ESA lifting body entry vehicle on the cusp of final approval

[someone_else]

Article

A video of the IXV doing its mission, another with the designer commenting

PARIS -- The European Space Agency should formally approve this summer the construction of an Italian-led demonstrator that will launch into space on a rocket, fly back to Earth like an airplane and parachute into the Pacific Ocean, according to the mission's project manager.

The Intermediate Experimental Vehicle is on track to blast off on a Vega rocket in late 2013, speed around the Earth at a peak altitude of nearly 300 miles, then drop from space and fly back to Earth with the help of aerodynamic flaps and a parachute.

Giorgio Tumino, the IXV project manager at ESA, said the craft passed its final critical design review in May. Senior ESA officials are now firming up the spacecraft's cost before signing a contract with Thales Alenia Space of Italy to build the vehicle.

Formal approval for the contract signature should come from an industry planning committee meeting at the end of June, Tumino said in an interview.

"We are in quite an advanced stage of the program," Tumino said. "It's not paper, but it's reality. There is an internal European process for the approval of all the activities. We should be able to sign the actual contract by the end of this month."

Sandrine Bielecki, a Thales spokesperson, said the company signed an agreement to be the IXV's prime contractor in 2009. Individual contracts for design work and hardware production are handled separately.

After ESA and Thales sign a final production contract, there is a 27-month schedule planned to manufacture parts, build the spacecraft and test it before shipping the vehicle to the launch site in Kourou French Guiana.

The total cost of the mission is about 100 million euros, or about $143 million.

ESA has the money to build the spacecraft, but funding for Vega launcher will only come at the agency's next meeting of member states' ministers in late 2012. If ESA signs a launch contract then, IXV could be ready to fly in the fourth quarter of 2013, Tumino said.

"The objective now is to place the contract, build the vehicle and qualify it, then have it ready to be shipped to Kourou," Tumino said. "We really are now going to procure the contract for all the pieces necessary to run the mission. Now what we are missing at the next Ministerial [Council] is only the Vega launcher. We'll have all the pieces there to meet the launcher."

Construction should begin in September, according to Tumino.

The IXV program is emerging from a reorganization at the last Ministerial Council meeting in 2008. Italy increased their financial commitment to the project, and Thales Alenia Space of Italy was appointed prime contractor. An industrial consortium of EADS Astrium and Finmeccanica previously held the position.

The reorganization "induced some delays" as Thales Alenia Space got up to speed on the program, but now the IXV is ready to enter the production phase, according to Tumino.

Its mission will last just a few hours, but the IXV is a big step for Europe. The demo flight will not go into orbit, but the craft is a prototype for future vehicles that could service the International Space Station, land on other planets, or carry people to orbit.

The IXV mission builds on years of ESA development, including the Hermes space plane program shelved by Europe in 1992. Hermes was supposed to be Europe's version of the space shuttle, conceived as a mostly reusable ship able to carry people back forth to orbit.


But no Hermes shuttle was ever built despite considerable technological developments in the program. ESA's atmospheric re-entry demonstrator mission in 1998 proved out the Hermes flight control algorithms, but the IXV will fly with more a more advanced heat shield and working aerosurfaces. And it's shaped more like Hermes.

The mission also recycles ESA's research for the NASA-led X-38 crew return vehicle, a lifeboat for the space station that was scrapped in the last decade.

The IXV will fly with approximately 28 advanced ceramic heat shield tiles on its belly, while white ablative material will insulate the top of the vehicle during entry.

With no wings and a peculiar blunt cigar shape, the IXV won't land on a runway like the space shuttle. Instead, the 16-foot-long ship will gently fall into the Pacific Ocean under a parachute, where it will be retrieved by the Italian Navy or a commercial vessel. There is no landing gear.

But even without wings, the IXV is shaped as a lifting body, meaning it can maneuver in the atmosphere through a series of roll reversals. Movements of two electromechanical body flaps at the rear of the vehicle will steer the IXV during entry.

