Swarmwatch Signals: Issue 03

This week, two veteran ESA satellites made carefully targeted returns through the atmosphere, giving researchers a rare opportunity to observe how spacecraft break apart during re-entry.

China gained another medium-lift rocket, a Japanese radar constellation continued to grow, and a private servicing spacecraft came close to a NASA observatory even though it could no longer complete its rescue mission.

Taken together, these stories remind us that the orbital environment is shaped by much more than launch numbers. Access to orbit matters, but so do commissioning, servicing and the safe disposal of spacecraft at the end of their lives.

Swarmwatch Signals selects a small number of developments that deserve attention and considers what they could mean for space infrastructure, security and resilience.

For constellation sizes, launch histories and orbital activity, visit Swarmwatch.

The final two satellites from ESA’s Cluster mission re-entered the atmosphere over the South Pacific on 31 August and 1 September.

Samba and Tango had previously been manoeuvred onto trajectories that would bring them down over a remote area. Their re-entry locations were predictable enough for researchers to observe both events from an aircraft operating from Tonga.

ESA reports that 29 of the aircraft’s 30 scientific instruments captured data from both re-entries.

Samba re-entered at 21:39:38 UTC on 31 August. Tango followed at 21:30:31 UTC on 1 September. The final prediction for Tango’s re-entry was accurate to within seconds.

ESA calls the approach a “targeted re-entry”. It was not a powered descent. Once the final orbital adjustments were complete, natural changes to the satellites’ highly elliptical orbits brought them into the atmosphere at the selected place and time.

Why it matters: Engineers still have limited real-world evidence showing precisely how satellites heat up, break apart and release material during re-entry. Observations from Cluster will help improve re-entry models and inform the design of satellites intended to burn up more completely.

The campaign also shows that operators can sometimes improve the disposal of satellites not originally designed for controlled re-entry.

Source: European Space Agency

Galactic Energy’s Pallas-1 rocket reached its intended orbit during its maiden flight on 1 September, according to the company and Chinese state media.

Pallas-1 is a two-stage, liquid-fuelled medium-lift rocket. Galactic Energy has positioned it for China’s growing commercial launch market, including the deployment of large satellite constellations.

The company already operates Ceres-1, a smaller rocket powered by solid fuel. Pallas-1 represents a move into a more capable class of launch vehicle and has been designed with partial reusability in mind.

No operational payload was disclosed for the maiden flight.

The first stage was not recovered. The mission demonstrated that the rocket could reach orbit, but it did not demonstrate the reusable capability around which some of Pallas-1’s longer-term promise has been built.

Why it matters: China’s constellation plans require a substantial and sustained increase in launch capacity. That demand cannot easily be met by the country’s existing state-owned launch vehicles alone.

If Galactic Energy can establish a reliable flight cadence and eventually recover the rocket’s first stage, Pallas-1 could become an important part of China’s constellation infrastructure. One successful flight is an encouraging beginning, but reliability and reuse can only be demonstrated over time.

Sources: Space.com and the State Council Information Office of China

Japanese Earth-observation company Synspective has deployed the eleventh satellite in its StriX synthetic-aperture radar constellation.

The satellite was launched by Rocket Lab from New Zealand on 2 September and placed into a 575-kilometre orbit. Synspective will now test and commission the spacecraft before bringing it into service.

Synthetic-aperture radar satellites can observe the ground through cloud cover and during darkness. Synspective is developing the constellation to support disaster response, infrastructure monitoring, urban planning and the management of natural resources.

Rocket Lab has provided all 11 of Synspective’s launches since 2020. A further 16 missions are booked to continue building the constellation before 2030.

Why it matters: Synspective and Rocket Lab illustrate a deployment model based on dedicated launches of individual satellites.

A small launcher can place a spacecraft directly into a selected orbit and give the operator more control over deployment timing. That can be useful when building or replenishing a constellation, although it will generally cost more per satellite than sharing a larger rocket.

Sources: Synspective and Rocket Lab

A private servicing spacecraft has approached within 15 kilometres of NASA’s Neil Gehrels Swift Observatory, even though the planned rescue mission had already been abandoned.

Katalyst Space Technologies launched its Link spacecraft in July with the intention of helping raise Swift’s declining orbit. Link subsequently entered an uncontrolled spin. Although controllers recovered the spacecraft, it used more propellant than expected and could no longer safely attempt the original mission.

