductors strategy.
The cynical part of me is wondering how long the naming committee took to come up with that...
"The cynical part of me is wondering how long the naming committee took to come up with that..."
From the people who bought you "Le Transporter 3" perhaps?
> how long the naming committee took
12 lobster dinners in 12 different resorts around the planet, one imagines.
"SpaceX Falcons ... still look likely to beat any government outfit you care to name on cost".
Newsflash: ESA does not design and build the rockets. Arianespace was the first commercial space transportation company, already since the 1980's. With Astrium and EADS the space business has been commercialized since decades .The Americans are a few decades behind with that concept! Perhaps the mains reason space ships have been cheaper to build and operate generally for ESA the last two decades! Now some of those concepts are starting to be employed only now in a cash strapped NASA ecosystem?
While one could argue government cash flows and partial shareholding still might justify a term like "government outfit", the implied uniqueness of some non-governmental SpaceX sounds rather unrealistic and dated. The main difference is US cash flow and the local industrial ecosystem that puts SpaceX in a brilliant position to compete with the rest. And that's good.
Check out the customer list of "government outfit" that delivers the Ariane technology.
" ESA does not design and build the rockets. A"
ESA collects the cash off member states.
ESA hands it to the French space agency CNES.
CNES Hands most of it to EADS Astrium
EADS Astrium do the design and dish out the mfg work in proportion to whatever countries coughed up the cash. So Belgium got the Epic Fail that is the VAB GNC package (It's carbon fibre, it's an FO INS system and A5 is 1/2 the diameter of the Saturn V but it weighs the same as the unit doing the same job with 50Kg spinning metal gyros and a 100Kg GN2 tank designed to support a 100 mt payload sitting on top of it) while the UK did the exhaust pipes from the gas generators on the Vulcaine 2 engines.
Then CNES "transfers" the results to Arianespace, (which it partly owns).
Presumably Arianspace hands ESA something back for developing its next product, but I'm not quite sure how much. If I got handed a multi $Billion dollar product every 5-10 years with no development costs I would expect to make a profit too.
Aside from not having to absorb those costs Arianespace is meant to be very good at financing launches.
Arianspace is nowhere near Spacex. It is quite close to ULA, although without the blatant "Give us a $1Bn a year or we'll have to walk away from the launch biz" that ULA indulges in.
VAB GNC package ... it's an FO INS
Lighter on the acronyms please.
The VAB is French for the ring of hardware at the top of the stack holding the Inertial Navigation System, computers and other stuff. The parts in A5 are little bigger than a pack of cigarettes (and only a little bit more expensive, given the price of a pack of 20 these days) while those on the the Saturn 5 weighted about 100lb and spun up not electrically but with a 200lb Nitrogen gas tank. I may however be wrong in call them Fibre Optic based, but they are certainly laser based).
Just on size alone it should less than 1/2 that weight and with a maximum payload on A5 of 1/8 that of Saturn V it should be lighter still. As it sits at the top of the stack any weight saving would go directly to useable payload mass.
Given the 20+ years between them I was not very impressed by it's performance.
Arianespace was created to operate and market the launch vehicles, it's not responsible for design. That responsibility remains with ESA, which contracts it out to national space agencies and private industry.
It is considered the first commercial operator, because until the Space Act was reformed by the Reagan administration in '84, only NASA could operate launch vehicles in the US (Military excluded). Following the reforms manufacturers such as Boeing and McDonnell Douglas became launch service providers as well as manufacturers, able to operate and market their own vehicles as Arianespace did.
However, they failed to gain significant commercial payloads and with a few exclusions, these companies merged their products to become ULA.
CNES Hands most of it to EADS Astrium
I seriously doubt the "geo-return" (industrial handout in proportion to pay-in) percentages are fully in the hand of CNES.
They are however a royal pain in the arse and cause havoc with sensible allocation of tasks. Moreover, some aerospace companies are based in several countries and collect in each of them.
"I seriously doubt the "geo-return" (industrial handout in proportion to pay-in) percentages are fully in the hand of CNES."
Quite true. AFAIK it's set by who puts what in the ESA cash bag.
EADS Astrium then has the job of ensuring roughly the same portion of work is handed back to the partners.
Part of the reason why Europe is quite good at large systems of structured documentation. The sort needed to support large space projects like ISS, is it's SOP for each Ariane iteration.
Of course ESA/CNES/EADS has been a pretty cosy relationship for years. The same argument about subsidies was brought up in the Boeing versus Airbus case at the WTO: result US and European governments are guilty of subsidising their industries; in Europe it's more explicit but the contracts awarded to Boeing, Lockheed and co. perform the same function.
