Maybe they are doing this, but when they target us, we're looking in another direction. We don't have omnidirectional receivers, so we're only likely to receive something if it is broadcast continuously.
Ground operations for 2010 reusable launchers would be more expensive than ground operations for 2010 throwaway launchers. 2010 reusable launchers would be more expensive than 2010 throwaway launchers (though less would be needed). 2010 reusable launcher design and qualification would be more expensive than 2010 throwaway launcher design and qualification. Whether 2010 reusable launchers would be overall cheaper than 2010 throwaway launchers is not at all obvious. Looks like SpaceX have a shot at trying to prove it so, but they aren't there yet.
As to spaceplace like designs, they simply can't be built with 2010 technology; and you can't start such a project today with technology that isn't provably achievable (Apollo was known to be achievable in the early 60s).
No one knows how to build those planes. Sure, you can use a B-52 to lift a rocket that will put a 200KG payload in LEO, but those things don't scale.
wrt recovery, wings or landing rockets are pretty, but also very heavy. If a parachute system is the lightest, then it's also the cheapest. Remember, an extra pound of landing gear expands to 20-40 extra pounds of launcher mass.
These are all research programs, far away from production. I agree those are the best bet for the future, but you can't start a launcher program based on those.
Horizontal takeoff designs are no go. Wings are only efficient at very low speeds and altitudes (there's a reason the Concorde is offline); you're increasing efficiency for the first 1000 m/s and 30 km but you have to carry them for the other 7000 m/s and 200 km (less if you have two stages, but still horribly inefficient).
Engine reusability can be had with recoverable missiles (see SpaceX).
The ground operations staff increases with reusability instead of decreasing since you have to inspect and repair your reusable spacecraft; this is what killed the shuttle economically. These engines operate so close to the edge of the envelope you have to trade efficiency for maintenance time, and you just can't afford to lose efficiency.
Suitable air breathing engines have been a decade away for at around 50 years now. No one knows if they're even possible beyond Mach 5.
Not to mention making it manned, which increased complexity, weight, and cost again. Launch vehicles must be as slim as possible, any excess pound taken to orbit is at least an extra 20 pounds launcher mass.
So far, missiles are the best launch vehicles by far. This will remain so until we can build engines which don't require air with a specific impulse greater than 800.
The shuttle's failure comes from sticking a plane on top of a missile, that alone increased launcher size by a factor of 4 at least (for the same payload).
It's not obviously true that reusability is the best way. Reusability increases the launcher complexity and weight, hence design costs and launcher costs. You produce less launchers, so gain less from mass production. You can produce fewer launchers, but you need to pay for recovery and turnaround.
It may still turn out to be the best way, as SpaceX are trying to prove, but it isn't obvious.
We're only now starting to be capable of detecting earthlike planets, and only in very specific circumstances. It's only to be expected we haven't detected any yet.
Per person, it's horrendously expensive. It will cost billions to put each man on mars, billions more to support them. Fixing this cost is much, much cheaper when you divide it by the population.
Many small rockets mean many more engines, a lot more mission planning and control, and reduced mass efficiency (smaller rockets carry less payload as a fraction of total mass). There's a reason why we deliver goods on trucks and not motorcycles.
Having fuel stations in orbit would be nice, unfortunately you can't lay fuel pipes to orbit.
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We're not monitoring 1400 star systems. They could be illuminating us wondering why we don't reply.
The closer you aim the higher the probability you will be heard if anyone is listening, but then the probability of anyone listening drops.
It's unreasonable to assume life in such a small sample.
Why would they point it at our system? There are 10-100 billion systems in the galaxy.
Maybe they are doing this, but when they target us, we're looking in another direction. We don't have omnidirectional receivers, so we're only likely to receive something if it is broadcast continuously.
Why would they target anything at us? We're not sending them anything, as far as they know this place is empty.
How much time? Years?
Oh, and they're right next to a star. So lots of noise.
