Back in August I mentioned NASA’s solar sail plans beyond NanoSail-D in the context of a larger survey of sail designs and experimentation. It’s great to see multiple sail projects in motion, and before I return to NASA I should mention not only the Planetary Society’s ongoing sail effort but the CubeSat sail being built by a consortium from the University of Surrey and aerospace firm Astrium, an aerospace subsidiary of the European Aeronautic Defence and Space Company (EADS). Then there’s the German space agency DLR and its Gossamer sails, experimental designs being worked on with the European Space Agency. Surely energized by the success of the Japanese IKAROS sail, work on this fledgeling space technology is beginning to ramp up.
NASA’s next step in sail design builds upon the earlier work the agency performed with aerospace contractor L’Garde Inc., of Tustin, California, which deployed and tested a 20m X 20m sail at the agency’s Plumbrook facility in Ohio. The plan is to build a solar sail demonstration mission that will create a sail quadruple the size of the Plumbrook sail and conduct operations in space to demonstrate attitude control as well as passive stability and trim adjustment using beam-tip vanes. The demonstrator mission will also allow the craft to execute basic navigation operations.
Image: A four-quadrant solar sail system sits fully deployed in a 100-foot-diameter vacuum chamber at NASA’s Glenn Research Center Plum Brook Station in Sandusky, Ohio. NASA’s solar sail propulsion team at the Marshall Space Flight Center in Huntsville, Ala., and its industry partner, L’Garde, Inc., of Tustin, Calif., successfully deployed the solar sail system during testing at the Plum Brook facility in early July 2004. The tests included temperatures as cold as minus 112 degrees Fahrenheit to simulate conditions of open space. Credit: NASA/L’Garde, Inc.
Technology demonstrator missions like this one provide near-term spacecraft that can show the feasibility of new technologies, and that means flight hardware tested in space. The plan is for the sail mission to piggyback with other payloads aboard a commercially available launch vehicle, with launch scheduled for 2015 or 2016, and a one to two year period of spacecraft operations and analysis. NASA talks about future solar sail capabilities in the realm of satellite deorbiting (essentially using the sail as part of a satellite payload for this purpose) and station-keeping, allowing ‘pole-sitter’ sails, for example, for geosynchronous high-latitude operations.
The final purpose, as noted in this NASA news release, is to develop sails for deep space propulsion, but we’ll need to build up a sail capability much closer to home before we can think of committing serious payloads for these purposes. We’ll doubtless see attempts at something like GeoStorm, which would place solar storm warning satellites at positions between the Earth and the Sun to increase our warning time for solar flares. The demonstrator sail is a precursor to all these applications, and NASA’s work with L’Garde and the National Oceanic and Atmospheric Administration should be seen as part of firming up sail techniques as we aim for bigger missions.
Another part of that process would be to move into space-based experimentation on microwave beaming. Back when the Planetary Society was planning for the ill-fated Cosmos 1 sail (lost evidently without achieving orbit in a booster accident), the plans included an attempt to measure the effect of microwaves on the sail using the Goldstone dish. It would be heartening to see this kind of thinking continued in the next round of missions. My own take is that beamed sails offer huge advantages for deep space, including not just the fact that the spacecraft does not carry fuel onboard but that the physics of microwave beaming to a sail are comparatively well understood. More on beamed sail concepts soon as we look at some of Jim Benford’s thoughts on the idea.
In this context it would be worth mentioning the ongoing effort to build an electric solar sail, Esail. The electric sailing propulsive principle is to use the impulse needed to deflect charged particles in the solar wind and use the resulting impulse. The envisioned system is a very large but feasible structure with tether booms at lengths up to 10s of kilometres. The project is championed by Professor Pekka Janhunen at the Finninsh Meteorological Institute. More info can be found at http://www.electric-sailing.fi
(Please excuse this blatantly promotional comment but I figured the project was of interest in this context of solar sails.)
Emil, although I didn’t discuss his work in this post, you’ll want to search for Dr. Janhunen here on the site, as I’ve written about the electric sail many times here. I was also happy to meet Pekka at the Aosta conference two years ago, where we discussed the concept. I agree with you that this is a project well worth study.
Solar sails could be used for many different things, but it might be worth the effort to think about how they could play a decisive role in a general exploration scheme. If and when good candidates for really earthlike planets are identified , it may be atractive or necesary to send a fast probe there to get more information . In this role , a solar sail does not need to slow down more than can be done by using the target stars own light pressure, there woulld still be enough time to record tons of information while zipping through the system.
A solar sail of this kind would not necesarily have to be very big , as long as it is big enough to send back to earth its recorded information .Having travelled for 50 years to reach the star , it would not be too bad if it took a few more years to comunicate at a slow rate . If a very lightweigh AND structuraly distributed system of longdistance comunication can be designed , the structural demands of the system might be come almost nonexistent , which would deminish the whole sail to a managable size. To boost even a small sail to the benchmark speed of 10% of lightspeed , will take a serious quantity of power , perhabs comparable to a major powerstation opperating continously for 50 years . In short the cost of energy will only alow a small sail to reach the benchmark velocity .
Instead of solar sails, what about MagSails? Or are they the same?
Paul, I followed your advice and was pleased to find an accurate description of the electric sailing technology. As I do have some insight to the project I can add that from 2010 there is an ongoing EU project aimed at developing key technologies necessary for the realization of the concept such as the tethers. Progress is steady.
NASA investigates sending CubeSats to Phobos and back
By Brian Dodson
23:23 April 3, 2012
NASA’s Innovative Advanced Concepts Program provides funding to study a small number of highly advanced spaceflight concepts, with the goal of understanding the technological possibilities which will guide the development of future space missions.
Under this program, a JPL (Jet Propulsion Laboratory) researcher has proposed the use of a pair of CubeSats for an autonomous mission to retrieve samples from Phobos, Mars’ larger moon.
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So how do CubeSats get to Phobos on a budget? The study mission is based on the use of two coupled CubeSats, one of which is specialized as the drive vehicle and the other as the sample collector. A European study of a small, solar-powered ion motor for small satellites such as CubeSats has recently appeared, that suggests its use for lunar missions. The JPL study, however, focuses on solar sails.
Once placed in Earth orbit, the drive vehicle deploys a solar sail, which produces a thrust that can be controlled in magnitude and direction by embedded nanoactuators. This thrust slowly increases the altitude of the coupled CubeSats and directs them toward a suitable Lagrange point – perhaps the Earth-Moon L1 point located between the Earth and the Moon.
Full article here:
http://www.gizmag.com/cubesats-phobos-nasa/22037/