Suborbital Spaceflight Picks Up Speed 51
RocketAcademy writes "The race to develop low-cost, suborbital spaceflight is heating up. On Thursday, Virgin Galactic's SpaceShip Two successfully completed its second powered test flight, reaching a speed of Mach 1.4 and an altitude of 69,000 feet. Meanwhile, XCOR Aerospace has begun posting daily reports on the progress of its Lynx spaceplane, which is expected to begin flight tests sometime around the end of this year. This means one of both companies are likely to begin commercial service by the end of next year. XCOR still plans to move its headquarters to Midland, Texas later this year, but Midland may not be the only suborbital spaceport in the Lone Star state. On Wednesday, the Houston Airport System revealed renderings of its proposed spaceport at Ellington Airport, near Johnson Space Center just south of Houston. Citizens in Space (also based in Texas) has begun training five citizen astronauts to fly as payload operators on the XCOR Lynx and evaluating biomedical sensors for use on the flights. Details of those astronaut activities were also released this week."
Summary can't make up it's mind (Score:5, Funny)
Suborbital Spaceflight Picks Up Speed
...then it'd be orbital spaceflight.
suborbital spaceflight is heating up
...and now it's crashing back down through the atmosphere.
Sheesh, this is elementary physics, make your mind up editors!
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Re:Summary can't make up it's mind (Score:4, Funny)
Layman here... (Score:1)
Re:Layman here... (Score:4, Insightful)
Obligatory XKCD "What If?" (Score:4, Informative)
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Billions on fuel?
Kerosene and LOX are not that expensive. There are a lot of other costs than fuel. Getting out of the atmosphere is easy and relatively cheap, getting up to orbital speed is a whole other ballgame.
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Billions on fuel?
Kerosene and LOX are not that expensive. There are a lot of other costs than fuel. Getting out of the atmosphere is easy and relatively cheap, getting up to orbital speed is a whole other ballgame.
But when you throw away the fuel tank and rocket motor every time you fly... it is very expensive.
Car analogy time: Rocketry is like buying a new car and wrecking it every time you want to travel to the next city.
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Those are expensive, but they are not fuel.
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even the rocket fuel is so expensive you probably cant afford it
Not really. For the Space Shuttle launches, the catering budget for the press corps covering the launches was usually more than the cost of the actual fuel that went into that rocket. The cost for the amount of rocket fuel needed to get somebody into orbit is about a thousand dollars or so (or at least that order of magnitude). Essentially the price of a first-class ticket on a trans-continental airliner. In order to get to Mars, round trip, (or just about anywhere else in the Solar System) you need abo
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there wont really be any real space travel until we find some way to get out of the atmosphere without spending billions of dollars on fuel.
Currently, we spend on propellant at worst hundreds of dollars per kilogram of what gets into space. A billion dollars of propellant covers several thousand tons of stuff, up to around ten thousand tons for diesel/LOX burning rockets like the Proton or Falcon 9.
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In fact, 1 billion dollars would fuel around 5000 Falcon 9 launches, each lifting 13 metric tons of payload to LEO, for 65000 metric tons total. For the Falcon 9 (one of the lowest cost launchers), propellant is about 0.4% of the launch cost.
The real costs are in the hardware and in operations. The problem is that there really hasn't been a huge amount of incentive to reduce costs. Especially in NASA's launcher programs, where things like Constellation and the SLS are specifically intended to keep Shuttle p
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I think a lot of this space plane stuff in the minds of civilians misses that last point. When you don't understand what is really happening you might well assume just getting high up is enough.
Turns out though it is fine for suborbital space flight, which is great for tourists.
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a plane flying into space and land by itself should be the real race shouldn't it?
Sometimes the sci-fi vision is prescient. Sometimes it isn't. A flip-phone looks like the original Star Trek communicator. Yay! The new phones don't. Oh well. The 3.5 floppy looked just like the storage used on the original series also. The floppy also came and went.
The Space Shuttle was the closest we've come yet to the sci-fi vision of the space plane to which you refer. It still had to drop a lot of stuff before
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The Space Shuttle was the closest we've come yet to the sci-fi vision of the space plane to which you refer. It still had to drop a lot of stuff before reaching orbit. I've always wondered to what extent our problems there came because we allowed ourselves to be lead astray by the sci-fi vision. Meanwhile, the Russians continued to perfect un-glamorous but relatively reliable rockets and long duration space flight.
The problem with the Space Shuttle is that it was a 1st generation prototype. Not only was it a prototype that never really evolve into subsequent generations, it was a lousy design in the first place which had explicit design constraints to meet missions that were rarely or even never actually used. By far and away the best possible use for the Space Shuttle, to give an example, is to bring heavy objects down from an orbital flight profile back to the Earth. I think that was done precisely twice in the
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So assuming the Star Trek communicators inspired flip phones, carry that one out the rest of the way. They made us think of communication systems with tiny electronics and no wires. Those are still the identifying characteristics of cell phones regardless of the form factor. Uhura had her non-Bluetooth earpiece, and now we have Jawbones. Yeoman Rand had Kirk signing a tablet, and while William Shatner could have signed on a Palm Pilot fifteen years ago, you can do even better on your iPad Mini or your K
Re:Layman here... (Score:4, Interesting)
A single stage to orbit vehicle is very difficult. The amount of fuel a rocket needs to carry increases exponentially with the ratio of the required velocity change to the exhaust velocity. The options are very limited.
