Slashdot Mirror
DARPA's ALASA Could Pave Way For Cheaper, Faster Satellite Launches
hypnosec writes DARPA is all set to take its Airborne Launch Assist Space Access module (ALASA) program to the next level after the program has shown promising results toward its mission of sending 100-pound satellites into low Earth orbit (LEO) for just $1 million per launch."
ALASA is a new program that seeks to streamline production and encourage re-usability and interchangeability in satellite systems.
And not, say, NASA? Somebody explain, please.
From your link:
Failures of the 21-meter wingspan, multi-lobe composite material fuel cells during pressure testing ultimately led to its cancellation as a federal program in 2001. Lockheed Martin has conducted unrelated testing, and has had a single success after a string of failures as recently as 2009 using a 2 meter scale model
A 2-meter scale model of a suborbital craft doesn't sound like we're close to SSTO at all.
I don't understand why the idea is being implemented in such a modest manner. The animation has the rocket stage carried aloft for ignition at high altitude by what looks like an F-18. While I don't doubt the performance of the Hornet's engines, wouldn't it make more sense to extend the payload capacity with a larger carrier craft? Say something on the order of the 747-based shuttle carriers? You would be able lift a proportionally larger rocket stage that is able to deliver a more massive payload into LEO or a proportional payload (planetary probe?) even further. It has always felt to me that an airborne launch of a space vehicle has so many more benefits. You are not restricted for being tied down to any one physical terrestrial location. Launches are additionally more versatile due to the more numerous varieties of orbits available at lower costs. Is there a good engineering reason why concepts such as the Soviet-era MAKS was not pursued?
Stay sentient. Don't drink bad milk.
You are aware that mentally ill people and drug addicts are always going to spend whatever cash they are given, and remain homeless, right?
Those are a small minority of poor people. Even regular drug users can manage their lives if the basic needs are fulfilled. If they can't deal with cash, don't give them cash but free housing, food and medication.
Use it to throw up satellites with a designated lifespan into very low earth orbit and maybe you can have the damn things fall back to earth rather than cluttering up our gravity well...
I wonder what portion of early spacefaring civilizations actually strand themselves on the planet by putting a mess of space junk in their planetary orbits. We're well on our way. There's even shit up there. No, literally--from the early days of the space program. Rumor in the space community is they found some of it by (messy) accident on a later mission.
For the general problem, see http://en.wikipedia.org/wiki/K...
> You are aware that mentally ill people and drug addicts are always going to spend whatever cash they are given
You have obviously no clue.
The single biggest reason is can you see some rich person buying a used one, like John Travolta bought a used 707, and deciding to take a planeload of ceramic coated rebar to orbit and drop it on peoples heads at 22,000 MPH?
Someone could do a lot more damage just by crashing the 707. For that matter, a 1 meter length of #8 rebar is about 4 kilograms, so, at 22,000 MPH would have about 193 MJ of kinetic energy, if it actually reached the ground with the same amount of energy it had before de-orbiting (which would be ridiculous). That's about 8% more than the equivalent mass of gasoline (and, once again, by the time it reaches the surface, it would be a lot less). Of course, gasoline gets to cheat on the energy density factor by using oxygen. You could argue that it's only fair to compare it to something where the energy is entirely self-contained. That's not really valid since the final destination is inside the atmosphere, but we'll give you that one anyway. We'll consider methane, which requires twice its mass in oxygen to combust. That ends up giving it 38.26% of the theoretical maximum of your de-orbiting rebar pieces by mass.
In other words, someone could do a lot more damage just by dropping various sorts of conventional bombs from a 707. Or from a smaller plane for that matter. Or going on foot. Heck, probably just by running around and beating random people with a piece of rebar considering how unlikely it is for the orbitally delivered rebar to both retain significant energy and actually hit a target.
The "rods from god" concept (usually considered with a much larger projectile of the densest practical materials rather than relatively light projectiles prone to tremendous drag like pieces of rebar) is easily shown to be not worthwhile (if you're launching the projectiles from earth with chemical rockets anyway) compared to just about any method of blowing things up. Any physicist or decent engineer with a napkin and a ball point pen can demonstrate it pretty easily. For some reason, the idea keeps coming up.
You are aware that mentally ill people and drug addicts are always going to spend whatever cash they are given, and remain homeless, right?
You are aware that you're both mischaracterizing what was said and that you're spouting nonsense, right? The GP didn't say "throw money at mentally ill and drug-addicted homeless people".
Ad you realize that poverty is defined as a certain percentage of the population at the bottom end of the bell curve, right?
Not legally it's not. Economics... life in general, in fact, isn't the kind of zero-sum game you seem to be implying it is. Poverty is defined by a number of guidelines. There are a number of factors. Whether the subject actually has adequate nutrition is an important one. Under those guidelines, 16% of Americans and 20% of American children live in poverty.
And you're aware that basic health care is already fixed, and was before the ACA, sincethe hospitals are legally required to treat you if you present at the ER, right?
What idiot/liar keeps spreading this load of nonsense around? Hospitals are legally required to _stabilize_ you! That means that, if you show up dying of something acute, they have to take you in, but can kick you out the door the moment you're not in critical condition anymore. If you show up, for example, with a terminal case of cancer, they don't have to treat, or even diagnose your cancer. If you have immediate, life-threatening symptoms, they have to provide some treatment for those symptoms. In a practical sense, it pretty much just means that they have to provide a bed for you to die in when you're ready to drop. I'm not sure they're even legally required to provide painkillers for someone dying in excruciating pain. The laws you're talking about are basically just to stop people dropping dead in the ER, and they don't even manage to stop that from happening sometimes.
