Virgin Galactic successfully reaches space
bbc.com
bbc.com
[1] https://en.wikipedia.org/wiki/SpaceShipOne#Development_and_w...
[2] https://en.wikipedia.org/wiki/RocketMotorTwo#Related_test_pr...
SpaceX isn't in that game; they're trying to get the Falcon 9 crew-rated for orbital flights. If Blue Origin's New Glenn ever gets off the ground, they may pursue an orbital crew rating as well.
Are you having doubts?
I'm mainly pointing that it's odd to compare aspirations with accomplishment. I've thought about climbing Everest, and even planned a route and bought some gear, but that doesn't put me in the same category as Norgay or Hillary.
Virgin Galactic has nothing in development with anywhere near the velocity capability for low earth orbit. Going up in a parabola to 100 km or 150 km and then coming back down again, a few hundred km down range, is a very different sort of delta-v requirement versus putting something in a stable orbit.
They are in "about the same place" for things that are flying now, but for the next generation beyond that, Blue Origin is far ahead.
However, the performance of Spaceship 2's engines has fallen short of the original design goal, making it incapable of reaching 100km, so they are now using a different definition of Space for PR purposes.
>Probably the closest thing to [an internationally agreed upon boundary for "space"] comes from the World Air Sports Federation, or FAI, which uses 100km (the Karman line) to delineate the boundary of space for the purposes of establishing world records. However, this organization says it is looking at lowering this boundary from 100km to 80km, due to "Recently published analyses (that) present a compelling scientific case for reduction in this altitude."
>Much of the push for a lowering of the boundary has come because of work by Harvard University astrophysicist Jonathan McDowell, who has argued that orbiting objects can survive multiple perigees at altitudes around 80 to 90km and that this altitude range is consistent with the highest physical boundary of the atmosphere, the mesopause.
Does anyone here know more about this? How recent is this work? How controversial is it, if it is at all? This is the first I've heard of work along these lines.
[0]: https://arstechnica.com/science/2018/12/virgin-galactic-just...
https://en.wikipedia.org/wiki/Jeannette_Piccard
It's interesting where we define what is an isn't space, with its own cultural ramifications.
Tereshkova has a much better claim to being the first woman in space.
The Mesosphere is defined as ending at an altitude of 85km. The next and last layer of the atmosphere is the Thermosphere, which end at 690km, but this is higher than the altitude at which most Shuttle missions orbited, for example.
(The "Exosphere" is above the Mesosphere, extending out to 10,000km, but gas particles in this layer are so far apart they do not behave as a "gas".)
So the most reasonable "boundary" of space would seem to be 85km.
As an aside: The lowest altitude at which an object in a circular orbit can complete at least one full revolution without propulsion is approximately 150km.
The "sky" does not turn completely black until 160km.
> Jonathan C. McDowell
> In this paper I revisit proposed definitions of the boundary between the Earth's atmosphere and outer space, considering orbital and suborbital trajectories used by space vehicles. In particular, I investigate the inner edge of outer space from historical, physical and technological viewpoints and propose 80 kilometers as a more appropriate boundary than the currently popular 100 km Von Kármán line.
Virgin and Branson are very good at marketing and PR, so they probably chose the lower definition to say they had reached space.
https://en.wikipedia.org/wiki/United_States_Astronaut_Badge#...
As the air gets thinner you have to travel faster in order to displace enough air to keep you aloft, and there comes a point where you're in orbit anyway, so the lift isn't needed.
Different planes have different lifting surfaces, so I have always wondered if the line was set more or less arbitrarily using some 'standard' plane, or if all planes approach the same limit together.
Looks like there are some interesting things to read here!
They fly short (~30sec) sub-orbital parabolas in a regular commercial jet (with a custom interior). It's not quite like going into "space" but it is quite literally only 2% of the cost for (IMHO) >80% of the value. The total amount of zero-G time is about the same as it will be on the VG sub-orbital flight (~5 mins). I've done it and it's an awesome experience.
Rollercoasters can do over 6g which is about twice the g force for most manned launches iirc.
In fact if you play any sort of ball sports you likely experience jerk movement well above 1g nearly all the time, and you don’t even want to get started with full contact sports like (American) Football.
