National Aeronautics and

Space Administration

Quick Start

Guide to

Payload Design

March 2, 2022
National Aeronautics and

Space Administration

Quick Start

Guide to

Payload Design

GETTING

STARTED

March 2, 2022
It can be a long journey from having a great 

idea for a science investigation in space 

to seeing it operated on the International 

Space Station and receiving the results. 

This Quick Start Guide provides a high-level 

road map to help you, the Payload Developer, know who you’ll encounter, understand 

what milestones are ahead, and give you an 

idea of the path you’ll travel on that journey. 

In addition, this Guide provides a foundation 

to assist you in designing your payload within NASA’s constraints using best practices 

and lessons learned from more than 20 

years of payload development experience. 

Are you just getting started and need inside 

information for your discipline on conducting experiments on the station? The ISS 

Researcher’s Guide series provides links 

to 17 free downloadable booklets that serve 

as introductions for potential users of the 

station platform. Each guide provides discipline-specific context for conducting station 

research, including available hardware and 

laboratory environments, to assist researchers in their efforts to connect to research 

opportunities. Since each payload requires 

both a sponsor and funding, these Guides 

provide an overview of the most applicable 

pathways to connect to these resources.

Once you’ve determined how to plug into 

one of the available methods to connect 

your payload to the International Space Station activities, you’ll work with your Sponsor 

to create the contracts required to secure 

funding and begin integration of your payload into the station program. 

As projects are selected and approved, the 

https://www.nasa.gov/station-researchers-guides/

The ISS Researcher’s Guides are available at the following web address:

Getting

Started

From Here To There
integration process begins and you will be 

assigned a Payload Integration Manager 

or PIM. The PIM is considered your primary point of contact or interface with the ISS 

Program, and will be your guide on your payload’s journey to and from the Space Station. 

In a nutshell, the PIM’s job is to help ensure 

the safe launch, integration, operation, and 

data return for your payload. The PIM will 

build an integration schedule to keep you on 

track as you approach key milestones and 

reviews together. The PIM will also facilitate 

PIM Tag-Ups that will include you and the 

integration team to keep everyone in sync 

along the way. In addition, PIM-led orientation meetings provide more in-depth explanations of the topics provided in this Guide. 

Speaking of the PIM, during your payload 

development journey, you will encounter 

acronyms - lots of acronyms (after all, who 

wants to say Payload Integration Manager 

when PIM is more efficient?). NASA is full 

of acronyms because each piece of equipment, each formal meeting, each process 

and organization and role has its own long 

name that can contribute to cumbersome 

conversations without the use of their short 

names. Don’t worry – we have links for that! 

(See our FAQs.) If an acronym (or conversation full of them) is not clear to you, be sure 

and ask for clarification.

Entering the integration phase brings with 

it a decision of consequential importance: 

what to name your payload/investigation. 

Typically, a working name will be used 

during the initial phases of development, but 

once your payload is added to the Integrated 

Payload List (IPL) and a Payload Integration 

Agreement (PIA) is developed and signed, 

it can be very difficult to change the name. 

So think carefully about your payload name, 

including any resulting acronym. Note that 

many payloads have a long, descriptive 

name and a short name by which it is known 

in conversation for meetings and during 

on-orbit operations. Discuss your ideas with 

your assigned PIM, who can make sure your 

chosen name is not a duplicate or too similar 

to another payload or investigation. 

Other topics covered in this Guide include 

information on Payload Engineering and 

Payload Safety. These sections, along with 

the FAQs, provide an introduction designed 

to get you started. Additional detailed information will be provided as you need it by your 

PIM and the appropriate team member.

In these sections, you’ll see guideposts labeled as Tips ( ) or SOS ( ). A Tip provides 

helpful information that can make your planning and design progress more smoothly. An 

SOS indicates what to do if you run into problems or concerns and need help.

Also be sure to check out the FAQs for additional information on how to interact with 

NASA’s payload integration processes successfully.
National Aeronautics and

Space Administration

Quick Start

Guide to

Payload Design

FREQUENTLY ASKED 

QUESTIONS (FAQs)

March 2, 2022
PEOPLE — WHO WILL HELP?

