Solar array protectors should be a requirement, incorporate them into the panel design. Same holds true for other delicate components such as thermal louvers or antennas. These shall be considered during the layout of the s/c envelope wrt the shipping, lifting, and test configuration, as well as operational envelope of any MGSE.

In general, use commonality in parts and approach as much as possible. For parts, this maximizes cost savings in non- recurring engineering, drafting, and fabrication setup as well as the possibility of confusion during assembly and installation. In approach, commonality of joints, for example, can simplify procedures, tooling, and analysis.

Keep in mind for planning at the conceptual level to account for schedule and hidden costs that will be associated in developing any new processes; if developed techniques satisfy the requirements, use them.

An experienced fabrication planner familiar with manufacturing and material processes needs to be involved in the design process to review the drawings with the stress analyst and the design engineer. These engineers should participate and be accountable in the monthly Directorate Status Reviews (DSR's).

Use of at least cobalt drill bits is required for drilling of titanium - make sure they are in supply.

For locally machined/manufactured hardware, plan on weekly visits to the facility to progress/status the schedule specifically for your job; this should be accomplished by the fabrication planner or a project representative.

For hardware being manufactured outside the local area (e.g. solar panel, damper, honeycomb), budget enough travel for the subsystem to properly support technical interchange meetings as well as status throughout the job.

For Integration and Test (I&T), provide a handling dolly which offers the greatest flexibility of access and S/C orientation; every conceivable one will be requested.

Take advantage of the tools and personnel expertise around you.

It is extremely beneficial to have small peer reviews comprised of knowledgeable engineers in the appropriate areas of expertise before committing either a lot of time or resources to a design(e.g. structure, dolly, mechanism, etc.) for a fresh, outside, unbiased look.

Incorporate time into the schedule for critical or major I/F fit checks as early as possible.

A standardized list of mechanical requirements was and should be used for all black box components in the ICD's.

If templates are to be used for components (highly recommended), they should utilize slip bushings rather then pressed bushings. Usage instructions should be indicated on the template.

The use of a detailed schedule was an invaluable tool for internal subsystem flow, logic, and status; however, a less detailed scheduled must be used to track only more significant or major milestones to the project.

Transportation of the S/C should be recognized as a subsystem early in the development of the S/C. Their representative should be responsible and accountable to the project with schedule and cost as a subsystem and they should participate in the monthly DSR's.

Verify that the parties outside your organization which share in the delivery of your subsystem agree with your estimates (cost and schedule) up front. Furthermore, identify a person as the representative in the organization for that job; make them a member of the team and give them the responsibility, visibility, and authority.

Establish a good system for traceability, i.e. CERT logs, work orders, photos). Take lots of photos, including vendor deliverable hardware.

Beware of using too many applicable documents in a specification. If there is a particular requirement desired from the reference, pull it into the spec or call it out directly. Try to avoid referencing the whole document unless that is the intent. This will significantly drive the cost of the desired product up because the vender will respond to every aspect of the document to cover his bases.

Typically, the I&T managers background is in electrical engineering. Having a deputy I&T manager with a mechanical engineering background involved with all scheduling and planning proved to be highly efficient.

Daily short (<15 minutes), standup meetings need to occur early in the morning and mid afternoon to assess work to be accomplished and work for the next day. It is the subsystem manager's responsibility to plan and schedule ahead of time with the I&T/deputy at the weekly meeting.

As a result of those meetings, a lot of the subsystem manager's time is spent not on technical issues, but on scheduling and 'greasing the skids' for a smooth integration to happen; for this to work effectively, a lead engineer who supports the subsystem manager needs to be utilized and have the time to work the smaller technical everyday issues.

Separate meetings to discuss overall flow, strategy and big picture issues need to occur weekly and need representation from all subsystem managers, I&T/deputy managers, and system folks.

I&T procedures must include the actual time, date and data files as run for each test or operation.

Even though this job had relatively few partners or I/F's (two universities) and the S/C bus was developed in-house; one individual, such as the lead mechanical engineer, needs to be responsible for developing and maintaining a red/green tag list which defines the S/C configuration to be used though observatory testing as well as at the launch site. This becomes significant when working a job like HST or EOS which has multiple players including International participation.

At concept level, thought to deployable configuration (booms, arrays, etc.) from a ground test feasibility must be accounted for. Adequate confidence, cost, and schedule will be driven by this consideration during the verification process.

