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SpaceShipOne Flight Completed Successfully
knothead99 writes "CNN is reporting the successful liftoff of SpaceShipOne from a runway in the Mojave desert. Around 10:30 EDT the craft will reach an altitude of 50,000 feet and they'll separate from White Knight and ignite the rocket for space entry. More information can also be found at the Mojave Airport website" Update: 06/21 15:36 GMT by S : An MSNBC story confirms that SpaceShipOne 'glided safely back to Earth, landing back at the Mojave Airport' around 8.15AM PST.
...the successful landing!
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get the blow by blow here.
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It's more a question of speed than of height - with the current design, Spaceship One won't be capable of reaching orbital speeds, which far exceed Mach 3.
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it's not a matter of height, it's a matter of speed.
Here is a nice orbital velocity calculator.
Getting up to that speed is not the only problem, you have to loose all that kinetic energy before you land, unless you fancy spreading yourself thinly across a continent.
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Generally somewhere between 250-300 km (where air drag starts to become important) and 1000 km (where the inner van allen radiation belt starts to get serious). Low earth orbit usually implies a modest inclination to the equator, (i.e., the lowest achievable from the launch site). The Space Shuttle flies in low Earth orbit.
For more information see this article from ScienceWorld
Basically at first, they said the engine cut out early on their own (they were supposed to be switched off by the pilot instead). They don't know why the engine cut out early.
As a result, they weren't sure if they reached the 100km mark at first, but were told they did afterward.
On the glide back to the landing strip, some loud pops were heard coming from the back of the rocket. Chaser planes inspected, and reported everything looked ok.
Hooray for private spaceflight!
Next time please provide a link to the actual story so that when CNN takes it off their front page due to the next Clowns Fighting for the White House story breaking, we can still see "stuff that matters" mmkay?
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Low Earth Orbit is 350 km (217 mi). Obits lower than this are not stable.
In addition, they would have to be going about 8 times faster to reach orbit.
Show me on the doll where his noodly appendage touched you.
CNN is reporting in a developing story that SpaceShipOne attained an altitude of over 62.5 miles (100 km) in its historic flight earlier today, making it the first privately built craft to fly in space. More information can be found courtesy of Scaled Composites here and Space.com also has a story.
... One that history will note was done for the benefit of everyone."
"Space flight is not only for governments to do," Rutan said. "Clearly, there's an enormous pent-up hunger to fly into space and not just dream about it." "We are heading to orbit sooner than you think," he said. "We do not intend to stay in low-earth orbit for decades. The next 25 years will be a wild ride.
If they hit the 100 km mark, as planned, it was obviously not premature, although it might have been shut down earlier than planned due to any of many reasons (better conditions aloft, etc.) If it was earlier than planned, and they made the target altitude, then that shows they have planned well and the systems worked. Everything I would expect from these people.
Nothing here...move along.
Faith is the very antithesis of reason, injudiciousness a critical component of spiritual devotion. Jon Krakauer
I read that too, and was frustrated that I couldn't figure out where they were coming up with that. According to this story:
"For a few minutes after SpaceShipOne began its descent, it was unclear whether Melvill had reached his goal. But the mission announcer finally said the mission had been successful as the craft prepared to land at Mojave Airport, accompanied by three chase planes. "
Looks like Globe and Mail just jumped the gun. thpt.
I was listening to the radio relay on the bbc.co.uk live video feed.
On the way back (I think after completing the 'feather'), Mike reported a 'loud bang' and his chase plane, the Alpha-Jet reported that an aft fairing had buckled.
When they got back down they were saying that they suspect the loud bang was caused by that same panel.
Ripping an new rectum in the fabric of spacetime.
Achieving orbits is a 2-step process. You need to get high enough that the atmospheric drag is small enough that it's possible to acheive orbital velocity. Then you have a vehicle with enough thrust to kick you into orbit. Height/velocity isn't the only issue. If you accelerated a vehicle to escape velocity at the earth's surface, it would have the energy to leave the earths gravity well completely; however, the energy would turned into heat by friction with the atmosphere, and the craft would be vaporized.
