My fantastic visit at MT Aerospace – a main supplier for components of ESA Ariane 5 & 6 launchers (Part III)

Link to German version/Deutschsprachige Version


I a m proudly presenting our mini Ariane-6 (with two solid rocket motors) at MT Aerospace in Augsburg – in comparison to a huge Ariane-6 model with four boosters. In the display to the left you can see models of Ariane 1, 2, 3, 4, 5 and an early but outdated Ariane 6 version.


The MT Aerospace site in Augsburg is well connected to the European history of spaceflight. At the moment important components for Ariane 5 are produced. In the past components for all Ariane ESA launchers (1, 2, 3 & 4) were assembled here starting at the end of the 1970s. This story of success will hopefully be extended with the participation of MT-A in the Ariane 6 program of ESA and the Ariane Group.



I had the pleasure to meet the huge Ariane 6 model seen in the image above already last year – at the exhibition stand of MT Aerospace/OHB during my visit of the ILA fair in Berlin in 2016.


The Ariane 6 will be the new main launcher of ESA lifting medium and heavy payloads to space. If all goes as planned the first launch will happen in July 2020 from the European spaceport Kourou in French Guayana.


Video animation provided by ESA showing the launch of  an Ariane 6 with four solid rocket motors (AR64).

The design of the Ariane 6 was optimized to get a very reliable and versatile launcher for reasonably low launch costs at the same time. Versatility is guaranteed by having 2 versions of Ariane 6: one with two solid rocket motors (AR62) and one with four (AR64). The AR62 will be well suited for medium sized payloads. The AR64 can lift a heavy payload or two communication satellites as Ariane 5 can do now.



Cutaway model of an Ariane 6 at the Odysseum in Cologne, Germany, provided by the German Aerospace Agency DLR. I am standing in front of one booster. The solid propellant is coloured in brown. The propellant is contained in the booster case. The case serves as a combustion chamber at the same time. These AR6 booster cases will be produced by MT-A in Augsburg.


The main component of such an AR6 solid rocket motor is the so-called booster case.   Such a booster case is not only the container for 137 tons (!) of solid propellant, it is the combustion chamber for this propellant at the same time and needs to withstand very high temperatures and pressures. You may remember that steel segments are being used for the Ariane 5 booster cases. Steel is relatively heavy. A different material needs to be used for boosters with lower weight. The choice for the material of AR6 booster cases was made with Carbon Fiber Composite (CFC). Besides from the low weight in comparison to steel CFC has another advantage. The entire booster case can be made in a single piece!



In the Ariane 6 Project Office of MT-A I was allowed to watch this movie showing a test booster case that was produced by MT-A and DLR Augsburg with a new low cost process. It has a diameter of 3.5m as the AR6 booster case will have.  With 6m length it is half of the size of an AR6 booster case. This unit was recently successfully tested. More information about this test is avialable here.


As Ariane 6 will need two or even four of these solid rocket motors it is important that the booster cases can be produced with low costs. Therefore MT-A and the German Aerospace Center (DLR) Augsburg have developed a low cost production process called infusion method. The carbon fibers are wounded in dry condition. After the wounding process for the entire case is complete the binding material (Epoxy) is applied. Until now wounding and applying Epoxy had to happen at the same time what is a very complicated and expensive process.



Cut through a piece of test material for a CFC booster case. You can see the single carbon fibers bounded by Epoxy. The CFC technology allows to produced large but very stable units. Thus, the entire booster case can be produced as a single piece. Additionally, the case has a lower weight than a similar case made of steel.


Thanks to this innovative new technology and the increased financial contribution of Germany to the development costs of Ariane 6 MT Aerospace will produce booster cases for Ariane 6 in Augsburg. There is a second location for the production of Ariane 6 booster cases in Italy. The Avio Group will produce AR6 booster cases as well as the same-sized cases for the first stage of the Vega launcher.



Me inside of the tank for LOX (Liquid OXygen) of the main stage of the Ariane 6 model at the Odysseum in Cologne. I am standing at the low LOX tank dome, above is the upper dome. Below is the upper tank dome of the LH2 (Liquid Hydrogen) tank. All AR6 tank domes have the same diameter of 5.4m and are made  of a leight-weight Aluminum-lithium alloy.


Additionally to booster cases all AR6 tank domes for the main stage and the upper stage will be assembled at MT Aerospace Augsburg. To keep the costs for the production of the domes low they all have the same diameter of 5.4m and can therefore be produced with the same tooling. Up to 11 Ariane 6 launches are planned per year. As 8 tank domes are needed for one Ariane 6 the annual demand could reach 88 domes allowing a series production of the domes.



The upper stage of the Ariane 6 model at the Odysseum in Cologne.  All four tank domes have the same diameter of 5.4m – the same as the domes of the main stage. The same tooling can be used to produce all 8 tank domes of an Ariane 6. All AR6 tank domes will be assembled in Augsburg.


MT Aerospace will not only produced booster cases and tank domes for Ariane 6. They will also produce the cylindrical tank sections between the domes. These sections for the upper stage will be combined with the domes made in Augsburg in the new MT Aerospace plant in Bremen. The assembled upper stage tanks will only need to be transported down the road to the Airbus/Ariane Group plant in the neighbourhood in Bremen for further integration.



Me in front of the new MT Aerospace factory in Bremen. The cylindrical tank sections of the AR6 upper stage will be produced here and connected to the tank domes. The tanks will be transported easily to the neighbouring Airbus/Ariane Group factory for integration of the entire upper stage.


And these are still not all components that MT Aerospace will produce for Ariane 6. There will be the Aft Bay Cylinder, that will contain the Vulcain main engine of the core stage and serve as connection point for the lower staps for attaching the boosters, too. Additionally, the LOX and LH2 tanks of upper stage and main stage will be connected by Inter Tank Structures made by MT-A.



This graphic by ESA shows in which country the single components of Ariane 6 will be produced. We have marked the contributions by MT-A in red. Note that the graphic may be outdated as it is from 2016.


Finally, the Rear Skirts and the Front Skirt Rings of the Ariane 6 Solid Rocket Motors SRM will also be produced by MT Aerospace in Augsburg. Now all components with a MT-A origin are listed in the hopefully case I have not forgotten anything.



