The Marshall Space Flight Center (MSFC) is developing x-ray mirror modules for the ART -XC instrument on board the Spectrum-Roentgen-Gamma Mission under a Reimbursable Agreement between NASA and the Russian Space Research Institute (IKI.) ART-XC will consist of seven co-aligned x-ray mirror modules with seven corresponding CdTe focal plane detectors. Currently, four of the modules are being fabricated by the Marshall Space Flight Center (MSFC.) Each MSFC module provides an effective area of 65 cm2 at 8 keV, response out to 30 keV, and an angular resolution of 45 arcsec or better HPD. We will present a status of the ART x-ray module development at MSFC

Elsner, R.

Gubarev, M.

Kilaru, K.

Lapshov, I.

McCracken, J.

O'Dell, S. L.

Pavlinsky, M.

Ramsey, B.

NASA Technical Reports Server

 
 
Development of Mirror Modules for the ART‐XC Instrument  
 
M. Gubarev1, B. Ramsey1, S.L. O’Dell1, R. Elsner1, K. Kilaru1, J. McCracken1,  
 
M. Pavlinsky2, A. Tkachenko2, I. Lapshov2 
 
1NASA Marshall Space Flight Ctr., Huntsville, AL 35812, USA 
2Space Research Institute, Moscow, Russia 
 
ABSTRACT 
 
The Marshall Space Flight Center (MSFC)  is developing x‐ray mirror modules for the ART‐XC  instrument on board 
the Spectrum‐Roentgen‐Gamma Mission under a Reimbursable Agreement between NASA and the Russian Space 
Research  Institute  (IKI.) ART‐XC will  consist of  seven  co‐aligned  x‐ray mirror modules with  seven  corresponding 
CdTe focal plane detectors. Currently, four of the modules are being fabricated by the Marshall Space Flight Center 
(MSFC.)  Each MSFC module provides an effective area of 65 cm2 at 8 keV, response out to 30 keV, and an angular 
resolution of 45 arcsec or better HPD. We will present a status of the ART x‐ray module development at MSFC. 
 
 
 
https://ntrs.nasa.gov/search.jsp?R=20120016503 2019-08-30T23:13:21+00:00Z
M. Gubarev1, B. Ramsey1, S.L. O’Dell1, R. Elsner1, K. Kilaru1, J. 
McCracken1,  
  
M. Pavlinsky2, A. Tkachenko2, I. Lapshov2 
  
1NASA Marshall Space Flight Ctr., Huntsville, AL 35812, USA 
2Space Research Institute, Moscow, Russia 
Development of Mirror Modules for the ART-XC 
Instrument  
Parameter ART eROSITA 
Energy Range  5-30 keV 0.2-12 keV 
Effective Area 455 cm2 at 8 keV 2500 cm2 at 1 keV 
Field of View  32 arcmin 1 deg 
System Angular 
Resolution (on axis) 
1 arcmin 15 arcsec  
Energy Resolution 1.4 keV at 14 keV  130 eV at 6 keV 
The Spectrum-Röntgen-Gamma (SRG) mission is a Russian-German X-ray 
astrophysical observatory that carries two co-aligned X-ray telescope systems.  
 
The primary instrument is the German-led extended ROentgen Survey with an 
Imaging Telescope Array (eROSITA), a 7-module X-ray telescope system that covers 
the energy range from 0.2-12 keV. 
 
The complementary instrument is the Russian-led Astronomical Roentgen Telescope 
– X-ray Concentrator (ART-XC or ART), a 7-module X-ray telescope system that 
provides higher energy coverage, up to 30 keV. 
Parameter Value 
Number of Mirror Modules 7=4+3 
Number of Shells per Module 28 
Shell Coating  > 10 nm of iridium (> 90% bulk density) 
Shell Total Length, inner and outer 
diameters   
580 mm, 50 mm, 150 mm 
Encircled Half Energy Width Less than 1 mm diameter, center of field of view 
Less than 2.5 mm diameter, 15 arcmin off axis  
Mirror Module Effective Area ≥ 65 cm2 at 8 keV (on axis) 
Module Focal Length 2700±1 mm 
Allowable Total Mass per Module 17 kg including thermal control system 
Minimal resonance frequency 40 Hz 
Operating Temperature Range 17⁰ C to 23⁰ C 
MSFC has designed and is fabricating four ART x-ray optics modules under an 
International Reimbursable Agreement between NASA and with IKI.   
 
Deliverables:  1 engineering unit (6 shells + mass simulators) and 4 flight units (28 
shells/unit)  
 
MSFC is utilizing electroformed-nickel replication 
(ENR) to fabricate four ART X-ray mirror modules. 
 