It has a lift-over-drag radio of 0.7, giving the IXV "more controllability during flight, more maneuverability, and eventually a precision landing," Tumino said.

The craft's shape means it flies through the atmosphere instead of falling like a capsule.

Engineers are targeting an error ellipse of about 3 miles on the IXV mission, but follow-on vehicles could land with even more precision.

"This is a demonstration mission. We will be launching from Kourou with a Vega launcher, and we have a set of ground segment stations which will support the mission," Tumino said. "Where the vehicle meets the atmosphere, the conditions will be equivalent to a return mission from low Earth orbit, so basically a 7.5 kilometers per second [16,777 mph] entry speed, so that we can experience all the key environmental features of such a re-entry mission."

The craft's nose will pitch up 40 degrees during re-entry, and it will bleed off speed in a series of roll maneuvers like the space shuttle.

Once officials wrap up contract negotiations this summer, some of their attention will turn to studying applications for the technology to be tested by the IXV. Tumino said the analysis will help prepare a proposal to ESA member states for the continuation of the program after the 2013 demo flight.

"We see opportunities and the possibility to go into orbit and perform ground landings, so to have a retrievable and reusable system," Tumino said. "It's not the space shuttle, which has a huge cost because it's a huge system. It would have to be contained in cost so it would be affordable for Europe to pursue."

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Wow, the ESA is beginning to do serious research in space vehicles.
And it's an italian company the one that will make the prototypes.

And they are working on a tiny rocket too. Vega, scheduled to be launched somewhere in the 2011 and mostly designed and payed by Italy.

I wonder what you think about the IXV design.

[erik_t]

It'll be nice to get more flight test data; it always is. However, it's just further populating a flight regime we already know a fair bit about. Combined with the rather limited instrumentation, it's not exactly groundbreaking. It's not a bad test vehicle or research program, but it's no HTV-2 either.

All of the IXV talks I've been to haven been pretty snooze-inducing.

[Falarica]

Could this new vehicle be the basis for a return capsule for the ATV? Assuming of course an Ariane V can lift both of them at the same time.

Still waiting on Skylon to be approved.

[someone_else]

Still waiting on Skylon to be approved.

if this is to be trusted, Skylon's main issue is not engineering, but having enough money.

[Sarevok]

Nah. The big question is will Skylon be cheaper than a conventional rocket.

[someone_else]

It will depend from the payload. There is no Solution-For-All.

Reusable vehicles in general should shine in carrying people (when they are relatively new) and supplies/propellants (after they are no longer safe enough for people, and they keep going up and down until failure). In any case, there is no real need for a pilot now.
Both relatively frequent and not overtly bulky cargo. Which is the best kind of mission profile for a reusable vehicle. The Shuttle was supposed to break even when making 25 missions per year. Something less stupid (and smaller) may be able to break even with 10 or even 5 missions per year.
Skylon is more or less on this league (theoretically). The payload isn't impressive per-se, but it should be able to fly often, much more often than anything else.

Real payloads (station sections, big sats) will still have to be lifted on rockets, since they won't be overtly frequent and any kind of rocket remains (and will likely remain) *vastly cheaper* than any reuasable vehicle that isn't working more or less constantly.
Designing a reusable vehicle with such very big payloads in mind is not practical for now, since they are too rare to have the vehicle fly enough times to break even (see the Shuttle as an example).

[erik_t]

Still waiting on Skylon to be approved.

if this is to be trusted, Skylon's main issue is not engineering, but having enough money.

Yeah, um, I wouldn't be holding my breath.

[someone_else]

yup, 17 billion $$$$ aren't going to be easy to find for a private company.

[erik_t]

Well, I'll give you one thing, it's rather more plausible than the hypersonic eco-train. This isn't exactly high praise.

[Skgoa]

It will depend from the payload. There is no Solution-For-All.