The next gerenation is celebrating the Ariane 6 already as can be seen in this picture taken at the Odysseum in Cologne. Hopefully, Ariane 6 will become another story of success with a strong participation by German industry and institutions!


To conclude, we can state that MT Aerospace will be a main supplier of components for Ariane 6. Ariane 6 will be another ESA launcher that will have also German origins. We hope that we can contribute a little bit to make Ariane 6 more popular in Germany. As some of you know, I am a big fan of the Ariane 6 launcher: for my #MoonDot missions to the MoonDotStation missions I am always launching with a mini Ariane 6 as you can see in the following video:


Additionally, we have several other Ariane 6 models in different scale and with two or four boosters for different purposes.



Launch complex  for Ariane 6 Ariane as seen in an ESA animation. MT Aerospace ist also involved in constructing the real AR6 launch complex in Kourou. We hope to build a mini version of this launch complex with support by MT Aerospace and ESA.


Furthermore, we plan to construct a mini launch complex for one of our mini Ariane 6 launchers. A flame trench will be build, a service tower, lightning towers and a mobile gantry very similar to the real ones in Kourou. By coincedence, MT Aerospace is involved in the construction of the real launch complex in Kourou, too. I could tell you more about that now, but this report is long enough already I think. Another time …



Happily I am posing with some MT-A staff in front of models of Ariane 4 and 5. Many thanks for the warm welcome and the great hospitality!


Now we (my mission director @SpaceHolgar & yours truly) would like to thank MT Aerospace for the great opportunity of visiting the factory in Augsburg. We were highly impressed by all the information and insights about the production of Ariane 5 and 6 we were allowed to get. We had some fantastic tours in the different halls of the factory. Many thanks for the invitation for another visit after the production of components for Ariane 6 has started before the end of this year 2017. We would love to be back – anytime! 😉

Special thanks go the Mrs. Holsworth for enabling and organizing this great visit including the guided tours. Many thanks and some special greetings are send this way to Augsburg! Dankeschön!

Yours truly,


Teil 1: Booster segment production for Ariane 5

Teil 2: Tank domes and other things


My fantastic visit at MT Aerospace – a main supplier for components of ESA Ariane 5 & 6 launchers (Part II)

Link to German version/Deutschsprachige Version

In part I of my report I had the pleasure to show you how booster segments for the ESA launcher Ariane 5 are being produced by MT Aerospace in Augsburg, Germany. In part II I will talk about other main components for the Ariane 5 that are constructed in the same factory.


Cutaway model of an ESC-A Ariane 5 upper stage at MT-A (left image) and a real ESC-A upper stage at DLR in Lampoldshausen (right). MT-A is building the inner tank dome of the top LH2 tank.

Let me start with talking about dome structures for Ariane 5 tanks. MT Aerospace one of the leading companies that is producing large domes for the tanks of launchers. Thus, MT-A is producing and assembling most of the tank domes for Ariane 5.


The tiny me with my mission director @SpaceHolgar in front of an inner tank dome for a LH2 tank of an Ariane 5 ESC-A upper stage. It is made of a single piece of Aluminium.

For instance, the large inner dome of the LH2 (liquid hydrogen) tank of the ESC-A upper stage is produced here. It is made from a single piece of Aluminium and has a diameter of about 4 m. To reduce the weight of the tank dome large pieces of Aluminium are cutted via milling. A stable grid structure is remaining as can be seen in the image above.


Giant Ariane 5 core stage tank dome. It consists of 8 segments welded together giving the dome a diameter of impressive 5.4 m.

The tank domes for the main stage of Ariane 5 are assembled in Augsburg, too. The domes with a diameter of 5.4 m are significantly larger than the inner dome of the upper stage LH2 tank. Therefore they cannot be produced in one single piece but are assembled from 8 different segments. These 8 segments are welded together in a complicated and challenging process.


Transport canister for a dome of an Ariane 5 tank. The tank domes are transported in this canister on the road to factories of the Ariane Group in Bremen and Les Mureaux for assembling the entire tanks.  (Published with permission of M. Trovatello, ESA HQ).

The tanks of the Ariane 5 launcher are not assembled at MT Aerospace in Augsburg. The ESC-A upper stage is assembled in Bremen, the main stage tanks in Les Mureaux, France, both in facilities of the Ariane Group (formerly known as Airbus Safran launchers). Therefore the tank domes produced in Augsburg need to go on the road to these factory in special transport canisters. We were lucky to see some of these canisters. A photo of one of these canisters can be seen above. Note, that we needed to get a permission by ESA to publish this image as ESA is the owner of these special transport units.


I have spotted an SLS poster at the MT-A factory. For more info about this please read the report. 😉

To my surprise I had spotted a small poster of the future heavy launcher of NASA called SLS (Space Launch System) while touring MT Aerospace. The main contractor Boeing is building this giant launcher for NASA to enable spaceflight beyond LEO (Low Earth Orbit).

Some of you may remember that we use the giant SLS in my universe, too. It is the heavy lifter for my American friends to fly to the MoonDotStation. Here is a short video of a launch:


There is a huge scaled SLS launcher in usage in the Mausonautic Universe by my American friends to fly to our MoonDotStation. Note that MT Aerospace Augsburg is building dome tanks segments for the real SLS of NASA/Boeing.

Back to this universe: We learned that MT-A is a subcontractor and is providing dome segments for the tanks of the SLS main stage as well for the EUS upper stage. These tanks are gigantic in size and have a diameter of 8.4 m. If you want to know more about this topic please have a look here. Did I had the pleasure to spot such a SLS tank dome segment? Well, I am not permitted to deny or confirm this.  😉


Front skirt for an Ariane 5 core stage. Here are the forward attachment points for the boosters and the large parts of the avionics located. The upper stage will sit on top of the skirt.

Tank domes and boosters are important components for the Ariane 5 launcher. Nevertheless, additional components for the Ariane 5 are produced by MT Aerospace in Augsburg. One big component is the front skirt of the Ariane 5 core stage. This skirt is sitting atop the LOX (liquid oxygen) tank of the core stage and it connects the core stage with the upper stage. The nosecones of the booster are attached here. Additionally, large parts of the avionics for guiding the flight are located in this front skirt. Thus, this front skirt is a very crucial component of the Ariane 5. Almost all things come together here. 😉

Furthermore, some smaller components for the Ariane 5 are produced in Augsburg: small tanks for the core stage, thermal insulation for the boosters as well as the lower connecting ring for the boosters. You see that it is well justified to say that the staff at MT Aerospace Augsburg is building significant components for the ESA launcher Ariane 5. The staff at MT-A can be very proud of this accomplishment.

