Maybe in the very longterm. SpaceX is at the moment in orbit where NASA was in the 60s. Going to the moon is a much greater distance than most people imagine. Not even speaking of Mars.
For some more perspective. The layman should know that actually getting into Low Earth Orbit is BY FAR the most fuel-consuming burn of any rocket mission. Even on a mission to Mars, the most predominantly fuel-consuming burn will be to LEO.
Getting to the moon from LEO takes less than half the delta-v that it takes to get to LEO, and WAY less fuel (because by this time you've dropped so much weight getting to LEO)
So the real problem will always be the stupidly inefficient method by which we conduct space flight. We send all of our supplies out of an enormous gravity well with a thick atmosphere.
Imagine what we could build if we already had everything in space for us already.
The only way we'll be able to become truly space-fairing is if we either become an astroid-mining civilization, or if we build something that lets us virtually ignore Earth's gravity well, like a space elevator.
This is all true, and is all well and good for unmanned space exploration (yes, getting to LEO is halfway to anywhere), but for manned spaceflight time is also expensive - every day spent in flight adds mass for life support and supplies, and also increases the human risk of a failure.
For yet more perspective - an astronaut on the ISS in LEO is at most a couple of hours from the ground-based facilities in an emergency, probably more accessible than researchers at the South Pole. Sending people to Mars (on the order of magnitude of a year round trip, with very limited opportunities for early return) would require them to carry with them not only more expensive redundant systems, but also more advanced medical equipment and repair systems than anyone has had to carry into space before (which requires yet more mass, and hence a bigger and better launcher).
Of course, Orion itself doesn't deal with any of these issues - it's meant to be used for ascent and Earth return only, and to be attached to the larger systems that deal with the challenges of a Mars journey. Which indicates pretty well how little of the engineering work has been done towards NASA's Mars mission.
> So the real problem will always be the stupidly inefficient method by which we conduct space flight. We send all of our supplies out of an enormous gravity well with a thick atmosphere.
True, but it doesn't actually cost very much to do so. The cost of fuel for getting into orbit is only 0.3% of the total cost for the rocket [1], so if we could rapidly re-use them, we could potentially launch them every day of the year for not a lot of money.
I ask you this question because you seem to know what you're talking about, whereas I simply don't.
Watching the launch today, I couldn't help wonder why they don't use standard jets to get the vehicle to a height where a rocket could take over.
The highest a jet has flown is about 37km and LEO is considered to start at about 160km. That 37km though in my mind would be the toughest and most fuel costly to ascend.
Would it not save both weight and money to use jets and fixed wings up through the low altitudes before turning to rockets for the higher altitude ascent?
I don't entirely buy this. You don't get to go any slower if you are going to Mars, which is not orbiting the Earth in any way. Or if I just want to escape Earth orbit and go drift in space, why do I need to be moving fast relative to the Earth? Why can't I be moving slowly but steadily away?
Everyone's responses are spot-on. But I can understand that it still may not be intuitive to you.
The difficulty is that we see pictures and videos of our satellites and shuttles in orbit, and they look peaceful and serene. What's missing from those images and videos is a visceral feel that they are going over 17,000 mph. If they went less, they would leave orbit, and hit the Earth.
Objects in orbit are not "outside" of Earth's gravity; they are not just up there, just floating in space. The reason they don't "fall to Earth" is that they are falling to Earth. Constantly. It's just that their horizontal speed relative to the Earth is so large that they are - literally - falling around the Earth.
> Or if I just want to escape Earth orbit and go drift in space, why do I need to be moving fast relative to the Earth?
Because gravity. If you aren't going fast relative to Earth, you aren't going to escape Earth orbit [0]. Heck, if you aren't going fast relative to Earth, you aren't even going to be in Earth orbit [1], you are going to be falling back to the surface.
The premise of your question is wrong. If you are in Earth orbit, you are moving fast. It's actually being in orbit that allows you to move slowly away, because you can take as long as you want to apply the force. If you're not in orbit you have to quickly apply enough force to escape Earth's influence in one go or you will fall back to Earth.
I can highly recommend having a play with Kerbal Space Program to get an intuitive grasp of orbital mechanics.
Basically, if you don't go fast enough, you're going to come back down to earth. Once you get to a speed that's fast enough that you aren't going to come back to earth, you'll find you are now in orbit around the sun, in a path remarkably similar to the one the earth is on. To get to Mars you need to get up into a higher orbit around the sun, so you need to go even faster.
It's not the height, it's the speed. (Though, Virgin is trying something like this for their rocket).
LEO isn't that far away, but it goes by _really_ quickly. And getting going that fast requires a lot of propellant mass, and that's judged by the tyranny of the rocket equation.
That's pretty much the approach of Virgin Galactic. Reasons why it works for them, but not for NASA would have to be explained by someone more qualified. I do know that VG barely gets into LEO, whereas NASA's requirements are much higher. In any case, I presume the scientists at NASA (and SpaceX & co) have considered just about every alternative, and the current approach still remains the most efficient for their needs.
Orbital Sciences is doing something similar, IIRC.
They are the two big approaches to cheap space being done now. 1) Be cost-effective at making rockets, 2) launch from jets. My money is on #1, which SpaceX is doing, but #2 has some things going for it that could prove me wrong. #2 is also strictly limited in just how big you can make a payload, while for #1 you can get up to around 200 ton payloads before things start working against you.