((1 MW) / ((4 light year)^2)) * (100 (m^2)) = 6.98311557 × 10^-26 watts
So even if there are aliens in the closest star broadcasting using a 1 MW transmitter, the output here is way to low to measure.
They're probably sitting there wondering why they don't receive anything either.
Ground operations for 2010 reusable launchers would be more expensive than ground operations for 2010 throwaway launchers. 2010 reusable launchers would be more expensive than 2010 throwaway launchers (though less would be needed). 2010 reusable launcher design and qualification would be more expensive than 2010 throwaway launcher design and qualification. Whether 2010 reusable launchers would be overall cheaper than 2010 throwaway launchers is not at all obvious. Looks like SpaceX have a shot at trying to prove it so, but they aren't there yet.
As to spaceplace like designs, they simply can't be built with 2010 technology; and you can't start such a project today with technology that isn't provably achievable (Apollo was known to be achievable in the early 60s).
No one knows how to build those planes. Sure, you can use a B-52 to lift a rocket that will put a 200KG payload in LEO, but those things don't scale.
wrt recovery, wings or landing rockets are pretty, but also very heavy. If a parachute system is the lightest, then it's also the cheapest. Remember, an extra pound of landing gear expands to 20-40 extra pounds of launcher mass.
These are all research programs, far away from production. I agree those are the best bet for the future, but you can't start a launcher program based on those.
Horizontal takeoff designs are no go. Wings are only efficient at very low speeds and altitudes (there's a reason the Concorde is offline); you're increasing efficiency for the first 1000 m/s and 30 km but you have to carry them for the other 7000 m/s and 200 km (less if you have two stages, but still horribly inefficient).
Engine reusability can be had with recoverable missiles (see SpaceX).
The ground operations staff increases with reusability instead of decreasing since you have to inspect and repair your reusable spacecraft; this is what killed the shuttle economically. These engines operate so close to the edge of the envelope you have to trade efficiency for maintenance time, and you just can't afford to lose efficiency.
Suitable air breathing engines have been a decade away for at around 50 years now. No one knows if they're even possible beyond Mach 5.
Can you suggest an alternative?
Not to mention making it manned, which increased complexity, weight, and cost again. Launch vehicles must be as slim as possible, any excess pound taken to orbit is at least an extra 20 pounds launcher mass.
So far, missiles are the best launch vehicles by far. This will remain so until we can build engines which don't require air with a specific impulse greater than 800.
The shuttle's failure comes from sticking a plane on top of a missile, that alone increased launcher size by a factor of 4 at least (for the same payload).
Planes fly around 300 m/s. To get to orbit you need 8000 m/s. Launching horizontally means you have to fight air resistance all of the way.
It's not obviously true that reusability is the best way. Reusability increases the launcher complexity and weight, hence design costs and launcher costs. You produce less launchers, so gain less from mass production. You can produce fewer launchers, but you need to pay for recovery and turnaround.
It may still turn out to be the best way, as SpaceX are trying to prove, but it isn't obvious.
They aren't sending it for your benefit.
Falcon 9 is much cheaper.
It isn't a stupid question, and yes, by counteracting drag thrust can get you to true freefall.
Where's the gold this time?
You forgot the tiny liquid oxygen tank.
We're only now starting to be capable of detecting earthlike planets, and only in very specific circumstances. It's only to be expected we haven't detected any yet.
Check again in ten years.
Per person, it's horrendously expensive. It will cost billions to put each man on mars, billions more to support them. Fixing this cost is much, much cheaper when you divide it by the population.
The Earth-Mars round trip time lag is way beyond the attention span of an average Homo Sapiens.
Many small rockets mean many more engines, a lot more mission planning and control, and reduced mass efficiency (smaller rockets carry less payload as a fraction of total mass). There's a reason why we deliver goods on trucks and not motorcycles.
Having fuel stations in orbit would be nice, unfortunately you can't lay fuel pipes to orbit.