Reusable vehicles in general should shine in carrying people (when they are relatively new) and supplies/propellants (after they are no longer safe enough for people, and they keep going up and down until failure). In any case, there is no real need for a pilot now.
Both relatively frequent and not overtly bulky cargo. Which is the best kind of mission profile for a reusable vehicle. The Shuttle was supposed to break even when making 25 missions per year. Something less stupid (and smaller) may be able to break even with 10 or even 5 missions per year.
Skylon is more or less on this league (theoretically). The payload isn't impressive per-se, but it should be able to fly often, much more often than anything else.

Real payloads (station sections, big sats) will still have to be lifted on rockets, since they won't be overtly frequent and any kind of rocket remains (and will likely remain) *vastly cheaper* than any reuasable vehicle that isn't working more or less constantly.
Designing a reusable vehicle with such very big payloads in mind is not practical for now, since they are too rare to have the vehicle fly enough times to break even (see the Shuttle as an example).

Higher payload will also result in more structure around that payload and that will make even MORE structure around(/under) THAT neccessary for re-entry. Thus, for a reusable vehicle the price-payload function grows faster than for a non-reusable launcher. Making your reusable launch vehicle a single stage to orbit concept/pipedream like Skylon... lets say I doubt its going to be economically viable and leave it at that.

Oh and one factoid about launch cost: the rule of thumb for costs in a space mission is that roundabout a fifth of the whole costs are in the actual launch vehicle hardware. The biggest cost factor is the money the very highly skilled people take home every month. Thats a (relatively) fixed amount that doesn't change much even if there is a big increase in launches. Therefor ANY launch vehicle's cost per launch scales very favourably with the number of launches in lets say a year.

[Sarevok]

High performance jet engines have lifespans measured in hours. This is what worries me about Skylon. It's engines have to meet demands way beyond any rocket or jet engine in service. Then there is the reentry issue which again subjects the craft to unforgiving conditions. I am not an aerospace engineer so please forgive me I am wrong but I am on the impression that no machine built using real materials last for long under such conditions of high temperature and speed. Parts like the engines, which cost a huge sum, have to be thrown away and replaced often.

Just exactly how reusable is Skylon going to be if the craft requires to be essentially rebuilt after each flight ?

[someone_else]

Oh and one factoid about launch cost: the rule of thumb for costs in a space mission is that roundabout a fifth of the whole costs are in the actual launch vehicle hardware.

Good to know. I've been looking for something like this for ages.

It's engines have to meet demands way beyond any rocket or jet engine in service.

That's how something new is born. Technically even the first jet engines had a lifespan measured in days (then had to be more or less overhauled). And let's not talk at how crappy the first aircraft was (an impressive 12 seconds of powered flight!! OMFG!!!).
I'm fine with it. It's progress.

The article I linked above contains a link to a paper where experts review the design and don't find any real engineering issue, and that's pretty good news.

Even if Skylon proper will never fly (various good reasons, mostly the fact there is no request for such service for now), its SABRE engines (or their tech anyway) will still be useful for whatever the fuck else. Faster fighters, mach 5 high-endurance civil aircraft (that makes slightly more sense than Concord, and can be the next B52 bomber), and other SSTO concepts OF THE FUTURE!!!!

The engines are really the only revolutionary thing of Skylon, the rest is pretty conventional stuff.

Then there is the reentry issue which again subjects the craft to unforgiving conditions.

The system they plan to use for reentry is more focused on smarts than on heavy armor.
Their main trick is doing a longer trajectory to keep the temp around 1100 kelvins, and the vehicle shape and control surfaces allows them to do that (a little like the lifting body in the OP of this thread).

For comparison, Shuttle thermal protection had to withstand from 1500 to 1923 kelvins (depending on the place).

Shuttle designers opted to take a faster reentry for some reason (I hope they had a good reason, I don't know). But you don't have to necessarily go down so fast, and if you take a slower ride you can save on thermal protection.
And this means they don't have to use those tiles that are a pain in the ass when servicing the vehicle.

