Space travel, with Brian Blessed
Reaction Engines, the British firm aiming to build an enhanced "Skylon" space shuttle which would take off from a runway without external tank or boosters, says it expects to test its revolutionary "SABRE" rocket/jet engine within "three to four years". Here's the basic Skylon movie, for those few Reg readers who may not have …
Let's see. We have a matt black spaceship spending quite a lot of its time in strong direct sunlight ... it has liquid helium tanks for cooling air on the way up, which will require some sort of refrigeration ... which in turn produces more heat than is extracted/input (entropy) ... (unless vented to space?)
oh yes and it also has fuel tanks which have had heat dumped into them... lightly broiled passengers not optional I take it?
"Let's see. We have a matt black spaceship spending quite a lot of its time in strong direct sunlight ... i"
Such quickness in putting fingers to keyboard. You might have read a bit of background first (and there's *plenty* of it)
The vehicle is matt black because that's the default color (Yes Black is not a color but it is commonly descried as such) of the French made carbon fibre (IIRC) reinforced SiC composite they are planning to make the aeroshell out of.
*Unlike* conventional rocket structures it is a separate aeroshell/insulation/ truss structure/tank design.
The insulation is is a mix of spray on PU foam on the tanks and multi layer insulation or MLI. The vehicle vents (like the Shuttle payload bay) as it ascends so the MLI acts as a series of convection stop layers and reflectors of all radiation. MLI is the *most* effect insulation *provided* the separate layers are kept at vacuum, which they will be in orbit.
"it has liquid helium tanks for cooling air on the way up, which will require some sort of refrigeration .."
Wrong. The helium operates in a closed loop heat exchanger. It is used to transfer heat out of the *incoming* air and into the *Hydrogen*. This design reduces overall system weight. The loop is going to be fairly high pressure so while at *room* pressure LH2 is *not* cold enough to return He to liquid it *might* be at higher pressure.
(unless vented to space?)
As it happens Skylon carries *more* LH2 than needed and does indeed dump the excess into a spillway where it is burnt with some of the onboard LOX to offset some of the losses.
Realizing this *is* the best use of *most* of the LH2 used to cool the airflow is one of the *critical* features of the design.
"oh yes and it also has fuel tanks which have had heat dumped into them... "
No. It has *fuel* that has heat dumped into it before being partly routed to the engines and the rest dumped. there is a difference.
lightly broiled passengers not optional I take it?
Passengers (and crew) are optional. Despite what people may think ascent and descent heating are actually on *very* different scales, by one or two *orders* of magnitude.
Unlike the Shuttle (which is pretty dense) Skylon (once its tanks are empty) is a *very* large structure with relatively little left inside it. this gives it a *very* low area loading. Big area + Low area loading + good aerodynamics = *gradual* fairly slow heating, allowing that black skin to re-radiate the heat back out into space.
There are question marks over some aspects of the design but you'd have to actually *read* something about it to identify them.
12 billion quid? That's quite a bargain, if it's true. Personally, I believe they'll probably spend at least 30 billion euro on it before it reaches orbit.
What's wrong with NASA, btw? They claim they need 35 billion $ to finish their Ares rocket. One would think that designing something that's not new, and which has already been done dozens of times ..
What's wrong with them? They have no reason to be anything other than a slow-moving, risk-averse bureaucracy. NASA has been a pretty worthless organization ever since the Soviet Union stopped existing. Now the only thing that motivates them is self-preservation; taking risks like actually doing stuff is dangerous and requires that someone, somewhere, swallow the pill bureaucrats dread most: Responsibility for something. Thus, it is in their best interest to do as little as they can while still securing funding from Congress. Isn't that what anybody would do if they thought they could get away with claiming that they needed $35bn to do something we already did in the sixties?
By the way, the Ares rockets, along with the lest of the Constellation project, are getting the axe. There were a few pretty good articles about it here, in fact. Obama and company decided the price wasn't right and that they'd rather support people who have every reason to get payloads into space safely and yet more efficiently and cheaply than NASA: Commercial firms that lose high-paying customers if they screw up.
Good luck to them, I can't wait to see a working Skylon. We badly need spacecraft that can just fly up into space much more like conventional aircraft. :)
Plus from the side, it looks a bit like Thunderbird 1 :) ... Imagine a fleet of Skylons all taking off together! ... Thunderbirds are go!
"Looks more like the Avro 730 Mach 3 reconnaisance/bomber "
Quite so as others have noted. Were you to move the engine mods to about mid span and stick a couple of canted inward vertical tails on it and you'd have a rough SR71 layout.