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The X-15 could do everything required to win the X-prize except carry three people. It reached 100km, and it was flown repeatedly, for a total of 199 X-15 flights of three aircraft.
Your post is kind of misleading. May I remind you that escape velocity is defined as the initial velocity necessary to leave the Earth's gravity well provided that there is no additional acceleration. As long as your acceleration away from Earth is greater than than the Earth's gravitational acceleration at your distance from it, you will eventually escape Earth's gravity well, and at a speed of much less than Mach 25 to boot. Think of a balloon: they certainly never travel very quickly, but they get very far towards escaping on very small velocity.
A spaceship is not launched like a cannon, but rather, it has engines on it that provide thrust. In this way it is possible to escape Earth's gravity with continual acceleration and never actually experiencing speeds of Mach 25. You are right, to get into a low-Earth orbit one would need to be travelling at Mach 25, but that is simply a result of the Newtonian mechanics of an orbit plotted at that arbitrary altitude. Any number of different orbits - such as a parabolic orbit arcing away from the Earth - could have any number of different (higher or lower) necessary velocities.
And besides, once you are in space, without having to worry about air resistance, it's trivially easy to build up that extra velocity. Your post makes it sound like getting to Mach 3 is trivial and they need to put in eight times the work to reach LEO. This is simply not true. Getting to 100km through most of the atmosphere has already accomplished most of the work. The rest is easy. It's not as simple as looking at the difference between the numbers 3 and 25 and saying, "Oh, they have eight times more speed they need to get!"
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You're too young to remember that we've been here before. Kennedy went to space for political reasons too. Americans were trying to one-up the Russians. Check this and this out. For those who don't like to RTFA:
"Weapons should be hardy rather than decorative" - Miyamoto Musashi
I think that goes for OS's too
You were right on the first guess. They usually look for damage or other external problems (like the landing gear not actually being down). There really isn't anything they can do to help, except warn the pilot that something has gone wrong.
Not true. It is not trivially easy to build up that extra velocity, because you have to lug all of the extra propellant through the atmosphere. The amount of propellant doesn't rise linearly, either: it rises exponentially. If they want to keep their current launch design, they're going to need the world's largest carrier plane to take them to altitude.
It gets worse: currently they're hardly addressing *the* most difficult concept for cheap reusable spacecraft: reentry. This single problem has contributed to the majority of the space shuttle's turnaround cost. Standing on the shoulders of giants (as the vast majority of their work thusfar has been), they can at least avoid the ceramic tile mistake; however, they still need to solve the problem somehow.
They're not 3/25ths done - they're *less* than that.
I just invaded Grammar Czechoslovakia and duped Grammar Neville Chamberlain; now it's on to Grammar Poland.
...Reagan Cold War
You mean the Truman, Eisenhower, Kennedy, Johnson, Nixon, Carter, Reagan, Castro, Krushchev, Brezhnev, Andropov, and Gorbachev Cold War don't you? It's not like Reagan started this all on his own in '46.
My apologies to readers from the UK for leaving out Churchill from that list (given that he coined the term "Iron Curtain").
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Rocket Equation Calculator
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Specific Impulse
For a 400 s specific impulse, getting to mach 3 requires a 1.276 takeoff to payload ration. On the other, making Mach 25 requires 7.66 takeoff to payload ration. That's why Spaceship One is self contained, whilst the Shuttle requires vast external fuel tanks and external boosters. It's hardly trivially easy.The folks at JP Aerospace are using baloons for assist--in fact they are taking this even further and claim they can take a lighter than air craft to orbit using ion drives or something similar.
It's about both height and speed. Speed required for a stable orbit is inversely proportional to altitude. All you have to do is balance the centripetal (F = (m*v^2)/r) with the gravitational force (F = G*m1*m2/(r^2)). The only special case is geo-synchronous orbit, in which case you must be at a specific altitude in order for the period of your orbit to match that of the earth's rotation. Other than that you can "orbit" at any speed (v) you want as long as your altitude (r) makes the above equations balance.