Just exactly how reusable is Skylon going to be if the craft requires to be essentially rebuilt after each flight ?

They plan to make it fly after a pit-stop of 2 days or so.
It's a challenge. It may not be a reachable goal (although doing better than Shuttle isn't anywhere near impossible, even if we ignore the obvious design flaws, it is damn old, and we also have the benefit of learning from its mistakes).

This isn't a government project, they won't build a goddamn thing it if it is *massively* sub-optimal like Shuttle. (I'm half-convinced that they will build the mach 5 aircraft and make profits out of that well before attempting any serious Skylon)
They don't have the money to keep the zombie alive just for kicks ala Shuttle if it does not turn a profit (it's already a miracle if they will find enough money to reach the end of the development).

Your bitching is ok for government projects, that waste time and money of taxes on stuff that is sub-optimal at best (and clearly dumb at worst) and gets built regardless, but hell, Skylon is using private money (his own and money from like-minded individuals) to make his dream come true. It's something that should be encouraged imho.

[Scorpion]

First of all, GO EUROPE!!!

This isn't a government project, they won't build a goddamn thing it if it is *massively* sub-optimal like Shuttle.

Why do you say the STS is sub-optimal? I'm genuinely curious. Thanks in advance for any enlightenment you may provide!

Scorpion

[Simon_Jester]

Some of the design requirements for the shuttle undermined its usefulness as a reusable heavy-lift vehicle.

For example, the Air Force made specifications about the space shuttle in terms of its "cross-range" capability- its ability to alter its path during reentry by making course changes. One of the big motives for that was so the Air Force could fly shuttles in polar orbits from Vandenberg Air Force Base for military missions. But redesigning the shuttle so it could make a lateral course change of over a thousand miles during reentry meant giving it bigger wings- which meant a heavier spaceplane with a bigger, bulkier thermal protection system.

Cross-range maneuvering capability isn't very useful for the east-to-west orbits flown by all historical shuttle missions; the capability was added- and with it, the weight and other design constraints- to allow for a mission that the shuttle was never used for.

[erik_t]

The crossrange requirement forced the delta wings (instead of the DC-3 that Faget preferred), but it was certainly not the only suboptimal aspect of the design. Perhaps more relevantly, at the time we just didn't know as much about the aerothermal environment that would be encountered by a high L/D reentry vehicle. For example, wall catalysis of radical species was a complete unknown, and the STS TPS was designed with the (very conservative) assumption of a fully catalytic surface (every free O is assumed to combine with another at the surface, dumping that binding energy into the surface), with the usual safety factor on top. The predicted heating rates for STS thus resulted in a TPS overdesigned by about a factor of two.

None of that changes the fact that I have to stifle laughter every time I look at anything related to Skylon.

[Skgoa]

Even worse than the crossrange requirement was the payload weigth/size one, imho. In order to get DoD approval/funding, NASA had to embiggen the orbiter to a size that was absolutely overkill for the missions it was supposed to go on.* So NASA ended up with a huge as orbiter that they have to get into space and back many times. (Fun fact: the orbiters have flown less missions in a greatly longer timespan than what they had been designed and built for.) And then the missions they wanted to fly didn't get funding. Yeah, great... you spend a metric fuckton of money on an HLV that - due to it being an RLV, too - requires a standing army of technicians to be on the payroll regardless of wether or not it actually flies that week/month/year and then they go and cut funding for almost anything you wanted to use it for. :bang:
Still, shttle launches themselves actually aren't as costly as many people think and over the whole lifetime of the program STS wasn't as uneconomical as the alternatives at the time.


* Which led to the problems simon and I already outlined in previous posts.

[K. A. Pital]

Still, shttle launches themselves actually aren't as costly as many people think and over the whole lifetime of the program STS wasn't as uneconomical as the alternatives at the time.
* Which led to the problems simon and I already outlined in previous posts.