It’s not just how many g’s you pull but also the duration, the longer it is the more stress it puts on your body but nearly anyone without any major health conditions should be able to experience 2-3g for a fairly prolonged time without adverse effects and much much higher momentary g force than that as long as you are securely strapped.
It is an extremely taxing activity, but the weight loss is mostly water.
“Believe it or not the driver has to apply over 930kg of pedal load per lap in Canada - an incredible 65,590kg over the course of the 70-lap race - and it’s all down to the Circuit Gilles Villeneuve’s unique blend of high-speed straights and tight bends.“
https://www.formula1.com/en/latest/features/2015/6/under-pre...
You have the takeoff part backwards; you experience a few g upward when you jump. If you're just standing on Earth, you experience 1 g upward, not downward; the force you feel is not gravity pulling down on you, it's the Earth pushing up on you and preventing you from free-falling downward in response to gravity. When you jump up, your legs exert additional upward force.
(When you land, your legs exert upward force again to stop you from falling down any more, so you have that part right, as well as the zero g part.)
You also then experience higher than 1g forces when you land as the deceleration is abrupt.
They also ease you into it by doing a few 1/3 G (Mars gravity) and 1/6 G (lunar gravity) parabolas before going to zero G.
FYI, being "fit" doesn't necessarily help. People with higher blood pressure actually do a little better than those without.
Earth's gravity in low-earth orbit is almost the same as on the surface [1]. What makes things on the ISS float isn't their distance from earth. It's horizontal (or more accurately, tangential) speed. Objects in orbit are in free fall.
To replicate that, parabolic flights free fall. (Parabolic paths are similar to the elliptical paths orbiting objects take [2].) They then stop free falling (to avoid hitting the ground) before climbing back up and doing it again and again. And again.
[1] https://en.wikipedia.org/wiki/Low_Earth_orbit#Orbital_charac...
ISS constantly falls down to earth. It is also moving so fast that it constantly misses earth.
I'm gonna have to roll up some herb while you explain this comment further.
It just has more horizontal speed, so it travels sideways a decent amount during its fall.
Anyways, yes, the ISS is scooting sideways so fast that, in the time it would have taken to fall straight down, the ground beneath it has dropped away by an amount equal to its initial height, so the thing stays at the same altitude.
[1]: *This hurt my brain when I first heard it, but I promise it’s true: it’s just that cannons are normally fired at an upward angle, giving them upward velocity and thus “hang time.”
Do you have a citation for this? I'd expect, as with all physics questions, there's a caveat.
In this case, "... over sufficiently small distances."
If you fire, say, the main guns of a battleship "over the horizon" (from your initial vantage point), I'd strongly suspect this doesn't hold.
In order for it to, the gravitational force vector, integrated over flight path, would have to perfectly counter the curvature of the Earth... which doesn't seem like it would line up so neatly.
In reality, air friction and maximum muzzle velocities probably render most of these concerns moot for practical purposes.
Air.
This is Newtonian physics.
Obviously, air, other things, friction mess it up.
But essentially that's it.
Horizontal motion of a body won't affect gravitations vertical pull.
Right. Assuming a perfectly spherical earth, at below orbital velocity, it hits the ground somewhere; at orbital velocity up to (but excluding) escape velocity it (assuming the cannon gets out of the way) orbits with the low point at (and opposite) the firing position, and beyond escape velocity it takes a curving path getting ever farther away.
Does this hold true as an object's ballistic trajectory approaches significant fractions of a planet's diameter?
Granted, the object is constantly being accelerated towards the center of the planet.
But that force vector's direction changes with respect to the initial "horizontal" launch vector as the object continues on a straight path, until they're longer orthogonal.
If I'm wrong, I'd love to hear exactly why, but regurgitating basic physics doesn't resolve the difficulties in modelling a straight flight path around a curved surface, in relation to a dropped object.
...then you are not firing horizontally, but upwards. If you would insist on orienting those guns perpendicular to the gravity vector you would get a very big splash not too far away.
I'm not an artillerist, but as far as I know (and supported by a quick glance at Wikipedia), the range advantage of those big guns over smaller ones doesn't come from higher muzzle velocity (which is limited by the physical property of the propellant independent of gun size), but from the much higher kg/CdA value of their very big projectiles.