 In this process a thin nickel or nickel-alloy mirror 
shell is electroformed onto a figured and super-
polished electroless-nickel-plated aluminum mandrel, 
from which it is subsequently separated in chilled 
water by differential thermal contraction.  
 
Wolter I prescription for ART mirrors. The goal 
angular resolution for the ART mirror module is 30 
arcseconds HPD. 
 
 
The science-derived effective area requirement for the 
optics is > 65 cm2 at 8 keV on axis  
 
 
 
Calculated effective area of ART x-ray 
optics module 
0
10
20
30
40
50
60
70
80
90
100
0 5 10 15 20
cm
2
keV
On axis 5 arcmin 10 arcmin 15 arcmin
FOXSI : Focusing Optics X-ray Solar 
Imager 
• Focal Length: 2 m 
• Number of modules: 7 
• Number of shells: 7 (10) 
• Optics Type: Wolter I 
• Outer shells radius: 51.51 mm 
• Inner shell radius: 37.99 mm  
                                    (32.48 mm) 
• Shell length: 60 cm. 
• Energy range: 4 – 15 keV 
Similar launch loads 
Shell thickness – 250 microns 
Two spider support structure 
The predicted resonance frequency spectrum matches well to  
measured during vibration tests 
Two FOXSI  outer shells show gravitational sag due to the way they 
are supported 
One spider design allows to increase the thickness of outer shells (250 – 350 micron) 
 
Lowest calculated resonance frequency is  52.44Hz  with requirement of 40 Hz 
 
Estimated weight margin is 1kg  
 
The mechanical stress estimates are conservative ; the margin is 1.7  (requirement is 1.5.) 
 
 
Three most inner shells 
 
Three most outer shells 
 
Three mass simulators to replace missing shells (diameters 
are 74, 101.3 and 126.4 mm) 
 
Spider has the same design as for the flight modules 
 
The clips have the same size grooves for the shells, but the 
grooves for the simulators are deeper. 
Mass simulators installed on the spider 3 mass simulators  and 6 shells installed on the spider 
1.E-11 
1.E-09 
1.E-07 
1.E-05 
1.E-03 
1.E-01 
10 100 1000 
A
cc
e
le
ra
ti
o
n
 (
g
2
/h
z
) 
Frequency (hz) 
PSD Response to Z direction 
Input 
(F) Z-in 
(F) Z-X 
(Q) Z-X 
Spider for the qualification unit 
To support the aggressive ART 
module fabrication schedule, MSFC 
has greatly expanded its 
infrastructure: 
 
-5 polishing stations dedicated to 
ART 
 
-Built an additional electroform bath 
 
- five alignment stations (scaled 
down versions of the FOXSI 
alignment system) are being built 
 
-two coating chambers are built 
 
-Two optical interferometers and the 
vertical long trace profilometer are 
dedicated to the ART project 
Polishing stations One of two  plating baths 
ART coating chambers 
ART alignment station  
 Opto-mechanical design is completed. The design 
review was held at the IKI in February 
 All aluminum blanks are coated with the electroless 
nickel 
 20 mandrels are diamond turned, 10 are being polished, 
5 completed 
 Testing of the iridium coating chambers is completed; 
 13 shell mirrors has been plated, 5 mirrors are coated 
with Ir. The acceptance x-ray tests are under way. 
 Spider, clips and mass-simulators for the qualification 
unit are fabricated 
 Spiders for the flight units are fabricated 
 Alignment systems are being assembled 
Mass simulators for qualification unit 
Spiders with bafles for 5 (4 + 1 spare) 
flight and 1 qual units 
 Qualification unit to be tested in September 
 Mandrels to be completed by October 
 Mirror shell fabrication to be completed by January 
 Delivery – June 2013 
 MSFC is developing four x-ray mirror modules for the ART-XC 
instrument on board the SRG Mission under an International  
Reimbursable Agreement between NASA and the IKI.  
 
 To support the aggressive ART module fabrication schedule, MSFC 
has greatly expanded its infrastructure to meet the demands of 
mandrel polishing, shell fabrication, shell coating, and module 
assembly.  
 
 MSFC is on schedule to deliver flight units in the Summer of 2013.  
 