STS mostly was a space station ferry. Alternative to that is the Soyuz. I heard Soyuz launches are cheap, so was it really cheaper than the alternatives (by which I mean stamping more Soyuzes, of course)?

[Skgoa]

Soyuz wasn't exactly available during the cold war.

[Scorpion]

Thanks from the replies, guys! I'd heard (don't remember where, probably a documentary somewhere) that the early STS concept was something like Burt Rutan's Spaceship One, a spacecraft carried to the upper atmosphere by a mother-aircraft and then launched, which would've been the optimal configuration (or so the doc claimed), but that the US Airforce wanted it to be vertically launched strapped to a rocket so it would be a kind of orbital bomber that could be launched on a moment's notice... Don't know if that's right...

[Simon_Jester]

Still, shttle launches themselves actually aren't as costly as many people think and over the whole lifetime of the program STS wasn't as uneconomical as the alternatives at the time.
* Which led to the problems simon and I already outlined in previous posts.

STS mostly was a space station ferry. Alternative to that is the Soyuz. I heard Soyuz launches are cheap, so was it really cheaper than the alternatives (by which I mean stamping more Soyuzes, of course)?

If STS had been designed as a space station ferry, and if the space stations it was designed to ferry people to had actually been built, with the heavy-lift mission being assigned to proper heavy-lift rockets, it would have been a much smaller, lighter, cheaper craft.

This is what Skgoa touched on.

Of course, we could have gone for an evolved version of the Apollo capsule for personnel transport, something more closely analogous to Soyuz, but there was never a compelling reason to do so.

And yeah, Scorpion, that's about the size of it. Though shuttles launched vertically strapped to a rocket aren't that unusual- the high speed aircraft mothership is a concept dating back to the '60s, but the job of actually designing and building the plane turned out to be very difficult.

What's screwy about the shuttle is that it's designed to be an orbital bomber and a heavy-lift vehicle capable of carrying large payloads into LEO and a personnel transport and reusable. That combination made it a very big, complicated craft.

[Sea Skimmer]

Actually the shuttle was designed with ferrying cargo and people to a space station as a prime mission. This would allow assembly and fueling of larger craft at the station which would then do interplanetary stuff, as well as mundane cargo like satellites. But all this depended on rather absurdly optimistic planning on usability. The shuttle was supposed to have a 14 day turnaround time on the ground. The shuttle was built without enough R&D budget to do what NASA wanted so its never fit any role well.

[someone_else]

Nah, air-launch has never been a particularly smart idea for any decent sized payload. The reason?

The biggest aircraft in the world today is the an 225, whose payload is around 250 tons inside or 200 tons outside.

The shuttle orbiter (the airplane-looking thing) weights around 100 tons alone. It will still need the same big orange tank full of fuel to reach orbit (at least).
No airplane ever imagined can lift enough weight to have a shuttle-like orbiter. It will be hard to place in orbit even a capsule with an existing aircraft.

Also, air-launch does not add a lot on the final goal (yeah, you have less problems with the first stage, but it's usually not worth the pain). You want to reach 7-7.6 km/s otherwise you don't reach orbit and fall down. That's mach 25. Any aircraft with a payload do speak of does not go at more than mach 1.
Reaching orbit isn't reaching orbital height (which is a joke for any rocket and even Virgin Galactic could do it with air-launch), but orbital speed (which is a pain in the ass).

Skylon hopes to reach mach 5 while still air-breathing. How good that will do to it is still debatable.

Why do you say the STS is sub-optimal? I'm genuinely curious.

To add my point to other stuff pointed out, Shuttle was designed to have a decent endurance and act as a small space station to do experiments and stuff. Which is suboptimal since not only you have to carry up and down the equipment's mass, but also the additional mass of a bigger reentry shield for that mass.

A better idea would have been placing a "crew living module" in orbit (that goes up just once, and then awaits you there), and inhabit it only when necessary. Eventually grow it into a fully-fledged space station.