No, it doesn't, because the Earth is curved, and air resistance. With a relatively dense, aerodynamic shell and energy sufficient for only a short flight time, both of these effects are minimal, so it's approximately true, but lose any of those and it stops being a good approximation.
I think this is assuming the ground is flat, which isn't a good assumption when talking about orbits.
I discuss orbits in the next paragraph, where I hope it’s evident I don’t assume a flat plane :)
Anything in orbit it literally the exact same. You get something moving fast enough horizontally that even though the Earth's gravity is still pulling on it, its trajectory towards earth is perfectly parallel (actually often not perfectly, but in principle) with the curvature of the planet. But by doing it high enough in the sky, you can escape the atmosphere of the earth, to where there is no wind resistance, meaning once you get up to a high horizontal speed, you can turn off the engines and coast perpetually without slowing down.
So everything in orbit, from the ISS to satellites, to the moon, are all in Earth's gravity well and are falling towards the planet, but they have a horizontal speed as well that keeps them from colliding with the surface. The Earth and the rest of the planets in the solar system do the same thing in terms of their orbit with the Sun.
It's also why sometimes satellites or space junk that have been in the sky for years will come crashing down to Earth. Sometimes the calculations for how fast you need to be going are off, or something will throw off it's horizontal momentum, and that will cause it's trajectory to dip just enough that it is no longer orbiting the earth perfectly, but instead is spiraling ever so slightly towards the surface, and will over the course of months or years or decades dip closer and closer until it enters the atmosphere, at which time air resistance becomes a factor again and it breaks up and really plummets.
Not quite. Ignoring air resistance, any throw you could possibly produce will have a parabolic trajectory, which means it could be parallel with the mountain slope only if the slope itself is parabolic.
A uniform gravitational field is such a good approximation for the situation described that I didn't think of including that proviso. Ballistic trajectory calculations close to the Earth's surface assume constant g.
The force always pointing towards a single point is what causes an ellipse to form. If the force always pointed down it would be a parabola, and over short distances on the surface this is a really good approximation.
Actually that's not quite correct, I believe it is not quite out of the atmosphere completely and as such there is a (very) small amount of air resistance and they have to fire engines to boost back into the appropriate orbit every once in a while.
("Zero G" is admittedly a bad term, since there's no such thing as "zero G" literally anywhere in the universe. It's all freefall.)
The reason is that the air itself is imparting substantial acceleration upon you from you hitting it, which leads to terminal velocity. Once you reach terminal velocity the air pressure is imparting exactly the same kind of force against you to repel gravity as the floor would be at ground level, so you experience one full g. You only really feel weightless the moment you jump off a surface, before you've accumulated any velocity and thus before you're being accelerated by air resistance.
And what's interesting, is that what feels "down" is actually "up". Which is one of the gotchas in flying.
> You only really feel weightless the moment you jump off a surface, before you've accumulated any velocity and thus before you're being accelerated by air resistance.
This is a very useful thing in ice skating, skiing, martial arts, etc. Especially combined with changing moment of inertia.
G is a unit. 9.81 Newtons. So 3G is 3*9.81 newtons.
The same: in both cases the vessel is falling toward earth accelerating at 1g, so for the passenger that are also experiencing 1g of gravity it feels like they're floating
So why horizontally? Imagine there was no air resistance on Earth. If you shot a bullet that bullet would keep going until the force of gravity pulled it down and it hit the Earth. But now imagine that you shoot it fast enough that the vertical distance gravity is pulling it down is less than the vertical distance it gains due to the curvature of the Earth. That equilibrium is exactly what orbit is. It also leads to the highly counter intuitive fact that the height of a given circular orbit is determined exclusively by how fast an object is moving relative to the body it's orbiting. Mass doesn't matter.
Okay so back to the plane. If it's not intuitive yet imagine throwing a ball. It works exactly the same as our bullet, but we can visualize one important part easier. The ball's trajectory will be a parabola. And at the highest point of that parabola the net vertical force on the ball is zero. It's where the force you exerted on it to send it up, and the force of gravity pulling it down eventually reach an equilibrium. Something inside of that ball would experience 0g at the moment when it was at its parabolic peak. And that's exactly what these planes do. They simply 'throw' the planes into a parabolic path, and the passengers experience near 0 g while traveling through the parabolic peak.