Consider ground testing of the deployables into the design of the ground support equipment. These design considerations can greatly simplify the test setup.

Design the deployment to be operated and tested on the ground (either with or without the use of g-negation).

Early life testing of actuators was invaluable in determining suitability of the design, as well as leaving time for recovery in case of a detected failure.

Budget should allow for purchase of spare dampers, potentiometers, thermostats, and heaters.

Gimbal and antenna operational travel envelope must include: connector backshells, harness bend radii, thermal blanket, release mechanism components, and harness clamps.

Mass mock-ups must be simple and should be inexpensive for vibration and T/V tests. Design and fabricate antenna and gimbal mass mock-ups at the front of the program and use them for early boom deployment system tests. This provides a great work around or insurance to save schedule and cost; often times the gimbal and antenna which are complex in nature get delivered late.

Allocate ample time to study and understand the harness routing carefully up front. Consider temperature effect, looping around hinges, clamping technique, envelope for both stowed and deployed configurations.

It is highly recommended that the clamp used to secure the harness loop around the base hinge to the S/C should be designed as part of the base hinge; i.e. the clamping points on both sides of the movable section of the harness should be controlled on the deployable side rather than on the S/C side. Along with a pigtail disconnect, this effectively eliminates any disturbance or change of geometry from sub-system to system level testing.

Use Braycote 602 grease at the separation I/F of the release mechanisms, even if these I/F's have hard coatings (anodize or tiodize), provided the operational environment is within the capability of the grease (i.e. temperature, pressure, etc.).

Always design a kick-off spring for any one time deployment system.

If the system can take the impact locking/lock-in torque without using a damper, then the system should be designed without a damper. Dampers are complex and can reduce system reliability.

If dampers are to be utilized in the system, consider the placement and installation of heaters and thermostats (primary and redundant) early in the design.

If the system can deploy without a g-negation system, then it should be designed that way; however, the stress analysis (due to locking/lock-in impact torque) shall be carefully performed because the system will deploy faster on-orbit (no gravity).

Obtain co-axial and electrical harness samples early in the program to test stiffness @ hot and cold and for different routing configurations.

Order extra GSE heater strips for the hot and cold deployment test because temperature gradient between components and sub-assemblies is very important during thermal deployment tests.

Try to utilize heritage as much as possible; however, the lead engineer must study and completely understand the previous (heritage) application. Designs which utilize heritage can get you in trouble with a false sense of security if you don't understand all the background and reasons behind the design.

Kinematic mounts should be utilized whenever possible to reduce the stress due to mis-alignment and the launch environment on the system in the stowed configuration.

Verify MGSE has all proof tags up to date and valid throughout the launch window along with any launch site requirements such as NDI tags, etc. Consider proof testing MGSE just prior to shipping.

There will be several high level meetings with a lot of project personnel required at the launch facility, but make sure the travel budget reflects several technical interchange meetings (TIMs) for key mechanical and electrical technical personnel for several years prior to launch. These meetings are invaluable as far as making informational contacts, understanding physical or facility limitations, and planning for integration and test procedures to be used at the facility.

For negotiated services( i.e. electrical outlets, dry air or nitrogen supply, compressed air, etc.), verify with launch site support manager (LSSM) acknowledgement of the requirement and physically check out I/F at the first opportunity.

Projects need to set up a consistent CM program up front prior to drawing development. We used our own system on XTE and ended up duplicating efforts later in the program as a result.

Project needs to assemble motivated and experienced subsystem leads. Super leads or system managers/engineers (mechanical, electrical, thermal) should be identified at the beginning of the program and be involved in the writing of component specs to identify all requirements early prior to contract award.

A project emergency 'credit card' proved invaluable for the purchase of small items required in real time.

Make sure all long lead items/spares are identified into the schedule early in the program and initiated.

Use of a dedicated procurement Tiger Team significantly reduces duration of the procurement cycle.

Components make up the most significant costs of the S/C bus; buying power of common or multiple buys of components had significant cost savings wrt non-recurring engineering, manufacturing, and qualification. XTE and TRMM combined requirements/specifications for common buys on torquer bars, reaction wheels, reaction wheel electronics, digital sun sensor and electronics, batteries, transponders, IRU (gyros), coarse sun sensors, SDS, shipping container, and star couplers. Also, creative money planning let XTE primarily foot the bill up front until TRMM fiscal dollars were available which provided cost savings to NASA