April 88, 1998

Advanced X-ray
Astrophysics Facility

CCD Imaging Spectrometer

ACIS Monthly Progress Report

January-March 1998

Submitted to: Submitted by:
George C. Marshall Space Flight Center
National Aeronautics and Space Administration
Marshall Space Flight Center, AL 35812
Center for Space Research
Massachusetts Institute of Technology
Cambridge, MA 02139

1.0 General

This report covers the period from January 1, 1998, to March 31, 1998.

1.1 Accomplishments

1.1.1 Project Management

With the agreement of the AXAF Program Office at MSFC (Max Rosenthal), ACIS has switched from a monthly status report to a quarterly report. Basically, the ACIS instrument has been delivered, integrated on the SIM, and continues to work correctly. Much of the status information on the ACIS instrument now comes from MSFC and TRW, rather than MIT.


Since ACIS was delivered to MSFC on April 14 of last year, standard Monthly Status Reviews were terminated. The last review was on August 4 at LMA.


ACIS participated in the weekly AXAF telecons on Jan 6, 20, and 27; Feb 3, 10, 17, and 24; March 3, 10, 17, 24, and 31. There was no telecon on Jan 13.

ACIS also participated in SI interface telecons with TRW, MSFC, and HRC on Jan 15 and 22, as well as numerous telecons on specific topics (thermal vacuum test planning and procedures, CARD, stray light testing at TRW, etc.).

ACIS Hardware

The following is a brief summary of the status of the main ACIS elements:

  1. The ACIS flight instrument was delivered to the XRCF on April 14 of last year. The hardware/software has continued to work correctly through the XRCF activities at MSFC, SIM integration at BASD, T-V testing at BASD, shipment to TRW, acoustic and EMI testing at TRW.

  2. The flight detector assembly continues to be checked for leaks at every opportunity. During this reporting period, the detector was tested at TRW in late February and then again in late March, after acoustic testing. The measured leak rate continues to show the very low value of about 0.8 torr per week (the spec is 1 torr per day).

  3. At this point in time, ACIS is just part of the ISIM. Testing (short form or long form functional) occurs periodically to verify continued proper operation after or during various environmental exposures. These include: thermal vacuum cycling at BASD in January, shipment to TRW about Feb 1, acoustic testing at TRW in early March, and operation during the AXAF self-compatibility (EMI) testing at TRW in early April. No anomalies with the ACIS flight hardware have been observed.

  4. PSMC. The modification to the PSMC to remove and replace capacitors of questionable reliability was completed at LMA in early December. The flight PSMC was then sent to BASD and reinstalled on the ISIM on December 13. A functional test of the ACIS instrument (including the modified PSMC) was successfully completed on December 22. No problems with the PSMC were noted during the T-V testing at BASD in January.

  5. PSMC Lockheed Martin Corp has found quality problems with certain lots of Bussman fuses used in some of their "black" projects. An Alert is in preparation at LMA. To support the determination of the scope of the Alert, every project at LMA (including ACIS) has submitted a quantity of fuses from its flight stock to the LMA Mission Assurance organization for testing - continuity, thermal shock, DPA, etc. ACIS has also sent a small quantity of each flight fuse lot to MSFC for testing. At the time of preparation of this report, the Alert has not encompassed the ACIS flight fuses, but this is subject to change at a moment's notice.

ACIS Hardware
  1. The main activity at MIT during this reporting period is the continued close-out of paperwork. All CEI and ICD verification test reports have been submitted, but new items continue to surface and we close them out. These include: final Ground Safety Hazard reports related to the VGSE, CARD inputs, a verification report for the VVA for post-acoustic performance, an analysis of the impact on ACIS of several TRW SCN's to SE29, etc.

  2. During this reporting period, MIT completed negotiations with LMA for the Change Order related to the work on the PSMC and the flight shades. This Change Order has been submitted to MSFC for approval. In addition, a proposal has been submitted to PSU for the post-launch Data Analysis and Instrument Support activity at MIT.

Schedule Status

As of the successful test of ACIS with the modified PSMC at BASD on Dec 22, ACIS is ready for launch. The only tasks remaining are to assist BASD and TRW with AXAF integration and testing activities.

Personnel Status

Due to the continued positive status of the ACIS instrument and schedule, the following personnel have been let go:

Dorothy Gordon Electrical Engineer Jan. 1, 1998
Gordon Gong Electrical Engineer Jan. 1, 1998

1.1.2 Project Science

Backup focal plane selection

All backup CCD calibration was finished in 1997.