However the earth is a sphere and the direction of the free-fall constantly adjusts itself to point towards the center of the sphere creating an orbit.
It is literally throwing oneself at the ground and missing.
This is not correct. If we count gravity as a force, then it is pulling on the ball just as much at the peak of the parabola as anywhere else, and once the ball leaves your hand gravity is the only force on the ball (leaving out air resistance); your hand doesn't magically exert force on the ball once it's thrown.
If we do not count gravity as a force (which is the approach taken in General Relativity), then there is no force on the ball at all (leaving out air resistance) once it leaves your hand.
There is no vernacular in my post. When I use the word force, I am stating it in a purely colloquial sense. And in this regard everything is completely cogent and clear description of the forces (har har) in play. By contrast look at the top post. It provides a couple of sentences along with a link to Wiki for further elaboration that immediately jumps into orbital mechanics, assuming an understanding of delta v, etc. There's nothing wrong with the comment in and of itself, but it's an absolutely awful comment in regards to the audience it's talking to.
And I think this pedantry a big part of the reason that so many individuals are completely scientifically illiterate. Most of all science is relatively simple, but one of the biggest issues is vernacular. And indeed within a field there is extremely good reason for this vernacular. It is not only vastly more concise than trying to obtusely explain every single concept from the ground up, but it is also more precise. Do I mean force? Do I mean momentum? Speed? Velocity? Every concept is entirely different, but in the world outside outside of the field -- none of this matters. Theories are just ideas, speed and velocity are same thing, and so on.
The point of this is, do you think my post would be clear and accurate in what it is understood to mean from the demographic that the message was directed at? I think the answer is absolutely yes. And the casual use of terms that have more precise meanings within a vernacular is in no way going to mislead them as to the meaning of what is said. Far from it, in my opinion - using more appropriate terminology is likely to lead to a less elucidating post!
Yes, and did you notice that I didn't object at all to the part of your post that corrected the "escaping Earth's gravity" misconception? That's because there was nothing wrong with it. I only objected to the part of your post that was incorrect.
> he knows nothing about orbital mechanics and, most likely, next to nothing about physics in general.
In which case the last thing you should want to do is to tell him things about physics that are wrong. Which is why I corrected the wrong thing you told him.
> There is no vernacular in my post.
My objection had nothing whatever to do with your choice of words. You made a factually incorrect statement and I corrected it. That's all there is to it.
It’s factually wrong to say that the net force is zero at the peak, when what is zero, is the vertical speed.
What was questioned was the feeling of weightlessness. You imply that weightlessness is only felt at the peak of the parabolic path. When the ball leaves the throwers hand, the only force, disregarding air resistance, acting on the ball is the force of gravity, until it hits the ground. Someone inside the ball will feel weightlessness all the way from leaving the throwers hand to hitting the ground. There is no special feeling at or around the peak.
Not everything you said, no. That's why I objected. If you want more detail, you said:
> The ball's trajectory will be a parabola. And at the highest point of that parabola the net vertical force on the ball is zero. It's where the force you exerted on it to send it up, and the force of gravity pulling it down eventually reach an equilibrium. Something inside of that ball would experience 0g at the moment when it was at its parabolic peak.
Actually, the net force on the ball (disregarding air resistance) is the same throughout the entire trajectory once it leaves your hand. (Here I'm taking the Newtonian view that considers gravity to be a force.) That's why the ball continuously accelerates downward by the same amount throughout the entire trajectory once it leaves your hand--which it has to in order for the trajectory to be a parabola. The force you exert on it to throw it upward stops as soon as it leaves your hand, so the only force thereafter is gravity. And since the force of gravity is not felt, the ball is in free fall, feeling 0 g, for the entire parabola.
So the part of your post that I quoted was not a "completely cogent and clear description of the forces"; it was a wrong description of the forces. That's why I corrected it.