That is all I want to tell you about Ariane 5 and MT Aerospace. Part III will deal with the future: Ariane 6. Stay tuned for updates!

Yours truly,



Part I: Ariane 5 booster segments

Part III: Ariane 6 and MT Aerospace



My fantastic visit at MT Aerospace – a main supplier for components of ESA Ariane 5 & 6 launchers (Part I)

Link to German version/Deutschsprachige Version

Some time ago I had the great honour to take a look behind the scenes of one of the top aerospace companies in Europe: MT Aerospace in Augsburg, Germany. Until 2005 this company was belonging to the MAN group. Then the ownership changed to the OHB group and the new name MT Aerospace was introduced.


In front of the company MT Aerospace in Augsburg, Germany. You can see that some construction activities are going on. A new facility for producing parts for the new ESA launcher Ariane 6 is being built.

MT Aerospace is producing important components for the European and the international aerospace community.  One of their products are fuel tanks for satellite (see an example in the image below). Their main products are key components for the ESA launcher Ariane 5.  In the near future MT Aerospace will begin to built several important components for the new ESA launcher Ariane 6. A new production facility is under construction to enabling to Start to build Ariane 6 components before the end of this year. This is necesssary as the launch date for the very first Ariane 6 is fixed for July 2020!


1:1 test fuel tank of the ESA satellite Alphabus.

First let us go back to the current production activities at MT Aerospace – the production of components for the Ariane 5 launcher. The Ariane 5 launcher is the current heavy lift launcher of ESA and Arianespace and is well known for its reliability. The last 80 consecutive successful launches are a fabulous record! About 50 percent of all commercial communication satellites were launched with this launcher during recent years.  Additionally, Ariane 5 has lifted heavy ESA satellites like the 5 ATV cargo vessels going to the ISS. A relatively new task is to launch the European Galileo navigation satellites. Ariane 5 allows to launch four Galileo sats at once.  Another launch with four Galileos is planned for the end of this year.


An Ariane 5 model with some cuts revealing the components that are built by MT Aerospace.

Which components for the Ariane 5 launcher are produced at the factory in Augsburg? There are the steel segments for the solid rocket boosters. The boosters are about 30 m tall and cannot be produced in a single piece. Therefore a booster is compromised to consist of three different units. We had the honour to tour the entire production facility for the booster units and were even allowed to take some pictures. So please join me for a tour through this air-conditioned facility!


Several booster segments in different states inside the booster segment production facility of MT Aerospace.

The booster segments are made from steel tubes with a wall thickness of several centimeters. After some prepatory work these rings are being pressed into the correct shape for a booster segment. The wall thickness is reduced to about 8 mm. The diameter of the segments is finally 3.05 meters. For reaching this a very big machine is necessary: a counter roller flow former. This machine exerts forces of several hundred tons from both sides of the steel wall! That is enormous!


The gigantic counter roller flow former is pressing the steel rings into the perfect shape. With a force of several hundred tons the wall thickness of a few centimeters of the segments is reduced to 8 mm.

The entire cylindrical part of an Ariane 5 booster case consists of 7 segments. 2 x 3 segments are welded together here at the factory in Augsburg. They form the lower and the central part of the booster case. The upper part is a single segment. The lower and the upper part have end domes with openings for the noozle or the igniter.


Several finished booster segments and two end domes for the lower booster case.

The edges of the booster segments need special treatment before they are ready for welding. A giant turning lathe is been used for this. The entire booster segment is rotating while the processing is going on. I was allowed to take a short video of this process:


The next step is to weld three booster segments together. A special welding method is been used here: electron beam welding. Two three-piece units and a single-piece unit form the entire cylindrical part of the case for an Ariane 5 booster.


A finished lower booster case unit consisting of three pieces welded together. At the lower you can see a metallic ring with several drilling holes. Here the central booster case unit will be connected with a few hundred bolts.



The surface of the booster segments is been coated with several layers of anti-corrosion material. Now the booster segments have the typical white look that you see during the launch campaigns in Kourou. The European spaceport Kourou is also the location were the three case units forming a booster are being connected after filling them with the solid propellant. This connection is done with a special flange at the egdes of the booster case units. This flange is been produced here in the Augsburg factory. How does such a flange connection work? You can see an example for such a connection in the image below.


Cut through a flange connection between case units of an Ariane 5 booster. Holes for the connecting bolts are missing. You can recognize two spaces for some special sealing rings. Some of you may know that the Solid Rocket Boosters of the Space Shuttle had similar sealing rings called „O rings“.

The flange connection is been fixed with a few hundred bolts. Holes for these bolts are being drilled here in the Augsburg factory. This is a very sensitive process. After drilling each single hole the exact location of the hole is determined. The measured location influences where the next hole will be drilled. This is to make sure that the case units can be connected with the bolts without using any heavy force.


Transportation container for a long Ariane 5 booster case unit. (Published with permission by M. Trovatello/ESA HQ. Thank you, Marco !)

Finally, the finished three different booster case units are being transported on the road to Italy via a heavy goods transport. In Italy internal insulation material and other components are added before the booster units are shipped to Kourou.

With this I finish the first part of my report. Two additional parts will be published soon.

Yours truly,



Part II: Tank domes and other things

Part III: Ariane 6 and MT Aerospace




Ein Blick hinter die Kulissen von MT Aerospace in Augsburg (Teil 1)

Link to English version/Englischsprachige Version

Vor kurzem hatte ich die außerordentlich große Ehre hinter die Kulissen des Luft-und Raumfahrttechnologieunternehmens MT Aerospace in Augsburg schauen zu dürfen. Einige mögen MT Aerospace noch als Teil vom MAN-Konzern kennen, seit 2005 gehört der Betrieb allerdings zur OHB-Gruppe und nennt sich seither MT Aerospace.


Vor dem MT-Aerospace-Werk in Augsburg. Mit dem Baukran wird eine neue Fertigungshalle für Teile der Ariane-6-Rakete der ESA gebaut.