CCDs were selected for the backup focal plane. Six focal plane locations will be populated. The four imaging locations will be populated with calibrated, flight- quality chips as follows: I0(w216c3),I1(w210c3r),I2(w215c1) and I3(w192c1r). Locations S2 (w198c4) and S3(w79c3-BI) will be populated with engineering- grade devices. In the event that the backup focal plane is required for flight, the 2 engineering-grade devices will be removed and the ACIS spectroscopy array will be populated with the following calibrated, flight-quality, front-illuminated devices: S0(w202c3r); S1(w163c3r); S2(w461c4) S3(w185c3r); S4(w459c1); S5(w163c1r).

Testing of ACIS integrated into ISIM at Ball Aerospace.

We supported science-related tests of ACIS at Ball Aerospace in January. In particular, we obtained data on continuous clocking mode, on the status of the ACIS filters (using the internal ACIS LED) and on new graded histogram mode flight software patch. We encountered no unpleasant surprises.

Reviews and Meetings

We participated in technical reviews of AXAF general observer proposals.

We attended several scientific meetings:

1.1.3 Flight Software

Detailed Software Design

Revision A of the Detailed Software Design Document has been submitted to the Project office.

External Interfaces

The following deliverable is still under review:

ECO 36-957 -- ACIS Software Users' Guide, Revision B

A description of ACIS commands has been re-delivered to TRW to assist in the preparation of ODB Release 6.0 and to correct various errors in ODB 5.2 used for AXAF thermal vacuum testing.

Software Delivery

Release 1.5 of the Flight Software (ECO 36-940) has been burned into the flight and engineering units. Any remaining software problems will be fixed via patches.

Verification Testing

The current status of ACIS software verification is detailed on an ACIS Web page.

No new flight software problems have been found and no reports have been filed. Patches have been developed and tested to circumvent the 3 remaining problems.

A list of software problem reports may be accessed via the ACIS Web server

Stored Command Sequences

The flight software team is collaborating with the ASC ACIS team to define stored ACIS command sequences. The following have been completed:

Name Description
1. SILSSCS Shed Spacecraft Power Load
2. SIPUSCS Power-Up Science Instrument After Eclipse
3. SISAFE Enter Science Instrument Safe Mode

Orbit Activation and Checkout

The flight software team is collaborating with the ASC ACIS team to define procedures to be used during OAC. The following have been completed:

OP03 Name Description
1. §2.4.1 open_lvv Open Little Vent Valve
close_lvv Monitor Temp. and Press. during OI
monitor_tp Monitor Temp. and Press. during OI
4. §2.4.3 open_vv Open Large Vent Valve
abort_opvv Abort Opening Large Vent Valve
close_vv Close Large Vent Valve
abort_clvv Abort Closing Large Vent Valve
fs_dump Dump flight SW
9. §2.4.5 ablff Abridged Long Form Functional Test
10. §2.4.1 open_door Open ACIS Camera Housing Door
ccd_raw Raw Data from each CCD
12. §2.4.8 ccd_dark Dark Current Measurement
ccd_int1 Internal Cal Source Measurement at -90°C
ccd_int2 Internal Cal Source Measurement at -110°C
ccd_int3 Internal Cal Source Measurement at -120°C
16. §2.4.7 ccd_obf OBF Integrity Test
17. §2.4.14 ccd_orbbkg1 Characterize Bkgrnd before opening door
ccd_orbbkg2 Characterize Bkgrnd after opening door
ccd_fcm HRMA Flux Transfer Standard Sources
ccd_rghbore_s Rough Boresight with ACIS-S
ccd_focus_s Focus Plate Measurements with ACIS-S
ccd_focuschk_s Best-focus Verification with ACIS-S
ccd_finbore_s Fine Boresight with ACIS-S
24. §2.4.12 pgf_bakeout Bakeout Mode

1.1.4 Performance Assurance Quality Assurance


Coordinated with Don Whirley to obtain access to the MSFC Website and start receiving MSFC Alerts electronically. Initial notification is made through normal E-Mail. The Alert Notification Cover Letter, Alert Problem Summary Chart, and individual Alerts are then accessed through the MSFC Alert Notification Page on the Web.

Thirty-eight (38) Alerts from NASA/MSFC were received over the report period. These Alerts are detailed in the attached list. Each ALERT was compared with the MIT ACIS Parts and Materials lists. None of the parts and materials are used on AXAF/ACIS flight hardware.