You owe it to yourself to see these amazing videos filmed on planes that simulate zero G:
OK Go - https://www.youtube.com/watch?v=LWGJA9i18Co
Physics Girl - https://www.youtube.com/watch?v=q1_AJWZajEk
Veritasium - https://www.youtube.com/watch?v=SAQ-iIJkLzA
"Contrary to popular misconception, the 0 g freefall phase of flight begins as the aircraft climbs, and does not occur solely as the aircraft descends. Although the aircraft has upward velocity during the initial 0 g phase, its acceleration is downward: the upward velocity is decreasing" [1].
All of those orbits represents trajectories in which you are in free fall.
The primary reason these orbits don't "exist" is that they impact the surface of the Earth [1]. However, if you "ride" one of these orbits briefly, you still get the free fall effect, just as if you were in orbit! It's just that you can't stay on the orbit freely because of the minor issue of surface impact.
When you juggle or something, the balls are actually, very briefly, in orbit. Minus air resistance, which is a big deal for a ball. (I initially wrote "throw a baseball", but air resistance becomes a factor very quickly even then.) With a powered projectile, like, say, an airplane, you can deliberately overcome the air resistance for a while and stay in the orbit for longer, even through the atmosphere.
It may seem like a bizarre idea of "powering" through an orbit, but it's perfectly reasonable. It's still a gravitational orbit, it's just that electromagnetic forces (contact forces) are getting involved and mucking up the purity of the orbit, so we cancel them out briefly with other ones via the jet engines. If you had a device that could continue powering through the Earth, you could stay at free-fall even through the rock.
[1]: The secondary reason is that the Earth isn't the aforementioned point mass. A neutrino could hypothetically "orbit" through the Earth for a while before being captured, but its orbit will be complicated by the fact that as it goes below the surface, the "mass" of the Earth starts dropping. Which makes me wonder if there ever are any such neutrinos. The only thing stopping such a thing from existing is the need for a process to create neutrinos that have less than escape velocity for the Earth, and I'm not sure if there is such a process.
Basically, gravity can accelerate you all that it wants, but if there is no force resisting that acceleration (air drag, your feet against the ground, the seat pushing on your back in an airplane) then you don't feel that acceleration.
https://en.wikipedia.org/wiki/G-force
"Gravitation acting alone does not produce a g-force, even though g-forces are expressed in multiples of the acceleration of a standard gravity. Thus, the standard gravitational acceleration at the Earth's surface produces g-force only indirectly, as a result of resistance to it by mechanical forces. These mechanical forces actually produce the g-force acceleration on a mass. For example, the 1 g force on an object sitting on the Earth's surface is caused by mechanical force exerted in the upward direction by the ground, keeping the object from going into free fall."
You can choose your frame of reference when considering interacting masses. I choose mine, which gives the interpretation above.
[1] ignoring buoyancy and drag from air, which are small in this scenario.
If you're in an elevator, and the elevator cable snaps, you'll be in free fall (at least initially), although you are nowhere near the escape velocity.
Even less! 1.94% of the cost. :)
Part of the experience that I'm looking for is the perspective of seeing so much of the planet at the same time Ride in a U2: https://www.youtube.com/watch?v=w-COlil4tos
You can get a ride up pretty high (and fast in a Mig too) https://migflug.com/flights-prices/mig-29-edge-of-space/
I'm not sure how much it was: I did it back in the 90s.
It was a prop plane, but I remember probably ~5-10 seconds of perceived weightlessness. Which seems longer than you might expect when your stomach and contents are suddenly floating freely in your chest cavity. ;)
I'd definitely recommend it. It was... unique
Being weightless can be accomplished on any rollercoaster, a fraction of a fraction of what you are proposing, with no view of space!
Funny to see this as the top comment when it’s so off base.
The closest cheap thing is probably the few seconds you get on a trampoline.
Your comment about the 80% of the value came out as dismissive of Virgin Galactic's achievement. This is a company that is trying to come back after a deadly crash that could've stopped further work and to initiate space tourism. I get the usual HN contrarian skepticism, as I've participated in it also, but to see this comparison as one of the top comments here is disappointing.