Space shuttle put around 100 tons of stuff in orbit every fucking mission, of those at least 78 tons returned down to Earth. Von Braun is still laughing at this madness.

Shuttle's engine and tankage specs allowed it to carry enough payload to go to the moon if assembled as a conventional rocket, all this was wasted in just reaching LEO and placing some 25 tons of payload every once in a while.

Still, shttle launches themselves actually aren't as costly as many people think and over the whole lifetime of the program STS wasn't as uneconomical as the alternatives at the time.

Yup, that's what allowed the program begin, because each launch was cheaper than Saturn V, if you don't factor the fixed costs of the system.

[phongn]

Actually the shuttle was designed with ferrying cargo and people to a space station as a prime mission. This would allow assembly and fueling of larger craft at the station which would then do interplanetary stuff, as well as mundane cargo like satellites. But all this depended on rather absurdly optimistic planning on usability. The shuttle was supposed to have a 14 day turnaround time on the ground. The shuttle was built without enough R&D budget to do what NASA wanted so its never fit any role well.

The design goal was 160 hours, for 40 flights out of KSC and 10 flights out of VAFB per year for a five-orbiter fleet. In reality, the most aggressive launch schedule (planned in the pre-Challenger disaster era) called for 14 flights a year.

Thanks from the replies, guys! I'd heard (don't remember where, probably a documentary somewhere) that the early STS concept was something like Burt Rutan's Spaceship One, a spacecraft carried to the upper atmosphere by a mother-aircraft and then launched, which would've been the optimal configuration (or so the doc claimed), but that the US Airforce wanted it to be vertically launched strapped to a rocket so it would be a kind of orbital bomber that could be launched on a moment's notice... Don't know if that's right...

Not quite - the plan was for a fully-reusable first stage (which were generally winged or lifting-body). That later evolved to using an expendable first stage (S-IC was a serious proposal, including a flyback varient).

What's screwy about the shuttle is that it's designed to be an orbital bomber and a heavy-lift vehicle capable of carrying large payloads into LEO and a personnel transport and reusable. That combination made it a very big, complicated craft.

Well, the bomber mission was never very serious - but the "toss satellite over hostile territory and land immediately" mission was. STS also had the mission requirement of bringing significant payload back from the station.

Space shuttle put around 100 tons of stuff in orbit every fucking mission, of those at least 78 tons returned down to Earth. Von Braun is still laughing at this madness.

It's not the worst idea in the world. Fuel is not horribly expensive (even PBAN). It would've been worth that cost if they could get launch rates anywhere near the original proposal (and perhaps with a reusable first stage).

[Simon_Jester]

What made them think they could do it? How much was inexperience, how much was things like trouble with the heat shield?

[someone_else]

It's not the worst idea in the world. Fuel is not horribly expensive (even PBAN). It would've been worth that cost if they could get launch rates anywhere near the original proposal (and perhaps with a reusable first stage).

Fuel costs are irrelevant, I agree.

And I'm perfectly fine with drop tanks (less enthusiastic about solid boosters, but anyway). It's not like we are going to end aluminum soon.
Flyback first stages are complex to make now with robotics up to the task, go figure at the times (where they needed a human pilot). They are indeed juicy performance-wise, but pretty complex to make.
I'm also a fan of using drop tanks for cheap space station construction skylab-style (No, space shuttle's were not good for that, their orange insulation material would deteriorate in space and create a fuckton of hazardous high-speed debris).

But making it lighter would have made either its payload bigger (bigger than 25 tons? why would you need that at all?), or decreased the size and complexity of the launch system overall (like for example using only 2 SSMEs).
The second option would have dropped the launch-rate-to-go-even down to something that could have actually happened and you would have had a Space Shuttle that was actually a success and would still be operational today (maybe with new improved orbiters). Not 25 launches per year, which was insanity at the day and is still insanity today.