So as long as the ship has the guts to get far enough from the earth, it can certainly go fast enough to be in orbit.
=Smidge=
I disagree that it's easy. Although accelerating at a height of 100km isn't too hard, you need to get the fuel and oxidizer up to that height and keep burning it. Carrying enough propellants up through the atmosphere in order to burn your way up to about 7,500 m/s velocity is pretty difficult.
Another way to look at it is to use the equation for kinetic energy (1/2*m*v^2). Since it's proportional to v-squared, if you need 8 times more velocity, that's 64 times more energy. As you say, "The rest is easy." :)
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You MUST be trolling.
YOu are simply incoprrect when you say that you do NOT have to reach 25,000 (or Mach 25 as you out it) to escape Earth's gravity because of the *engines* on a craft sigh). In point of fact you simply DO.
Out and out wrong. The escape velocity is merely the speed at which the craft would be traveling if it had fallen toward the Earth from infinity. You do not have to travel at the escape velocity to move away from the Earth. If you have a source of thrust, you may move at whatever velocity you please.
The rest of your post is (unfortunately) just a layperson's opinion about physics and I'm sorry but a rather poor opinion at that.
And you're what, a professional physicist? Certainly not, since your error is a grievous one.
At any rate, your post should be marked "troll," not "informative."
And little different from what Alan Shepard did in the original Mercury/Redstone launch. But it's a start. And it does count as "space flight".
And don't forget...to go that fast you need special materials to withstand the heat effects (>1000 degrees F) that occur at such velocities when back in atmosphere.
That's not necessarily true. There have been designs for aluminum-based thermal protection systems. Of course, most of them make use of complex transpiration-cooling systems to stop the aluminum from melting :-) Personally, I would wager that Rutan and Co. will go with some form of ablative shielding (like the old Mercury/Gemini/Apollo capsules), probably a spray-on ablator that can be reasonably quickly replaced. That kind of approach seems in line with the general philosophy of the SpaceShipOne design (for example, their use of a hybrid rocket engine).
but he's NO WHERE NEAR achieving a true suborbital flight
Actually, they just achieved suborbital flight. It's orbital flight that they are still a ways from achieving.
The truth has a tendency to be true, unlike your post. Let me just give my background for disclosure - I'm a rocket scientist.
No, you don't. If you were blasted off from the surface of the Earth at Mach 25 and the atmosphere didn't exist, then (to use the kind of lax definition of infinity that us physicists are proud of) you'd come to rest at infinity and wouldn't fall back into the Earth. However, if you provide a continual thrust that everywhere is greater than the local acceleration due to Earth's gravity, you will never fall back down. You could achieve this at a constant velocity of 1m/s if you liked, by suitable modification of the thrust.
To go forward in space, throw something backward. To go forward in the atmosphere, throw enough stuff backward to push enough air out of the way. It's easier in space - as you don't have to overcome resistive drag (unless the solar wind is non-negligible) then the same acceleration can be had for less driving force - the net force is the same yes. This means you can take it easy, and do something like throwing photons or ions out of the back of your spaceship.
As opinions go, it was just as valid as anyone else's. As statements of physical understanding go, it was superior to yours.
One of the teams competing for the X-Prize is planning on balloon lift for that purpose. The da Vinci Project, as I recall.
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Escape velocity has nothing to do with orbit. Escape velocity is what you need to attain to leave Earth completely, for example if you wanted to go into Solar orbit. Balloons never do anything remotely approaching "escape" in this context.
Getting into orbit is way, way, way harder than getting to 100km. It takes 24 times the energy to get to orbit, and you therefore need massively larger fuel tanks and engines to do so. You are correct that "eight times more speed" is misleading, but you got it backwards; since kinetic energy goes up as the square of the speed, you need more than eight times the energy to reach orbit.
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--I'm sure somebody else has come up with the idea, but is anybody pursuing it?