My suspicion is this is *not* accidental. The principals of RE are all ex BAE or ex Rolly Royce and I'm guessing that (one way or another) they have access to a *lot* of the groundwork done on that project before todger Sandys tried to destroy the UK military aircraft industry. The materials science is mostly useless but stuff like heating rates, ram jet effects (you can bet at this speed like the SR71 a fair bit of the thrust is from ram compression rather than turbo compression) and stresses throughout the flight plan would give them a leg up on the ascent (and to a lesser extent) the descent modeling.
Just as much as the various spacecraft designs the Russians have floated the last couple of years. Nobody bites with funding, so it'll just quietly go away.
But at least it's better than this side of the pond, where we have Congress actively crapping on the commercial space sector as hard as it can, just to save some pork.
"Nobody bites with funding, so it'll just quietly go away."
I thought so to.
In 1989, when I read the original outline of the design in Spaceflight.
Amazingly year after year they have limped along and *more* amazingly they have whittled down the *apparently* insane claims (and by space launch standards it *is* radical inside as well) to reality.
When they started the UK did not even *have* a space agency (BNSC was a satellite services buyers club without even a line of budget entry) and UK civil servants viewed their concept (which they believed RE were asking the to fund) as the "Son of Concorde," and I don't mean that in a good way.
"Having placed the satellite, the SUS can then return to rendezvous with the Skylon and be stowed away again in the payload bay for return to Earth, refuelling and re-use."
The SUS will have quite a lot more kinetic energy than the SKYLON at this point. It's going to "rendezvous" and be "stowed" much like the SM-3 missile that rendezvoused with and was stowed in satellite USA-193.
In orbit you slow down to move inwards and speed up and speed up to move outwards and slow down.
Assuming we stick with the simplest most fuel efficient orbital changes and circular orbits, a manouevering sattelite's "speed" at any given height relative to sattelites (moving in the same direction) in stable orbits at that same height is negligible.
That of course assumes constant acceleration/deceleration for the entire journey. Since that's not how rockets work and most of the acceleration and deceleration takes place at the beginning and end of the journey, there can in fact be a fair bit of diference in velocity along the way with respect to freely orbiting objects at any given height. That's what collision avoidance is for.
However the problem you envisiage is a non-starter. At the begining and end of the trip, the SUS and Skylon will come together with all the violence of a butterfly's kiss.
"Since Obama shut down NASA"
People say the British look on the dark side. Only in the American space industry could a multi *billion* dollar budget *increase* be grounds for gloom
" I'd much rather catch a ride to space with you than the Ruskis!"
Would you settle for a South African with a US passport? Elon Musk is currently the probably front runner with the Boeing CST 1000 capsule and Orbital Science Corp Cygnsu/Taurus II vehicle in the rear.
For the more err "Fiscally challenged" there is always the Virgin Galactic sub-orbital space experience (and it *will* be space, just not for as long people might think).
"£12bn development cost is low cost?"
Depends what you're comparing it *to*.
Approximate Shuttle system development costs were IIRC $6Bn 1972. Allowing for 30 years of inflation and that is probably more like $30Bn. On *that* basis it *is* a bargain.
The nearest European equivalent would be the Airbus A380, which is only *roughly* similar in size, being crewed and human carrying from day one.
Note that conventional *expendable* launch vehicle programmes are *not* particularly comparable.
Bearing in mind what you get for the money at the end of the programme.
ELV. A production line of use-once-throw-away launch vehicles in the 100s of millions of $ range good (maybe) for 1 successful launch (launch failures for *mature* expendable systems are about 1 in 20) which cannot be exported *anywhere* outside the US giving a cost of c$10k per Kg
Skylon A production line of *reusable* vehicles which (in their first generation) are designed to deliver up to 200 20mt (presuming it makes orbit. A partial orbit with recovery to another launch site could make that *much* bigger) payloads into LEO. Over the c200 launches of the first gen design that would equate to roughly $100 per Kg. BTW the propellant costs add roughly $10/kg to this.
There was something similar about 20 years ago, when project HOTAL was started and several years later was cancelled due to over spend. It was ahead of it time, where a air breathing jet engine could switch over to liquid oxegene and travers into space and return under its own power.
What this video shows is a plane that takes off under its own power and then glides back to earth, like the space shuttle...no second trys if you over shoot your landing.
"There was something similar about 20 years ago,"
" when project HOTAL was started"
" and several years later was cancelled due to over spend."
No, when the UK government was asked to actually spend *something* toward it. there was *no* actual *spend* as such to begin with.
"It was ahead of it time, "
The outline of the idea dates from the US "Aerospaceplane" of the early 1960's
"where a air breathing jet engine"
That's rocket engine, most normal jet engines run on air on this planet.
"like the space shuttle..."
Apart from throwing away about 3/4 of its structure on the way up and mounting the engines on the wing tips the resemblance is astounding.
