Here's All the Science Hitching a Ride on Artemis 1 – IEEE Spectrum


IEEE websites place cookies on your device to give you the best user experience. By using our websites, you agree to the placement of these cookies. To learn more, read our Privacy Policy.
A small fleet of CubeStats joins three mannequins, fungus, algae, and more on a trip to the Moon and back
This Artemis 1 mannequin—nicknamed Commander Moonikin Campos—will be traveling farther out into space than any human astronaut ever has.
NASA’s Artemis-1 mission launched early in the pre-dawn hours this morning, at 1:04 a.m. eastern time, carrying with it the hopes of a space program aiming now to land American astronauts back on the moon. The Orion spacecraft now on its way to the moon also carries with it a lot of CubeSat-sized science. (Some satellites have even, as of press time, begun to tweet.)
And while the objective of Artemis 1 is to show that the launch system and spacecraft can make a trip to the Moon and return safely to Earth, the mission is also a unique opportunity to send a whole spacecraft-load of science into deep space. In addition to the interior of the Orion capsule itself, there are enough nooks and crannies to handle a fair number of CubeSats, and NASA has packed as many experiments as it can into the mission. From radiation phantoms to solar sails to algae to a lunar surface payload, Artemis 1 has a lot going on.
Most of the variety of the science on Artemis 1 comes in the form of CubeSats, little satellites that are each the size of a large shoebox. The CubeSats are tucked snugly into berths inside the Orion Stage Adapter, which is the bit that connects the Interim Cryogenic Propulsion Stage to the ESA service module and Orion. Once the propulsion stage lifts Orion out of Earth orbit and pushes it towards the Moon, the stage and adapter will separate from Orion, and the CubeSats will launch themselves.

A metal cylinder five meters across rests in a clean room with scaffolding around it, with ten small boxes mounted on platforms insideTen CubeSats rest inside of the Orion stage adapter at NASA’s Kennedy Space Center.NASA KSC
While the CubeSats look identical when packed up, each one is totally unique in both hardware and software, with different destinations and mission objectives. There are ten in total (three weren’t ready in time for launch, which is why there are a couple of empty slots in the image above).
Here is what each one is and does:
While the CubeSats head off to do their own thing, inside the Orion capsule itself will be the temporary home of a trio of mannequins. The first, a male-bodied version provided by NASA, is named “Commander Moonikin Campos” after NASA electrical engineer Arturo Campos, who was the guy who wrote the procedures that allowed the Apollo 13 command module to steal power from the lunar module’s batteries, one of many actions that saved the Apollo 13 crew.

A mannequin in an orange flight suit lies on its back in a testing roomMoonikin Campos prepares for placement in the Orion capsule.NASA
Moonikin Campos will spend the mission in the Orion commander’s seat, wearing an Orion Crew Survival System suit—essentially a spacecraft itself, the suit is able to sustain its occupant for up to six days if necessary. Moonikin Campos’ job will be to pretend to be an astronaut, and sensors inside of him will measure radiation, acceleration and vibration to help NASA prepare to launch human astronauts in the next Artemis mission.
Two blue female mannequins, one wearing a bulky black vest, strapped into the interior of a space capsuleHel­ga and Zo­har in place on the flight deck of the Ori­on space­craft.NASA/DLR
Accompanying Moonikin Campos are two other female-bodied mannequins, named Helga and Zohar, developed by the German Aerospace Center (DLR) along with the Israel Space Agency. These are more accurately called “anthropomorphic phantoms,” and their job is to provide a detailed recording of the radiation environment inside the capsule over the course of the mission. The phantoms are female because women have more radiation-sensitive tissue than men. Both Helga and Zohar have over 6,000 tiny radiation detectors placed throughout their artificial bodies, but Zohar will be wearing an AstroRad radiation protection vest to see how effective it is.

A dozen researchers in masks stand in front of two blue bags in a NASA laboratoryNASA’s Biology Experiment-1 is transferred to the Orion team.NASA/KSC
The final science experiment to fly onboard Orion is NASA’s Biology Experiment-1. The experiment is really just seeing what time in deep spaces does to some specific kinds of biology, so all that has to happen is that Orion successfully hauls some packages of sample tubes around the Moon and back. Samples include:
There is some concern that because of the extensive delays with the Artemis launch, the CubeSats have been sitting long enough that their batteries may have run down. Some of the CubeSats were able to be recharged, but for others, recharging was judged to be risky enough that they were left alone. Even for CubeSats that don't start right up, though, it's possible that after deployment, their solar panels will be able to get them going. But at this point, there's still a lot of uncertainty, and the CubeSats’ earthbound science teams are now pinning their hopes everything going well after launch.

