10 Mar 2021

NASA’s water-hunting lunar robot now has a workspace prepped and ready at the agency’s Johnson Space Center in Houston, where it will be built for its upcoming mission to the Moon. The Volatiles Investigating Polar Exploration Rover, or VIPER, has a new 1,000-plus square-foot clean room, called the Surface Segment Integration and Test Facility, where engineers will assemble and outfit the rover.

Located in a corner of the center’s Space Vehicle Mock Up Facility, the VIPER team recently launched the assembly of a full-scale replica of the rover. The “assembly pathfinder” activity will last roughly three months and serve as a dress rehearsal for the flight version.

Faced with a pile of mock components and a heap of requirements for cleanliness and safety, documentation and protocols, the team is blazing a trail toward a rover that’s ready for launch. This way, NASA will be as efficient as possible when the real flight equipment arrives – and avoid any unwanted surprises.

“We need to work out the bugs now,” said David Petri, VIPER’s system integration and test lead at Johnson. “That could mean a lot of things, from discovering there isn’t enough clearance in one corner of the rover to turn a wrench, to realizing team members need additional training to get the job done. These are the kind of unforeseen challenges that could slow development down.”

NASA’s VIPER will be built in the summer of 2022, bound for the lunar South Pole in 2023, where it will search for ice in deep, dark craters and other places to create the first water resource maps of the Moon for future space exploration. This work will help advance the Artemis program to establish a sustainable human presence on the Moon.

All About Assembly

Since this work is focused on assembly, not a functioning rover, there are no moving parts. Instead, the parts are precision-made from VIPER’s designs – mostly 3D-printed, and some made out of sheet metal. The real test comes when determining the order in which the parts are put together. Should they screw part A to part B, then bolt that to part C – or join B and C, first? That’s the kind of detail to know before getting too far into assembling a bookshelf, much less a spacecraft.

If there’s no easy solution for the assembly team, they may ask the rover’s designers for small but essential changes. The current test will make that kind of adjustment possible.

VIPER’s New Clean Room

The year leading up to this dry run of VIPER’s assembly was spent turning an ordinary workspace into a controlled workspace, or clean room. New air filtration units and particle counters help keep the space extremely clean. This was necessary to prevent any debris or contamination from getting into the spacecraft, where it could potentially interfere with the scientific instruments’ measurements or make the solar arrays or radiator work less efficiently, for instance. A highly sensitive video fire-detection system keeps the hardware safe from flames. And everything inside the room has mitigations against creating sparks, which could damage circuit boards in the rover’s sensitive electronics.

There are so many things to think of when building something to meet NASA’s rigorous requirements for spaceflight. How will you keep the parts super clean on their way to the workspace? Are the wrenches calibrated? Do you have every necessary nut and bolt? Has someone scheduled the quality inspectors? And so on. The assembly team works long hours to make sure all the bases are covered, but it’s worth it.

“You get to work on something that’s going to the Moon, and you’re doing it with people who will do whatever it takes to be successful,” said Petri. “You don’t want to let them or the mission down. And it’s mutual. So, that makes it exciting!”

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(B) From left, VIPER system integration and test lead David Petri, NASA structural engineer Michael Grace, VIPER system integration and test deputy James Rice, and NASA structural engineer Aristeo Rios. Grace and Rios attach a riser base plate to the riser column, with Petri and Rice directing the operation. The risers will hold the full-size VIPER rover model securely in place during the assembly pathfinder exercise to practice building a replica of the spacecraft before the real flight vehicle is assembled.

(C) Structural engineer Michael Grace, left, system engineer Joshua Wilkins, VIPER system integration and test deputy James Rice, and VIPER system integration and test lead David Petri, right, successfully installed the neutron spectrometer data processing module onto the starboard heat spreader as part of the VIPER assembly pathfinder activity. The neutron spectrometer system is one of three scientific instruments the VIPER rover will carry when it explores the South Pole of the Moon.