Yes the Canadian Team called The da Vinci project
"The da Vinci Project, led by Brian Feeney of Toronto, Ontario, Canada, registered as a contender for the X PRIZE on June 2, 2000. A reusable helium balloon will lift our spacecraft, "Wild Fire" to an altitude of 80,000 feet. This is where Wild Fire's rocket engines will fire and propel the crew to the 100 km altitude goal -- space."
They developed the project in a kind of "open process" way; every people who wants to contribute is invited to join the project and can even open a local club in is university. They accept help from people of all fields: engineering, public relations, marketing etc...
"The all-volunteer da Vinci project is the largest volunteer technology project in Canadian history with upwards of 100,000 man-hours having been spent on the project thus far."
They amased a huge amount of sponsers and are well advanced in the project.
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To get to 100km height, you need m * g * h in energy. per unit of mass you get: g * h = 9.8 * 100 *10^3 ~=~ 1 MJ /kg.
In orbit, you'll circle the earth every 1.5 hours. That means a speed of about 7.4km/sec. This requires (again per unit of mass) 1/2 * v^2 = 0.5*7400^2= 27 MJ/kg.
So, reaching (low earth-) orbit requires about 27 times more energy than what was demonstrated now.
Now there are a few things to keep in mind. You'll have to lug along the fuel to accelrate the last part of your ascent. That means that just taking 27 times more fuel won't cut it.
We're at least two orders of magnitude away from commercial manned spaceflight. (where spaceflight is defined as "in orbit"). Sure: Big step, but not quite there yet....
There's some info on the Air Force's desires for the Shuttle on NASA's History Site. From the article:
One Air Force requirement that had a critical effect on the Shuttle design was cross range capability. The military wanted to be able to send a Shuttle on an orbit around the Earth's poles because a significant portion of the Soviet Union was at high latitudes near the Arctic Circle. The idea was to be able to deploy a reconnaissance satellite, retrieve an errant spacecraft, or even capture an enemy satellite, and then have the Shuttle return to its launch site after only one orbit to escape Soviet detection. Because the Earth rotates on its axis, by the time the Shuttle would return to its base, the base would have "moved" approximately 1,100 miles to the east. Thus the Shuttle needed to be able to maneuver that distance "sideways" upon reentering the atmosphere.
Given a choice between straight and delta wings, the latter perform much better in terms of cross range capability. Delta wings produce more lift at hypersonic speeds, enabling more maneuverability (Heppenheimer, p. 220). Given the requirement for cross range capability, a delta-winged vehicle became the clear choice. Additionally, delta-winged vehicles do not heat up as much as straight-winged vehicles during atmospheric reentry (Draper et al., p. 26), thus decreasing the need for expensive and potentially heavy thermal protection systems, although the thermodynamics are too complex to cover fully in this paper. Moreover, some aerodynamicists argued that delta-winged vehicles were a proven technology that provided good balance, stability, and aerodynamic control (Draper et al., pp. 29, 35).
Now you know why the Space Shuttle has stubby delta-wings for hypersonic flight. I'll see if I can dig up some other links.
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That isn't it.
The air force wanted "large cross range capability", in other words, the ability to glide in large distances. The Air Force's desire for 1100 miles of cross-range doesn't put the shuttle anywhere near the capability of doing a low altitude flyover of Soviet airspace-- Florida is a LONG glide from Russia for something that effectively drops like a brick.
The nefarious use of cross range capability would be for the Shuttle to be able to enter a polar orbit, grab a spy satellite, and come back around and land in the same field. The problem is, in the hour and a half that orbit would take, the Earth would rotate about 22 degrees. So for the Shuttle to land at the same field, it would need to glide about 1000 miles (depending on how far from the equator it was).
This has pretty obviously not been used. But the versatility that the high cross range capability provided has greatly eased shuttle operations and also makes the vehicle safer by adding additional abort capabilities.
Another point: cross range capability has nothing to do with the heat shields. The Shuttle has a huge amount of kinetic energy that has to be dissipated one way or another; and really, you don't have a lot of choice in how quickly you aerobrake. The high cross range capability required more wing area and wing mass; and if you had a lower surface area to mass ratio, you'd actually aerobrake more quickly and require additional shielding.