Dort in Augsburg werden neben Treibstofftanks für Satelliten (siehe auch Bild unterhalb) hauptsächlich diverse Teile für die Ariane-5-Trägerrakete der europäischen Weltraumbehörde ESA gebaut. Und in naher Zukunft wird dort auch die Produktion von Teilen für die neue Ariane-6-Rakete der ESA beginnen. Darum wird auch viel am Standort gebaut. Schon am Ende des Jahres soll die Herstellung von Ariane-6-Teilen beginnen können, denn die Ariane-6 soll bekanntlich schon im Juli 2020 zum ersten Mal starten.


1:1-Testmodell für einen Tank des Alphabus-Satelliten der ESA.

Aber zurück zur Gegenwart – der Produktion von Teilen für die Ariane-5. Die Ariane-5 ist der gegenwärtige Schwerlastrakete der ESA und zeichnet sich durch seine besondere Zuverlässigkeit aus. Die vergangenen 80 Starts waren alle 100% erfolgreich – ein unglaublicher Rekord! So wurden neben vielen kommerziellen Kommunikationssatelliten auch die 5 ATV-Transportraumschiffe der ESA zur Internationalen Raumstation ISS gestartet oder im vergangenen Jahr auch gleich vier Galileo-Navigationssatelliten auf einmal.


Dieses Ariane-5-Modell zeigt die wichtigsten Teile für diese ESA-Trägerrakete welche in Augsburg gebaut werden: Boostergehäuse und Tankdome für die Hauptstufe und den Flüssigwasserstofftank der ESC-A-Oberstufe.

Doch welche Teile für die Ariane-5 werden denn nun genau in Augsburg hergestellt? Fangen wir mal mit den Stahlsegmenten für die zwei riesigen 30-Meter hohen Feststoffbooster der Ariane-5 an. So ein Booster wird aus 3 Einheiten zusammengesetzt. Und wie diese hier in Augsburg hergestellt werden durften wir uns anschauen und auch einige Fotos anfertigen. Also hereinspaziert in die riesige klimatisierte Fertigungshalle für die Boostersegmente!


In der riesigen Boosterfertigungshalle von MT Aerospace sieht man diverse Boostersegmente in verschiedenen Fertigungszuständen.

MT Aerospace erhält dafür recht unscheinbare Stahlringe mit einer Wandstärke von einigen Zentimetern. Nach einiger Vorbehandlung werden diese Ringe in die richtige Form für ein Boostersegment gepresst. Bei einem Durchmesser von 3,05 Metern haben die Boostersegmente dann nur noch eine Wandstärke von 8 Millimetern. Um dies zu erreichen benötigt man eine sehr spezielle Maschine. In dieser Gegenrollendruckwalzanlage werden Kräfte von mehreren Hunderten Tonnen auf das Stahlsegment ausgeübt! Wau! Da steht ja nicht ohne Grund „Vorsicht Quetschgefahr“ auf der Anlage! 😉


Die Gegenrollendruckwalzanlage: hier werden die einfachen Stahlringe in die perfekte Form für ein Boostersegmentelement gebracht. Die mehrere Zentimeter dicken Ringe werden werden dabei mit einer Druckkraft von mehreren Hunderten Tonnen auf 8 Millimeter Wandstärke zusammengepresst.

Der zylindrische Teil der Ariane-5-Boosterhüllen besteht aus insgesamt 7 einzelnen Segmenten. Mit einem speziellen Schweißverfahren werden jeweils 3 Segmente zu einer längeren Einheit verbunden: zur unteren bzw. mittleren Boostereinheit. Das einzelne verbleibende Segment bildet den oberen Teil der Boosterhüllen zusammen mit einer Verschlußeinheit.


Einige fertiggewalzte Boostersegmente. in der Mitte sieht man zwei Endstücke für die Boosterhüllen.

Die Enden der Boostersegmente müssen zum Verschweißen speziell bearbeitet werden. Dazu gibt es eine riesige Drehbank, auf der die gesamten Boostersegmente zur Bearbeitung rotieren. Hier ist ein kurzes Video von so einem Bearbeitungsvorgang:


Hier wird ein Ende eines Boostersegmentes auf einer riesigen Drehbank bearbeitet.

Nach dieser Bearbeitung kann man die Segmente dann zu Einheiten verschweißen – mit der speziellen Methode des Elektronenstrahlschweißens.  Zwei lange und eine kurze Einheit bilden dann die Hülle eines Ariane-5-Boosters.


Fertiggestellte lange untere Ariane-5-Boostereinheit. Man erkennt gut die vielen Bohrungen für die Bolzenverbindungen mit der nächsten mittleren Boostereinheit. Diese Einheit steht folglich auf dem Kopf.

Die Oberfläche der Boosterhülleneinheiten wird dann noch beschichtet um sie vor Korrosion zu schützen. Die 3 Einheiten eines Boosters werden nicht hier in Augsburg verbunden, sondern erst am Startort in Kourou. Denn dort werden sie auch erst mit dem ebenfalls segmentierten Feststofftreibstoff befüllt und können danach verbunden werden. Auf dieses Verbinden bereitet man die Boostersegmente allerdings in Augsburg vor. Eine Flanschverbindung wie im unteren Bild zu sehen ist Teil der Konstruktion.


Schnitt durch die mechanische Flanschverbindung von zwei Boosterhülleneinheiten. Man erkennt deutlich die zwei Räume für Dichtungsringe – auch bekannt als „O-Ringe“ der Verbindungen von Shuttle-Boostersegmenten.

Diese Flanschverbindung wird dann mit Hunderten von Bolzen fixiert. Die Bohrungen für die Bolzenverbindungen erfolgen in Augsburg. Das ist ein sehr aufwendiger Prozess da nach jeder einzelnen Bohrung nachgemessen muß um kleinste Abweichungen feststellen zu können. Diese auch noch so kleinen Abweichungen müssen dann bei der nächsten Bohrung berücksichtigt werden damit beim Verbinden auch alle Bolzen perfekt passen.


Transportbehälter für lange Ariane-5-Boosterhüllensegmente (veröffentlicht mit freundlicher Genehmigung von M. Trovatello/ESA HQ).

Die drei verschiedenen Boostereinheiten werden nach erst per Schwertransport auf der Straße nach Italien und dann per Schiff zum Startort in Kourou gebracht.

Soviel erst einmal für heute. Zwei weitere Teile folgen demnächst.

