NASA to launch Capstone, a 55-pound CubeSat to the Moon

In the years to come, NASA will be busy on the moon.

A giant rocket will launch a capsule without astronauts on board around the moon and back, perhaps before the end of the summer. A parade of robotic landers will drop experiments on the moon to collect tons of scientific data, especially on the water ice locked in the polar regions. In a few years, astronauts will return there, more than half a century since the last landing of Apollo.

These are all part of NASA’s 21st century lunar program named after Artemis, who in Greek mythology was the twin sister of Apollo.

Early Monday, a spacecraft named CAPSTONE is set to launch as the first piece of Artemis to head for the moon. Compared to what is to follow, it is modest in size and scope.

There will be no astronauts aboard CAPSTONE. The spacecraft is too small, about as big as a microwave oven. This robotic probe won’t even land on the moon.

But in many ways, it’s unlike any previous moon mission. This could serve as a model for public-private partnerships that NASA might undertake in the future to achieve better value for money on interplanetary travel.

“NASA has been to the moon before, but I’m not sure it’s ever been organized like this,” said Bradley Cheetham, chief executive and president of Advanced Space, the company that manages the mission for NASA.

Coverage of the launch will begin Monday at 5 a.m. Eastern Time on NASA TV. The rocket must be launched at a specific time, at 5:50 a.m., for the spacecraft to be placed on the correct trajectory.

The full name of the mission is the Cislunar Autonomous Positioning System Technology Operation and Navigation Experiment. It will serve as a scout for lunar orbit where a crewed space station will eventually be built as part of Artemis. This outpost, named Gateway, will serve as a way station where future crews will stop before continuing on their way to the lunar surface.

CAPSTONE is unusual for NASA in several ways. For one thing, it’s sitting on a launch pad not in Florida but in New Zealand. Second, NASA did not design or build CAPSTONE, nor will it operate it. The agency doesn’t even own it. CAPSTONE is owned by Advanced Space, a 45-employee company located on the outskirts of Denver.

The spacecraft takes a slow but efficient trajectory to the moon, arriving on November 13. If weather or a technical issue causes the rocket to miss that instant launch moment, there are additional chances until July 27. If the spacecraft descends from the ground by then, it will still reach lunar orbit on the same day: November 13.

The CAPSTONE mission continues NASA’s efforts to collaborate in new ways with private companies in hopes of acquiring additional capabilities more quickly at lower cost.

“It’s another way for NASA to find out what it needs and reduce costs,” NASA Administrator Bill Nelson said.

Advance Space’s contract with NASA for CAPSTONE, signed in 2019, cost $20 million. The journey to space for CAPSTONE is also small and cheap: just under $10 million for a launch by Rocket Lab, a US-New Zealand company leading in delivering small payloads into orbit.

“It’s going to cost less than $30 million in less than three years,” said Christopher Baker, program manager for small spacecraft technology at NASA. “Relatively quick and relatively inexpensive.”

“I see this as a scout for how we can help facilitate trade missions beyond Earth,” Baker said.

CAPSTONE’s primary mission is to last six months, with the possibility of an additional year, Dr Cheetham said.

The data collected will help planners of the lunar outpost known as the Gateway.

When President Donald J. Trump said in 2017 that one of his administration’s top space policy priorities was to return astronauts to the Moon, the buzzwords at NASA were “reusable” and “sustainable.” .

This led NASA to make a space station around the moon a key part of how astronauts would get to the lunar surface. Such a staging site would make it easier for them to reach different parts of the moon.

Artemis’ first landing mission, currently scheduled for 2025 but likely to be pushed back, will not use Gateway. But the following missions will.

NASA decided that the best place to place this outpost would be in what is called a near-rectilinear halo orbit.

Halo orbits are those influenced by the gravity of two bodies – in this case, the Earth and the Moon. The influence of the two bodies helps make the orbit very stable, minimizing the amount of propellant needed to spin a spacecraft around the moon.

Gravitational interactions also keep the orbit at an angle of about 90 degrees to line of sight from Earth. (It’s the nearly straight part of the name.) So a spacecraft in this orbit never passes behind the moon where communications would be cut off.

The orbit that Gateway will travel is about 2,200 miles from the moon’s North Pole and loops up to 44,000 miles as it passes over the South Pole. A trip around the moon will take about a week.

In terms of the underlying mathematics, exotic trajectories like a quasi-rectilinear halo orbit are well understood. But it’s also an orbit where no spacecraft has gone before.


