The US military depends on satellites for communications and location-based information when soldiers are in remote areas of the world.
But what do soldiers do when there is no satellite within range, or they can’t receive satellite downlinks? The Defense Advanced Research Projects Agency (DARPA) wants to solve that problem by designing disposable satellite clusters that the military can send into orbit cost-effectively and that will burn up when no longer in use, leaving no debris behind.
The SeeMe program aims to develop a constellation of small satellites that will cost a mere fraction of the millions current systems cost, according to DARPA. Soldiers will communicate directly with the satellites using handheld devices. One constellation will be comprised of about two dozen satellites designed to last 60 to 90 days in very low orbit.
An artist's concept depicts how DARPA's SeeMe program would work. The program aims to design disposable satellite clusters that will give soldiers location-based information in places where they would typically not have satellite coverage. (Source: DARPA)
An aircraft would take off and ascend to a cruising altitude and launch a missile that would enter into low-earth orbit. The missile’s outer shell would then disengage from the missile to reveal the satellite inside, which would then enter its designated orbit. Once the SeeMe satellite clusters are in place, soldiers will be able to access communications with them within 90 minutes of their deployment, basically by pressing a button on a handheld device asking the system to “see me.” Soldiers then will receive images of their precise location.
The military plans to use SeeMe satellites as an adjunct to current use of unmanned aerial vehicles (UAV) that provide location information and images. However, UAVs have limits in terms of range and time of use due to refueling needs, according to DARPA, which posted a video about the SeeMe program online. (Watch the video below.)
Rather than costing millions of dollars, as typical satellites do, DARPA aims to keep the cost of the satellites down to about $500,000 or less through design and the materials used to build them. The agency aims to use off-the-shelf components, such as those used in the mobile industry, to develop SeeMe satellites. Other technologies used in the design include advanced optics, power, propulsion, and communications technologies to keep the size and weight down, according to DARPA.
To send the satellites into orbit, DARPA is designing a companion low-cost, rapid-deployment satellite launch system called the Airborne Launch Assist Space Access (ALASA) program. The agency is currently soliciting initial technology proposals for the SeeMe program.
Low orbit altitude is defined as 100 - 1240 miles high. Any pilot that goes over 50 miles up or higher gains an astronaut rating. The lower the orbit, the lower the speed needed. I don't know what altitude will sustain a satellite for 3 months, but I would think it can lower than 100 miles. Anyone?
In the articles I've seen on space debris, I haven't seen anything about clean-up. Not sure you can. NASA is tracking it, though. As for a satellite that disposes of itself, I don't see how that happens in space unless it is sent into the atmosphere, which would burn it up.
It's good these satellites are launched in a way they become self-disposing. But touting the price ignores the cost/benefit ratio.Yes, they are a fraction of the cost, but you get a small fraction of the capacity, for a small fraction of the coverage area, for a small fraction of the day, for a small fraction of the nominal service life of other SATCOM systems.There is nothing lost in looking at technologies, and plenty to be gained from a pragmatic evaluation of the VALUE of these kinds of solutions.Sometimes it just makes sense to spend more, add another future-junk-satellite to the list, and get greater utility out of our tax dollar.
Beth, it depends on how high the debris is. Junk in LEO will come down by itself, eventually. Skylab did, as did Kosmos 954 (scattered radioactive debris over a 600 km swath of Canada in 1978). They were in fairly low orbits.
The toolbag that slipped away from a spacewalking astronaut in November 2008 eventually reentered in August 2009. The space station orbits at about 230 miles above the surface.
The higher the junk is, the longer it stays up. Satellites in geosynchronous orbit (22,000 miles aren't going to come down, which poses a different problem. The geosynchronous orbit is unique (a satellite orbiting the equator at that altitude appears motionless to an observer on the ground), and the real estate there is precious. When geosynch satellites are decommisioned, they now get boosted even higher, up out of that special orbit, to make room for new satellites.
Cleaning up the orbitals is going to cost. Getting some sort of device up there to pick up the garbage is going to cost $2000-$10000 per POUND just to get the device into orbit.
Naperlou, thanks for your thoughts on the launch issue. My first reaction when I saw this video is, how can they launch so easily? (Anyway, it looks easy in the video.) NASA's fabled X-programs spent decades trying to launch aircraft (like the National Aerospace Plane) into space, with limited success. They found that flying into space is difficult. That's why NASA spent so many years dropping gigantic multi-million-dollar booster rockets into the ocean. So how are they able to launch these things into space with such apparent ease?
Beth, space junk has been a growing problem for decades. The idea of sending yet more trash into orbit appalls me, too. The only "disposable" products of any kind we should be making these days should be compostable or recyclable. The myth that things can be thrown "away" becomes even m ore obvious when you look at space junk. There is no "away" in a closed system.
I guess I'm either naive or aren't as up to date on the current state of space exploration. I am absolutely appalled by that news. Does anyone know if we have programs to clean it up or if that is even possible? What happens to the debris--it just floats around forever?
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