Euer Mausonaut


Teil 2: Tankdome und mehr

Teil 3: Ariane 6 und MT Aerospace




Mission #4 to MoonDotStation – on the way to orbiting the Moon

Version in German
It is about time for me to launch into space again. Another time I will launch to my MoonDotStation currently in an orbit around Lagrange point 1 of the Earth-Moon system.

The MoonDotStation in its current configuration: ATV-like core module (right), node module „Friendship“ with cupola and airlock (center) & a Cygnus cargo ship (top). To the left you can see an Orion spaceship undocking from the station. The Orion with two American friends on-board was the last ship to leave the station.

My main task during the MoonDot mission will be to prepare the new APP (Advanced Power & Propulsion) module for operations as an integral part of the MoonDotStation. The APP has two big Solar panels. They are huge, really huge! The generated power will help to supply the station. More important, the electric power will be used for the 8 Hall ion thrusters of the module. The entire MoonDotStation complex will be relocated to an orbit around the Moon with the help of this Solar-electric ion propulsion system. An orbit around the Moon is more suitable for the station than the EML-1 orbit – if you want to go from the station with a Lunar lander to the Moon as we want to do. That is an important step for our plan to build a small international village on the Moon – a MoonDotVillage !

The APP module with the two HUGE Solar panels before launch. The module will arrive at MoonDotStation during my stay at the station. In the image to the right you can see the APP  module mounted at the top of the mini #Ariane62 launcher before incapsulation in the payload fairing.


The APP module was launched on February 14, 2017, with a mini #Ariane6 launcher equipped with two solid rocket boosters. The initial orbit of the APP module was an highly elliptical Earth orbit. The ion propulsion system of APPM is being used to stretch the elliptical orbit even more until the gravity of the Moon is pulling the module towards the Moon. When this will happen the APP module will perform a maneuver sideways to get into an orbit around the Lagrange point #1 between Earth and Moon. Afterwards APPM will slowly close in to MoonDotStation.

I will be on-board of the station when the APP module is arriving. My task will be to grapple the module with the help of the mini CanadArm and to latch it to the station.

During my 4th MoonDot-Mission to the MoonDotStation I will have to fulfill these main tasks:

  • NEW: Approaching the APP module for a visual inspection for damage
  • Loading of the Cygnus cargo ship with trash
  • Unmate and release the Cygnus
  • Capture  and mate the APP module to the MoonDotStation
  • Assist the docking of the Dragon-2 cargo ship
  • perform a spacewalk for refuelling the Xenon tanks of the APP module

This challenging MoonDot mission will last at least three weeks – in the case that all is going as planned. You never know what really will happen. You all know what is being said about space: „Space is hard“!

In the following I will list all highlights of the mission after they have happened. Please check from time to time for updates!

Launch attempt #1: March 23, 2017


Woohoo! Finally I successfully launched to my new mission. The launch attempt was almost scrubbed due to violation of weather constraints for launching. There were some strong gusts violating the weather constraints. Fortunately the gusts were becoming very infrequent at the end of the launch window. Thus the launch director was able to sign a waiver for the wind gust rule.  Signals were going to green:


The countdown resumed. The service tower of the launch pad was retracted after a final check of the ignition system:

Finally, at 4:42 pm UTC my journey to MoonDotStation begun with the roaring launch of my mini version of the Ariane 6 launcher.


Liftoff of the mouse-rated mini version of the ESA launcher Ariane 6. I am sitting in the small brownish #MoonDot capsule at the top of the launcher.

Ariane 6 will be the new launcher of the European Space Agency ESA optimized for low launch costs. More information about the Ariane 6 can be found here.

All remaining phases of the launch all went very well – similar to what can be seen in this Ariane 6 launch animation by ESA:

At 7:24 pm UTC I was able to report a successful TransLunar Injection (TLI) maneuver. I was on the way to visit MoonDotStation.

Please check back later for updates including replays of my stunning launch like the following one. Thank U.





That is a lot of smoke and fire, right? Therefore we plan to develop a flame trench for this mini Ariane 6 launcher. Actually, we want to build an entire mini launch complex. I am sure the kids will enjoy that complex!

Are you interested how these stunning mini launchers are constructed? If yes please go to Twitter and look for the hashtag #htbAR6. You will find a sequence of tweets showing the construction of this particular Ariane 6 model. Enjoy! And if you have questions please ask me or my mission director @SpaceHolgar ! Thank you.

Mission day #2 March 24, 2017: The flight plan is changing

Under the original flight plan an inspection of the exterior of my MoonDot spaceship with help of a mini satellite was foreseen for this day. But this plan was dropped as a course correction was ordered by mission control. The new first destination of this mission is now the APP module already launched back on February 14, 2017.

The APP module is on a slow trajectory to MoonDotStation. It has a powerful ion propulsion unit that will allow to relocate the entire MoonDotStation after docking with the APPM to an orbit around the Moon. That assumes that the huge Solar panels of the APPM deliver full power to the ion thrusters.


Here you can see the 8 Hall ion thrusters of the APP module during preparations for launch. They will need the full power levels generated by the two Solar panels of the module to move the entire MoonDotStation from the current orbit around Lagrange point 1 of the Earth-Moon system to a Lunar orbit.

Last week something happened to the APP module. For a short while contact was lost. After contact was resumed the power level generated by one of the Solar panel was 20 percent lower than expected. It is not understood if the panel itself is damaged or the electronics for control. That is why I was ordered to change the course to go to the APP module asap to do a visual inspection. If I can determine what exactly happened to the module there may be one way to repair the APP module, hopefully during this mission. Let us keep the fingers crossed that we will find a quick solution to avoid longer delays for going to Moon orbit.

Mission day #3 March 25, 2017: Inspecting the exterior of the MoonDot spaceship

This day of the mission was a relatively relaxed one in the middle of the cruise towards the APP module. My main task was to release a small satellite equipped with a camera to take pictures from the exterior of my #MoonDot spaceship.


My #MoonDot spaceship as seen by the mini satellite. For more information about my ship please have a look here.

With help of these pictures we are looking for anomalies of the systems of the ship. Additionally,  the exercise is a good first test for the camera satellite as we want to take many more stunning pictures during the entire mission with it.