Arianespace currently operates successfully in a competitive environment (it has to tout for business because European governments don't spend as much money on spy satellites) and has a very impressive track record - this is important as insurance premiums are going to be significant for any new entrants to the market until they have established track records. SpaceX has had a very impressive start and it's to be hoped that it and other companies, including Arianespace, can continue to improve the market but, as we can never expect NASA to put any of these contracts out to fully competitive tender, ESA is going to continue to have a preferential relationship with EADS.
ESA still has ExoMars, JUICE and Solar Orbiter in its plans.
And they're funding the SABRE engine that might end up in Skylon.
That's true, but I think that the line you are refering to is talking about launchers for humans/deep space, not those projects per se.
I suspect that A6 will kill A5 ECA / A5 ME. A5 seems to have logistics problems finding a pair of medium heavy+medium light birds to fly together and ATV is finished. There probably aren't enough heavy loads launched each year to keep it going.
However the agency has already decided that they won't launch Solo - Nasa will do it - what could ever go wrong there; I mean they don't change their priorities every year and suddenly drop projects, do they (shhh don't mention Exo Mars)
Juice is due to be launched by A5, but Juice should arrive at the same time as A6. Depending on the timing, it should be OK for an A5, but the next heavy mission after Juice may not be so lucky.
We could always use the Proton M for heavy luanches of stuff like Exomars and new projects though.
The future is robot spaceplanes....
Funding for SABRE? I must have missed that snippet of information!
The Ariane 6 seems to be aimed at replacing the Soyuz spacecraft that ESA are currently operating from Kourou. They've got the Vega solid-fuel launcher (aka Berlusconi's Bottle Rocket) for small scientific payloads up to about 3 tonnes into LEO, the Soyuz for anything up to 8 tonnes or so and the full-fig Ariane V for the dual-GEO comms launches and Big Jobs like the ISS ATV cargoship (20 tonnes total into LEO). That gives them a full-spectrum launch capability that's not dependent on the Soviet^Russian Soyuz which is getting a bit long in the tooth. I don't know, for example, if the licencing agreement would allow ESA to fly military or intelligence payloads on Soyuz vehicles.
The only weirdness I can see is the intended use of the fully-cryogenic Da Vinci upper stage on the Ariane 6 as that adds expensive launchpad fuel handling problems that were mostly negated by the move to solids. A storable-propellant (N2O4/UDMH) upper stage would have been a better bet, methinks although probably giving less delta-V per tonne for payload insertions than LOX/LH2.
The Ariane 5 ME will continue to fly after (and if ever) the Ariane 6 starts taking GEO orders from its big sister. The comms people are designing bigger and bigger birds (Intelsat-20 was about 6 tonnes, too big for Falcon 9 v1.1 to launch into GTO) and at the moment the Ariane 5 has that market sewn up.
I thought Arianes' big selling point twas that although it wasn't the biggest mass to orbit launcher it's third stage was so precise you didn't need to waste mass/cost/time on putting a lot of booster technology in your payload?
ps Is there actually a market for GSO communications satellites anymore? I thought their capacity was so laughably behind fiber there was no point for phone calls and everybody was now watching ESPN and FOX over cable?
"ps Is there actually a market for GSO communications satellites anymore? I thought their capacity was so laughably behind fiber there was no point for phone calls and everybody was now watching ESPN and FOX over cable?"
Want to make an phone call from the middle of the ocean (any ocean) or a ship or plane and you're not a member of the US govt?
You're a news reporter who wants to send a report from a s**thole anywhere int he world to pretty much anywhere else?
There is also film distribution and (hard to believe) horse race and betting data broadcasting.
The main commercial market for GEO satellites is direct-broadcast and that's still big business especially in places like India and the Pacific where fibre to the home isn't really practical or cost-effective. The bigger the satellite the more transponders it can carry, the more manoeuvering fuel it can start with, more redundancy of components, larger solar arrays etc. etc. Intelsat-20, the heaviest GEO bird ever launched (along with a smaller GEO satellite by an Ariane 5 last August) has three tonnes of fuel on board and it is expected to operate for 15 years. It replaces two other satellites positioned to the south of India and covering large chunks of east Africa, central Russia, Indonesia, Korea and at the edge of its coverage it can transmit to Japan. If you've got a decent-sized steerable dish and are in the UK it's possible you might be able to pick up a signal from one if its transponders pointed at the Middle East.
>Want to make an phone call from the middle of the ocean (any ocean) or a ship or plane and you're not a member of the US govt?
Then you use a LEO relay system like Iridium or inmarsat.
You don't use a 3m dish accurately pointing at a GSO satelite 20,000 miles away
Comms are like roads: traffic always grows faster than capacity. Plus, anywhere of low population density is generally better served by satellite, for television at least.
Isn't Inmarsat Geostationary any more?
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