December 2, 2022

NASA will be busy on the moon for years to come.

A giant rocket will launch a capsule around and on the back of the moon without astronauts, possibly by late summer. A series of robotic landers will conduct experiments on the moon to gather a wealth of scientific data, especially about water ice locked in polar regions. Astronauts will return there in a few years, more than half a century since the last Apollo moon landing.

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

Earlier Monday, a spacecraft called CAPSTONE was scheduled to launch as the first Artemis spacecraft to travel to the moon. It’s modest in size and scope compared to what follows.

There won’t be any astronauts on the CAPSTONE. The spaceship is so small, about the size of a microwave oven. This robotic probe won’t even land on the moon.

But it is different from any previous lunar mission in many ways. It could serve as a template for future public-private collaborations that NASA could pursue for better gains on interstellar voyages.

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

Emission coverage It will air on NASA TV Monday at 5 a.m. ET. The rocket must be launched at the exact moment of 5:50 am to lift the spacecraft to the correct orbit.

The full name of the mission is the Earth-Moon Autonomous Positioning System Technical Operation and Navigation Experiment. It will serve as a scout in lunar orbit and will eventually build a manned space station as part of Artemis. That outpost, called Gateway, will serve as a staging point where future crews will stop before continuing on to the lunar surface.

CAPSTONE is unusual for NASA in several ways. For one thing, it’s not in Florida but on a launch pad in New Zealand. Second, NASA did not design or build the CAPSTONE and will not operate it. The agency doesn’t even own it. CAPSTONE is part of Advanced Space, a 45-employee company based in suburban Denver.

The spacecraft is heading to the moon in a slow but efficient orbit, arriving on November 13. If weather or technical issues cause the rocket to miss an instant launch, there’s an additional chance until July 27. If the spacecraft leaves by then, it will still reach lunar orbit on the same day: November 13.

The CAPSTONE mission continues its efforts, with NASA partnering with private companies in new ways, hoping to gain additional capabilities faster and at a lower cost.

“It’s another way for NASA to figure out what’s needed and reduce costs,” said NASA administrator Bill Nelson.

Advance Space’s $20 million CAPSTONE contract signed with NASA in 2019. CAPSTONE’s journey to space is small and cheap: Rocket Lab, a U.S.-New Zealand company leading the way in putting small payloads into orbit, cost less than $10 million to launch.

“It’s going to be under $30 million in three years,” said Christopher Baker, director of NASA’s Small Spacecraft Technology Program. “It’s relatively quick and relatively inexpensive.”

“I do think it’s a pathfinder for how we can help facilitate commercial missions beyond Earth,” Mr Baker said.

Dr Cheetham said CAPSTONE’s main mission was to last six months, with the possibility of a further year extension.

The data it collects will help planners of lunar outposts known as gateways.

When President Donald J. Trump announced in 2017 that the top priority of his administration’s space policy was to return astronauts to the moon, NASA’s buzzwords were “reusable” and “sustainable.”

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

The first Artemis landing mission, currently scheduled for 2025 but possibly delayed, will not use the gateway. But follow-up missions will.

NASA decided that the best place to place the outpost would be in a so-called near-straight halo orbit.

A halo orbit is an orbit that is affected by the gravity of two objects – in this case the Earth and the Moon. The effects of these two celestial bodies help keep the orbit highly stable, minimizing the amount of propellant needed to keep the spacecraft orbiting the moon.

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

The Gateway will orbit about 2,200 miles from the lunar north pole and circle 44,000 miles away as it passes the south pole. It takes about a week to circle the moon.

In terms of basic mathematics, exotic trajectories like near-rectilinear halo orbits are well understood. But it’s also an orbit that no spacecraft has been to before.

Hence the vertex.

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

In practice, without any GPS satellites orbiting the moon to pinpoint it, it may take some trial and error to figure out how best to keep the spacecraft in the desired orbit.

“The biggest uncertainty is actually knowing where you are,” Dr Chisholm said. “You never really know where you are in space. So you can always estimate where it is, with some uncertainty around it.”

Like other NASA missions, CAPSTONE will triangulate its position using signals from NASA’s Deep Space Radio Antenna Antenna Network and then, if necessary, push itself back to the desired point after passing the point furthest from the Moon. trail of.

CAPSTONE will also test another method of finding location. It is unlikely that anyone would spend the time and expense building a GPS network around the moon. But other spacecraft, including NASA’s Lunar Reconnaissance Orbiter, are orbiting the moon, and more are likely to arrive in the coming years. By communicating with each other, fleets of spacecraft in different orbits can essentially establish a temporary GPS.

Advanced Space has been developing the technology for more than seven years, and it will now test the concept by sending signals back and forth from CAPSTONE with the Lunar Reconnaissance Orbiter. “Over time, we will be able to locate the two spacecraft,” Dr Chisholm said.

When developing CAPSTONE, Advanced Space also decided to add a computer-chip-scale atomic clock to the spacecraft and compare that time to the time broadcast from Earth. The data can also help determine the position of the spacecraft.

Because Advanced Space owns CAPSTONE, it has the flexibility to make changes without needing permission from NASA. While the agency still works closely on such projects, this flexibility is a boon for both private companies like Advanced Space and NASA.

“Because we have commercial contracts with suppliers, we don’t have to do a lot of scrutiny from government contract officials when we need to change something,” Dr Cheetham said. “From a speed standpoint, that helps.”

On the other hand, because Advanced Space had negotiated a flat fee for the mission, the company could not ask NASA for additional funding (though it received additional payments due to supply chain delays due to the Covid-19 pandemic). More traditional NASA contracts, known as “cost-plus,” pay the company a fee and then add a fee — earned as a profit — that provides little incentive for them to control costs, beyond that.

“As things develop, we have to figure out how to deal with them very efficiently,” Dr Cheetham said.

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

Before CAPSTONE, Advanced Space’s work was largely theoretical—analyzing orbits and writing software for its ad hoc GPS—rather than building and operating spacecraft.

The company isn’t really in the spacecraft manufacturing business yet. “We bought the ship,” Dr Chisholm said. “I tell people that the only hardware we make at Advanced is Lego bricks. We have a great Lego collection.”

The proliferation of tiny satellites known as CubeSats over the past few decades has enabled more companies to rapidly build spacecraft based on standardized designs that each measure 10 centimeters or 4 inches. The CAPSTONE is the largest at 12 cubes, but Advanced Space was able to buy it almost off the shelf from Tyvak Nano-Satellite Systems in Irvine, California.

There are still many problems to be solved. For example, most CubeSats are in low-Earth orbit, just a few hundred miles above the surface. The Moon is nearly 250,000 miles from Earth.

“No one has ever driven a CubeSat on the moon,” Dr. Cheetham said. “So it makes sense that nobody made the radios to fly the CubeSat on the moon. So we have to really get into a lot of the details and work with a few different people to have a system that works.”

Gateway project manager Mr. Hartman is excited about CAPSTONE, but says it’s not critical for advancing the lunar outpost. NASA has contracted to build the first two modules of the Gateway. The European Space Agency also contributed two modules.

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

But he added, “Anytime you can reduce the error bars in the model is always a good thing.”

Dr. Cheetham is considering what comes next, perhaps more lunar missions for NASA or other commercial partners. He also thought further.

“I’m very interested in thinking about how we can do something like Mars,” he said. “Actually, I’m also personally interested in Venus. I don’t think it gets enough attention.”



Source link

Leave a Reply

Your email address will not be published. Required fields are marked *