“We think we’ve characterized it very, very well,” said Dan Hartman, program manager for Gateway. “But with this particular CAPSTONE payload, we can help validate our models.”

In practice, without any Global Positioning System satellites around the moon to pinpoint precise locations, it may take some trial and error to determine the best way to keep the spacecraft in the desired orbit.

“The biggest uncertainty is where you are,” Dr Cheetham said. “You never know in space where you are. So you always have an estimate of where it is with some uncertainty around it.

Like other NASA missions, CAPSTONE will triangulate an estimate of its position using signals from NASA’s Deep Space Network radio dish antennas, then, if necessary, swerve back to the desired orbit just after having past the farthest point of the moon.

CAPSTONE will also test an alternative method to find its position. It is unlikely that anyone will spend the time and expense building a GPS network around the moon. But there are other spacecraft, including NASA’s Lunar Reconnaissance Orbiter, orbiting the moon, and more are likely to arrive in the coming years. By communicating with each other, a fleet of spacecraft in disparate orbits could essentially set up ad hoc GPS.

Advanced Space has been developing this technology for over seven years and will now test the concept with CAPSTONE sending signals back and forth with the Lunar Reconnaissance Orbiter. “We will be able to determine where the two spacecraft are over time,” said Dr Cheetham.

When it began developing CAPSTONE, Advanced Space also decided to add a computer-chip scale atomic clock to the spacecraft and compare this time with what is broadcast from Earth. This data can also help pinpoint the location of the spacecraft.

Since Advanced Space owns CAPSTONE, it had the ability to make this change without getting permission from NASA. And while the agency still collaborates closely on such projects, this flexibility can be a boon to both private companies like Advanced Space and NASA.

“Because we had a commercial contract with our suppliers, when we needed to change something, it didn’t have to go through extensive review by government contract officials,” Dr Cheetham said. “It helped from a speed perspective.”

The flip side is that because Advanced Space had negotiated a flat fee for the mission, the company couldn’t go to NASA to ask for additional money (although it did receive additional payments due supply chain delays caused by the Covid-19 pandemic). More traditional NASA contracts, known as “cost-plus”, reimburse companies for what they spend, then add fees – received as profit – on top of that, giving them little incentive to keep costs under control.

“As things came up, we had to figure out how to handle them very effectively,” Dr Cheetham said.

This is similar to NASA’s successful strategy of using fixed-price contracts with Elon Musk’s SpaceX, which now transports goods and astronauts to and from the International Space Station at a much lower cost than space shuttles. of the agency. For SpaceX, NASA investments have allowed it to attract non-NASA customers interested in launching payloads and private astronauts into orbit.

Until CAPSTONE, Advanced Space’s work was mostly theoretical – analyzing orbits and writing software for its ad hoc GPS – not building and operating spacecraft.

The company is still not really in the business of building spacecraft. “We bought the spacecraft,” Dr Cheetham said. “I tell people that the only hardware we build here at Advanced is Legos. We have a large Lego collection.

Over the past two decades, tiny satellites known as CubeSats have proliferated, allowing more companies to rapidly build spacecraft based on a standardized design in which each cube measures 10 centimeters or four inches. CAPSTONE is one of the largest, with a volume of 12 cubes, but Advanced Space was able to purchase it, almost off the shelf, from Tyvak Nano-Satellite Systems of Irvine, California.

This still required a lot of problem solving. For example, most CubeSats are in low Earth orbit, a few hundred kilometers above the surface. The moon is nearly a quarter of a million miles away.

“No one has flown a CubeSat on the moon,” said Dr Cheetham. “So it makes sense that nobody built radios to fly CubeSats to the moon. And so we had to really dive in to figure out a lot of those details and partner with a few different people to have the systems that could work.

Mr. Hartman, the Gateway program manager, is excited about CAPSTONE but says it’s not essential to move forward with the lunar outpost. NASA has already awarded contracts for the construction of the first two Gateway modules. The European Space Agency also contributes to two modules.

“Can we fly without him?” Mr. Hartman said of CAPSTONE. “Yes. Is it mandatory? No.”

But he added: “Anytime you can reduce the error bars in your models, that’s always a good thing.”

Dr Cheetham ponders what might come next, perhaps more moon missions, either for NASA or other commercial partners. He also thinks further.

“I’m very intrigued by the idea of ​​how could we do a similar thing on Mars,” he said. “I’m actually quite personally interested in Venus as well. I think it doesn’t attract enough attention.

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