EXOLAUNCH TestPod EXOpod User Manual
- June 3, 2024
- EXOLAUNCH
Table of Contents
EXOLAUNCH TestPod EXOpod
Introduction
Purpose
This User Guide describes the features of the Exolaunch TestPod and defines
the interface requirements for the Cubesat for developers, who are utilizing
the TestPod for mechanical testing, fit-check purposes or shipping. The tested
is designed and based on Exolaunch’s EXOpod Cubesat Deployer and complies with
the Cubesat Design Specification Rev. 14.
Quality Assurance
Quality assurance for the Exolaunch TestPod is ensured at every step of
production. The entire production process fulfils the highest quality
assurance requirements. The facilities which manufacture Exolaunch products
such as the TestPod are certified with ISO 9001:2015 standard, which requires
regular inspection of the manufacturing and assembly facilities and ensures
stable quality of the final product.
Applicability
This document is applicable until it is canceled or replaced by another issue.
This User Guide is a living document open for all corrections and amendments
which occur in the lifetime of the tested.
Exolaunch TestPod
Introduction
The Exolaunch TestPod has been developed to facilitate the mechanical testing
of Cubesats. It allows performing the full mechanical qualification of a
Cubesat inside the tested. The TestPod can be easily mounted on a shaker table
or other testing devices and creates a realistic environment, with all
mechanical interfaces being the sameas in the EXOpod deployer that is used
during an actual launch. This has the additional benefit of enabling the
tested to perform Cubesat fit-checks and also allow a Cubesat to be shipped
safely in a tested if required. The system offers both a combination of the
highest reliability and user-friendliness. This document describes the family
of TestPods suitable for Cubesats from 1U to 16U, Exolaunch has detailed
documentation on each of the different TestPod sizes that it offers, which is
available upon request.
Components and Features
The main components of the 3U, 8U and 16U TestPods are shown in Figure 2. It
features
- A clamping mechanism
- Set screws
- Access windows
- A rigid chassis
- Several mounting interfaces
Sizing Features
Using adapters, it is possible to fit smaller Cubesats inside a larger
TestPod. Typically, this involves a Cubesat going to the next sized up
TestPod, for example a 1U CubeSat or 2U Cubesat using a 2U or 1U adapter
inside a 3U TestPod. These adapters are standard U sizes but can be customized
if the Cubesat is uniquely sized. The adapters are inserted into the TestPod
before the Cubesat is integrated.
Clamping Mechanism
The clamping mechanism pushes several clamping feet along the TestPod’s rails
inwards when the door is closed. This compensates for any tolerance gaps that
may exist between the tested and the Cubesat in the lateral directions. The
Cubesat is held in place safely and unwanted movement is prevented. The same
clamping mechanism is also utilized in Exolaunch’s EXOpod Deployer.
Set Screws
The set screws on the door of the TestPod compensate for dimensional
tolerances in the deployment axis and help fix the satellite in place after
the door is closed. This follows a similar purpose to the clamping mechanism
and helps prevent unwanted movement. The door itself is closed and secured by
two screws (this position is taken by RBF pins on the deployer).
Access Windows
There can be up to 16 access windows in total, depending on the size of the
TestPod. These access windows are present on both sides of the TestPod and
allow access to the Cubesat during testing, permitting accelerometer placement
and visual inspection. Access windows on the TestPod are located in the same
place as the EXOpod.
Chassis
The TestPod’s stiff construction guarantees structural integrity and
longevity. The flange is part of the structure and allows easy mounting of the
TestPod on the shaker table with several individual mounting hole patterns
.
TestPod Porperties and Interfaces
Physical Dimensions and Mass Properties
The outer dimensions of the three different sizes of TestPod are showing in
Figures 3 to 5.