ALERT # MSFC # Part Number and Manufacturer Part or Material Name
FJ5-P-96-01A 6921A Genicom Corp. Relay, Electromagnetic, 4PDT
XT5-P-97-01 7091 Square D Company Hanging Electrical Controls
QL-P-98-02A 7092A Microchip Technology Inc Test/Destructive Physical Analysis (DPA) Service
JSC TWX-A-97-24 7100/A/B RGA Labs. Inc (Sigma Test Labs) Test Services
H9-A-98-01 7100 C&D RGA Labs. Inc Test Services
M4-P-97-01 7101 Defense Supply Center, Columbus Ceramic Capacitors
QU-P-98-01 7102 Mfr. is N/A Cadmium Plated Bolts
LX-P-97-01 7103 Communication Instruments Inc. Relay MIL-R-39016/11-041P
F4-A-97-01 7104 Wyman Gordon Heat-treated forgings
W6-A-98-01 7105 Thomas & Betts Corp. Connector, Male Header, 90°, PCB
JSC TWX A-98-01 7106 various QPL manufacturers Silver Coated Wire
JSC TWX A-98-02 7107 Connectec unknown
G6-P-98-01 7108 Mfr. is N/A Ammonium Perchlorate
9Q-A-98-01 7109 Ticorm, Inc. Material Heat Treatment (Aluminum)
NASA TWX 7110 7110 Papco Oil Company Tank Line, Inc. Potentially Contaminated Fuels
NASA TWX 7111 7111 NASA Jet Propulsion Lab. (JPL) incompatibility of propellants
EB7-P-98-01 7112 Vishay-Dale Electronics Resistor, Fixed, Metal element
F3-P-98-01 7113 N/A Rivet, solid
CU2-P-98-01 7114 Glenair, Inc. Cap, protective, electric connector
WR-S-98-01 7115 Ontario Knife Co. knife, scraping, 3 inch
H6-P-98-01A 7116/ 7116A DEB Manufacturing Inc. viscous damper
BW-P-98-01 7117 Boeing Information, Space & Defense Systems material substitution error
HB1-A-98-01 7118 California Instruments Corp. 3 phase AC power supplies
QU-A-98-01 7119 Sermatech Materials Laboratory Landing gear, aermet 100
EA-P-98-01 7120 Dow Corning Corporation Reinstatement of qualification to MIL-I-46058
K4-S-98-01 7121 Mil Spec Heat Treating Nut, rigid, tube connector
T2-S-98-01 7122 McCartney H.V. Enterprises Inc. Wire rope assembly, Trident 1
JE5-A-98-01 7123 Deutsch e.c.d. Defense/Aerospace Electrical connector, inline junction
VV-A-98-01A 7124 BICC Brand-Rex Co. Wire, electrical, copper, Fluropolymer-insulated,
GB4-A-98-01 7125 United Technologies Microelectronics Center Inc. (UTMC) Microcircuit, memory, digital, CMOS
C5-P-98-01 7126 Ram Company Solenoid, fuel, electrically actuated
XP3-A-98-01 7127 Thomas and Betts Corp. Wire, crimping tool
F3-A-98-02 7128 Crystalonics Inc. Transistor, surface mount
EB7-P-98-02 7129 Vishay - Dale Electronics Resistor, Fixed, Wirewound, Power RWR81
F3-A-98-01 7130 Microsemi Corporation Transient voltage suppresser
G2-A-98-01 7131 Hypertronics Corporation Connectors, printed circuit subassembly
QB-A-98-01 7132 Tubesales schedule 160 stainless steel pipe
EQ3-A-98-01 7133 West Coast Aluminum Heat Treating Co. extrusion, aluminum alloy

Waiver/Deviation Status

MIT waiver request 36-016, Use of Overstressed Wire, was disapproved. All other waivers have been approved or withdrawn.

Nonconforming Material Reports/Material Review Board

Submitted three (3) Nonconforming Material Reports (NMRs) to MSFC, all identical, relating to DEA power. These NMRs have a "Use as is" disposition and therefore were processed through, and approved by, the Material Review Board.

The above NMRs reflect a problem in calculating DEA power through telemetry. This occurs each time MIT performs a short or long form test on the ACIS instrument. MSFC has concurred that future nonconformances of this specific DEA power measurement will not require a NMR or MRB action. Parts Engineering

All forty-six (46) ACIS Nonstandard Parts Approval Requests (NSPARs), data requirement SPA03, have been submitted to and approved by MSFC.