Solid propellants have much too low exhaust velocity for this to be workable.
Kerosene / Oxygen is a typical rocket propellant, but the exhaust velocity is low enough that a single stage to orbit would require an unreasonable ratio of fuel to rocket mass. I don't remember any design concepts for kerosene / O2 rockets for single stage to orbit.
Hydrogen / Oxygen has higher exhaust velocity but liquid hydrogen is very low density so the fuel tanks become enormous, and heavy. There have been design studies for Hydrogen / oxygen single stage to orbit, but it doesn't look very practical - you basically have an enormous flying fuel tank.
The more exotic chemical fuel mixes don't improve things a lot and are too toxic and expensive for atmospheric use. Fluorine / Beryllium / Hydrogen tri-propellant has good specific impulse but is insanely deadly in multiple ways.
Nuclear thermal (like NERVA) could probably do it, but people are understandably unwilling to put 100GW class nuclear reactors in rockets and launch them.
Airbreathing rockets (like ram-jets / scram jets) don't need to carry their own oxidizer and in principal do much better. The problem is that hypersonic ram-jets are very difficult to build and wind up heavy and inefficient. (Mach ~8, only 1/3 of orbital speed, 1/10 orbital energy) is the highest speed ramjet that I am aware of. For various fundamental reasons you expect the performance of ramjets to drop with velocity. Since ramjets also don't work at low speeds, you wind up needing a 3 stage rocket: conventional, scram-jet, conventional, and it ends up not having any advantage over just conventional rockets.
The basic technology for getting things into orbit hasn't changed in over 50 years, and really isn't likely to change - just no clear path. The best approach is probably what Space-X is doing, optimizing the design, and working to make each of the stages recoverable to reduce costs.
The "tourist" sub-orbital rockets don't seem to me to be developing technologies that are applicable to orbital flights. They may attract a few people who are willing to spend $100K for a few minutes of zero-G, but I suspect that most wealthy thrill-seekers will quickly find that a ride in a MIG-29 is a lot more fun and less expensive.
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I was considering a SSTO to include return, since as you say it doesn't do much good to get the entire rocket into orbit, but then need to throw it away.
I don't think it is completely impossible, but so far it hasn't been practical. People have worked VERY hard on materials for spacecraft, and they do adjust the H2, LOX mixture to include tank weight (and engine temperatures). One indication of how well launch vehicles are optimized is how little the technology has changed in 40 years. The LEO payload to
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The concept of a combined air-breathing engine / rocket is reasonable - and has be around since the 60s. One very serious technical difficulty is the need to slow the input air to sub-sonic speeds without creating too much drag. Their design airbreathign speed of about mach 5 is probably limited by this.
Then the question is whether carrying all of the extra weight of the more complex engine into orbit loses more energy than you gain from using air-breathing to get to mach 5.
It might be a better fit as an
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Hi. I'm Jack's spleen. Nice to meet you.
Suborbital is not Orbital (Score:2)
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Games as a teaching tool (Score:5, Interesting)
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...and that's with KSP making it far easier to get to orbit too (2 km/s orbital speed rather than 8 km/s as for Earth, and a planet whose atmosphere ends at 70km, with 1/10th of the radius of Earth)
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Those terrible renders... (Score:2)
I must be in the wrong career field. I should have become an architect so I can design shit that makes no sense.
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Anyone else take a look at those renders for Ellington Airport? I just love how the roads and platforms make no engineering sense whatsoever.
Well, you need customers at your spaceport, so therefore you need roads. If you build them, they will fly. Obviously, you'll have full commuter ships leaving for space every 30 minutes, so you'll need four lanes of freeway to deliver all those people, and they're all going to want to park next to the building, so make sure you have a really big terminal. A giant grass bridge over the freeway lets people wander aimlessly beneath the glory of your rocket-filled sky, so make sure to include one of those. A
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Suborbital just isn't that hard (Score:2)
KSP tells us that all you need for a suborbital flight is a fuel tank, a medium-sized liquid-fuel engine, and a fear-crazed Kerbal. What's the hold-up?
werent they supposed to start flights in 2010? (Score:2)
It's my understanding... (Score:2)
Ok I remember reading that Virgin Galactic is expecting its first passenger flight this year... Christmas Day...
Here it is:
Virgin Galactic first flight expected in 2013 [wired.co.uk]
Richard Branson: first Virgin Galactic flight on Christmas Day [ausbt.com.au]
Virgin Galactic to launch on Christmas [macombdaily.com]
And he plans to take his kids:
Our 500th Astronaut [virgingalactic.com]
I'm sure it could all fall through, or some regulator will pop their head in, but my bets are with the exuberant billionaire.