Connecting people matters to me beyond work and music.
I’m a husband, father of two young women,
and an active member of the wider Krusenstiern family.
CDMU — XMM-Newton main computer patch (Ada) +CDMU — Central Data Management Unit
To enable the MTR (Main Tank Replenishment) on the spacecraft side, the A-Side hardware LTP (Low-Temperature Protection) had to be switched off, allowing us to cool the hydrazine to the lower B-Side temperature limits. Disabling hardware redundancy is inherently undesirable, so this CDMU software patch partly compensates for the reduced redundancy by extending the existing TCD/TCL (Thermal Duty Cycle/Thermal Control Loop) patch to protect the state of the HLCLs (Heater Latching Current Limiters) in software.
HEPI — INTEGRAL instrument hardware (FPGA/ASIC) +HEPI — Hardware Event Preprocessor for IBIS
To turn the raw photon stream of IBIS into usable science data, every detected event has to be preprocessed on board — that is the job of HEPI, an Application-Specific Integrated Circuit (ASIC) developed at the University of Tübingen for the gamma-ray imaging instrument aboard ESA’s INTEGRAL satellite. IBIS observes with two detector planes — ISGRI (INTEGRAL Soft Gamma-Ray Imager), a cadmium telluride detector optimised for lower energies, and PICsIT (PIxellated CsI Telescope), a caesium iodide scintillator detector for higher energies — covering roughly 15 keV to 10 MeV.
HEPI interfaces with both planes, processing individual photon events, synchronising their timing and identifying coincident events — used to reconstruct photon interactions and improve background rejection. During the engineering phase the design ran on Field-Programmable Gate Arrays (FPGAs) — reprogrammable chips that allowed the logic to be tested and revised before it was committed to the fixed ASIC.
The full development is documented in the diploma thesis (in German) submitted at the University of Tübingen in 1998.
To command and monitor the IBIS instrument and process its science data on board, the instrument application software IASW — developed at the University of Tübingen — runs on the Data Processing Electronics (DPE), a radiation-tolerant 1750A processor clocked at 13 MHz with only 2 MB of memory. Its priority-controlled tasks run under a preemptive multitasking operating system shared by all INTEGRAL instruments.
Besides handling telecommands and housekeeping, most of the processing effort goes into fetching and compressing histogram blocks and evaluating the single-photon events supplied by HEPI — applying loss-free compression, rejecting out-of-view Compton events and distributing the limited telemetry rate between data types according to their priority.
Spacecraft Operations Engineer
02
Operations
MTR — XMM-Newton Main Tank Replenishing (Ada, Fortran 77, Jython) +MTR — Main Tank Replenishment
To keep the thrusters firing before the main tank runs dry, the fuel remaining in XMM-Newton’s other tanks — unusable by design — has to be moved into tank 1: a week of special operations each year, a tank-to-tank transfer never foreseen for a satellite built for a ten-year life.
No one had ever shifted fuel between tanks of this design on a satellite in orbit, so the procedures had to be developed anew, with changes at every level — on-board software patched in Ada, new derived parameters (DP) computed in Fortran 77, and new telecommands (TC). To support the intensive manual operation, extensive automation was designed and validated in MOIS and Jython, followed by five days of Flight Control Team simulations in the large Main Control Room at ESOC, with advice from Airbus and the fuel system’s now-retired designer.
Together with an orbit-control change that cut fuel consumption to under two kilograms a year, the yearly MTR keeps XMM-Newton flying into its third decade.
To give the flight control team situational awareness on demand, NRT — a Python toolset — analyses XMM-Newton’s telemetry in near real time as it is downlinked during ground-station contacts, turning housekeeping and instrument parameters into dedicated plots every ten minutes — an automatic, always-ready overview that neither the mission control system nor ad-hoc plots by individual team members provide.
During the yearly MTR, this lets the team quickly check all related subsystems and follow how each parameter develops over the five days of special operations.
To replace cumbersome clicking through different tools on different machines, TLgenAssist generates timelines for XMM-Newton and INTEGRAL in seconds from a single command-line call — written in Python.
A timeline is a file of timed commands the ground sends automatically — the on-board queue only holds about 200 time-tagged commands — built from prepared flight-dynamics products. It is also the input to MOIS, the Manufacturing and Operations Information System used for the operations procedures.
To strengthen two small German engineering companies — startups from the ESA business incubator in Darmstadt — with scientific and technical expertise. The consulting role ran for several years and has since ended.
Living Globes Consultant +Living Globes — The Whole Earth, at Home
To let everyone see the whole Earth as astronauts saw it from the Moon — and so reconnect us with the living planet we live on — the Living Globes Society, a non-profit founded by Sten Linnander and advised by a board that includes an ESA spacecraft-operations engineer, creates digital spheres displaying real-time satellite images for homes, classrooms and public spaces.
MEX fuel estimation +MEX — Mars Express Fuel Estimation
To plan how long the orbiter can keep flying, fuel estimation tracks how much propellant Mars Express has left — bookkeeping tank pressure, temperature and burn history. Mars Express, ESA’s first mission to another planet, has orbited Mars since 2003 and is flown from ESOC in Darmstadt.
A new, independent method was developed and applied in a dedicated study of the fuel on board — its results later backed up by Boris Yendler’s study Active Propellant Management.
To perform the first all-sky survey in the medium X-ray band — mapping galaxy clusters, black holes and the signatures of dark energy — eROSITA, the main instrument of the Spektrum-Röntgen-Gamma satellite, was launched to an L2 orbit in 2019. Operations support helps keep that survey running.
When the eROSITA team at MPE in Munich hit a communication deadlock — astrophysicists and engineers circling a blocking problem in different mental models and wording — a two-hour workshop of asking questions and rephrasing each side’s answers in the other’s model brought the teams back to mutual understanding.