Provided die lot data on the Crystal Semiconductor CS5012A, A to D Converter to MSFC/Tony Lavoie. Reliability Engineering

All thirty-nine (39) ACIS Material Usage Agreements (MUAs), data requirement SHF04, have been submitted to and approved by MSFC. System Safety

Provided data to H. Hooper at MSFC for JSC Form 44, Ionizing Radiation Source Data Sheet, for the external sources. Software Quality Assurance

See Software Quality Assurance under paragraph 1.1.3 above. Performance Assurance and Safety Plan

There has been no activity on the Performance Assurance and Safety (PAS) Plan. The PAS Plan in effect is revision B. Cleaning/Vacuum Conditioning and Contamination Control

There has been no activity in this area during the report period.

1.1.5 Lincoln Laboratory

During the last three months, the Long-Term Soak Tests have come to a conclusion. Three flexprints (9632-3I, 9632-4D, 9632-4F) were placed on a cold plate in a vacuum chamber to test the effects of long-term exposure at -125°C. They spent a total of 391 days under the cold conditions with some interruptions for testing (every 3 months or so). The devices were removed from the chamber on January 20, 1998, and all tests indicate that the long-term exposure had no effect on the electrical conduction of the flexprints. The devices which failed were to be cross-sectioned to look for deterioration of the vias; this has not been performed since there was no electrical failure caused by the via holes.

Agreement has been reached with campus about the placement of chips on the back- up flight paddle, and we are awaiting delivery to begin population. The assignment of chips is as follows:


The premise for placement in this paddle is to use engineering-grade devices in the spectrometer so they might be removed and then all six spectrometer positions can be filled if it is necessary to use this back-up paddle as the primary paddle. This strategy leaves several flight devices as candidates, if replacements are needed for only one or two of the first flight paddle slots.

1.1.6 Lockheed Martin Activities General


This is the first of a series of Quarterly Progress Reports for the ACIS program. The format of this report has been slightly modified to accommodate quarterly reporting and to ensure that all subjects are addressed within its body.

During this reporting period, the ACIS team at Lockheed Martin in Denver completed the PSMC DESC 87106 Capacitor change-out in the PSMC and documented the results from re-verification of PSMC test requirements. Following capacitor change, the team was off-loaded to other programs to reduce costs to the program. Each of the key technical personnel, i.e.; Ed Sedivy, Neil Tice, Scot Anderson, Brent Reschak, Ky Gardner, and Ted Corcoran, remain available to support ACIS should the need arise.

Several trips were taken by ACIS personnel during this reporting period to support re-integration of ACIS onto the ISIM at Ball Aerospace in Boulder, Colorado, and subsequently, to support integration of the ISIM onto the AXAF-I Spacecraft at TRW in Redondo Beach, California.

In an effort to consolidate ACIS records, including drawings, specifications, reports, and customer-furnished paper, Mr. Robert (Bob) Hoffman was brought onto the ACIS program. Bob's primary task is to collect, collate, document in a data base, and file all of the ACIS documents, including those from MIT and TRW. This effort is expected to last 2-3 months, and will result in a searchable data base for ACIS documents. Duplicate and obsolete documents are being destroyed during this process. This effort is in support of the future contract closeout activities.

Additionally, an effort to store soft copies of ACIS computer files from those persons leaving the program has been started. The "soft" files are being stored by author's name onto "Zip disks" for future reference. The "Zip disks" will be maintained by the ACIS program manager at Lockheed Martin.

Planning and Scheduling

The AXAF-I Launch Date was changed to be no earlier than 3 December, 1998. After reviewing the Shuttle manifests available on the Internet, it is most likely that the AXAF-I Launch will occur during the month of February, 1999. There is a planned Shuttle launch on 9 December, 1998, another on 4 January, 1999, and the next planned Shuttle launch is during the month of March, 1999. This leaves the month of February, 1999, open for the AXAF-I Launch. For planning purposes, Lockheed Martin - Astronautics is using a February 1999 launch date.

Contracts and Finance

Because of the AXAF-I launch date change, Lockheed Martin - Astronautics is anticipating a change order to extend the period of performance for the ACIS contract to include the month of March 1999 for post-launch support activities.

Anne Howard was assigned to the ACIS program as the Finance person during the first quarter of 1998. Anne Howard replaces Anne Hoover who has been very supportive of ACIS for more than 1-1/2 years through three program managers. Our thanks go to Anne Hoover and we welcome aboard Anne Howard.

If that wasn't confusing enough, Lockheed Martin - Astronautics successfully negotiated Change Order #72 during this reporting period. This change order effected two hardware modifications. Change Order #72 authorized and funded replacement of the DESC 87106 capacitors in the PSMC and added Vaccum Deposited Aluminum (VDA) over Gold on the Sun and Telescope Shades. Systems Engineering


Nothing to report for the 1st Quarter of 1998.

