
When Iridium needed a global Push-to-Talk satellite service, it wasn’t an aerospace prime that delivered it. It was a deep tech consultancy in Cambridge, England.
Stewart Marsh is Head of Satellite and Space at Cambridge Consultants, the deep tech arm of Capgemini Invent. He has spent more than 25 years in aerospace and telecommunications, leading programs that translate satellite system architecture into commercial products. His portfolio includes the Iridium Extreme PTT, a satellite phone offering group Push-to-Talk functionality anywhere on Earth using proprietary radio protocols that lock onto the next available satellite and establish a connection in under two seconds. The same team contributed core technology to Iridium NEXT, a constellation upgrade that replaced all 66 operational satellites in orbit. More recently, Cambridge Consultants partnered with Flylogix to develop a beyond-visual-line-of-sight drone solution using low-power satellite connectivity, demonstrating how LEO infrastructure can extend the reach of autonomous platforms.
The consulting model is distinctive. Cambridge Consultants operates as a technology development partner, not a system integrator or prime contractor. The company works across industries from medical devices to defense, but its satellite practice has grown in step with the commercialization of space. Capgemini’s broader space division, which encompasses defense and naval programs across Europe, provides institutional reach. At MWC 2026 in Barcelona, Capgemini and Cambridge Consultants presented analysis on the convergence of terrestrial and non-terrestrial networks, tracking how 5G and 6G architectures are incorporating satellite links as native infrastructure rather than fallback connectivity. SatNews reported in September 2025 on a 5G direct-to-device demonstration led by Thales Alenia Space with Capgemini and Thales for CNES under the France 2030 program. In April 2026, SatNews covered Iridium’s expanding role in Artemis II and next-generation PNT at the Space Symposium, a constellation that Cambridge Consultants helped modernize.
At SmallSat Europe, Marsh joins the opening panel on Day 1: “The European Pulse: A 2026 Market Outlook for SmallSats.” The session brings together BryceTech’s Carissa Christensen, ESA’s Dietmar Pilz, Neuraspace’s Chiara Manfletti, Canopy Aerospace and Defense’s Dr. Marco Villa, and Thales Alenia Space’s Dr. Marino Fragnito. The discussion addresses emerging trends, shifting supply-chain dynamics, and the business models driving innovation across the continent. Marsh’s contribution is the deep tech lens: how technology readiness translates into market readiness, and where the engineering bottlenecks sit between concept and commercial product.
The industry has operators, manufacturers, and agencies. The question is who builds what they can’t build themselves. Marsh has the answer sheet.