Development of Mirror Modules for the ART-XC Instrument  
M. Gubarev1, B. Ramsey1, S.L. O’Dell1, R. Elsner1, K. Kilaru1, J. McCracken1,  
  
M. Pavlinsky2, A. Tkachenko2, I. Lapshov2 
1NASA Marshall Space Flight Ctr., Huntsville, AL 35812, USA 
2Space Research Institute, Moscow, Russia 
2. Chemical clean  
and activation  
& Electroless Nickel  
(EN) plate 
3. Precision turn  
to sub-micron 
figure accuracy 
4. Polish and 
superpolish to 
3-4 Å finish 
5. Metrology  
On mandrel  
1. CNC machine, 
mandrel formation  
from Al Bar 
Electroform Nickel Replication Process 
7. Electroform nickel 
shell onto mandrel 
6. Ultrasonic clean  
and passivation to 
remove surface 
contaminants 
8. Separate optic 
from mandrel in 
cold water bath 
(+) (+) (-) 
Hero  Foxsi ART 
Abstract 
  
The Marshall Space Flight Center (MSFC) is developing x-ray mirror modules for the ART-XC 
instrument on board the Spectrum-Roentgen-Gamma Mission under a Reimbursable Agreement between 
NASA and the Russian Space Research Institute (IKI.) ART-XC will consist of seven co-aligned x-ray 
mirror modules with seven corresponding CdTe focal plane detectors. Currently, four of the modules are 
being fabricated by the Marshall Space Flight Center (MSFC.)  Each MSFC module provides an effective 
area of 65 cm2 at 8 keV, response out to 30 keV, and an angular resolution of 45 arcsec or better HPD. A 
status of the ART x-ray module development at MSFC is presented 
Different types of X-ray shells 
fabricated at MSFC 
Down to 50 m thick Up to 50 cm diameter 
Down to 2.5 cm diameter 
60 cm length – 5 cm diameter 
- 250 µm thick 
X-ray Optics Projects at MSFC 
ART optics requirements  
Parameter Value 
Number of Mirror Modules 7=4+3 
Number of Shells per Module 28 
Shell Coating  > 10 nm of iridium (> 90% bulk density) 
Shell Total Length, inner and outer 
diameters   
580 mm, 50 mm, 150 mm 
Encircled Half Energy Width Less than 1 mm diameter, center of field of 
view 
Less than 2.5 mm diameter, 15 arcmin off axis  
Mirror Module Effective Area ≥ 65 cm2 at 8 keV (on axis) 
Module Focal Length 2700±1 mm 
Allowable Total Mass per Module 17 kg including thermal control system 
Minimal resonance frequency 40 Hz 
Operating Temperature Range 17⁰ C to 23⁰ C 
MSFC has designed and is fabricating four ART x-
ray optics modules under an International 
Reimbursable Agreement between NASA and with 
IKI.   
 
Deliverables:  1 engineering unit (6 shells + mass 
simulators) and 4 flight units (28 shells/unit)  
 
One spider design allows to increase the thickness of 
outer shells (250 – 350 micron) 
 
Lowest calculated resonance frequency is  52.44Hz  
with requirement of 40 Hz 
 
Estimated weight margin is 1kg  
 
The mechanical stress estimates are conservative ; the 
margin is 1.7  (requirement is 1.5.) 
 
 
Calculated effective area of ART x-ray optics module 
0
10
20
30
40
50
60
70
80
90
100
0 5 10 15 20
cm
2
keV
On axis 5 arcmin 10 arcmin 15 arcmin
oMSFC is utilizing electroformed-nickel replication (ENR) to 
fabricate four ART X-ray mirror modules. 
 
oWolter I prescription for ART mirrors. The goal angular 
resolution for the ART mirror module is 30 arcseconds HPD. 
 
oThe science-derived effective area requirement for the optics 
is > 65 cm2 at 8 keV on axis  
 
 
 
Spider for the qualification unit 
Mass simulators for 
qualification unit 
Opto-mechanical design is completed. 
The design review was held at the IKI in 
February 
All aluminum blanks are coated with the 
electroless nickel 
20 mandrels are diamond turned, 10 are 
being polished, 5 completed 
Testing of the iridium coating chambers 
is completed; 
13 shell mirrors has been plated, 5 
mirrors are coated with Ir. The 
acceptance x-ray tests are under way. 
Spider, clips and mass-simulators for the 
qualification unit are fabricated 
Spiders for the flight units are fabricated 
Alignment systems are being assembled 
MSFC is developing four x-ray mirror modules for the ART-XC instrument on board the SRG Mission 
under an International  Reimbursable Agreement between NASA and the IKI.  
 
To support the aggressive ART module fabrication schedule, MSFC has greatly expanded its 
infrastructure to meet the demands of mandrel polishing, shell fabrication, shell coating, and module 
assembly.  
 
MSFC is on schedule to deliver flight units in the Summer of 2013.  
 
Heritage 
Spiders with baffles for 5 (4 + 1 spare) flight and 
1 qual units 
X-ray Optics Module design 
Three part design of the ART spider 
Design and Optical Performance 
Status 
Conclusions 


Development of Mirror Modules for the ART-XC Instrument

Development of Mirror Modules for the ART-XC Instrument

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