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SpaceShipTwo Tests Its Rocket Engine and Goes Supersonic
ehartwell writes "It's official. This morning, after WhiteKnightTwo released SpaceShipTwo at an altitude of around 50,000 feet, pilots Mark Stucky and Mike Alsbury ignited the engine for a roughly 16-second blast. After the engine cutoff, the plane coasted back to its landing back at the Mojave airport. Virgin Galactic tweeted that the pilots confirmed 'SpaceShipTwo exceeded the speed of sound on today's flight!' Its predecessor, SpaceShipOne, first went supersonic December 17, 2003."
So after exceeding the speed of sound the next step is the speed of light? ;-)
Hideki!
Why is it taking Virgin Galactic so long for development? Is it a financing or technical issue?
SpaceX was founded in 2002 and is already making re-supply missions to the ISS. Granted that's not quite the same as human spaceflight but it seems like there's a lot faster advancement occurring at SpaceX than at Virgin Galactic.
theycutdownonspacestosaveonfuelcosts?
When Spaceship One blasted off to win the X-Prize. I remember being very excited. I watched the launch and read as many articles about it as I could.
That was 10 years ago. Now we have SpaceX and Orbital Sciences making orbit. Tremendous new things seem possible now with Falcon Heavy and Grasshopper reusable stage coming in the pipeline. SpaceShipTwo? A bigger version of SpaceShipOne that carries passengers, but still only suborbital with no further prospects. Where is the Tier Two orbital program that Rutan hinted at? Why did it take so long to get SS2 off the ground? Did Scaled get lost and rudderless with Burt retiring? Did they lack funding? What's the deal?
What is their long term goal for this program? Surely it can't be just taking tourist to the edge of space and back. Could this lead to high speed air transport or something?
Flying to Orbit, with an update for SpaceShipOne
http://world.std.com/~swmcd/steven/stories/orbit.html
I think the "Space" part of it is a side show to what Virgin is really pushing for.
The bigger goal, IMO is being able to enable flight from the US/Europe to Australia in a matter of hours by a "plane" jumping into low Earth orbit and circling the globe in 2 hours. Imagine being able to "jump" to the other side of the Earth in an 1 hour? A 2 hour flight to China? Australia? Europe?
It takes 88 minutes in LOE to circle the globe.
It would simply be revolutionary. IMO that is the near term end goal of Branson's interest in space flight. I think the "manned space flights" are tangential to what the immediate goals are. Hammering out the science to allow cheap cross earth flights, is simply incredible.
They suck at space. Space is a bitch of a place to try to do business. Operational decisions **must** be made by engineers and astronauts...not businesspeople or actuarial risk analysts.
First, I was happy to see SS1, but it was also sad. Why? It was 40's technology dressed up with plastic and circle windows. SS1 was mostly **hype**
2. SS1 was a C- business concept at best. Hype aside, people need stuff in space, so even though we all knew SS1 was kinda silly, we figured it would be the first of many (progreessively better) companies. It would *start a trend* so we endured and played along with the hype.
The progress never happened. Why? Geeks have great concepts but there is a disconnect between the concept and the execution. All the innovation gets stripped when you let sub-moronic 'investors' make the operational decisions.
Solution: We must speak with a united voice at what needs to happen next in space. No singularity bullshit. No ridiculously expensive missions to 'find life'...no...fuck that shit. We go to asteroids and the moon and we *fucking mine that shit*
mining = money = more spaceflight
Thank you Dave Raggett
The X-planes that hit the edge of space were carried aloft by a modified B52 mothership (the famous "Balls Eight"), they didn't really "take off... properly, on wheels".
Nope, no X-plane ever made it into orbit. They were very-high-altitude rocket planes, and were much too small to contain enough fuel to reach orbit. More fuel would necessitate a bigger plane to contain it, and hence a bigger motor to propel it, and hence more fuel to run the bigger motor, etc... That's why rockets get around this problem with multiple stages. They jettison excess mass on the way to orbit. A true "space plane" that lands and takes off on a runway and doesn't dump stages along the way would need to be Single-Stage-To-Orbit (SSTO). So far, there are no true SSTO vehicles, even rockets. A space plane would need to haul along landing gear, wings, conventional engines, etc, and would be much more difficult to do than a simple SSTO rocket.