The issue is that people confuse getting into space with getting into LEO. Virgin Galactic are not even close to getting into LEO – their plan is to fly a ballistic trajectory which takes them just above 100km before falling back to Earth.
Since they don't need to achieve anywhere near the required velocity to enter LEO, they can use a much smaller solid-fuel rocket engine and launch from a jet.
I think there are strength/scaling issues with winged aircraft that, given the fuel requirements for any sizable payload to orbit even from the speed/altitude a jet can achieve, makes this extremely challenging, but its something people keep working on.
I'm sure this has been studied to death, but my guess is that the extra risk during flight/separation, and the extra weight of designing the rocket to handle the different forces encountered when attached to the mothership are not compelling enough to make it worth the extra few % in delta-V. (SpaceShipOne went to Mach 3, not 25, so the boost was greater by percentage)
Orbital velocity at LEO is ~28,000 km/hr, but as you get further away from the Earth, your velocity decreases. Orbital velocity at the distance of the moon is only ~3,700 km/hr. (Obviously this all depends on your reference frame...)
when talking about space travel, speeds and distances aren't relevant the same way they are planetside. in space travel, it's all about who's gravity well you're stuck in, and how much delta V itll take to transfer to a different gravity well.
if we're talking about probes, the delta V aspect becomes a lot more fun when you consider the web of gravity slingshots that can be pulled off to up your dV
Not really. Planetary Robotics Laboratory at Carnegie Mellon University is building a lunar rover named Andy and they have already purchased a launch slot from SpaceX to send their rover to the moon. The projected launch date is October 2015. This team are also competiting for Google Lunar X Prize.
How much of NASA's $20 billion budget is spent on spent flight? It's budget is quite small. Apple made $100 billion in fiscal 2014. Now can you imagine what a SpaceX with that kind of revenue could do? A self-sustaining business model is the better way to develop space technologies.
While for profit sounds great, and does work amazingly well at a large number of US, EU, and multi-national corporations. It also doesn't.
Complex scientific programs can have developmental studies measured in decades. Which even very healthy multi-nations can't stomach. Selling a 50+ year ROI R&D program is really hard, and will likely get you laughed out of the boardroom.
But this is ultimately something that happens in academia. Due to largely public funding. Because as an charitable entity profit doesn't necessarily interfere with development and/or research of new ideas. Your goal is literally to piss away money experimenting on things.
While business and innovation to go hand in hand very happily. Business by definition don't transcend profitability. It is their goal. So while they do join hands for the short term, this is a short fling, not a life long love affair.
:.:.:
Also SpaceX does seem impressive. But everything they've currently done was done in the 1960's, without modern computing, or even integrated circuits. I like SpaceX but they are literally riding NASA's coat tails.
A structural analysis of a rocket engine can be done in a CAD simulation. Instead of by 5 guys with slide rules, and an IBM batch processing computer barely performing 100 KFLOPS.
>But everything they've currently done was done in the 1960's, without modern computing, or even integrated circuits. I like SpaceX but they are literally riding NASA's coat tails.
has been for now. Significant differences though start to appear -
1. their rockets are modular from the start (even Russia has trouble to get similar system - Angara - off the ground)
2. GrassHoper - self-explanatory
3. "Raptor" full flow staged combustion engine - once they get that one, they will become way ahead of any previous development.
> their rockets are modular from the start (even Russia has trouble to get similar system
I'm glad a US company can do in 2014, what a cash strapped USSR couldn't in 1970/1980. Luckily there have been few technological innovations in the past 30 years to allow this to be a fair comparison.
>3
Once again, we are hedging our bets on what may happen. Not what has. Until it happens its vaporware.
>I'm glad a US company can do in 2014, what a cash strapped USSR couldn't in 1970/1980.
actually it is cash rich Russia which is trying to do it today with much less success than SpaceX.
>So you confirm my argument.
my point here is that while the both functions have the same value, the SpaceX's has much higher first derivative at present and that, for all practical purposes, guarantees that it will be well ahead tomorrow
> actually it is cash rich Russia which is trying to do it today with much less success than SpaceX.
Russia has put people in orbit on a yearly basis since the 60's. SpaceX is successful at coming up with promising designs, but it's quite a bit early to call them more successful than Russia.
Russia as its government (not its people) has been very oil rich during the last decade. It is another question where it has directed the money though. It didn't have any issues to spend $50B for Olympic Games for example (of course most of this money were stolen by those oligarchs, like childhood friends of Putin).
The issues with Russian space isn't money. It is widespread corruption which is able to drain any amount of money and lack of educated professionals. The "old guard" is retiring and new people are too young/inexperienced. People who should have come into the industry during the 199x are pretty much missing. Add to that especial Russian government and near-government corporate ineptitude, lack of modern technological base across the country, especially in electronics/communication...
You should read how US (DoD) buys rocket engines from Russia - US buys them from Florida 5-guys shop (all guys are very well connected Russian guys, some of them are even officially sanctioned by US :) for say $10/engine while the Florida shop buys them from the Russian state corporation at $1/engine while the cost of the engine is something like $2/engine, so the Russian state is something like losing the money here :)
> A self-sustaining business model is the better way to develop space technologies.
It's a good way to improve space technologies. SpaceX builds on a lot of the research and development NASA did with taxpayer dollars, just as Apple benefited from government subsidy and investment in things like early computers and the Internet.
