NASA's new heavy lift rocket isn't the only massive space propulsion system the agency has in the works. The largest solar sail the solar system has ever known is headed to the launchpad in 2014 on a mission that will eventually take it nearly 2 million miles from Earth. The demonstrator mission aims to show that the technology lessons learned from NASA's smaller NanoSail-D mission and JAXA's IKAROS solar sailing space vehicle can be leveraged into a large-scale space-traversing propellantless propulsion system.
The Sunjammer mission--the name is borrowed from an Arthur C. Clarke short story about an interplanetary yacht race--will unfurl a solar sail that dwarfs those that have thus far been tested in space. Where NanoSail-D's diminutive sail measured just 100 square feet and Japan's IKAROS measures something like 2,000 square feet, Sunjammer's sail possesses a total surface area of nearly 13,000 square feet. Yet collapsed it weighs just 70 pounds and takes up about as much space as a dishwasher, making it easy to stow in the secondary payload bay of a rocket headed to low Earth orbit.
The sail will be made of Kapton, a super-thin film developed by DuPont that is used in all kinds of things, from space suits to flexible circuitry. The special layer of Kapton film developed by DuPont along with NASA is just 5 microns thick. Once unfurled, it is light enough that its own weight isn't a hindrance yet strong enough that it can tow a support module across space using pressure provided by the sun in the form of photons as propellant, much as a maritime sail uses the wind to pull a sailboat across a body of water.
The destination for Sunjammer is the Earth-Sun Lagrange Point 1, a gravitationally stable spot way out there between us and our nearest star. And while Sunjammer is a demonstration mission and won't be pulling an independent scientific mission along with it, the technology it is expected to enable could allow for a range of missions that are currently not possible with conventional chemical propellant systems. Particularly applicable would be missions to build a sun-monitoring space weather warning system, which could help protect infrastructure here on Earth from potentially harmful solar flares.
But Sunjammer does have a mission profile. Via Houston-based company Celestis Inc., Sunjammer will be carrying the cremated remains of various individuals, including Star Trek creator Gene Roddenberry and his wife Majel Barrett Roddenberry. It's not exactly the Enterprise, but Sunjammer will be boldly going where no solar sailing spacecraft has gone before.
A cosmic kite strung out of notary dead people, omg!
Foot, feet, pounds, miles, microns? Sorry, don't you have microinches somewhere in the closet? I think it's about time to get the metric system introduced everywhere, so that your "seudo-scientific" articles get readable?
What's psuedo-science about a project NASA has planned for the near future? Why complain about the standard we Americans use while reading an American publication?
Hang on, if this is propelled by photons, how is its target located toward the sun instead of away from it?
I'm pretty sure NASA is using the metric system themselves.
@kflotlin: I'm not sure if the solar sail works exactly like a sail, but sailboats can go towards the wind, I think it's called either "beating" or "windwarding" in English.
Gotta love windsurfing on such a scale. Things will be better when we've moved up to surfboards with The Power Cosmic. We should make a Cup Race soon. Think about it. With the cash outlay on a modern typical 40 meter America's Cup yacht and team support and logistics, it could be done today.
This will be very practical for lunar towing missions in that stretch of space between Earth and the moon.
Is this the same project that the Planetary Society directed by Bill Nye is a part of?
It is a little odd that the solar sail is heading to a point BETWEEN the earth and our sun. So it is, supposedly, heading towards the sun.
The only direction photons head in space is AWAY from the sun and, unlike sail boats here on earth, a solar sail cannot exactly tack against the solar wind.
To my knowledge, The Bernoulli Effect does not apply to photons. It is a phenomenon that manifests itself soley in a gaseous environment.
I am guessing that the only way they can get it to where it needs to go is to have it slingshot around several of our planets in a carefully orchestrated trip.
Once it has the momentum it needs, I suppose gravity will steer the ship.
As much as I think this is cool, I don't see too much practical use for interstellar flight. By the time a solar sail gets to Pluto, it is experiencing maybe 1/1000 the force that it is here near earth.
This may be useful for interplanetary travel, but I think the speed of the ship is limited by how much momentum the solar wind can impart to the ship and by the amount of energy our largest planet can impart to the ship in a gravity slingshot.
How to tack towards the sun
I suppose that is "space tacking" ... but then you'd have to think of any of our spacecraft coming back to Earth as tacking towards the planet as they enter the atmosphere.
@ Far Out Man; Taking this sail exactly what it is, but adding technologies changes your potentials, yes? The sail is great because you can also make one to store and redirect the particles in the wing, or you can link with the physics of a hotsource and charge them as well.