Q: Who will I encounter during the payload development process (names, affiliations, 

roles, responsibilities, contact info)?

A: An integration team of individuals from relevant offices and departments is assigned to 

support your project for its duration, based on the specific needs of your payload. You 

will meet some of these team members at your project’s Kickoff meeting. Contact lists 

with names, titles, affiliations, roles, phone numbers, and email addresses are typically 

provided. Note: Your primary contact will be your assigned Payload Integration Manager (PIM), who will be able to connect you with the rest of the team (more about the PIM 

below).

Q: When will I interact with these individuals and/or teams?

A: Taking a payload or experiment from concept to flight will take time, and you will go 

through a methodical process that evolves as payload development matures. At different junctures of this integration flow, you will work with different individuals with various 

areas of expertise.

Q: Where can I find a directory of everyone?

A: There are a number of locations for finding contact information:

● Your PIM

● Roster files made available at your Kickoff meeting

● PIM Roadshow materials

● ORBIT database, (see ‘List of Contacts’ file for your payload) 

● NASA Global Address Directory

Your PIM can show you how to access each of these resources.

Frequently Asked

Questions (FAQs)

?
Quick Start Guide to Payload Design: FAQ 3

Q: Who are the key personnel?

A: Your most important and frequent contact is the Payload Integration Manager (PIM), 

who will guide you through the integration process, answer questions, make referrals, 

and enlist additional support, if needed. You are encouraged to go to your PIM for assistance first. He or she is your central liaison to NASA. PIMs typically work for Boeing 

or GC Controls.

The PIM’s role is:

● To act as your point of contact and guide on this journey. 

● To assist you to ensure the safe launch, integration, operation, and data return for your payload.

● To build an integration schedule to help keep your project 

on track as your project approaches key milestones and 

reviews.

● To facilitate regular PIM Tag-Ups that include you and the 

integration team to routinely keep all project components, 

personnel, milestones, and issues in sync.

You may also occasionally interact with a Research Portfolio Manager (RPM), a civil 

servant from the ISS Research Integration Office (Code OZ at NASA/Johnson Space 

Center) who supports the sponsor and NASA’s ISS Research Integration Office in 

collaboration with the PIM.

Q: What if my PIM is not available when needed?

A: Often a backup PIM is assigned to whom you can reach out. Also, the manager or lead 

of the PIM team can be contacted for assistance.

Q: What will I need help doing during the process vs what ought I expect to accomplish independently?

A: Some payload developers or implementation partners might feel well-equipped to 

facilitate certain aspects of their project development on their own; however, there are 

specific areas within the integration and operations process that require NASA support. 

You will be advised when these items come up, and subsequent NASA guidance will 

help to ensure the safe launch, integration, operation, and data return for your payload.

Q: What if things aren’t working out with someone?

A: If an issue arises that is inhibiting your progress and does not involve your PIM, first 

have a conversation with the PIM about your concerns. In addition, you can contact the 

ISS Client Service + Satisfaction (CSS) Team, a neutral, unbiased team that collects 

feedback on clients’ experiences with NASA’s people, processes, and tools. CSS monitors a 24-hour ISS Research Client Helpline that you can contact to request assistance 

on an issue, confidentially or otherwise, if desired. The Helpline can be reached via 

phone at 281-244-6187 or via email at: jsc-iss-research-helpline@mail.nasa.gov.
4 Quick Start Guide to Payload Design: FAQ

PROCESS — WHAT SHOULD I EXPECT?

Q: How does the integration process work?

A: The ISS Program uses an orderly process for executing the end-to-end activities 

required to integrate station payloads. This structure provides a process flow tailorable 

to the specific needs and maturity of each payload. The process covers the entire lifecycle, from the point of receiving funding to the return of data results from experiment 

operation in orbit. Integration activities ensure that the information exchange between 

you as the Payload Developer (PD) and the Program are timely and that they support 

integration and flight readiness milestones. Throughout, the process focuses on early 

identification of risk and risk mitigation. Consider integration to be an orderly process 

of specific phases of activity all aimed toward launching your payload to ISS, have it 

operate on the station, and return results back to you.

Q: What kind and amount of paperwork should I anticipate?

