What started approximately seven years ago as research into electrolysis propulsion – using water as rocket fuel – has led to a Cornell engineering team earning a shot at space-flight history.
Cornell’s Cislunar Explorers – a student group led by Mason Peck, associate professor of mechanical and aerospace engineering – won the final ground competition and is one of three teams selected by NASA’s Space Technology Mission Directorate to have their spacecraft launched onboard the agency’s newest rocket, the Space Launch System (SLS), which is sending an unmanned Orion spacecraft into deep space in 2019.
NASA announced the semifinal winners of its Cube Quest Challenge on June 8, after completion of the last of four ground tournaments. The Cornell team, also led by doctoral student Kyle Doyle, won $20,000 for taking first in Ground Tournament 4. The Cornell team finished third in GT-1, first in GT-2 and second in GT-3, and won a total of $100,000.
“We are thrilled and really grateful, and even more, I think it’s important for NASA to be inspiring the nation with these opportunities,” Peck said. “In many respects, it levels the playing field, democratizes access to space. This is NASA saying, ‘You, too, can participate in space exploration.’”
Other top-three finishers in the Cube Quest Challenge are CU-E3, from the University of Colorado; and Team Miles, from Fluid & Reason LLC of Tampa, Florida.
The final phase of the Cube Quest Challenge – which features a prize purse of $5 million, NASA’s largest ever – includes the Lunar Derby, in which the Cislunar Explorers will compete, and the Deep Space Derby. If successful, Cornell will be the first university to build a spacecraft that reached lunar orbit.
In the Lunar Derby, teams must achieve a lunar orbit; prizes will be awarded for orbiting the moon, highest communication rate and total data communicated, and surviving the longest. In the Deep Space Derby, teams must demonstrate communications capabilities from a range of at least 2.5 million miles from Earth – more than 10 times the distance to the moon.
Peck said his group had been working on electrolysis propulsion – electrolyzing water, which breaks it down into burnable hydrogen and oxygen – for about four years when NASA announced the Cube Quest Challenge in 2014. That also was about the time that Doyle arrived at Cornell to begin his doctoral work in aerospace engineering.
The project quickly went from designing a spacecraft for Earth orbit to one for lunar orbit.
“Opportunities to launch to the moon are very rare, let alone for CubeSats,” Doyle said. “There’s never been one before.”
Peck said one of the factors that has made the Cislunar Explorers’ program so successful – in addition to a dedicated group of undergraduates, some of whom have been with the program since the start – has been Doyle’s thoughtful design concepts.
“What Kyle’s been particularly successful at,” Peck said, “is making problems fight each other.”
For example: The CubeSat – actually twin L-shaped spacecraft, which will separate after being released from the SLS – carries water, and the water has to remain a liquid. At the same time, the spacecraft will carry a radio with a 7-watt amplifier, which will get pretty hot from continuous transmission.
“We need to get rid of that heat somehow – so we use it to keep the water from freezing,” Peck said. “And the water helps to cool down the radio transmitter. Everyone’s happy.”
Also, the twin satellites will spin as they hurtle through space, keeping them in a fixed orientation as well as keeping the water where it needs to be – on the outside of the tank, away from the engine.
“We can pull the gas in from the inboard side of the tank, and always be sure that the engine is only ever ingesting gases, not water,” Peck said. “It’s a design that is successful because it tries not to be too subtle.”
The next step for the Cislunar Explorers – who built a radio ground station on top of Rhodes Hall to track their CubeSat – is completion of NASA’s phased safety review process. The team is working on phase 2 of the review, for the design of the spacecraft. Phase 3 will look at the completed CubeSat and determine if it’s safe to fly.
There will be an element of the unknown, however, as the completed CubeSat won’t be tested. Its first flight will be on Exploration Mission-1, the first integrated flight of NASA’s SLS and Orion spacecraft. The CubeSats will deploy when Orion separates from the SLS and heads into deep space.
“The challenge for any spacecraft,” Peck said, “is that you can’t test it in its fully complete form – ever.”
“We’ll test individual subsystems in as close to real conditions as possible,” Doyle said. “We do all sorts of mean things to them to prove that they’ll survive, then we build the actual flight units identical to that.”
The launch date in 2019 hasn’t been set.