Is It Better to Replace or Replenish Satellite Fleets?

Space is becoming something of a premium commodity due to the ever-growing list of satellite ventures and equipment being sent up, presenting widely-recognised problems involving debris . Less-well considered is the lifespan of the satellites themselves. It is typically around 10- to 15-years and when it is up, operators face the decision on whether to replace or revive their birds. Clunk and junk It is certainly not a novel issue: Analysys Mason published an article exploring the case for extending the life of birds a decade ago in which it noted satellites are effectively binned once they run out of fuel to power positioning thrusters. The research company assessed the viability of space tugs, vehicles which mount to the satellite and become the new thrust mechanism. It conceded tugs are a potentially clunky means of refuelling satellites, but explained variances in fuel caps and the possibility they were never meant to be operated remotely hindered bids to refill existing tanks. More recently, Sakthikumar Ramachandran, founder and CEO of OrbitAid Aerospace, argued servicing and refuelling satellites in space is a “practical alternative” to scrappage and a reasonable means of reducing debris. The executive made the argument in an article published by the World Economic Forum during July in which he explained the so-called “launch-and-replace” model for satellite deployments is no longer viable, particularly given the massive reliance people now have on services including location and nascent direct-to-device communications. Ramachandran is concerned more satellites will contribute to an ever-growing pile of space junk. He wrote there are 1.2 million debris fragments which are too small to track but “capable of catastrophic damage”. An important caveat here is OrbitAid’s entire business is in extending the operational life of satellites, though this does not lessen the impact of the debris numbers Ramachandran cites. Private engineering and technology group Sener also highlighted the growing reliance on satellite connections as a reason to explore changes to the traditional methods. In a blog published in May, its experts pointed to Earth observation and communications as examples of “essential infrastructure” reliant on satellites. Sener staff explained this means the traditional approach of abandoning birds either at the end of their life or in the event of sometimes simple failures is no longer viable. Sener stated robots can repair or replenish satellites, though noted a lack of common specifications could hamper such efforts and branded the development of standard interfaces a “strategic factor”. Economics Although sustainability and reducing debris are worthy goals, Sener noted there are cost savings to be had by keeping birds flying longer. Peer-reviewed journal npj Space Exploration discussed low Earth orbit (LEO) satellites in a multi-authored paper published in April. The authors predicted the worth of the space economy could hit $1.8 trillion by 2035, though like others covering the industry raised concerns over the sustainability impact of a single-use model which predominates in the modern LEO sector. Companies including SpaceX and AST SpaceMobile rest their entire business model on the ability to quickly launch vast numbers of small-sized LEO birds, with ongoing replacement cycles to account for relatively short service lives. The article’s authors quoted Environment America figures indicating the number of LEO satellites had grown by 127-times over a five-year period, pointing to potentially substantial costs in replacing the space hardware. They also touched on a key element in the replace or replenish debate, namely the business case for servicing geosynchronous Earth orbit (GEO) birds in orbit is greater because they tend to be larger than their LEO counterparts. Examples This differentiation is one Mobile World Live uncovered when speaking with Australian operator Optus and satellite service provider Globalstar, each of which recently publicised moves on either side of the coin. Optus just completed the initial phase of a project to refuel its GEO birds under the moniker Project Aurora and Globalstar is commencing a replacement plan for its LEO birds. Their respective approaches bear out the split between GEO and LEO strategies highlighted in the npj Space Exploration article. Harvey Wright, executive GM of Satellite at Optus ( pictured, right ), said the decision between replacing and replenishing “isn’t necessarily an either-or choice”. “For Optus, it’s about selecting the most effective approach to maintain service continuity, fleet resilience and long-term flexibility”. The D3 satellite Optus is working on launched in 2009 and is considered an important provider of capacity for the operator. Wright said Optus opted for replenishment to continue employing a “fully operational satellite asset while maximising the value of infrastructure already in orbit”. Optus is an “experienced satellite owner and operator, with more than four decades” of experience, giving it a solid idea of how changing technology capabilities can alter the strategy for its orbital equipment. “Project Aurora reflects that evolution, giving operators greater flexibility in how they maintain and extend critical space infrastructure,” Wright explained. The Optus executive noted there are “significant cost and lead time” benefits to be had through the replenishment scheme. He also highlighted greater flexibility in future fleet planning along with the sustainability matters outlined above. Wright noted “life extension does not remove the need for future satellite investment”. Instead, it effectively buys more time to make decisions on the next steps. “Project Aurora is ultimately about maintaining critical satellite capacity and resilience for customers including regional and remote communities”, Wright emphasised. Globalstar recently hailed the “milestone” launch of eight replacement LEO satellites, part of an ongoing strategy to upgrade its fleet. In a press statement at the time, CEO Paul Jacobs said the fresh birds had each reached their “intended orbital planes” and work was underway to bring them online “to provide additional resiliency”. The company told us it opted for replacement “because it does more than buy time”. “These satellites operate in the same frequency bands, at the same altitude and with the same service footprint as the fleet flying today, so customers see continuity”. The latest Globalstar LEOs have a service life of 12-years and comply with “current orbital-debris and end-of-life standards”. Globalstar agreed a replenishment strategy is better suited to GEO birds, but argued deriving the greatest benefits from LEO fleets is a numbers game. “Adding satellites to the planes is like adding spotlights: more spotlights make for a brighter light.” “Renewing the fleet delivers a stronger network and a longer runway than servicing ageing hardware could.” The outcome seems relatively clear cut: for higher flying satellites, the argument for replenishment is greater due to their typically larger size and resulting construction and launch costs. Lower-range items can be made more economically, tipping the scales towards a business model where replacement is more attractive. Questions over sustainability remain and it would be easy to assume replenishing existing birds would inevitably be the better choice. But even refuelling requires rocket launches and hardware to be deployed into orbit, which itself could ultimately contribute to the growing debris pile. For the moment, it looks like companies will take the decision which best-suits their fleet and long-term strategy. Optus and Globalstar provide solid examples of the processes and goals involved in those choices. The post Feature: Is it better to replace or replenish satellite fleets? appeared first on Mobile World Live .