This is the fifth time (and the final time according to current plans!?) that I have the pleasure to fly this kind of spaceship. For this mission we have made an important upgrade to the ship. I will tell you more about it later during the mission.


After finishing the imaging session I commanded the mini satellite back to the Service Module of my ship. The satellite was fixed to the module with help of magnets as we do not want to loose the satellite during any course correction maneuvers.

By the way, we did not find any damage to the exterior of my spaceship. 🙂

Mission day #4 March 26, 2017: Breaking into an orbit around the EML-1 Lagrange point and approaching the APP module

This was a very exciting day as I was able to take a first look at the APP module in space. But first I had to perform a maneuver with my #MoonDot spaceship to break into an orbit around the Lagrange point 1 of the Earth-Moon system (EML-1). The APP module is already in this kind of orbit.


My (simplified) flight path from Earth into the direction of the Moon and then sideways into a wide orbit around Lagrange point L1 of the Earth-Moon system.

Let me explain what such a Langrange actually is. It is a point in space where the gravitational forces of the planets, moons and stars cancel each other out. You can put a satellite at this point and it would keep its position. Such a Lagrange point does exist between Earth and Moon in a distance of about 55,000 km to the Moon. Actually, you are not putting a satellite directly at a Lagrange point but in a wide orbit around it. This is to avoid the shadows by Earth and Moon to allow power to be generated by Solar panels without interruptions.


The OME main engine used for breaking into an EML-1 orbit is located at the base end of the European Service Module ESM.

The first task of this day was to bring my #MoonDot spaceship into such an orbit around the EML-1 point in vicinity to the APP modul. For this I had to stop my spaceship from moving towards the Moon and then go a bit sideways into the desired EML-1 orbit. To achieve this I had to ignite the OME main engine of my European Service Module for 33 seconds. Interestingly, the OME engine was once an OMS engine of one the now retired Space Shuttle orbiters.


One of the few pictures of the APP module taken through the thick windows of my #MoonDot capsule. No damage to APPM is visible.

After the successful breaking into this EML-1 orbit the APP module was already relatively nearby. After a few minor maneuvers I was able to take a few first pictures of the troubled module. The pictures had quite poor quality as I was taking these through the very thick windows of my #MoonDot capsule from a safe distance. I did not see any damage to the APP module in these pictures. Nevertheless, one of the Solar panels of APPM is still generating less power than the other one. Mission control agreed to my idea to release the mini camera satellite for a close inspection. As we were running out of time (due to the not so funny 23 hour day as we were switching to Summer time 😦 ) this task is now planned for tomorrow.

Mission day #5 March 27, 2017: Close inspection of the APP module with the mini satellite 

This was the day for identifying the root cause for the drop in electricity generated by one of the two gigantic Solar panels of the APP module. To achieve this I had released the mini satellite equipped with a camera for flying around the APP module.


The camera satellite on the way to inspect the APP module.

The mini satellite took several pictures of the APP module covering all sides of the module. Here are some pictures of APPM for example:


After an analysis of HR versions of the pictures we detected 5 (!) holes in the defect Solar panel of APPM. It looks like the module had an encounter with a swarm of micrometeorites or space debris.


Five holes were identified in the defect Solar panel of APPM.

Now we have the very bold plan to replace the entire defect Solar panel during this mission at the MoonDotStation.


The mini Dragon 2 cargo ship (picture taken before the launch of my mission) will deliver a replacement Solar panel to MoonDotStation, and hopefully some cheese, too. 😉

We will have to fit a replacement Solar panel into a mini Dragon 2 cargo ship and then launch the ship with a mini Falcon 9 launcher. After arrival of the Dragon ship at MoonDotStation I will conduct a risky spacewalk to replace the bad Solar panel with the new one delivered by the Dragon. Let us keep the fingers crossed that we will be successful with this very challenging plan.

Mission day #6 March 28, 2017: Arrival at MoonDotstation

This was the day I was waiting for quite a while already. After more than 7 months I had the task to return to MoonDotStation. A complicated docking maneuver was lying ahead of me. This was my fourth docking at MoonDotStation already, but no docking is the same. The MoonDotStation had grown a bit and its configuration was different. This time I had to dock my ship to a side port of the node module „Friendship“ for the very first time.


My MoonDot spaceship during the docking approach as seen by the free flying mini satellite.


Additionally, I had to fly a very fuel saving docking maneuver because I had spent a lot of fuel during the inspection of the APP module already. That is why my approach was looking a bit strange coming sideways until I reached the final stop point for checking all systems of ship and station.


Finally, at 5:03 pm UTC the docking ring of my #MoonDot spaceship had first contact with the docking port of the station. Hooks were tightening the connection. Then I had to check if the connection was airtight and also linked some electrical and data connections between ship and station.


For this I had switched on a very special blue light in my MoonDot spaceship. Especially readers from Germany might have an idea what kind of light it is. 😉



My first stop at MoonDotStation: Enjoying the stars from the Cupola

After finishing the 2-hour checking process I finally entered the MoonDotStation. My first stop was in the Cupola to enjoy the billons of stars for a first time. Next, I was moving to the core module of the station where the main computer of the station was already waiting to take the official ingress photo. Here it is:


Woohoo! It is great to be back at the station! And in the next update I will tell you more about these boxes in the photo.

Mission day #7 March 29, 2017: The first day at MoonDotStation

This was a very busy, but not so exciting day. Basically, I had to move several bags with things not needed anymore from the interior of the station to the Cygnus cargo ship.


Most of these things to relocate are equipment and other stuff used by the previous crew – my two friends from America called Astros K. & S. For some reason they do not want to reveal their identity. They were spending record-breaking 6 months here at MoonDotStation leaving at the end of January 2017.


The Astros K. and S. and me on-board of the MoonDotstation in August 2016 during my third stay at the station. The Astros stayed on-board for 6(!) more months.

The Cygnus loaded with the unnecessary things the Astros left behind is expected to leave the station on Thursday.


Another important item on my agenda of the day was to greet some friends – the international organization „The Mars Generation“. By the way, you can join „The Mars Generation“ as a founding member. This is a perfect way to support space themed STEM education. Have a look here: Thank you.