A: Your PIM will explain what the paperwork expectations are for data submittals, other 

deliverables, meeting attendance, and more. You will be guided along the way, and 

there are resources and people to support you in providing required documentation, 

data input, etc.

As an example, the payload development process will typically include providing the following types of information:

● Payload hardware/science overviews, including science 

timelines, data requirements, and success criteria.

● Payload planning overview data.

● Hardware mass/dimension properties for manifesting.

● Safety/hazard information applicable to the payload.

● Hardware testing data/ISS interface verification data.

● Launch and return constraints data pertaining to turnover, 

scrubs, launch to activation timelines.

● Research planning data.

● Crew procedure information/training products, if needed.

Q: When will we be done and ready to fly?

A: Each experiment’s development and integration is unique, but on average, getting 

onboard takes 6 months to 2 years.

Q: Where will I have to go?

A: While much of the development and integration work is handled online using NASA 

database tools, teleconferences, emails, etc., during the activity at any given time 

throughout the process, you may be required to attend meetings in person. Your PIM 

will inform you about when or where you might be required to be present to support.

Q: How much am I responsible for?

A: Your PIM will explain what the expectations are concerning any data inputs, deliverables, meeting attendance, and other information. You will be guided along the way and 

resources and people are available to support you.
Quick Start Guide to Payload Design: FAQ 5

Q: Throughout the schedule outlined for development of my payload, will there be 

any flexibility in deadlines, if needed?

A: The schedule can be flexible to a degree. Please address any issues or concerns 

about the schedule with your PIM, and he/she will work with you to set the most realistic schedule, including working to revise it as necessary as your experiment/hardware 

develops.

Q: Where can I obtain any ISS Program documents listing out requirements for 

development of new payloads; e.g. SSP 57000 - Pressurized Payloads Interface 

Requirements Document?

A: Most of the ISS Program’s technical documents and publications are contained within 

the Electronic Document Management System (EDMS), an online repository housed 

within the NASA network. Once your payload development project is under way, you 

can capply for a NASA Domain Credential (NDC) account with NASA IT Personnel, 

and upon approval, you will be able to access the EDMS library and search and obtain 

technical documents. Your PIM can initiate the facilitation of this NDC access with you, 

as well as indicate which documents are pertinent to the data you will need.

Q: What kinds of meetings will I be expected to attend and how many are there?

A: The Development and Integration process is tailored to the particular investigation and 

the team developing and integrating the payload. Every payload/investigation must 

meet certain safety requirements and feasibility criteria. The integration team determines the number of meetings required for your particular payload, along with the 

schedule and meeting cadence, at the beginning of the integration process. As time 

progresses, the team may collectively determine what level of engagement is required 

until the payload is launched, executed, and returned (if applicable) to the Principal 

Investigator. However, the work will vary depending on payload complexity in order to 

help you gauge the amount or type of work will be involved.

Here are some examples of activity you can anticipate in 

conjunction with NASA: 

● Kickoff

● PIM tag-ups throughout the integration phase

● Safety reviews

● Verification requirements/testing coordination

● Shipping/final packaging/mass verification of hardware 

prior to turnover

Q: Where can I find a list of NASA acronyms?

A: NASA maintains a database called Acronym Central at this link:

https://www9.jsc.nasa.gov/acronymcentral/scripts/index.cfm

(note: this web page is viewable once you are granted access to NASA’s internal network)

In addition, the documentation or database tools you are provided usually will have 

acronyms spelled out or listed for reference. Your PIM also can answer acronym questions.
6 Quick Start Guide to Payload Design: FAQ

Q: Am I required to provide backup payload hardware as replacement for my original in case an accident occurs at launch or before?

A: Not in every case; there are plenty of payloads where the hardware flying is the only 

hardware that exists. Having a full replacement for your experiment could be very 

expensive. It is recommended, however, that if affordable, you should have some 

replacements for pieces that are most likely to fail so the hardware can be repaired if it 

goes down in the lab on the ground. Alternately, if the experiment has perishable components/samples, it is advisable to have back-ups of these elements in case the launch 

slips.

Q: What if I need resolution to an issue with the process?