System Design

The Sabre® software license was renewed by MIT during this reporting period. This license extension will carry the ability to use Sabre® for ACIS through to launch should the need arise.

Integration Support

On two separate occasions, trips were taken to TRW in Redondo Beach, California, during this reporting period. The first trip was taken by Scot Anderson on 2/16/98 to evacuate the ACIS Detector Housing after receipt of the ISIM from Ball Aerospace in Boulder, Colorado. Measurement of the Detector Housing pressure prior to energizing the vacuum pumps within the VGSE indicated a level of 4 TORR inside the Detector Housing. Using pressure data from an earlier evacuation of the Detector Housing at Ball Aerospace prior to shipping to TRW yields a leak rate of less the 0.2 TORR per day. This is much better than expected. The second trip to TRW was taken by Scot Anderson and Chad Carr to again evacuate the ACIS Detector Housing after performance of AXAF-I Spacecraft Acoustic Testing at TRW. Chad Carr went along to gain operating knowledge of the VGSE and to view the AXAF-I spacecraft configuration should his services be needed in place of Scot's sometime in the future. The second trip was taken on 3/24/98. Measurement of the Detector Housing pressure prior to energizing the vacuum pumps within the VGSE indicated a level of 4 TORR inside the Detector Housing. Using pressure data from previous evacuation of the Detector Housing on 2/16/98 yields a leak rate of 0.1 TORR per day. Again this is much better than expected, and verifies the proper operation of the ACIS Flight Vent Valve Assembly after exposure to proto-flight Acoustic test levels.

Engineering Specialties

Two Phase III Ground Hazard Safety Reports for the ACIS VGSE, G4 "Ignition Sources for Flammable Vapors/Liquids ACIS Vacuum GSE", and G16 "Leakage or Rupture of ACIS Vacuum GSE", were completed and submitted to MIT for subsequent submittal to MSFC in support of the NASA Safety review process. Power Supply & Mechanisms Controller

Re-verification reports for the successful completion of Vibration, Temperature-Cycling (not a CDRL item), and MSFC-SPEC-1238 Certification were completed and published during this reporting period. The tests requiring these reports were deemed necessary to validate workmanship of the PSMC following replacement of the DESC 87106 capacitors. Thermal/Mechanical

Flight Detector Housing

Nothing to report for the 1st Quarter of 1998.

Venting Subsystem

During a review of ACIS hardware verification events at Lockheed Martin - Astronautics in 1997 by personnel from MSFC, it was determined that the Vent Valve Assembly (VVA) was undertested for Vibration. This occurred because the VVA was attached to the ACIS Detector Housing during a combined hardware vibration test. The test levels were based on the requirements for the Detector Housing, which had a reduced level exclusion in the parent requirements document (Spacecraft to Science Instrument ICD, IF1-20). Because the VVA and the Detector Housing are attached when integrated, it was erroneously assumed that the exclusion extended to incorporate the VVA. To expedite delivery of the ACIS Instrument, it was then determined to wait for verification of the VVA until after Acoustic testing of the AXAF-I spacecraft at TRW. Acoustic testing of the AXAF-I spacecraft is now complete and, as reported above in the SYSTEMS ENGINEERING Integration Support section, the VVA successfully met the requirements for leak rate. A letter report documenting this event will be prepared and submitted to MIT and MSFC early in the next reporting period.

Thermal Control Subsystem

Shade Drawing Updates to reflect cutting of vent slits in the KaptonŽ shade surfaces and application of VDA were released during this reporting period.

A trip was taken on 2/3/98 by Theodore (Ted) Corcoran to TRW in Redondo Beach, California, to clean the Sun and Telecscope Shades. This trip was deemed necessary because the shade surfaces were covered with small particles, most probably the result of shipping the ISIM from Ball Aerospace in Boulder, Colorado, to TRW in Redondo Beach, California. The method of cleaning chosen by ACIS personnel was to blow the particles away using compressed air and an adjustable restrictive air nozzle. This effort was successful. Mechanical Ground Support Equipment

VGSE #1 was fully assembled, tested, and placed in clean storage at Lockheed Martin - Astronautics during this reporting period. This item will remain in storage and available for support of integration activities at TRW or Cape Canaveral should VGSE #2 fail and the need arise.

The VGSE Operating Manual document number ACIS-711-47-02 was updated to include safe operations during fuel loaded sequences at Cape Canaveral, published and submitted to MIT for further publication.

Last modified: Mon May 4 15:22:17 EST