Mission day #8 March 30, 2017: Departure of the Cygnus cargo ship

On this day the 5 month mission of this mini Cygnus cargo vehicle was coming to a successful end. The Cygnus had been launched on a mini Atlas 541 launcher in the end of October 2016. This „541“ actually explains the configuration of the Atlas launcher been used. „5“ means that a 5 (Mausonautic) meter diameter payload fairing is used. „4“ tells that 4 solid rocket boosters are firing during launch. Finally, „1“ explains that the upper stage has one engine (and not two).


Launch of the mini Cygnus cargo ship to MoonDotStation – by a mini Atlas V 541 launcher – in October 2016.

You may ask why such a powerful booster is necessary to launch a Cygnus ship as the Atlas rockets used to launch Cygnus vehicles to the ISS did not had any boosters. Well, for launching a Cygnus to the MoonDotStation in about 325,000 km distance from Earth towards the Moon instead of a 400 km Low Earth Orbit (LEO) it is obvious that you need a much more powerful launcher.

The cargo of the Cygnus ship was very critical for the extension of the mission of my American friends Astros K. & S. to a total duration of breathtaking 6 months. The ship served that purpose very well. And now it serves an additional purpose. Unnecessary things will be removed from the tiny station to make room for new things.


I was controlling the mini CanadArm of MoonDotStation to release the mini Cygnus cargo vessel.

The Cygnus is not designed to depart from the station by itself. We have the small manipulator from Canada called CanadArm 3 to release the Cygnus. I was controlling this arm from inside the Cupola as you have the best overview about the scene from here. I was grappling the grapple fixture of the Cygnus with the end effector of the CanadArm before I commanded the hooks of the station to set the Cygnus free. Slowly I was moving the Cygnus away from the station to the release position. The Cygnus was staying in that position for a while adopt to the new thermal conditions.


The next step was to release Cygnus by carefully retracting the CanadArm from it. After a while the cold gas thrusters of the mini Cygnus fired to make the Cygnus back away slowly from the station. The distance between station and Cygnus was increasing more and more. For a while I was thinking that I had seen a mysterious object in space but there was nothing at the radar. And the Cygnus was disappearing in the wide open space …

Eventually, the mini Cygnus will enter a wide orbit around the Moon for its final sleep. There was not enough fuel left for a controlled return to an Earth orbit.


The Cygnus cargo ship was disappearing into the wide open space.

And now, without the Cygnus, we have more space for the risky capture of the incoming large APP module.

Mission day #9 March 31, 2017: Arrival of the APP module – the transfer stage to Moon orbit

Finally, the day of the arrival of the APP (Advanced Power & Propulsion) module at MoonDotStation had come. Due to the low thrust of the Solarelectric propulsion system the APP module was only following my spaceship slowly on the way to MoonDotStation after the inspection on March 26./27. Towing the APPM to MoonDotStation was not possible as too much fuel of my spaceship had to be spent for that maneuver. And I need enough fuel for my spaceship to return to Earth. Therefore, the APPM and my spaceship had to fly on separate trajectories to MoonDotStation.


The APP module during the approach maneuver as seen from the Cupola.

The arrival of the APP module was a lot of hard work for me anyway. The APP module is quite huge mainly due the two gigantic Solar panels. This was causing some challenges during the capturing process. The APP module was not flying a direct approach to the connection point with the node module to minimize the risk that the Solar panels of APPM and my spaceship were getting into contact during the approach maneuver.


The APP module (left) is approaching MoonDotStation.

I was surveying the APPM approach from the Cupola of MoonDotStation. You have a nice overview of the situation from the Cupola. Thus, I was taking over the control of the APP module during the final approach. For being able to capture the APP module with the mini CanadArm the APP had to be maneuvered very close to the node module – about one meter. That was the moment with the highest risk for collision. But I was successfully able to stop the approach right on time. Now the APPM was keeping the distance to MoonDotStation automatically. With one eye I was checking the distance, and the second one was needed to operate the CanadArm. I had to capture the APPM asap to end this high risk phase. And I was succeeding with the first try to capture the APPM by the CanadArm – yeah! What a maneuver- what a relief! From now on the CanadArm was keeping the APPM away from the station in that hold position. The module was staying in that position for about two hours to allow that any tensions that had been built up in the CanadArm during the capturing process could being released.


The moment of capturing the APP module by the CanadArm. You can see the short distance between APPM and node module during that maneuver.

Next was to maneuver the APPM to the connection point with the node module of the station. With help of the Canadarm that is an relatively easy operation. After the contact between the docking rings of both modules some hooks were engaging to get an hard mate. Now the APP module was finally part of MoonDotStation. What a great success!


Timelapse of the multi hour APP module capturing maneuver …


… finally the APP module was mated to the „Friendship“ module of the station.

As almost always, the mini camera satellite had been released for free flight during this operation delivering stunning images for me and for YOU. I have created a short timelapse movie of the entire operation for you. Enjoy!

Mission day #10/#11 April 1 & 2, 2017: Weekend at MoonDotStation

The weekends here at MoonDotStation are a bit organized as the ones at the International Space Station ISS. Saturday is the day for cleaning the entire station with wet towels and a vacuum cleaner. Sunday is reserved for leasure time. You write your blog posts, write emails, watch movies or connect with your friends and family.


This time the weekend was a bit different as there was a „cheese crisis“. The next cargo ship with destination MoonDotStation is being prepared for launch. Our American partners have bought a Dragon-2 cargo ship from the company SpaceX commercially as well as the launch by a Falcon-9 launcher. Now there was a challenge to integrate additional cargo to that flight: a Solar panel as a replacement for the defect one of the APP module. Fortunately, the launch processing crew had found a way to stow the Solar panel in the trunk of the cargo Dragon ship. Unfortunately, now the cargo ship is to heavy for launch. Some other payloads need to be removed. Somehow an important item was removed from the list of payloads: my three cheese wheels! That is how the „cheese crisis“ has started.


View into the trunk of the cargo Dragon: the Solar panel can be seen mounted at the lower sidewall of the trunk. The two black tanks contain Xenon for resplenishing the tanks of the APP module. Remember that Xenon is the fuel for the ion thrusters of the APPM. The two guys in the orange suits are my American friends called „Astros K & S“.

