. 24/7 Space News .
Maintaining large-scale satellite constellations using logistics approach
by Staff Writers
Chicago IL (SPX) Jul 17, 2019

This is an overview of the multilevel spare strategy for a satellite constellation.

Today, large-scale communication satellite constellations, also known as megaconstellations, have been more and more popular. OneWeb launched the first batch of satellites of an initial 650-satellite constellation in February 2019, and SpaceX also launched the first batch of its 12,000-satellite constellation in May 2019. On July 8, Amazon also filed an application with the FCC for its planned satellite constellation with 3,236 satellites. These satellite constellations are expected to be a game changer by realizing the worldwide satellite Internet service.

However, the unprecedently large scale of these megaconstellations also brings numerous challenges, some of which are hidden and not well-explored. Researchers at the University of Illinois at Urbana-Champaign identified a critical hidden challenge about replacing the broken satellites in megaconstellations and proposed a unique solution with inventory control methods.

"Maintaining these large-scale megaconstellations efficiently is far more complex than the traditional space systems. In fact, it has become more and more like a ground logistics problem that FedEx or UPS has been working on. So we tackled this megaconstellation maintenance problem leveraging the idea from ground logistics, which turns out to be not only unique and interesting but also very suitable in this context" said Koki Ho, assistant professor in the Department of Aerospace Engineering at U of I.

"The challenge Ho described is to efficiently swap out a new satellite for one that breaks. For telecommunications companies, broken satellites mean interrupted communications and Internet service, which leads to disgruntled customers and loss of revenue.

"Deploying a large-scale constellation is one problem, but maintaining it is another possibly more challenging problem," Ho said. "When the satellites break, providing a spare quickly is important so there is little gap in the service.

Companies need continuous service to provide global coverage. In order to achieve that, we need to have sufficient spares in orbit. The question is: how many would be sufficient. Can we think of a smarter way to use as few satellites as possible to satisfy the gap requirement?"

In earlier satellite constellations, Ho said this was not a problem because the scale was small enough sophisticated methods to calculate the needed number of spares was not needed; just having a few spares per orbital plane was enough.

But with a constellation made up of hundreds of satellites, the strategy won't work. Also, new, small satellites are cheaper but have a relatively higher failure rate so many more spares are needed in each orbital plane, and that's inefficient.

"Our idea is to use something called a multi-echelon inventory control method in the ground logistics and apply it to the orbital mechanic's context," Ho said.

"In our solution, another orbit that is lower than the actual orbit, which we call the parking orbit; becomes an intermediate warehouse of the satellites. A small number of spare satellites are in the actual orbital plane for immediate replacement, while a larger inventory of replacement satellites is waiting in the parking orbit. The ones in the orbital plane cover an immediate need, the spares in the parking orbit can replenish the actual orbit."

The research also takes advantage of the J2 effect of the orbital plane, which is caused by the Earth's obliqueness, to deliver the spares. The Earth is not a perfect sphere, Ho explained, and because it's not a perfect sphere, the orbital plane will shift.

"That orbital plane shift rate is different depending on the altitude," Ho said.

"So when we have a parking orbit that is at a lower altitude than the original constellation orbit, their orbital shift rates are different. The mathematical model we created takes into account that rate shift and which plane is closer to the satellite in need of replacing so that you will have continuous coverage of the Earth.

"The method looks at which orbital plane is the first one that will match with the plane that has a demand and also consider whether that plane actually has spares in it. If that plane doesn't have spares, then we wait until the next plane," Ho said.

Ho said this method also removes the costly urgency to launch a replacement satellite.

"With this warehouse strategy, when there is a failed satellite, there is already an inventory of stock available to replace it. When the stock goes below a threshold, you can launch more to the parking orbit. This takes advantage of the batch launch effect. It's cheaper to send one rocket up with a bunch of satellites than launching each of them separately."

Ho believes this new supply method solves a timely problem.

"People are talking a lot about these megaconstellations but they haven't thought deeply enough about some of the new challenges they bring," Ho said. "Using a unique warehouse approach provided an efficient solution to address this complex problem."

Research paper

Related Links
University of Illinois College of Engineering
The latest information about the Commercial Satellite Industry

Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly

paypal only
SpaceDaily Contributor
$5 Billed Once

credit card or paypal

Maintaining large-scale satellite constellations using logistics approach
Chicago IL (SPX) Jul 13, 2019
Today, large-scale communication satellite constellations, also known as megaconstellations, have been more and more popular. OneWeb launched the first batch of satellites of an initial 650-satellite constellation in February 2019, and SpaceX also launched the first batch of its 12,000-satellite constellation in May 2019. On July 8, Amazon also filed an application with the FCC for its planned satellite constellation with 3,236 satellites. These satellite constellations are expected to be a game changer ... read more

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Major shuffle at NASA in rush to meet Trump's moon deadline

Virgin Galactic seeks space tourism boost with market launch

Russian Federatsiya spacecraft crew could be killed in case of water landing

What a Space Vacation Deal

NASA SLS rocket testing ensures astronaut safety, mission success

Fuel leak halted blastoff for Indian rocket: reports

India's heavy rocket Bahubali gearing up for Moon

Vega rocket fails after takeoff in French Guiana

Sustaining Life on Long-Term Crewed Missions Will Require Planetary Resources

InSight Uncovers the 'Mole' on Mars

Mars 2020 Rover Gets a Super Instrument

Methane vanishing on Mars

From Moon to Mars, Chinese space engineers rise to new challenges

China plans to deploy almost 200 AU-controlled satellites into orbit

Luokung and Land Space to develop control system for space and ground assets

Yaogan-33 launch fails in north China, Possible debris recovered in Laos

Maxar begins production on Legion-class satellite for Ovzon

Maintaining large-scale satellite constellations using logistics approach

To be a rising star in the space economy, Australia should also look to the East

Israeli space tech firm hiSky expands to the UK

Molecular thumb drives: Researchers store digital images in metabolite molecules

NASA funds demo of 3D-Printed spacecraft parts made, assembled in orbit

BAE nets $4.7M by DARPA to integrate machine learning into RF signals detection

Perseverance is key to NASA's advancement of alloys for bearings and gears

Astronomers expand cosmic "cheat sheet" in hunt for life

Scientists deepen understanding of magnetic fields surrounding Earth and other planets

Ejected moons could help solve several astronomical puzzles

A desert portal to other worlds

Jupiter's auroras powered by alternating current

Kuiper Belt Binary Orientations Support Streaming Instability Hypothesis

Study Shows How Icy Outer Solar System Satellites May Have Formed

Astronomers See "Warm" Glow of Uranus's Rings

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.