Mounting Interfaces
The 3U TestPod features two mounting hole patterns as shown in Figure 6, with
the mounting hole patterns of the 8U and 16U shown in Figure 7. All the
mounting holes are Ø11 mm through-holes for M10 screws with a nominal
tightening torque of 40.0 Nm. The mounting holes have an Ø 18 mm, 5 mm deep
counterbore for the screwhead. It is not intended for every screw to be used
to fasten the TestPod to the shaker table.
Note: A purchased TestPod can optionally be manufactured with a different hole
pattern if required.
Lifting Points
Every TestPod has four threaded holes on the top side which can be used to
attach lifting brackets. The location of the holes are shown in Figure 2, with
an example mounting shown below in Figure 8. The screws are tightened to 1.0
Nm. The brackets are strong enough to carry the weight of a fully loaded
TestPod with significant margin for lifting any additional masses, such as the
adapter plates.
Structural Characteristics and Lifetime
The primary structure of the TestPod was designed for rigidity and durability
allowing for a high number of test cycles. The natural frequencies of the
different TestPod models are shown below Figure 9. These frequencies have been
determined from a 0.2 g sine sweep test with no mass inside the TestPod. The
number of test cycles that can be run in a TestPod is only limited only by the
rails. A general limit is difficult to define, since the wear on the rails
depends mainly on the condition of the Cubesat rails tested inside the
TestPod. Experience shows that a set of rails can be used for 10 – 15 full
campaigns or more, provided that the Cubesat is fully compliant with the CDS
and integration and de-integration is performed with care. Figure 12 shows
examples of worn out rails (photo shows an EXOpod deployer).
Figure 4 and Figure 5 show the location of the all electrical interfaces of
the Xbox.
Flight Representativeness
The CDS does not specify requirements for flight representativeness of a
TestPod or test support device of any kind. The stiffness of the TestPod
structure, which is significantly higher when compared to a typical deployment
system on the market, does have an influence on load transmissibility and
levels experienced by the Cubesat. However, this difference is typically
accepted by various launch providers and altering the test levels is not
required. The internal mechanical interface in the TestPod is identical to
those of an Exolaunch EXOpod deployer.
Cubesat Interfaces
Introduction
The Exolaunch TestPod has been developed to follow the Cubesat Design
Specification (CDS). However, changes have been implemented which allow for
integrating Cubesats that exceed some dimensions which are specified in the
CDS, while still accommodating fully CDS-compliant Cubesats. Cubesats are
constrained by three separate elements on the deployers: the rails, the
deployment wagon, and the set screws located on the doors. The deployment
wagon is the same as in the EXOpod Deployer, only without the deployment
spring.
Maximum Cubesat Volume
General requirements of Cubesats are provided in the Cubesat Design
Specification Rev. 13. However, Cubesats in Exolaunch’s TestPods and Deployers
are allowed to exceed some of the constraints imposed by the CDS. The maximum
allowable volume for various Cubesat sizes are outlined in Figure 13 and Table
- Surface parallelism and roughness are given in Figure 14. The red areas
(rails) mark the Cubesat interfaces with the TestPod; these dimensions must be
followed in order for the Cubesat to fit inside the TestPod. The grey volume
can be used by the Customer in any desired way. The yellow area represents the
so-called Tuna Can, and may also be used by the Customer. The CDS states that
Aluminum 7075, 6061, 5005 and/or 5052 shall be used for both the main Cubesat
structure and the rails. The rails must additionally be hard anodized, and no
other processes or materials shall be used. Any deviation from the CDS, such
as but not limited to, the use of different materials or surface finishes,
i.e. other forms of anodizing or a chromate conversion dual finish, may
inflict damage to the rails. If the TestPod has been rented from Exolaunch,
any such deviation shall be communicated with and approved in writing
.