Thus, I was brainstorming over the weekend where mass can be shelved from the launcher, the ship or the payload. The mini Falcon 9 launcher does not have landing legs or any other landing equipment. Thus, no mass can be saved. The Dragon-2 cargo ship is a leightweight version already. The landing legs of the capsule were removed as the capsule will not land anywhere as there is not fuel to fly back to Earth or to the Moon. The capsule is equipped with a heatshield. Most parts of the heatshield are also part of the aerodynamic shape of the vehicle during launch and therefore cannot be removed. But the central heatshield tiles at the bottom of the capsule can be removed! Bingo! That is the solution! Thus based on my hint these parts of the heatshield were removed from the Dragon capsule. This actually ended the „cheese crisis“ as now one cheese wheel is back in the Dragon! There is (almost) always a solution for any challenge!


The end of the „cheese crisis“: a single cheese wheel before loading into the cargo Dragon.

P.S.: Please do not spread the news to SpaceX engineers how we have solved the „cheese crisis“. They probably do not like our solution to unmount parts of the heatshield of the Dragon. 😉

Mission day #12 April 3: Starting to prepare an exciting week with a Falcon 9 launch, spacewalk & the docking of the Dragon 2 cargo ship

One day before the launch of the mini Falcon 9 a final dress rehearsal was held at the launch site in Spain. Almost all procedures and processes leading to a launch were practized with the real hardware. The rehearsal was led by launch (and my mission) director @SpaceHolgar.


Launch director @SpaceHolgar with the mini Falcon 9 launcher during the dress rehearsal. He used the opportunity to send greetings to our friends of the „Mars Generation“.

I was following the dress rehearsal for the launch from MoonDotStation and was reliefed that all went smoothly. The launch was set for the next day.


The stars as seen from the Cupola of MoonDotStation – by my camera. The reality looks much better and is really mindblowing.

In the evening I used the opportunity to start taking pictures of the sky as seen from inside of the Cupola of MoonDotStation. Well, these were my firsts tries. The results were OK at best. I will try to improve my skills when I will have the opportunity again. Nevertheless, I think that the photos will never do justice to what you can really see with your own eyes.

And I hope that I can count one more star tomorrow, the launched Dragon 2 cargo ship. 😉

Mission day #13 April 4: Launch of the Dragon cargo ship with the mini Falcon 9

The day of launching the Dragon 2 ship with important cargo for MoonDotStation had finally begun. The replacement Solar panel and additional Xenon for the ion thrusterns of the APP module, water and food (especially my cheese) were sitting at the launch pad inside the Dragon ship waiting for liftoff.


My friends Astros K and S posing in front of the mini Falcon 9 launcher just minutes before the launch.

My friends Astros K. and S. were visiting the launch. That was well deserved as they had contributed a lot to fasten the prelaunch processing of the Dragon ship and the Falcon 9 launcher.


The weather conditions were perfect at the launch site in Spain. There were no technical issues during the countdown. Thus, the mini Falcon 9 launcher was lifting off with loud roaring right at the beginning of the launch window at 3:13 pm UTC. All 9 first stage motors were working as expected as well as the single upper stage motor. Now the Dragon ship was right on a trajectory to MonDotStation. GREAT WORK!

I was watching and commenting the launch from MoonDotStation. That was great but any launch that you do not watch live in person is a missed opportunity because space launches are AWESOME IMHO. 😉

Several hours after the launch I got a bunch of very impressive photos sent up to MoonDotstation. I would like to share the most impressive ones with you. Here is the corresponding image gallery. Enjoy!


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Mission day #14 April 5: Preparations for the first spacewalk

During this day I had to finish the final preparations for the first planned spacewalk on the following day. I was collecting all tools needed and some additional things. Among these things was the name plate for the „Friendship“ module. The module had the fancy name MPEM (Multi Purpose Exploration Module) when it was arriving at MoonDotStation during my last MoonDot mission. During my mission I made the call to my Twitter friends for proposing a new name. Many proposals were sent in. After a preselection of names a voting contest by the Twitter fans selected the great name „Friendship“ for the MPEM module. Many thanks to all contributors.


The „Friendship“ nameplate for the module formerly known as MPEM.

And now it is my task and honour to mount the „Friendship“ nameplate at the exterior of the module during my spacewalk.

Mounting the name plate will not be the main task of the spacewalk. The main task will be devoted to a different device. And this huge device I had to unwrap in the capsule of my MoonDot spaceship. That was quite a task. And tomorrow I will mount it at the exterior of the APP module you will see.

Mission day #15 April 6: The first spacewalk of this mission

This was my longest spacewalk I have performed so far with an duration of almost 4 hours. After leaving the Airlock me and an adpater were moved with the help of the CanadArm to the first worksite at the APP module. My task was to mount the adapter. That was complicated as I had to link several connections for power, data and cold gas. It took me more than 30 minutes to finish the task.


Egress from the airlock of the station.

My next job was to extract the still secret device from my MoonDot capsule. That was complicated as the device was quite large. It was actually impossible to move the device through the station as several hatches were too small for it. Therefore I had to extract the device directly from my MoonDot capsule with the big squared hatch.


Going to the next worksite with help of the CanadArm.

Now it was time to reveal what the device actually is: a supercool jet pack for me. We call it the Moused Maneuvering Unit MMU. It is a backpack with several nitrogen thrusters that I can control by my voice! It is like flying your own small spaceship. Sounds like fun? It really is I can confirm. My task was to test the MMU by doing a flyaround of the station. It was going very well and I decided to include some complications like flying through two Solar panels and flying in larger distance to the station. What a great job I have! I really enjoyed this task very much.


Testing the new jet pack by flying around the entire station.

Next was the installation of the „Friendship“ nameplate after retrieving it from the airlock. This job I was also performing with the jet pack. To use the CanadArm would have been an alternative.


With the „Friendship“ nameplate in my hand before mounting it at the node module.

My final task for this spacewalk was next: storing the MMU by connecting it to the adapter I had mounted at the APP module as my first task today. Remember that the MMU does not fit through the hatch of the airlock. The operation went very smoothly.

A very successful spacewalk was coming to an end with a duration of almost 4 hours. That was my longest and best EVA so far. Great that I will have another one later in the mission.

The mission report is continued with part II:

Live coverage via:

The tweets of the entire mission are connected as conversations. One conversion is in German only, the other one in English. This allows to see the entire mission on Twitter.

And here is the tweet that is the start of the mission! If go to this tweet on twitter (almost) all other tweets of the mission are connected and you can see all the details of the mission.

Live coverage in English only: