On December 6, 2015, two small satellites, or CubeSats, successfully launched to the International Space Station. As part of NASA’s Nodes mission, the CubeSats will soon communicate with each other and demonstrate the benefits of a networked “swarm” of spacecraft.
NASA Tech Briefs: What is the Nodes program? John Hanson: We’re looking to demonstrate ways of making swarms of spacecraft talk to each other. The two small spacecraft are CubeSats, roughly 15 x 10 x 10 cm. They are going to make simultaneous measurements of the charged particle environment in space. By having two spacecraft separated by tens to hundreds of kilometers, you get spatial information and correlation in two different positions.
NTB: How do the two spacecraft communicate?
Hanson: We want the two spacecraft to take the data that they collect, pass it back and forth between them, and then downlink it to the ground. One spacecraft is called the Captain, and is the only one that talks to the ground at that particular time. Then, four times [per day], the Captain will send a message over to the Lieutenant spacecraft asking, “Do you have any data for me?” The Lieutenant will respond with all the data that it has collected on the Earth’s charged particle environment. Those packets of data are stored in the Captain. Then, once a day, the Captain will make contact with the ground and downlink this data. We’re also going to send a command from the ground up to one spacecraft, and then it’s going to forward that command onto the other spacecraft. We can demonstrate ways of controlling a network of spacecraft in the future.
NTB: How were the Nodes satellites sent to space?
Hanson: They were launched to the International Space Station (ISS) on OA-4, which is the Cygnus/ Atlas V rocket launch out of Kennedy Space Center. They have been on ISS for the last few months in the NanoRacks-MicroSat-Deployer. We’re awaiting deployment, which we expect to happen in the beginning or middle of April. We’ll launch from ISS in a 55-degree incline [relative to the equator] in low Earth orbit. Over the course of a couple of weeks to a month, the two spacecraft are expected to drift apart slowly and communicate with each other.
NTB: What are the advantages of using CubeSats?
Hanson: I don’t want to build a swarm of ten spacecraft if each costs $100 million. By using CubeSats, we can tap into this growing industry where people are building lots of small, capable, low-cost spacecraft. We’ve used a lot of commercial off-the-shelf (COTS) hardware. By distributing the data collection, we are able to observe phenomena on the Earth from different points at the same time, to do synthetic aperture radar imaging, to do astronomical observations. We have a collection of little spacecraft out there; in aggregate, they form this large aperture that allows us to explore new regimes of science that we just couldn’t explore before.
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