For the rest of the science payloads, success mostly means Orion returning to Earth safe and sound, which will also be a success for the Artemis 1 mission as a whole. And assuming it does so, there will be a lot more science to come.
Evan Ackerman is a senior editor at IEEE Spectrum. Since 2007, he has written over 6,000 articles on robotics and technology. He has a degree in Martian geology and is excellent at playing bagpipes.
3,000x farther from Earth than Hubble—with a 25x greater download deluge
Technicians at Northrop Grumman Aerospace Systems facilities in Redondo Beach, Calif., work on a mockup of the JWST spacecraft bus—home of the observatory’s power, flight, data, and communications systems.
For a deep dive into the engineering behind the James Webb Space Telescope, see our collection of posts here.
When the James Webb Space Telescope (JWST) reveals its first images on 12 July, they will be the by-product of carefully crafted mirrors and scientific instruments. But all of its data-collecting prowess would be moot without the spacecraft’s communications subsystem.
The Webb’s comms aren’t flashy. Rather, the data and communication systems are designed to be incredibly, unquestionably dependable and reliable. And while some aspects of them are relatively new—it’s the first mission to use Ka-band frequencies for such high data rates so far from Earth, for example—above all else, JWST’s comms provide the foundation upon which JWST’s scientific endeavors sit.
As previous articles in this series have noted, JWST is parked at Lagrange point L2. It’s a point of gravitational equilibrium located about 1.5 million kilometers beyond Earth on a straight line between the planet and the sun. It’s an ideal location for JWST to observe the universe without obstruction and with minimal orbital adjustments.
Being so far away from Earth, however, means that data has farther to travel to make it back in one piece. It also means the communications subsystem needs to be reliable, because the prospect of a repair mission being sent to address a problem is, for the near term at least, highly unlikely. Given the cost and time involved, says Michael Menzel, the mission systems engineer for JWST, “I would not encourage a rendezvous and servicing mission unless something went wildly wrong.”

According to Menzel, who has worked on JWST in some capacity for over 20 years, the plan has always been to use well-understood K a-band frequencies for the bulky transmissions of scientific data. Specifically, JWST is transmitting data back to Earth on a 25.9-gigahertz channel at up to 28 megabits per second. The Ka-band is a portion of the broader K-band (another portion, the Ku-band, was also considered).
An illustration depicting different Lagrange points and where the Webb Telescope is.The Lagrange points are equilibrium locations where competing gravitational tugs on an object net out to zero. JWST is one of three craft currently occupying L2 (Shown here at an exaggerated distance from Earth). IEEE Spectrum
Both the data-collection and transmission rates of JWST dwarf those of the older Hubble Space Telescope. Compared to Hubble, which is still active and generates 1 to 2 gigabytes of data daily, JWST can produce up to 57 GB each day (although that amount is dependent on what observations are scheduled).
Menzel says he first saw the frequency selection proposals for JWST around 2000, when he was working at Northrop Grumman. He became the mission systems engineer in 2004. “I knew where the risks were in this mission. And I wanted to make sure that we didn’t get any new risks,” he says.
IEEE Spectrum
Besides, K a-band frequencies can transmit more data than X-band (7 to 11.2 GHz) or S-band (2 to 4 GHz), common choices for craft in deep space. A high data rate is a necessity for the scientific work JWST will be undertaking. In addition, according to Carl Hansen, a flight systems engineer at the Space Telescope Science Institute (the science operations center for JWST), a comparable X-band antenna would be so large that the spacecraft would have trouble remaining steady for imaging.
Although the 25.9-GHz K a-band frequency is the telescope’s workhorse communication channel, it also employs two channels in the S-band. One is the 2.09-GHz uplink that ferries future transmission and scientific observation schedules to the telescope at 16 kilobits per second. The other is the 2.27-GHz, 40-kb/s downlink over which the telescope transmits engineering data—including its operational status, systems health, and other information concerning the telescope’s day-to-day activities.
Any scientific data the JWST collects during its lifetime will need to be stored on board, because the spacecraft doesn’t maintain round-the-clock contact with Earth. Data gathered from its scientific instruments, once collected, is stored within the spacecraft’s 68-GB solid-state drive (3 percent is reserved for engineering and telemetry data). Alex Hunter, also a flight systems engineer at the Space Telescope Science Institute, says that by the end of JWST’s 10-year mission life, they expect to be down to about 60 GB because of deep-space radiation and wear and tear.

The onboard storage is enough to collect data for about 24 hours before it runs out of room. Well before that becomes an issue, JWST will have scheduled opportunities to beam that invaluable data to Earth.
JWST will stay connected via the Deep Space Network (DSN)—a resource it shares with the Parker Solar Probe, Transiting Exoplanet Survey Satellite, the Voyager probes, and the entire ensemble of Mars rovers and orbiters, to name just a few of the other heavyweights. The DSN consists of three antenna complexes: Canberra, Australia; Madrid, Spain; and Barstow, Calif. JWST needs to share finite antenna time with plenty of other deep-space missions, each with unique communications needs and schedules.
IEEE Spectrum
Sandy Kwan, a DSN systems engineer, says that contact windows with spacecraft are scheduled 12 to 20 weeks in advance. JWST had a greater number of scheduled contact windows during its commissioning phase, as instruments were brought on line, checked, and calibrated. Most of that process required real-time communication with Earth.
All of the communications channels use the Reed-Solomonerror-correction protocol—the same error-correction standard as used in DVDs and Blu-ray discs as well as QR codes. The lower data-rate S-band channels use binary phase-shift key modulation—involving phase shifting of a signal’s carrier wave. The K-band channel, however, uses a quadrature phase-shift key modulation. Quadrature phase-shift keying can double a channel’s data rate, at the cost of more complicated transmitters and receivers.
JWST’s communications with Earth incorporate an acknowledgement protocol—only after the JWST gets confirmation that a file has been successfully received will it go ahead and delete its copy of the data to clear up space.
The communications subsystem was assembled along with the rest of the spacecraft bus by Northrop Grumman, using off-the-shelf components sourced from multiple manufacturers.
JWST has had a long and often-delayed development, but its communications system has always been a bedrock for the rest of the project. Keeping at least one system dependable means it’s one less thing to worry about. Menzel can remember, for instance, ideas for laser-based optical systems that were invariably rejected. “I can count at least two times where I had been approached by people who wanted to experiment with optical communications,” says Menzel. “Each time they came to me, I sent them away with the old ‘Thank you, but I don’t need it. And I don’t want it.’”

source


Leave a Reply

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