Free fall is different. Yes, you can get brief periods of free fall on, say, a roller coaster, or by jumping off a high dive. I have done all of these things, so I can tell you authoritatively that being in free fall for 30 seconds, not strapped in, and with no wind rushing past you, is completely different than being in free fall for a third of a second (high dive) or even three seconds (roller coaster). YMMV, of course, but for me that feeling of floating is a big draw of going into space. I'm sure the view is very nice too, but I've seen it.
https://www.goodreads.com/quotes/123074-you-know-when-you-re...
I'd never heard of him, and it was too much of a paraphrase for the search services that I tried.
Maybe we need a search service that understands language, and can do "that sounds like ...".
eventbrite.com/e/zero-g-launch-party-tickets-53416542316
If you're interested in learning more about Zero-G, I'd love to see you there. We're hosting a Zero-G charter flight out of the Bay Area in March. If you're interested, please reach out to me at avery@shuttle.io!
Space tourism is pretty niche. A booking marketplace doesn't really make sense right now, so I assume your real goal is to create the market by incentivizing supply through crowd funding/aggregating demand for various "levels" of space tourism? What economies of scale are you targeting? Do you have a timeline for collecting deposits?
If I'm wrong, please consider the above anyway :) Personally, I won't settle for less than a few LEO laps.
>The company said the space ship's motor burned for 60 seconds, travelling at 2.9 times the speed of sound as it gained height.
So they managed to briefly beat the Concorde (top speed a bit of Mach 2) and are still well under half the speed of the X-15? I mean, good for them I guess but it seems pretty ridiculous to put VG in even vaguely the same game as anybody doing actual orbital work (not just SpaceX or BO but smaller outfits even). Mach 2.9 isn't even 1 km/s, and LEO average orbital is more like 7.8 km/s (and required delta-v for that will likely be at least a good extra 1.5 km/s over that accounting for drag/grav). Yes "space" may start at 100 km as the atmosphere drops sufficiently, but I think what most people think about when it comes to "going to space" and doing something useful involves orbit, even for tourism purposes (orbital space hotels say). The challenges of every bit of it, from delta-v to heating to in-orbit survival is all on an entirely different plane.
Meanwhile with the BFR it looks quite possibly that SpaceX may well drop below $500/kg to LEO, possibly by a lot. They claim to be aiming for $10m a flight which would be more like sub-$100/kg, but I take that as more a long term aspirational goal approaching the costs of fuel a minimal maintenance then anything in the immediately realizable future. But even a conservative guess of more like $40m would still mean being able to get people into real orbit for less money then VG's up-and-down. BO is pursuing similar cost economics, and both are fighting through the very hard R&D work in actually getting scalable long term cost reductions like methalox working right now.
Can anyone explain what if anything about VG's current R&D would actually carry over to a real spacecraft, or what they use case for it would be if it can't reach that? For merely going very high and very fast on Earth low boom supersonic R&D seems more promising, and for actual space, well this isn't it. What am I missing here?
Anecdotally, people in the space industry don't seem too thrilled with VG. This type of ship was great for the X prize, but it remains to be seen how robust it is. Some of the test flight footage has looked almost unstable. Also their hybrid motor approach (solid & liquid fuel) was said to have gotten all the drawbacks of both approaches with little benefit.
>The biggest change I saw was they floated the possibility of actually traveling this way- e.g. London to New Mexico or somewhere
Yeah, that definitely seems like a wild thing thrown out, particularly given research like the X-59 QueSST NASA is doing [1]. I can't see them possibly competing successfully with an air breathing supersonic aircraft capable of legal overland flight in terrestrial transport, so there's a squeeze from the bottom. And even from a joyride and "I've gone to space!" angle it doesn't feel that compelling vs actually going into orbit for a similar price (or less!). So it seems like a dead end, albeit a cool one, but also a significant amount of money just for that given the context of the times.
----
Why do you limit it to current R&D?
Build profitable “space” business. Make it cheaper, scale it up, reinvest to grow company, more R&D, ... trips into orbit, around moon...
Maybe VG never does but venture capitalists see a market and invest in more space ventures.
Lindbergh crossing the Atlantic sparked the next generation of flight.
There wasn't a direct path from search to self-driving cars, for example. Google makes its money with search ads then reinvests.
Google went in the self-driving car direction only after a) search became wildly profitable and b) search expanded to things like mapping, street view, and heavy investment in AI.