Table 1: Maximum Cubesat Dimensions for different TestPod sizes
Description
|
Letter
| 3U TestPod| 8U TestPod| 16U TestPod
---|---|---|---|---
1U/2U/3U| 6U| 6U XL| 8U| 12U| 16U
| | 1U: 113.5| | | | |
454.0
CubeSat Rail Length (Z) [mm]| A| 2U: 277.0| 340.5| 365.9| 454| 340.5
3U: 340.5
CubeSat Rail Width (X) [mm]| B| 100.0| 226.3| 226.3| 226.3| 226.3| 226.3
CubeSat Rail Height (Y) [mm]| C| 100.0| 100.0| 100.0| 100.0| 226.3| 226.3
Maximum Space Between Rails (X) [mm]| D| 87.2| 213.5| 213.5| 213.5| 213.5|
213.5
Maximum Space Between Rails (Y) [mm]| E| 87.2| 87.2| 87.2| 87.2| 213.5| 213.5
Tuna Can Diameter (except 5th tuna can)| F| 82.0| 82.0| 87.0+*| 87.0| 82.0|
87.0
12U Tuna Can Depth (except 5. tuna can)| G| 60.0| 60.0| –| –| –| –
16U Tuna Can Depth (except 5. tuna can)| G| –| –| –| 77.0| 77.0| 77.0
Number of Tuna Cans| –| 1| 2| 2| 2| 5| 5*
Distance Between Tuna Cans [mm]| –| –| 126.3| 126.3| 126.3| 126.3| 126.3
Maximum Mass [kg], RPM| –|
6.0
|
12
|
12
|
15
|
22
| 24
Maximum Mass [kg], BPM| 29
Rail Parallelism [mm]| –| 0.05
Surface Roughness [µm]| –| | | 1.6| | |
The fifth tuna can is located at the center of the deployment wagon with a
diameter of 62 mm and a height of 67 mm. **The adapter used to accommodate a
6U XL can be modified to fit custom dimensions.
Access Windows
The Access Windows are located on both sides of the TestPod and total 6, 8 or
16 depending on the model of the TestPod. These access windows allow for quick
and easy access to the Cubesat after its integration for attaching
accelerometers, visual inspection, or for a quick functional test using
external ports at any point during a test campaign. The exact dimensions and
location of these Windows for the 16U TestPod are shown in Figure 15.
Measurements start in the deployment wagon plane and from the guidance rails,
which are the contact planes of a Cubesat.
Rails and Clamps
The rails are made of hard-anodized aluminum. As a mechanical interface they
are identical to the rails used in Exolaunch’s EXOpod Cubesat deployers. This
provides a flight-like environment for the satellite. To fix the satellite in
the X and Y directions (perpendicular to the direction of deployment)
Exolaunch utilizes an array of adjustable clamps on one of the upper rails
that serve to restrain and hold the Cubesat stable when the TestPod’s doors
are closed, see Figure 16. These clamps compensate for any loose tolerances
and prevent the satellite from shaking and rattling around during
transportation and testing.
Deployment Wagon
The deployment wagon is situated between the back wall of the TestPod and the
Cubesat. In the EXOpod Deployer it serves to keep the spring in the correct
orientation ensuring that the spring force is delivered correctly to the
Cubesat. In the TestPod, the deployment wagon does not carry a spring. It
serves only as a mechanical interface and is fixed in place using four knurled
screws located on the back side of the TestPod. When these screws are removed,
a set of pusher tools can be used to facilitate Cubesat de-integration, Figure
17.
Door with Set Screws
The Cubesat is fixed in the direction of deployment by the deployment wagon at
the back of the TestPod with four set screws located on the TestPod door.
These are circled on the 3U TestPod as an example shown below in Figure 18.
The set screws are carefully tightened one by one to adapt to the individual
size of each satellite. Unlike the clamping mechanism, the set screws do not
apply any force onto the satellite but are only used to bridge any loose
tolerance gaps.
© 2022. All rights reserved. Disclosure to third parties of this document or any part thereof, or the use of any information contained therein for purposes other than provided for by this document, is not permitted except with express written permission of EXOLAUNCH GmbH.A
References
Read User Manual Online (PDF format)
Read User Manual Online (PDF format) >>