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<front>
<journal-meta>
<journal-id journal-id-type="publisher">EGUsphere</journal-id>
<journal-title-group>
<journal-title>EGUsphere</journal-title>
<abbrev-journal-title abbrev-type="publisher">EGUsphere</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">EGUsphere</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub"></issn>
<publisher><publisher-name>Copernicus Publications</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/egusphere-2026-1579</article-id>
<title-group>
<article-title>A Cubesat-optimized Magnetic Field Measurement Concept for Operation Beyond Low Earth Orbit</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Steinhöfler</surname>
<given-names>Raphael</given-names>
<ext-link>https://orcid.org/0009-0008-9523-8201</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Anger</surname>
<given-names>Marius</given-names>
<ext-link>https://orcid.org/0000-0001-7037-425X</ext-link>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Shalamov</surname>
<given-names>Roman</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Praks</surname>
<given-names>Jaan</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Fischer</surname>
<given-names>David</given-names>
<ext-link>https://orcid.org/0000-0002-8435-7220</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Magnes</surname>
<given-names>Werner</given-names>
<ext-link>https://orcid.org/0000-0003-0086-6288</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Wilfinger</surname>
<given-names>Josef</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Valavanoglou</surname>
<given-names>Aris</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Lentz</surname>
<given-names>Constant Michel Felix</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Space Research Institute, Austrian Academy of Sciences, Schmiedlstraße 6 AT-8042 Graz, Austria</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Department of Electronics and Nanoengineering, Aalto University, Maarintie 8 FI-02150 Espoo, Finland</addr-line>
</aff>
<pub-date pub-type="epub">
<day>15</day>
<month>06</month>
<year>2026</year>
</pub-date>
<volume>2026</volume>
<fpage>1</fpage>
<lpage>27</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2026 Raphael Steinhöfler et al.</copyright-statement>
<copyright-year>2026</copyright-year>
<license license-type="open-access">
<license-p>This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit <ext-link ext-link-type="uri"  xlink:href="https://creativecommons.org/licenses/by/4.0/">https://creativecommons.org/licenses/by/4.0/</ext-link></license-p>
</license>
</permissions>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2026/egusphere-2026-1579/">This article is available from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-1579/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2026/egusphere-2026-1579/egusphere-2026-1579.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-1579/egusphere-2026-1579.pdf</self-uri>
<abstract>
<p>This paper presents a CubeSat-optimized measurement concept for magnetic field, which was designed for missions beyond low Earth orbit targeting novel radiation belt studies. The instrument combines a miniaturized three-axis fluxgate sensor on a low‑mass deployable boom together with a compact sensor control unit that implements fully synchronous excitation, sampling, and digital control. A hybrid feedback module integrates three prototype fluxgate feedback microchips that provide low‑noise current sources with selectable full‑scale ranges (&amp;plusmn;3/&amp;plusmn;9 mA), enabling vector measurements over &amp;plusmn;70 &amp;mu;T while retaining sub‑nT resolution. The boom provides 65 cm standoff from the CubeSat and pointing knowledge of 1&amp;deg;. The designed boom length limits the tolerable magnetic dipole moment inside the CubeSat to 0.05 Am&lt;sup&gt;2&lt;/sup&gt;. Extended housekeeping includes voltage supply and thermal monitoring, an additional magneto‑inductive sensor on the sensor control unit for disturbance discrimination, and total ionizing dose tracking. Laboratory characterization demonstrates noise densities of 20&amp;ndash;30 &lt;span style=&quot;border-bottom: 1px solid #000; vertical-align: 70%; font-size: .7em; color: #000;&quot;&gt;pT&lt;/span&gt;&lt;span style=&quot;margin-left: -1.2em; margin-right: .3em; vertical-align: -15%; font-size: .7em; color: #000;&quot;&gt;&amp;radic;Hz&lt;/span&gt; at 1 Hz, with 128 vectors per second science data and linearity suitable for near‑Earth fields. As it is a pivotal element in the instrument, the prototype feedback microchip was tested for its radiation response. Heavy‑ion testing showed no single‑event latch‑up up to 100 &lt;span style=&quot;border-bottom: 1px solid #000; vertical-align: 70%; font-size: .7em; color: #000;&quot;&gt;MeV cm&lt;sup&gt;2&lt;/sup&gt;&lt;/span&gt;&lt;span style=&quot;margin-left: -2.7em; margin-right: 1.1em; vertical-align: -15%; font-size: .7em; color: #000;&quot;&gt;mg&lt;/span&gt;. Single‑event transients as well as single-event upsets were observed and are consistent with rare functional interrupts in the digital part of the signal chain. They are addressable by standard redundancy techniques. X‑ray tests up to 1 Mrad confirm functionality with worst‑case gain and offset drifts of approximately 600 &lt;span style=&quot;border-bottom: 1px solid #000; vertical-align: 70%; font-size: .7em; color: #000;&quot;&gt;ppm&lt;/span&gt;&lt;span style=&quot;margin-left: -2.1em; margin-right: .3em; vertical-align: -15%; font-size: .7em; color: #000;&quot;&gt;krad&lt;/span&gt; and 1 &lt;span style=&quot;border-bottom: 1px solid #000; vertical-align: 70%; font-size: .7em; color: #000;&quot;&gt;&amp;mu;A&lt;/span&gt;&lt;span style=&quot;margin-left: -1.4em; margin-right: .3em; vertical-align: -15%; font-size: .7em; color: #000;&quot;&gt;krad&lt;/span&gt; within 0&amp;ndash;100 krad. The prototype meets the performance requirements derived from the Foresail‑2 mission concept and demonstrates a path to high‑quality, resource‑efficient magnetometry on 3U&amp;ndash;6U CubeSat platforms suitable for operation in the Van Allen belts and other harsh radiation environments.</p>
</abstract>
<counts><page-count count="27"/></counts>
<funding-group>
<award-group id="gs1">
<funding-source>Research Council of Finland</funding-source>
<award-id>336805</award-id>
<award-id>336809</award-id>
</award-group>
<award-group id="gs2">
<funding-source>Österreichische Forschungsförderungsgesellschaft</funding-source>
<award-id>878878</award-id>
</award-group>
<award-group id="gs3">
<funding-source>Horizon 2020</funding-source>
<award-id>101008126</award-id>
</award-group>
</funding-group>
</article-meta>
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