"and then glides back to earth"
"no second trys if you over shoot your landing."
Unlike the Shuttle Skylon does not throw away its main propellant tanks. While there is not likely to be much left in them knowing their interest in intact abort I *suspect* they have factored in enough left over propellant for a once around (the airfield, *not* the planet) circuit to retry. Modern UAVs have had a *lot* of development in auto landing and auto approach software.
I am part of the Reaction Engines Team and thought a few facts from the inside might help this discussion.
John Smith 19’s reply is correct in all essentials so I will not repeat it.
The helium cooling is a closed loop, dumping its heat into the hydrogen fuel. But we do have a leakage allowance.
The dominating factor in determining the cost of an aerospace flight system is the dry mass which for SKYLON is in the 40-50 tonne region, the NASA systems are much heavier and therefore cost more to develop.
Although we have contact with several USA concerns (including NASA) and have an agent in the States we have a difficultly dealing with US organisation due to USA’s ITAR (International Traffic in Arms Regulations). At the moment SKYLON will be an ITAR free product.
SKYLON is indeed named after the 1951 sculpture.
The SUS performs a perigee burn to return to a 300 km circular orbit before its rendezvous with the launching SKYLON (kind of obvious I would have thought!). There is a video coming to show this mission, but no Brian Blessed this time I am afraid.
Robert Flatters is quite wrong; the HOTOL programme (that was indeed the precursor to SKYLON) was not cancelled because of cost over runs. The Government refusal to consider any funding and the Rolls Royce withdrawal were politically motivated, Both British Aerospace and Reaction Engines continued with legacy programmes, BAe kept Interim HOTOL going into the 1990s, and SKYLON, of course, is still going.
"The SUS performs a perigee burn to return to a 300 km circular orbit before its rendezvous with the launching SKYLON (kind of obvious I would have thought!). There is a video coming to show this mission, but no Brian Blessed this time I am afraid."
I think the criticism was that no mention was made of the substantial kinetic energy SUS would acquire during its "fall" back from geosynchronous orbit and how this would dealt with. The only obvious answers are a fairly substantial burn or some kind of aerobraking maneuver. I have presumed conventional propellants as I think an ion drive would need too many orbits through the Van Allan belts to bleed off enough energy for a safe docking.
BTW Thanks for the compliment. I'd always though that F1 cars would make a nice early adopter of the heat exchanger technology (tight constraints, prepared to pay for performance advantages, small mfg volumes) but I don't know if they even realise it exists.
"I think the criticism was that no mention was made of the substantial kinetic energy SUS would acquire during its "fall" back from geosynchronous orbit and how this would dealt with. The only obvious answers are a fairly substantial burn or some kind of aerobraking maneuver. I have presumed conventional propellants as I think an ion drive would need too many orbits through the Van Allan belts to bleed off enough energy for a safe docking."
The return is very simple, the SUS is a LOx/LH stage and just re-ignites its engines to perform the perigee return burn. Its payload is about 2 tonnes less than it is when used in expendable mode but is still over 6 tonnes into Geostationary Transfer Orbit. All the details are in the SKYLON User’s Manual which can be downloaded from the Reaction Engines Website.
"BTW Thanks for the compliment. I'd always though that F1 cars would make a nice early adopter of the heat exchanger technology (tight constraints, prepared to pay for performance advantages, small mfg volumes) but I don't know if they even realise it exists".
A while back we did have interest from the several F1 teams but the exchangers are too expensive and the purity requirements on the fluids means they seem, impractical for that application.
"The return is very simple, the SUS is a LOx/LH stage and just re-ignites its engines to perform the perigee return burn. "
I suspected as much. It does seem time to abandon solids and toxic storables in favor of a common propellant combination. Modern electrics ignition should be just as reliable but to simplify things even further I would guess you would needs something like the premixed catalytic ignitor Aerojet produced for NASA.
"Its payload is about 2 tonnes less than it is when used in expendable mode but is still over 6 tonnes into Geostationary Transfer Orbit. "
This seems very in keeping with the idea of setting up actual *infrastructure* services (either permanently space based or sold as part of the package). I've always liked the idea of a solar sail cycling between LEO and the Moon or Mars. No fixed mission. Just an orbit to orbit payload slot which will be available on a regular basis.
"A while back we did have interest from the several F1 teams but the exchangers are too expensive and the purity requirements on the fluids means they seem, impractical for that application."
Too expensive for F1 is a bit alarming but the *big* surprise is fluid purity. I recall seeing something that F1 engines cease up if not fed a constant flow of warmish lubricant due to the tight mechanical tolerance. I'd presumed all fluids were *very* tight on impurities and well filtered before being loaded.
Too bad. Seemed like a good candidate market.
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