Many of NASA's most famous spaceships towered above the engineers who built them: Voyager 1 and 2, Cassini or Galileo – all big machines that could drive to a school bus.
But over the last two decades, mini-satellites named CubeSats have made space for a new generation. These boxy boxes are more concentrated in their abilities and have a fraction of the mass – and cost – of some of the titans of outer space.
In May, engineers will watch as NASA launches its first pair of CubeSats spacecraft. The two spacecraft are called Mars Cube One or MarCO and were built at NASA's Jet Propulsion Laboratory in Pasadena, California.
Both MarCO spacecraft are launched on the same rocket that brings InSight, NASA's next robot lander, to Mars. The MarCOs will accompany InSight on its journey through space. If they survive the journey, each will be equipped with a foldable high-gain antenna to transmit data via InSight as it enters and lands in the Martian atmosphere.
The MarCOs will not produce their own science and are not required for InSight to send their data home (the lander will rely on NASA's Mars orbiter to additionally communicate directly with antennas on Earth). But the twins are a crucial first test of CubeSat technology beyond Earth orbit and demonstrate how they can be used for further exploration of the solar system
"These are our scouts," said Andy Klesh of JPL, chief engineer of MarCO. "CubeSats did not have to survive the intense radiation of a trip to space or propel it to Mars, and we hope to pave the way."
The official names of these two Scouts are: "MarCO -A" and "MarCO-B." But for the team that created them, the "Wall-E" and "Eva" nicknames are on Pixar Characters are based. Both MarCOs use a compressed gas normally found in fire extinguishers to push themselves through space, as Wall-E did in his 2008 film.
Survival is far from guaranteed. As the saying goes, the room is hard. The first challenge will be. The MarCO batteries were last reviewed in March by Tyvak Nano-Satellite Systems of Irvine, California, who put each CubeSat in a special dispenser that drives it into space. These batteries are used to install the solar arrays of each CubeSat in the hope that there will be enough energy left to turn on their radios. If the power is too low, the MarCO team can hear silence until each spacecraft is more fully charged.
When both MarCOs travel, they will test a communication method that could serve as a "black box" for future Mars landings. So engineers could understand the difficult process of bringing spacecraft safely to the Red Planet. Mars Landungs are notoriously hard to hold.
The MarCOs also proved that CubeSats are ready to go beyond the earth. CubeSats were first developed to teach university students via satellites. Today, they represent an important commercial technology that provides data from shipping routes to environmental change.
NASA scientists want to explore the solar system with CubeSats. JPL even has its own CubeSat clean room, where several flight projects, including the MarCOs, have been built. For young engineers, the thrill builds something that could reach Mars in just a few years instead of a decade.
"We are a small team, so everyone has experience working on several parts of the spaceship," said Klesh. "They learn everything about building, testing, and flying along the way, and we invent that every day."
The MarCOs were built by JPL, who directs InSight and MarCO for NASA. They were funded by the JPL Scientific Directorate and NASA. A number of commercial vendors made MarCO's unique technology available. A complete list and more information about the spacecraft can be found here.
NASA is preparing for the first interplanetary CubeSats on the next Mars mission