TEL AVIV, Israel — Israel’s Rafael Ltd. is putting many of the miniaturization, propulsion and control capabilities developed for the nation’s small imaging satellites into a new breed of fuel-efficient, micro-sized maneuvering systems designed for years of close-in spying from space.
Shaped like missiles with a sleek, drag-resistant silhouette, Rafael’s planned LiteSat-A and LiteSat-B measure a mere 1.5 meters in length, have a 30-centimeter cross section and weigh 100 and 85 kilograms, respectively. The former is chemically powered, but the latter uses solar-generated electric thrust — positioning it to become the space-based Toyota Prius, a pioneer in the emerging niche market for efficient, long-endurance micro-class satellites.
While most satellites in dense low orbits guzzle fuel to maneuver along their orbital paths, LiteSat-B aims to convert energy stored in solar panels into ionic-charged thrust, allowing it to maneuver into slightly different angles to capture specific targets of interest.
“If you take a regular satellite at this altitude, its lifespan will be one or two years. Or, conversely, you can prolong the life with a ton of propellant, which is usually what the big nations are doing with spy satellites,” said Jacob Herscovitz, chief systems engineer at Rafael’s Space Systems Directorate. “But we will demonstrate a microsatellite with a launch mass of 85 kilograms, give or take, that sustains itself in a very low Earth orbit for seven years, maybe more.”
Company funded and still in early development, LiteSat-B draws on lessons from Rafael’s Israeli Hall Effect Thruster, a first-generation hybrid electric propulsion unit that aims to operate exclusively on electric thrust, yet features eight backup hydrazine thrusters. The Israeli Hall Effect Thruster is slated for its first launch by early 2014 as part of a mini-class satellite built by Israel Aerospace Industries as part of the joint Franco-Israeli Venus scientific vegetation and Earth monitoring program.
Herscovitz said the second-generation, all-electric engine planned for LiteSat-B will allow the satellite to orbit around 300 kilometers up, a good altitude for submeter imaging, for seven years. That is far more than the two-year lifespan of chemically powered microsatellites now in orbit, he said.
“Electric propulsion is commonly used for large, expensive satellites weighing many tons, but we haven’t yet seen very small, microclass imaging satellites benefiting from the efficiencies of electric propulsion. This is an emerging technological sector where Rafael can take the lead,” Herscovitz said. “Our added value comes from combining propulsion technologies with the work we’re doing in applying missile design profiles, autonomous control algorithms and image process capabilities to this promising new niche sector of microsatellites.”
Rafael presented its LiteSat concept in January at an international space conference hosted by Israel’s Fisher Institute for Strategic Air and Space Studies.
The chemically powered LiteSat-A is slated for preliminary design review later this year, while LiteSat-B is in early concept feasibility studies, Herscovitz said.
Both satellites will require about four years before they are ready for launch, and Rafael executives acknowledge they have no firm contracts or near-term government funding pledges for either program.
Amit Bergman, Rafael’s microsatellite systems director, said LiteSat will have an imaging resolution of slightly less than 1 meter and will make use of the firm’s ImiLite imaging exploitation system initially developed to support unmanned aerial vehicles. The planned microsatellite was optimized for launch from aircraft, but multiple LiteSats could be delivered into space from a conventional ground-launched vehicle, Bergman said.
Ideally, government and industry sources here said, multiple LiteSats should be deployed simultaneously, operating as a constellation whose force-multiplying effect far exceeds the sum of its individual parts.
Chaim Eshed, the Israeli Ministry of Defense’s longtime director for space programs, was noncommittal about near-term ministry funds for the LiteSat concept per se. Nevertheless, he said the general concept represents a new capability that must be developed for security as well as commercial and civilian applications.
“The added value that comes from mating fuel-efficient propulsion and low-cost multimission microsatellites is obvious, and such a concept is an example of where we need to be in the not too distant future,” Eshed said.
Tal Inbar, Fisher Institute director for space and unmanned aerial vehicle programs, said the Rafael initiative could be used to establish Israel’s leadership role in a new era of formation flying for various applications.
“Rafael’s fuel-efficient Hall effect electric propulsion system is unique at this time in its ability to support a new class of very small and inexpensive remote-sensing satellites,” he said. “But without the budget, its added value will erode and we end up with yet another missed opportunity to establish ourselves as providers of innovative options for responsive space.”
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