The SR-71 was deployed in 1964 and had an operational elevation limit of 80,0000ft. What excactly are we breaking out the champaign for?
There is a vast difference between SSO, or even SST, and what you propose. SSO and SST just go straight up and straight back down. There is very little ground track in their flight envelope. In order to get to orbit, you need to go straight up, and then go about double that to really get out of the atmosphere, and then tack on around 8km/s velocity. You're looking at a few dozen times more energy, and around a hundred times more fuel. A sub-orbital transcontinental flight won't need quite that much, but you're still way up there in comparison. Add in the fact that you're actually going to need a real thermal protection system for re-entry. They're not even in the ballpark.
Photos of the Test showed a very dirty (looking) burning exhaust thrust, much like the Concord when it crashed on take-off from Paris Charles de Gaulle Airport: i.e. possible blown fuel feed pump. Maybe it went supersonic after the pilot shutdown the engine and went into a dive to extinguish any burning of aft section of the craft.
Be a long time before this thing goes 'Commercial.' I would not buy a ticket having seen this.
I think he meant just edge of space or was confusing it with that. I suppose you could orbit at 100km if you went fast enough and had something to keep the speed up..
http://en.wikipedia.org/wiki/X-15_Flight_91 went 100km+ "near space", air launch from a b-52. which is in the same ballpark as ss1.
I was excited about space ship one once. then I realized it wasn't something to be excited about, it's a nice plane and all, but not worth all the hubbub, I mean, it's getting way more publicity and nerd creds than what it deserves. I think the x prize goal shouldn't have been so modestly set.
spacex is pretty interesting now though.
world was created 5 seconds before this post as it is.
I prefer A.L.C.O.N. to 1942.
Get free satoshi (Bitcoin) and Dogecoins
Childish. Grow up.
Looking at the flame out of the back of the craft it looks more like a raw fuel dump than something that will sent the spaceship into supersonic flight.
They're not even in the ballpark.
Energy is not hard to come by. SpaceShipOne generated about a sixth of the delta-v it'd need to reach orbit. I consider that fairly close given the type of engine and relatively low mass fraction. SST is supposed to have slightly better performance in that regard. But neither is intended for this particular role.
But I think naysayers are overstating the difficulty of more delta v and a different thermal protection system. Sure, it might need a radical vehicle redesign. But guess who demonstrated that they can design such suborbital vehicles?
I think you're understating the difficulty of more d-V. Six times the d-V doesn't simply mean six times the fuel. Energy is proportional to velocity squared, so you immediately need thirty-six times the energy. When you factor in the exponential behavior of the rocket equation, and the fact that you need yet more fuel just to take up the additional fuel needed to accelerate the spacecraft itself, your fuel consumption balloons fast.
I think the "Space" part of it is a side show to what Virgin is really pushing for.
The bigger goal, IMO is being able to enable flight from the US/Europe to Australia in a matter of hours by a "plane" jumping into low Earth orbit and circling the globe in 2 hours. Imagine being able to "jump" to the other side of the Earth in an 1 hour? A 2 hour flight to China? Australia? Europe?
It takes 88 minutes in LOE to circle the globe.
It would simply be revolutionary. IMO that is the near term end goal of Branson's interest in space flight. I think the "manned space flights" are tangential to what the immediate goals are. Hammering out the science to allow cheap cross earth flights, is simply incredible.
Sadly I'm not sure the bulk market is there. You used to be able to hop on a plane in London and land in New York 3 hours later. Now it takes over 7.
I could see a market for a charter - sometimes as a business you need someone to be somewhere, and it's costing you $100k/hour that they aren't there, but that would require a lot of planes to be in key places ready for immediate launch (NY, LA, London, Tokyo, Singapore)
sounds like kittyhawk. interesting to think that first steps are so tentative decades later. we haven't changed that much, it seems.
In NSA America social networks join you!
In order to get to orbit, you need to go straight up, and then go about double that to really get out of the atmosphere, and then tack on around 8km/s velocity.