Probably not great for cheap spy satellites.
Cost is still $10,000 per pound to LEO. Some existing commercial launch systems already match that price. The 100 pound payload limit is a real problem though as effective recon sats will be considerably heavier in order to have big enough lenses for high res images as well as the transmitter, solar panels, etc. The best recon sats are expected to be roughly equivalent to the Hubble telescope. Note that the Hubble cannot take good images of the earth because it cannot track the ground.
From the article on KH-11 recon sat
The maximum diameter of the spacecraft is 10 feet or 120 inches with an estimated length something over 43 feet. The long telescope barrel is on the order of 8.94-9.3 feet in diameter. Titan-23D could place 24,600 lbs in polar orbit while Titan-34D could place 27,600 lbs into polar orbit. The KH-11 SSB mass application is about 3,289 lbs dry while its fueled mass is about 10,568 lbs. The whole spacecraft dry mass is about 13,289 kilograms and the fueled mass is estimated between 24,500-25,800-27,500 lbs at orbital insertion depending on which booster is used. The KH-11 KENNON spacecraft was replaced in the early 1990’s by the KH- Advanced Crystal spacecraft.
The real advantages to this design is the small launch cost and the short prep. time needed for a launch (24 hours).
This doesn't make a dent in cost effectiveness of Falcon 9 or PSLV.
Let us calculate per pound LEO costs for these vehicles:
ALASA: $1M / 100 lb = $10,000 / lb
Falcon 9: $61.2M / 28,991 lb = $2,111 / lb
PSLV: $20M / 7170 lb = $2,789 / lb
Tiny satellites at 100lb can easily tag along with bigger launches on these vehicles. Costs may be even cheaper for such secondary payloads or may even free in some cases. If SpaceX succeeds in first stage reuse, or ISRO per chance succeeds in RLV-TD plans, costs may come further down.
So ALASA sounds like a costly option for small satellites today and in future. But the technology as such may have potential if handled by a better managed private company that works on it as a commercial venture.
Hey, we have all this hardware and software laying idle, why not do a cost reduction exercise and sell the effing thingie in the commercial market?
Seriously tough, I have to wonder if the Chinese, Russians and all the other minions (Iran, North Korea) are not thinking this is a brilliant disguise to be able to deploy an extensive Anti Satellite system.
"If a boss demands loyalty, give him integrity. But if he demands integrity, give him loyalty." (John Boyd, 1927-1997)
There are at least 3 current companies working on a similar concept (air launched small to medium rocket), why are they inventing another when they could buy one of theirs for much cheaper? I can only see two reasons, they want it as a quick response orbital weapons platform and the "small satellite launcher" concept is just an excuse. Number two they're hoping to extract some good old fashioned blank check defense contractor money from the DOD. If its the latter they could have at least put a little more effort into the animation, it looks like one of those bad Sy-Fi channel movie special effects and even the flight profile looks totally unrealistic.
I laughed, then I imagined said person running around hitting people with rebar screaming "RODS FROM GOD! RODS FROM GOD!", and I laughed again.
Well, partially resusable anyway, and I don't know about a few months - I suspect they'll end up having to successfully land the first stage at least a couple times before they sort out whatever reusability issues are as yet undiscovered. Not to mention the challenge of getting a rocket from a barge in the ocean back to the launch facility without inflicting crippling structural or salt-water related damage - that alone may prove enough of a challenge that actual reusability has to wait until they can get approval to land back on solid ground.
Then again maybe a few guy-wires can keep it balanced on end so it can be brought to shore and transfered by, what, a size large cargo crane? Or maybe a heavy lift helicopter? Hmm. Okay - the F9v1.1 first stage has a dry weight of ~18,000kg, while the massive Mi-26 chopper can carry payloads of up to 20,000kg - just barely enough, with a 500 mile range. That would probably be the easiest way to transport it - avoiding all the complications of transferring it from ship to shore and then overland. Just carry it directly from the landing barge to the launch facility.
So hmm. Could be doable. Provided the ocean is calm enough to let the rocket remain balanced on end long enough for people to get to the barge and get guy wires in place to keep it there.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Of course this isn't a cost-saving approach, it's real goal is maximum convenience and flexibility. Let's say I want "eyes" on a particular location ASAP, but I don't have any "birds" on a good trajectory for several hours to come. This would allow me to put a satellite precisely on target in under an hour.
And if they can add a miniature projectile launcher into the same 100lb package, they've basically got a global "kill switch" for a limited range of targets. You wouldn't need more than a few pounds of depleted uranium, shaped into a steerable "bolt" and packed with some high explosive, and the necessary thrust could probably be provided by a simple spring mechanism, just like a crossbow.
With a 100lb mass budget, you could probably even allow enough propellant to get the bird back over the same spot (or near enough to shoot at it) on the very next orbit. Say the satellite costs a $mil, plus another $mil for the launch... that's cheaper, per shot, than some of the ordnance already in service. Or, if you don't mind launching two in rapid succession, you can use the first one as spotter and the second one as sniper.
XML is like violence. If it doesn't solve your problem, you're not using enough of it. --AC