Slashdot Mirror
Cosmos Solar Sail Getting Close To Launch
digitalcaffeine writes "The Guardian is reporting that US and Russian scientists are planning to launch a spacecraft that will use solar sails to move about in space. This venture, called Cosmos 1, is backed by the Planetary Society and Cosmos Studios. The spacecraft, finally due for launch in late 2004 or early 2005, will use a converted SS-N-18 submarine launched ballistic missile fired from beneath the Barents Sea to get it into a 800 x 1000 km elliptical orbit. It will then unfurl its 15m sails and start moving about. So, for all the governments that have been working on a similar project, the first solar-sailed spacecraft is going to be from a private venture." An update on the official site notes that "The world's first solar sail craft is nearing completion. All electronic systems are now flight qualified and were delivered to the spacecraft for final assembly and testing" - we previously reported on the Cosmos Project and the efficacy of solar sails.
Well, at least this privately funded space endeavour can't, or at least isn't as likely to, explode as the recent Canadian mishap, but then again... what happens when the sails get a gust? Last time I checked... there're no brakes in space... if you accelerate, you continue at that speed until something stops you. Personally, I think I'd rather take my changes with a potentially exploding spacecraft than one that might start and never be able to stop... ;)
I hope they were reliable. Somehow I don't think NORAD will care for excuses if an SS-N-18 starts dropping towards Chicago.
nos laetus epulor qui would domito nos
A private venture has had access to an intercontinental missile??
you just build a bigger sail. It's light, and that's the point. HUGE sails are possible in a weightless environment, and a bigger sail harnesses more energy.
Moo.
So why the sub? Extra publicity?
IANASSE (Solar Sail Expert), but 15m sounds a little small. I mean we are talking about pushing a satellite around with *photons*. I guess the amount of energy required to move a spacecraft in orbit is miniscule. I remember reading an article about early space efforts that said something like "the smallest rocket motors are little more than cap-gun ammunition but, they are sufficient to nudge a spacecraft in orbit"
What would this technology be used for in the short-term, though? It seems to me that without an immediate way to utilize this solar sail, there cannot be a profitable business application. It belongs more in the realm of the government at this time, as the government doesn't need to turn a profit.
Haec merda tauri est. Ceterum censeo Carthaginem esse delendam.
1) The 5 year solar sail propelled mission to Pluto - is there a way to decelerate as you reach Pluto? Actually, is it really 5 years constant thrust or does the solar sail's thrust decrease as an inverse square law as you get more distant from the sun?
2) Can you sail "upstream" into the solar wind? Is it possible to tack and jibe in a solar sail propelled craft?!
This is not a sig
Posted before under the Japanese Solar Sail Deployment:
Though Solar Sails are often associated with interstellar travel they have many extremely useful applications in Earth orbit and local solar system exploration. Most potential applications take advantage of the continuous thrust and zero fuel payload of a solar sail.
Near Earth, Solar Sails are particularly suited for high orbital inclination satellite missions. Weather forecasting and global positioning systems would directly benefit from satellites orbiting the poles. Most satellites take advantage of the natural speed of Earth's rotation to boost them into an orbit relatively close to the equatorial plane. Changing the plane requires a large fuel burn for a conventional rocket and greatly increases launch costs. With its small but continuous thrust, a solar sail can reach polar orbits without a massive fuel payload, making them more accessible to scientific research.
Away from Earth, Solar Sails offer a number of other interesting options. Missions have been proposed for asteroid rendezvous, travel to the inner planets (yes, solar sails can travel toward the sun), and an interesting idea using Lagrange points. More advanced solar sails could use their continuous thrust to enlarge the regions where they are able to "hover" well away from Earth. This allows much better observation of solar activity. Solar sails not only have an appealing sci-fi flair, but appear to be quite practical as well. I hope to see the technology develop rapidly.
But I thought the idea of solar sails had been scrapped due to the relaitve scarcity of interstellar hydrogen?
Actually, light alone is sufficient to produce thrust. The problem is that at 1.3kw/m^2 (the power that reaches Earth), you're not going to go very fast with the mass of the solar sails added on.
I've been keeping an eye on Mini-Magnetospheric Plasma Propulsion (M2P2) technology, myself. Basically, it uses an EM field to increase the surface area of the ship without the added weight of solar sails. As a bonus, the ship is protected from the most common forms of radiation and cosmic rays. The concept is particularly interesting when one digs the Orion concept out of memory.
The biggest problems with Orion were plate ablation and scalability concerns (scaling DOWN, not up). With an M2P2 shield, you could use larger pulsed units, and there's no plate to erode. As a bonus, radiation protection comes as a nice side-effect. (Although some steel would still be needed to block neutron radiation.)
Javascript + Nintendo DSi = DSiCade
How's that going to work with Orion? I can't imagine an M2P2 setup withstanding the force of a nuclear blast. Seems to me you've got to be pretty close to the propulsion unit to capture any decent fraction of its energy. It'd be like subjecting a soap bubble to a firecracker.
1. You have to calculate the effective range. i.e. The pulse units must be exploded far enough back so that the pulse doesn't damage the craft.
2. Orions aren't actually propelled by the explosion. The pulse units are sort of "shaped nuclear charges" where all the force is applied to a plate of propellant (tungsten, IIRC). The vaporized propellent collides with the pusher plate, resulting in thrust. The actual nuclear explosion itself would be far enough back not to impart much force on the craft.
In an M2P2 Orion design, you simply choose a propellant that interacts positively with the shield, and adjust the charge to spread it evenly across the surface of said shield.
Javascript + Nintendo DSi = DSiCade