Katalyst continued with a reduced operation. Link approached Swift, captured images and collected sensor data before withdrawing because of its remaining fuel level.

Swift is still operating, but atmospheric drag is gradually lowering its orbit. Without an intervention, NASA expects the observatory eventually to re-enter.

Why it matters: The mission did not rescue Swift, but it provided an opportunity to test navigation, imaging and proximity operations around an unprepared client satellite.

Future servicing missions will need to work with spacecraft that were never designed to be inspected, captured or moved. Link’s own technical problems also show how little margin can exist in a complex rendezvous mission.

Source: Associated Press

It is tempting to measure a constellation's development by counting the satellites placed into orbit. This week’s stories point towards a more useful test.

A sustainable constellation needs access to launch, but it also needs spacecraft that can be commissioned reliably, maintained in the correct orbit, replaced when they fail and removed when they reach the end of their lives.

Galactic Energy is developing Pallas-1 partly in response to growing Chinese demand for constellation launches. Synspective has secured a series of dedicated Rocket Lab missions that allow it to build its network progressively. Katalyst is attempting to create the capability to approach and eventually move satellites already in orbit. ESA is studying what happens when spacecraft return through the atmosphere.

These are different parts of the same industrial system.

The operators most likely to sustain large networks will not necessarily be those with the most ambitious filings or the largest number of proposed satellites. They will be those with dependable access to launch, disciplined orbital operations and credible plans for dealing with failures.

Servicing and disposal are particularly important. A constellation containing hundreds or thousands of spacecraft will experience failures, even if each individual satellite is highly reliable. At that scale, replacing and removing spacecraft becomes a routine operational requirement rather than an exceptional mission.

Launch may still attract most of the attention, but the long-term competition will increasingly be about the infrastructure that comes before and after it.

The final three satellites in SES’s current O3b mPOWER deployment have arrived at Cape Canaveral ahead of a planned September launch aboard a Falcon 9.

They are intended to join ten operational O3b mPOWER satellites in medium Earth orbit. SES says their deployment will complete the currently planned constellation and increase its capacity, coverage and resilience.

The satellites have reached the launch site, but they have not yet been launched or commissioned. Completion should therefore remain conditional until deployment, contact and initial testing are confirmed.

Why I’m watching: O3b mPOWER is a useful contrast with the much larger networks being built in low Earth orbit. SES is seeking global and regional connectivity from a smaller number of more capable satellites operating at a higher altitude.

The coming launch will complete the deployment phase, but the more meaningful test will be the performance and reliability of the full network once all 13 satellites are in service.

Source: SES

The OECD’s latest overview of the space economy examines government investment, private finance, satellite-enabled services, scientific capability and the changing structure of the commercial market.

It also covers some of the less visible constraints on further growth, including orbital congestion, debris, market concentration, supply-chain dependencies and reliance on essential satellite data and signals.

It is a broad report rather than a source of breaking news, but it provides useful context for understanding how deeply space infrastructure is becoming embedded in the wider economy.

Read: The Space Economy at a Glance 2026

The Sky Is Full

I’ve been working on an eight-part documentary podcast about how satellite constellations are reshaping communications, geopolitics and conflict.

The Sky Is Full travels from Ukraine’s battlefields and Chinese launch sites to Cold War bunkers and Silicon Valley boardrooms, tracing how low Earth orbit became some of the world’s most consequential infrastructure.

The trailer is out now.

Listen to The Sky Is Full + The Sky Is Full site

Swarm: The Rise of Megaconstellations and the Battle for Low Earth Orbit

My forthcoming book examines the larger story behind many of the developments covered by Swarmwatch Signals: how commercial satellite networks became strategic infrastructure, why governments increasingly depend on them, and what their expansion means for competition and conflict in orbit.

Swarm will be published by Potomac Books in January 2027.

Read more about Swarm

Did You Know? As of 7 September 2026, CelesTrak’s catalogue listed 16,508 tracked active satellites in Earth orbit.

It also listed 2,776 dead satellites, more than 2,100 rocket bodies and over 10,000 catalogued pieces of debris still in orbit.

Catalogue totals depend on how objects are classified and do not include every piece of debris too small to track. Even with that qualification, the figures show that managing the orbital environment involves far more than avoiding other operational satellites.

Source: CelesTrak Satellite Catalogue

Till next time,

Jay

Swarmwatch Signals