Volunteering
04
Non-Profit
KlangFolk e.V. (Board Member) +KlangFolk — Open Music and Dance in Tübingen
To open music and dance to everyone — whatever their background or skill — the non-profit association KlangFolk e.V. runs free weekly workshops in Tübingen: TüFolk, an orchestra learning traditional melodies from around the world by ear; Música con Señas, improvisation guided by a sign language; and Balfolk, traditional dances anyone can join. Members range from 16 to 85.
To make a practical contribution to the integration of refugees — “Taten statt Warten” (deeds, not waiting) — the volunteer association in Kusterdingen/Mähringen works together with refugees, building garden furniture and more in the Farrenstall workshop; it also runs a permaculture school project in Senegal and hosts cultural events on site.
To spread the sign-language approach to group improvisation in Germany, the German branch of the worldwide Ritmo con Señas movement coordinates groups in Tübingen and Darmstadt — collaborating nationally and internationally through joint workshops, festivals and exchanges. Its website gives groups without a site of their own a public face, letting them announce their workshops and concerts.
Talks · Lectures
05
Speaking
Our Planets — for Kindergarten and Primary-School Audiences +Our Planets — A Tour of the Solar System
To give the youngest listeners their first tour of our Solar System — a hands-on workshop for kindergarten and primary-school audiences.
Held outside, the children become the planets and orbit a central sun, with just one rule: run if you are an inner planet like Mercury, move very, very slowly if you are an outer one like Saturn. Without further explanation they discover that the planets live in a common plane — and that a lot happens among the inner planets while little goes on far outside.
To make black holes understandable for high-school students — a one-hour talk that builds the physics from the ground up.
First the four fundamental forces, then the Pauli exclusion principle and angular momentum. From there the life of a star: a molecular cloud collapsing into a protoplanetary disk, the young star igniting and burning on the fusion fires that stabilise it — and finally the collapse, where the mass decides between three routes: a white dwarf for a sun-like star, a neutron star, or a black hole.
Spacecraft Operations — Guest Professor, University of Würzburg+Guest Professor — University of Würzburg
To teach how satellites are flown — not just built — tailored guest lectures on spacecraft operations for SATEC, the University of Würzburg’s Satellite Technology master’s programme.
They cover how ESA works and how operations are done — ESA has never lost a mission within its designed lifetime — enriched with real stories of major anomalies, like when XMM-Newton went silent or the three hours that saved INTEGRAL, and how the team works together to recover.
To share how an ESA science mission really works — a 100-minute interview with Tim Pritlove covering the Planck spacecraft: on-board software maintenance, orbit control, data transmission and the planned end-of-mission shutdown.
To make the vastness of the universe graspable in a contemplative way, the Astronomisches Konzert pairs a few carefully chosen astronomical images — projected large — with a short introduction followed by fitting improvised acoustic music, leaving room for questions afterwards.
Performances include the Starkenburg-Sternwarte observatory in Heppenheim, where the concert was given in February 2016.
To let a whole group improvise music together without sheet music, a conductor shapes the improvisation in real time — an approach known as conducted improvisation. The sign language it uses, Ritmo con Señas, was created in 2006 by the Argentine musician Santiago Vázquez for his Buenos Aires ensemble La Bomba del Tiempo — more than 130 hand and body signs covering rhythm, melody, harmony and structure.
The Darmstadt group brings together about fifteen players — from beginners to professional musicians, with and without instruments — and meets in Darmstadt-Eberstadt to improvise together.
Wanderfeld (Guitar) +Wanderfeld — Music for Light and Instruments
To improvise music with light as an equal instrument, Wanderfeld — an audio-visual ensemble active since 2002 — combines around 25 to 100 light pyramids (an installation by Micha Armingeon) with guitars, saxophone and guests on keys or accordion, playing together over audible and visible patterns.
To qualify for water-rescue duty, the Wasserwacht — the water-rescue branch of the Bavarian Red Cross — issues the Leistungsschein, its proficiency qualification covering lifesaving swimming and rescue technique.
Advanced Open Water Diver — PADI+Advanced Open Water Diver — PADI
To dive deeper and more independently, the Advanced Open Water Diver — PADI’s second-level scuba certification — adds five adventure dives including deep and underwater navigation, qualifying the diver for depths of up to 30 metres.
To support the teams working in data centres — designing, implementing and validating their systems and training their staff — independent consulting and instruction, mainly on networks and firewalls, Oracle databases, Unix mainframes and Linux servers, and their administration.
Herschel & Planck (OBDH Engineer) +Herschel & Planck — On-Board Data Handling (OBDH) Engineer
ESA launched the two telescopes together in 2009 — Herschel to observe the cool far-infrared universe, Planck to map the CMB (cosmic microwave background).
OBDH engineering covered the systems handling the vast amounts of science data between instruments and ground, as well as the autonomous commanding and control of the spacecraft.
The mission — its on-board software maintenance, orbit control and planned shutdown — is covered in depth in a 100-minute Raumzeit podcast interview.
Sentinel-2 (OBDH Engineer) +Sentinel-2 — On-Board Data Handling (OBDH) Engineer
To monitor land and vegetation in high-resolution multispectral detail for the Copernicus environment programme, Sentinel-2 flies twin Earth-observation satellites. The OBDH engineering covered the same scope as described for Herschel & Planck above.
To keep observational data on accreting pulsating neutron stars available within days of each observation, INTEGRAL’s guaranteed-time programme scanned parts of the Galactic plane every fortnight from 2003 to 2006 — the Galactic Plane Survey (GPS). These pages publish the detected source fluxes for the JEM-X and IBIS instruments on a Science-Window basis, together with basic scientific information, literature references and links to the RXTE All Sky Monitor and BATSE data where available.