Ok, you read the latest issue here? You got the MIT prof that's working in box folds. The other one in Japan offered up that space jellyfish idea too. That jellyfish is cool, because as you go through space, you are actually going through less space, comparatively. Because you get to flow right up in your fuel stream, in a natural eating motion.
The box folds are significant because they are simple, with only limited counterforces for their natural tendencies as folds. Now envision a fine boxchain necklace, with a low reactive metal component that is light as a mesh for the overall boxchain link form, made of a nice custom HO mix from the moon, and your necklace strand as part of a wing, and viola. Your solar sail can now upgrade as a craft in self guidance because it is now your fuel source, and what you are eating as supplement is a product of magnetic self guidance based on your locale and choice. Basically, change course with angular deflection, otherwise, get on a stream and leave it alone for efficiency. Use the particle densities to model gravity, as typical. Theoretically, that environment is only limited by scale. The bigger your craft, the more capabilities and principle controls you add, and eventually you get a spacefaring colony craft.
Thank you, Salopianjerel for your response.
I can see now how the sail will get closer to the sun.
By slowing the orbital velocity of the sail, the centripetal acceleration of the sail diminishes and the sun's gravity pulls the sail inward.
As an American, we need to ditch our stupid system and transition to metric. I launched a weather balloon today and most of the confusion was caused by fractions of inches, pounds, and ounces. Metric is in increments of 10's before a unit changes it's prefix, and most of the time you go by thousands(oh, such a big scary number!),such as 1000 grams in a kilogram. It is much easier than counting in 32nds of inches, 16 ounces being equal to a pound, and 4 cups in a pint(I had to look up what unit was after the cup because I couldn't even remember!) Just admit it... "our" system is cumbersome. I am VERY patriotic and I think our system is antiquated, obsolete, and most of all stupid! Unit conversions in metric are also a breeze! Usually, decimals are SO much easier than fractions.
your lack of math skills has no bearing on what the rest of the US should or should not be doing. Fractions are just as easy to use and can be easier then dealing with a tens based system.
One example... How many grams is a third of a kilogram. A third of a pound is exactly 1/3, I can continue doing calculations with that number without any generational degradation. 1/3rd of a kilogram is approximately 333.33 grams, rounded to your preferred precision. That is always imprecise, and given enough generations will result in error.
Knowing the units of the english standard system is no scarier then knowing the terms of the metric system. 100 grams is a kilogram, how many makes a metric ton? Is that 100 kilograms or 1000? ..how does that relate to a megagram? How does any of that relate to an MTU (metric ton unit)?
If you know your system well enough to be a professional dealing in a given area you should be well comfortable with the units and their conversions. If you arent, then you aren't qualified to be in that field and you're just play acting.
sorry above 1000 grams is a kilogram not 100. huh.. guess just because I was writing in metric it didn't make me immune to errors. Go figure.
For those of you who would like more information (technical as well), please see following link to my thesis work on solar sails. (Info in metric system :) )
R. Sood, "Solar Sail Applications for Mission Design in Sun-Planet Systems from the Perspective of the Circular Restricted Three-Body Problem," M.S., December 2012.
I have visited some Popular Science pages that could be trying to infect your computer. Has anyone else experienced this?
Geez! This System Care antivirus program markets itself so aggressively it make AOL look tame!
You may also have trouble typing correctly when this damn program pops up. If anyone else is getting a message from System Care, let Popular Science know.
Some younger readers may not understand my AOL reference. AOL in the 1990's was an Internet Service Provider/Browser that marketed itself very aggressively. Literally, you would get a CD disk in the mail almost every month asking you to subscribe.
I remember wanting to take those AOL disks and use them for skeet shooting.
If you are getting a System Care message from these Popular Science pages, you should update your virus software.
I am having trouble navigating away from this stupid thing! System Care software is probably 10 times worse than AOL! I feel like I am being chased by one of those damn deer flies!
ARRRRRRGH! The stupid software is all over me!
Buy Me! You KNOW you want to buy me. Oh, come on, BUY ME! BUY ME NOW! I am going to bite you! BUY ME! BUY ME NOW!
DON'T YOU WALK AWAY FROM ME! I WILL *NOT* BE IGNORED!
Deer flies are tame compared to this!
OKAY! OKAY! I'M SHUTTING THE COMPUTER DOWN! MY GOD! SERIOUSLY! BE WARNED WHEN THIS SYSTEM CARE THING POPS UP!