But you don't need to go orbital, just a ballistic. While the trajectories of some of the longer flights like Sydney to London are approaching the energy needed for orbit, there are plenty of medium length ones like LA to NY, or NY to London that are well within the grasp of a scaled-up version of SS2.
Damn right. Those who do not understand rocket equation should go play Kerbal Space Program.
The difference between a rocket that can make it 100km up and a rocket that can actually reach stable orbit with any substantial payload is staggering.
He may have been thinking of the U2, which flew at the edge of (1950s) space, and took off and landed like, well, an aeroplane :)
No colour or religion ever stopped the bullet from a gun
Seriously, apart from the military, who the cares whether they can fly half way round the world in an hour for a face to face meeting?
If it could be done for the same price as a current air fare, fair enough, we'd all like to get to our holiday destination quicker. But when you're talking about $100K+ a trip, it seems like a tiny and uninteresting market.
To have a right to do a thing is not at all the same as to be right in doing it
Finally, you mention the rocket equation! I find it interesting how the people who talk about how hard it is, tend to be weak on the actual math. So you have some inkling of the difficulties. Now, use a more efficient engine, for example, LOX/kerosene optimized for vacuum.
I also was a bit in error. Delta-v for SpaceShipOne was a quarter what they needed to get in orbit. Using LOX/kerosene would boost that delta-v by about 40%. Sure, you still need a high propellant to dry mass ratio (something like 12 or 13 to 1 for achieving 9,500m/s starting from 300 m/s at 350 sec ISP, there's also a minute boost from the altitude, something like 20-40 m/s equivalent in delta-v and drop in air resistance and gravity losses, I'll stab at another 300 m/s) for a very good LOX/kerosene engine), but as I mentioned earlier, I don't think that's so hard.
For reentry, the key is surface area. The larger the cross sectional area of the return vehicle relative to its mass, then the less heating the vehicle will endure. Since these vehicles are launched above most of the atmosphere, the constraint on surface area (for air resistance losses and stress on vehicle) are greatly reduced. At 50k feet, I understand that pressure is about a tenth what it is at sea level. So those forces from air resistance tend to be a factor of ten smaller.
Well, thanks, v/informative. So if we were to have a tower design that would give them a Landing Field (powered launch takeoff platform) at 45,000 feet they might could make it. Hotels on the top. Stargazers Hotel. Elevator up the center for people and supplies... and would work on the Moon & Mars. Self-building just drop the package and builds itself, minus hotels and all that I suppose. But it would take a real genius. We need to put in a request for more ten year old geniuses.
I also was a bit in error. Delta-v for SpaceShipOne was a quarter what they needed to get in orbit.
You were right the first time. SSO only reached 112km, which is roughly equivalent to 1.5km/s of d-V. Between altitude and orbital velocity, LEO is around 9.5-10km/s. That's 6.5 times higher.
Have you not paid any attention to their design? The feather mechanism is supposed to negate the need for a heat shield.... keep the hull well below terminal velocity, no rapid heat up.
"Terminal velocity"... I don't think that means what you think it means...
You were right the first time. SSO only reached 112km, which is roughly equivalent to 1.5km/s of d-V.
Hmmm, when I last did the calculation, I thought there was considerable horizontal velocity (of 1,200 m/s, but that turns out to be the maximum speed during the trajectory). That is quite wrong since the trajectory was almost straight up. It does simplify the calculation though.
So let's take your number of 1.5 km/s of delta-v for the highest trajectory. For that trajectory, the engines burned for 80 seconds straight up (I had 65 seconds which I believe was for the first flight which barely passed 100km). That's roughly 750 m/s of delta-v lost to gravity losses, meaning the engine plus initial velocity produced roughly 2,250 m/s of delta-v. Even if we assume White Knight was flying at 300 m/s straight up when SpaceShipOne detached, that's at least 1,950 m/s of delta-v from the rocket engine.
So you still end up with roughly quarter of the delta-v required to get to orbit.
We drew up the plans for a orbital highway a long time ago, with hubs stationed in geosynchronous orbit with lasers providing power transport for them, but it requires a LOT of carbon nanofiber to hold it in place.