AoA doesn't really come into it much. Once you enter the atmosphere, you're losing huge amounts of velocity. At hypersonic velocities, L/D ratios are awful, pretty much no matter what your AoA is.
A sonic boom is heard onboard a supersonic craft when it catches up with and overtakes the noise it has recently produced.
There is no sonic boom associated with travelling at multiples of the speed of sound, since at multiples of the speed of sound it just leaves it's noise further and further behind.
A pizza of radius z and thickness a has a volume of pi z z a
Just got back home from the Mojave airport and let me tell you the experience of watching this amazing aircraft reach the edge of space was awesome. Six friends and I drove from Los Angeles to Mojave and when we arrived there around 3 am and the place was already full of people. For the next few hours we explored around the field, bought some very reasonably priced breakfast burritos and ran around the tarmac. All the vendors seemed to be local groups and didn't rip you off (except for coffee and krispie cremes which were a somewhat large dollar a piece).
Mojave airport is really cool in itself, no fences around and you can wander all over if you want. We got some good spots as near to the takeoff and landing as possible ( they did restrict where you could watch the event, and the ships wheels actually left the ground about 50 yards north of us) and camped out. Everybody around was really excited. Many had come from really far away, like this pair of guys we met from Seattle. I'm sure that there were many who were from much further than that. There was a big mix of people. Lots of old timer aviation types, college age kids, and families. I'm sure much of the town of Mojave were there. We talked to this one guy who was bringing a group of kids from the local high school who were in their special engineering program(something I didn't have at my HS).
When they announced that the ship was actually going to take off on time I was pretty surprised. I just had a feeling it was going to be delayed. At about 6:40 the low altitude chase plane took off, it was a bright red little single engine plane which according to the announcer was flown by the spaceshipone pilot the night before in order to pull 6G's so that he could go to sleep! Next (I think) came the medium altitude chase plane, which was this really cool and modern looking craft with propellers in the back and a little wing on the nose. Then came White Knight, carring SpaceShipOne which look completely unorthodox and bizarre in person, even if you've already seen pictures of them. It taxied along the tarmac that ran past the crowd did a U turn then sped up and soared off of the runway to a cheering crowd. As everybody watched the ship gain altitude, the high altitude chase taxied and lifted off. This jet was pretty interesting, It sort of looked like a fighter jet that had been squashed to make it all squat lookin, sort of a caricature of a fighter jet. The ship climbed really slowly, about an hour of circling around the airfield getting smaller and smaller. Then we got the word that the rocked was going to take off . The ship was about 2/3 of the way almost directly between the horizon and the sun (the sun being fairly low since this is about 7:45 am). Then all of a sudden this huge contrail appeared and traveled straight up just to the right of the sun traveling at an amazing speed. The crowd loved it , after watching the ship climb slowly for an hour this was really dramatic. The trail kept moving up until it seemed to be about 70degrees above the horizon when the engine cut off. After a few minutes with everybody searching the sky for the craft *boom*, a little sonic boom let loose and the ship then appeared. It circled around a few times on its way down and met up with the chase planes. They all flew in a pretty tight formation and the ship finally made an amazingly smooth landing considering it was an unpowered odd looking bulbous craft. Everybody was ecstatic as SpaceShipOne rolled by, this odd looking craft had reached the edge of space and had made it back in one piece. After that, the low altitude chase plane made a flyby, which was pretty cool but then the topper was when White Night flew towards the crowd then pulled up proudly displaying it's bizarre silouette.
I'm really really happy that I got to have this experience. This amazing flight was the first time in my 19 years that I felt that I was actually witnessing history being made with my own eyes.
Except the twit is saying you must reach 25,000mph in order to escape the Earth's pull, not simply "reach escape velocity". If I travel at a constant 1m/s up from the Earth's surface, I will eventually put enough distance between myself and the Earth that a mere 1m/s is enough to escape Earth's gravity well, as gravity's strength decreases exponentially the further away you get.
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