SRON Netherlands Institute for Space Research

NEBULA
Xplorer

Live
UTC--:--:--
Earth Tilt23.436°
ISS Alt408 km
GMST--:--:--
NEBULA Orbit550 km · 45°
5yr
Nominal mission
lifetime
161kg
Total spacecraft
mass
10×
X-ray concentrators
co-aligned
89W
Peak power draw
science mode
X-RAY ASTROPHYSICS ·
LOW-EARTH ORBIT ·
SRON NEBULA PROGRAM ·
FALCON 9 RIDESHARE ·
SILICON DRIFT DETECTORS ·
BINARY SYSTEMS ·
X-RAY ASTROPHYSICS ·
LOW-EARTH ORBIT ·
SRON NEBULA PROGRAM ·
FALCON 9 RIDESHARE ·
SILICON DRIFT DETECTORS ·
BINARY SYSTEMS ·
What we are building

Compact X-ray
space telescope

NEBULA-Xplorer is a compact, high-performance scientific satellite developed under SRON's NEBULA program. It delivers high-precision astrophysical observations from a 45° inclination orbit, studying the quasi-periodic behaviour of binary systems by detecting their X-ray emissions.

The instrument houses 10 X-ray concentrators with a focal length of just 0.8 m — short enough to fit on a SpaceX Falcon 9 rideshare. Gold-coated mirrors on an aluminium substrate concentrate X-rays onto silicon drift detectors on the focal plane.

01
X-ray Instrument
200 cm² effective area at 1 keV, 180 cm² at 6 keV. 10 co-aligned Wolter-type concentrators, 30 nested mirror shells each, gold-coated reflecting surfaces.
02
Attitude & Orbit Control
4× Rocket Lab RW3-0.06 reaction wheels in tetrahedral configuration. Star trackers provide 7 arcsec pointing accuracy. APE ≤ 240 arcsec.
03
Propulsion — Dawn SD5
Bipropellant N₂O / propylene system. 26.97 m/s total ΔV budget including 10 m/s margin. Total impulse 4.31 kNs.
04
Power System
SparkWing solar arrays with SADM, 0.76 m² area at 50V. 296 Whr battery capacity. Designed for 5-year EOL degradation.
Spacecraft model

NEBULA Xplorer

drag to rotate
Loading model — 0%
X-ray Instrument ...
Solar Arrays (PWR) ...
Propulsion — Dawn SD5 ...
Communications ...
AOCS ...
Engineering

Spacecraft subsystems

AOCS
Attitude & Orbit Control
4× Rocket Lab RW3-0.06 reaction wheels in tetrahedral configuration. Star trackers provide 7 arcsec pointing accuracy. 3× magnetic torquers for desaturation.
APE≤ 240 arcsec
Slew180° / 150 s
PROP
Propulsion
Dawn Aerospace Satdrive SD5 — bipropellant N₂O / propylene system. Self-pressurising, no pumps required. Switchable to cold-gas mode.
Total ΔV26.97 m/s
Isp250–280 s
PWR
Power
SparkWing solar arrays with SADM at 50 V bus. 296 Whr battery capacity (Enersys ABSL P20). Designed to 5-year EOL degradation at 45° MIO.
Peak draw89 W
Array area0.76 m²
COMM
Communications
Dual Satlab SRS-4 S-band transceivers in hot redundancy. iQspacecom quad-patch high-gain TX antenna (11.5 dB). KSAT ground station network.
Downlink8 Mbps
Storage32 GB
THM
Thermal Control
Full-spacecraft MLI (3.05 m²) with ITO-coated Aluminized Polyimide outer layer. Dedicated radiators for bus (+Y face) and instrument (−X face).
Op. range−35 to +80°C
Radiator0.24 m² total
C&DH
Command & Data Handling
AAC Clyde Sirius OBC with triple-redundant FPGA. SEE-tolerant storage. Handles science data burst from 20-Crab sources over multi-week windows.
Storage32 GB EDAC
Target60 GB preferred
Our experts

Led by scientists
& engineers

MG
Martin Grim
Section Head · Electronics Engineering
Authorized designer of the NEBULA-Xplorer DDD. Leads the electronics engineering section at SRON, overseeing instrument readout systems and spacecraft avionics.
NG
Nathalie Gorter
PA/QA · Product Assurance
Responsible for product assurance on the NEBULA-Xplorer mission. Ensures compliance with ECSS standards across all design phases from SRR through CDR.
BR
Benjamin Ricketts
PhD Candidate · SRON Leiden
Researcher contributing to the scientific case for NEBULA-Xplorer, focusing on X-ray binary systems and quasi-periodic emission behaviour in the high-energy regime.
NX
NEBULA-Xplorer Team
~400 students · 14 institutions
The mission is designed, built, and tested by students from Dutch MBO, HBO, and WO institutions — guided by SRON scientists and Dutch industry partners.
Mission partners

Built with 14 institutions