VG isn't in a similar situation - there's little reason to believe suborbital rides for tourists is going to be raking in billions of dollars of cash.
https://www.space.com/3097-virgin-galactic-anatomy-business-...
There’s probably more. I’ll leave the rest as an exercise for you.
I’m not sure why you can’t use your own imagination. I can easily see this being a catalyst for many other businesses.
Manned space flight is dangerous and progress is slow. I explained this 4 years ago:
At which point they were already five years behind schedule.
> Manned space flight is dangerous and progress is slow.
Yes, which is further evidence for my "maybe suborbital tourism won't be super profitable" argument.
My point is that people are dismissing the entire VG project, while I see it as forward progress, which could easily be a catalyst for many other possibilities.
Is this actually even a real possible thing? "Tourism" is actually pretty well defined since governments and industry take great interest in it, and generally that definition is something along the lines of:
>"The activities of people traveling to and staying in places outside their usual environment for more then one day and less then one consecutive year for leisure with no compensation from the destination."
That effectively matches common sense: someone is not a tourist if they're just going somewhere local, nor a tourist of City X if they're connecting through a City X airport and have a few hours layover there, and if they flat out move somewhere for a year+ (or even a few continuous months in many jurisdictions) then they're into "resident" territory which has different implications as well.
I don't think spending a few minutes somewhere is tourism, it's at most a joyride from the actual place that person is staying. I guess a suborbital near-space habitat might in principle be possible, but I don't think those could ever reach space? I think the highest high-altitude balloon ever remains BU60-1, which got to 50-someodd km. Which is impressive but far below 100km. Humans have reached 40+km with a balloon, so real mass is possible to lift but I haven't crunched the math on how ginormous a balloon would be needed to support multiple people for any significant time period. And would a rocket plane actually be worth using for a rendezvous there anyway?
All of which is kind of fun and cool to think about, but also to say that it's hard to see a case for this.
Because if all their current R&D is 100% worthless towards their future business (if any) then they aren't actually building any engineering fundamentals right now and might as well be starting from scratch when they need to pivot. It takes many, many years to build up to orbital flight, and everyone starts building that experience and capability at a smaller level. So it's very important if that "smaller level" actually is building towards the next step. Blue Origin for example has been doing a lot of suborbital work with New Shepard, but that is clearly directly building towards full orbital+reusable, they've been building their capabilities wrt vertical landing, scalable engine work, etc.
But if VG's hybrid engine and entire carry/plane concept is simply a fundamental dead end (because it will never have an acceptable mass fraction or hit orbital delta-v reqs or be able to handle orbital reentry say) then most/all of their current R&D is effectively being flushed down the drain. It's not building towards anything new. And that's ignoring whether it could possibly be competitive against what the others are doing.
>Build profitable “space” business.
But what business? Sounding rockets don't match this at all, point-to-point transport doesn't look like a real case for it either, and it also can't do space tourism, just joyrides. But it doesn't look like it'll even be able to do joyrides very well compared to competitors, nor more cheaply.
>scale it up
Some things don't scale up, particularly in rocketry. There is no escaping the rocket equation.
>trips into orbit, around moon
The problem is that from the looks of it not only is nothing they're doing capable of that, it will never be capable of that. I've done some more reading since my post and the hybrid engine concept really just looks like a dud. Their whole plane thing represents a huge amount of wasted mass and extra complexity too.
And again: there is competition here now. If this was all in the 80s/90s yeah it'd be more interesting, even if everyone concluded they'd need to start over from scratch to make a real orbital rocket perhaps there really would be a decade of joyride potential or odd niche uses or something to experiment with. But not against the likes of SpaceX or Blue Origin.
On the other hand, VG is much closer to starting offering suborbital rides than SpaceX is to starting offering interplanetary manned flights.
That, and the amount of pollution it dumps into the upper atmosphere is embarrassing. Not so bad, that way, as the old space shuttle with its strap-on boosters, though. Hydrogen-fueled rockets are the only non-embarrassing way to reach Earth orbit. (H2O2 is OK, but no one uses it for that.)
Update: 82k. Sorry, the article I looked at first said 60k, that was wrong.
