24/7 Space News
SPACE TRAVEL
Proba-3 tests formation flying systems on Earth
illustration only
Proba-3 tests formation flying systems on Earth
by Erica Marchand
Paris, France (SPX) Jul 01, 2024

The two Proba-3 satellites were positioned facing each other in a cleanroom, with cameras, LEDs, a laser, and shadow sensors activated sequentially to test the systems that will allow the pair to sense their precise positions relative to each other. This precision alignment is critical for their mission, aiming to achieve an alignment accuracy down to a single millimeter.

When two satellites approach within a few hundred meters, they typically execute collision avoidance maneuvers. However, ESA's Proba-3 mission involves a controlled formation flight, with the two satellites approaching as close as 25 meters.

Aligning with the Sun
When positioned around 150 meters apart, the satellites will align with the Sun, casting a shadow from one to the other to create artificial solar eclipses. This alignment will enable the observation of the Sun's faint outer atmosphere without the interference of its brightness.

To achieve this, the Proba-3 satellites utilize multiple sensors, similar to autonomous cars on Earth, to determine their positions relative to each other. These systems were tested together with the spacecraft software for the first time in the Redwire cleanroom in Kruibeke, Belgium.

"Proba-3 is a formation flying demonstration mission, and these systems really form the mission's core," explained ESA software and systems engineer Teodor Bozhanov. "To maintain the position of the two satellites to the necessary precision, we need to perform specific steps in sequence. If one of these steps is not successful, we cannot move on to the next."

Satellites face to face
The two Proba-3 satellites were placed over 15 meters apart in the Redwire cleanroom, the maximum distance available within the confined setting. In space, the pair will be flying around ten times further apart during the mission's formation flying operations.

Personnel from Proba-3 prime contractor Sener in Spain joined the Redwire and ESA teams for the week-long test campaign, along with experts from Danish space research institute DTU Space, which manufactured Proba-3's Vision Based Sensor system.

Radio, satnav, and stellar navigation
The satellites will maintain a connection using a radio-based inter-satellite link system from Tekever in Portugal, continuously updating their distance from each other. They will also determine their absolute positions in space using specially designed satellite navigation receivers, accounting for Proba-3's highly elliptical 60,000 km altitude orbit, which intersects the orbits of satnav constellations and extends high into space. Additionally, the satellites are equipped with star trackers, computer-linked cameras that recognize constellations to reveal each satellite's current pointing direction in space.

LEDs, cameras, laser - getting into position
Once the satellites are within 250 meters of each other, the relative navigation systems for precise formation flying are activated, trialed sequentially during the test campaign.

The first step involves the Vision Based Sensor system. A wide-angle camera tracks an LED pattern on the other satellite, providing coarse information on their distance and attitude. This is supplemented by a narrow-angle camera that locks onto a smaller LED pattern, offering relative positioning information down to about a centimeter.

Millimeter accuracy achieved
Next, the Fine Lateral and Longitudinal Sensor (FLLS) on the 'Occulter' spacecraft shines a laser towards a corner cube retro-reflector on the 'Coronagraph' spacecraft, reflecting back to the Occulter. This system provides relative positioning accuracy down to a millimeter.

The final positioning technology is the Shadow Positioning Sensor system, which uses photo detectors arranged around the coronagraph lens to monitor the Sun's corona. If the shadow is correctly centered, it should be equally illuminated on all sides; any discrepancy would trigger a correction.

First-time combined testing
"All these systems have been tested before at unit level and in simulations," said ESA guidance, navigation, and control engineer Jonathan Grzymisch. "But this was the first time all our hardware and software operated together as they will in space. The navigation system processed actual hardware inputs, progressing from coarser measurements to finer metrology.

"The confined test setup was complex because we were tricking the guidance, navigation, and control software to work outside its operational domain. We used a robot from our Guidance, Navigation, and Control Lab at ESTEC in the Netherlands to hold a laser retroreflector, as the layout didn't allow alignment with the real one on the Coronagraph satellite.

"However, the testing went smoothly, bringing us closer to launch readiness. The next time all these systems operate together will be in space, after the mission begins."

Proba-3 is scheduled to launch this autumn on an Indian PSLV-XL launcher.

Related Links
Proba Missions at ESA
Space Tourism, Space Transport and Space Exploration News

Subscribe Free To Our Daily Newsletters
Tweet

RELATED CONTENT
The following news reports may link to other Space Media Network websites.
SPACE TRAVEL
Kayhan Space Launches Comprehensive Spaceflight Intelligence Platform
Los Angeles CA (SPX) Jun 17, 2024
Kayhan Space has launched Satcat.com, a spaceflight intelligence exchange that aggregates historical and real-time data for objects and events in Earth's orbit. Satcat is designed for a wide range of users, from space enthusiasts to industry experts, offering a single platform for researching, analyzing, and referencing space-related data. While many resources provide essential information about orbital assets, there has been no single platform that combines data such as active and decayed satelli ... read more

SPACE TRAVEL
NASA Explores the Potential of Fungi to Grow Space Habitats

Proba-3 tests formation flying systems on Earth

Chang'e 6 mission raises potential for China-US space cooperation

NASA picks SpaceX to carry ISS to its watery graveyard after 2030

SPACE TRAVEL
Chinese rocket takes off during test, causing local fire

NASA insists Boeing Starliner crew 'not stranded' on ISS

The science behind splashdown

SSC and Firefly Aerospace plan joint satellite launches from Esrange

SPACE TRAVEL
Marsquakes could help detect underground water on Mars

NASA Parachute Sensor Testing Could Make EPIC Mars Landings

NASA's Mars Odyssey Captures Huge Volcano, Nears 100,000 Orbits

Mapping Mars with Open Science Tools

SPACE TRAVEL
Hainan Launch Center Completes Construction for First Mission

Ten make the cut for China's fourth batch of astronauts

China announces first astronaut candidates from Hong Kong, Macau

China Open to Space Collaboration with the US

SPACE TRAVEL
Terran Orbital and Hanwha Systems Form Strategic Partnership

Moon Base Construction: ESA's Innovative Use of 3D-Printed Space Bricks

SES completes euro 3 billion acquisition financing syndication

Iridium Expands Satellite Time and Location Service to Europe and Asia Pacific

SPACE TRAVEL
Space Machines and NewSpace India to Launch Optimus Spacecraft

Intelsat and Starfish Space Sign Agreement for Satellite Life Extension

Time to build zero-debris satellites

Myanmar ethnic fighters battle junta in ruby-mining hub

SPACE TRAVEL
Search for extraterrestrial life focuses on detecting exoplanet atmospheres

Scientists reveal the density differences of sub-Neptunes due to resonance

Artificial greenhouse gases may indicate alien terraforming

Hydrothermal Vents on Ocean Worlds Could Support Life, UC Santa Cruz Study Finds

SPACE TRAVEL
NASA's Juno Observes Lava Lakes on Jupiter's Moon Io

Understanding Cyclones on Jupiter Through Oceanography

Unusual Ion May Influence Uranus and Neptune's Magnetic Fields

NASA's Europa Clipper Arrives in Florida for Launch Preparation

Subscribe Free To Our Daily Newsletters




The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.