> The firm's SpaceShipTwo passenger rocket ship reached a height of 82.7km, beyond the altitude at which space is said to begin.
Well above he 60km mentioned.
Either way, it a fairly arbitrary point in a continuous gradient of decreasing atmospheric pressure that makes an even base-10 number in the predominant unit of measurement, so I guess you can pin this on Americans not using the metric system.
All they need to do to be the first private company to put a human in space is just choose to burn their rocket a little bit longer than they have already...
SpaceX and Blue Origin totally have the theoretical capability to put a man in space anytime now - Blue Origin has flown dummies to space, and SpaceX could fly a suborbital flight with their current Dragon capsule even if it wasn’t up to NASA human standards.
The biggest issue at this point is just cost vs bragging rights. SpaceX would have to pay so much more than the other two, that I would guess they will just wait to claim the first private orbital man in space crown.
Virgin Galactic would need roughly 10-15 times larger rocket to put human in the lowest orbit. They are not planning to do that and their system is not planned that in mind.
Space is not far. Space is just one hour drive with a car if you drive directly up. Getting to orbit of the same altitude is 10 times harder and that's the business where SpaceX and Blue Origin are.
This is in fact the goal of Copenhagen Suborbitals: https://copenhagensuborbitals.com/missions/spica/
Reaching space is one thing, staying there is something else.
cue elon re orbital velocity https://twitter.com/elonmusk/status/669131093379956736?lang=...
SpaceX, Blue Origin, and a few others have exceeded this. SpaceX regularly sends objects to the ICC, which is ~5-6x higher than what Virgin did.
IMHO, they didn't reach space since they didn't break the Karman line... They just achieved "very high atmospheric flight". It's still quite an achievement, and more than they've done in the past IIRC, but they still have a long ways to go.
http://news.bbc.co.uk/onthisday/hi/dates/stories/june/26/new...
This was very good for the Virgin/Branson publicity machine and important for the image of his airline and other ventures.
However, much like this new 'Galactic' effort, this was kind of done on the cheap. The Blue Riband had previously been contested in the days before the jet age by very large passenger ships carrying hundreds if not thousands of fare paying passengers. Branson's effort had just himself as a 'fare paying passenger'.
Sadly for Branson the efforts of Musk/SpaceX have downsized the publicity potential for what has gone on here. That time that SpaceX landed two of the rocket boosters was one of the most exciting moments in space thus far, the Tesla 'Rocketman' was also quite crazy. This should have persuaded Branson to throw in the towel on his 'space' ambitions but we all have our pride.
If you really want to see the edge of space then I am sure that if you ask the USAF nicely then they can oblige with a flight on a U2 plane. The view is pretty much the same on this tried and tested plane as what Branson offers with this 'Virgin Galactic' thing, which is far from Sagan's 'Pale Blue Dot' or Apollo's 'Earth Rise'. Top Gear presenters have had been to the edge of space (70 000 ft):
https://en.wikipedia.org/wiki/James_May_at_the_Edge_of_Space
I am sure the Russians could offer similar passage. you could even grease the palms of someone with a 50+ year old English Electric Lightning in private ownership to get you up to 70 000 ft. But nobody is beating a path to the door of those with planes capable of this, to come back to earth and demanding to go that bit higher. Consequently I very much doubt there is a market for Virgin Galactic. Maybe Virgin Galactic will have as much impact as the Virgin F1 team, canned after a few seasons lollygagging at the back of the grid. But Branson seems okay keeping these fun adventures going and good on him for that (even if a few test pilots die on the way or if he himself ends up free falling without a parachute). As billionaires go he isn't a bad chap but I ain't no fan-boy.
That was the same trip, and probably more exciting than anything since Apollo. Seeing those two rockets landing together before cutting to a dummy in a car blasting out of orbit, all choreographed to David Bowie, it looked like something from a movie.
However back when spaceship-one went to space (not orbit obv) and back twice in 2003, it felt like space was just around the corner. It took over a decade before SpaceX successfully landed their rocket to surpass that feeling.
Similar but different...haha
So...#worth.
There's a very good possibility that we'd be sending ourselves into the dark ages if space debris goes unmanaged. https://www.youtube.com/watch?v=yS1ibDImAYU&