A: Your first line of communication is always your PIM. You can also contact the ISS 

Client Service+Satisfaction (CSS) Team, a neutral, unbiased team that collects feedback on clients’ experience with NASA’s people, processes, and tools. CSS monitors a 

24-hour ISS Research Client Helpline that you can contact to request assistance on an 

issue, confidentially or otherwise, if desired. The Helpline can be reached via phone at 

281-244-6187 or via email at jsc-iss-research-helpline@mail.nasa.gov. 

TOOLS — WHAT TOOLS ARE AVAILABLE?

Q: What kinds of software and databases will I encounter?

A: Depending on the needs and requirements for info/data submittal, a range of online 

tools have been developed to help facilitate and share your info/data with NASA. For 

example, one of the most frequently used tools that captures much of your data inputs 

during the integration process is the ISS OZ Requirements Baselining and Integration Tool (ORBIT). ORBIT is a web-based software system intended to provide users, 

specifically International Space Station (ISS) payload developers, with a single-source 

location for input and communication of information required during the payload integration process for the purpose of launching, operating, and/or returning payloads on 

the ISS. 

Additional online tools you might encounter address research planning, payload interface requirements, general planning, flights, as examples. Your PIM and other support 

personnel will guide you on which databases will serve your particular set of needs. 

Orientation and training are included. 

Q: Do I have to use these databases? Even though the ORBIT online database is a 

comprehensive tool used for much of the integration process, it looks daunting. 

Will there be anyone to assist me in learning it, using it, etc.?

A: These tools are the go-to location for all the support organizations you rely on to fly 

your payload, so yes, their use is required. The tools were developed based on years 

of clients walking through the payload integration and operations processes with NASA 

support personnel and have been customized using essential client input to efficiently 

collect the most appropriate and accurate data applicable to your project. As always, 

crew and payload safety and experiment success remain prime objectives. If desired, 

you can request that the PIM assign a Payload Data Integrator (PDI), who will interact 

with the databases on your behalf. As the PD, you will still have to provide any data 

required/requested, but the PDI interacts directly with the tools to populate databases, 

etc.
Quick Start Guide to Payload Design: FAQ 7

Q: How do I learn enough to get up to speed?

A: Depending on which online application you are offered, you can access training classes, documentation, support personnel, user forums, payload data input personnel, 

helplines, and your PIM to help orient you. As an example, for ORBIT, there is a users’ 

forum held monthly for explaining any software updates and answering questions. Ask 

your PIM how to receive notice of this particular forum and any other user support for 

online tools.

Q: Who will provide support, technical and otherwise?

A: Your assigned PIM will be the primary point of contact who provides you with support 

services and guidance throughout the duration of your project. A variety of additional 

personnel and subject matter experts are available along the way for assistance with 

specific areas of activity.

Q: Will I be able to use NASA’s online database tools for integration in either a Windows or Mac environment? What about a mobile platform; are there apps available? 

A: NASA’s online database tools functions in either Windows or Macintosh operating 

systems. Regarding use of mobile platforms and corresponding apps, mobile devices 

are not fully approved for use at this time, so computer workstations are the primary 

systems for interacting with integration online database tools. For further information, 

please consult with the IT technical support personnel made available to your team.

Q: Will I need to apply for and receive access to a NASA IT account so I can use NASA’s 

online database tools for integration?

A: Yes. NASA’s online database tools are accessible via a NASA IT account. Typically, an 

RSA SecurID token is issued to you for purpose of logon. Your PIM will help guide you 

through the steps to apply for the account and token.

Q: Where can I suggest improvements?

A: You can always provide suggestions to your PIM. There is also an opportunity to offer 

suggestions and recommendations for improvements during your one-on-one interviews with the ISS Client Service+Satisfaction Team rep assigned to your project. A 

client interview is conducted approximately midway through project development, and 

another when it comes to completion. These conversations provide you a chance to 

convey your reflections of NASA’s people, processes, and online database tools. You 

can also submit ideas for improvements to the ISS Client Helpline at:

jsc-iss-research-helpline@mail.nasa.gov.
National Aeronautics and

Space Administration

Quick Start

Guide to

Payload Design

PAYLOAD

ENGINEERING

March 2, 2022
While engineering designs vary as widely as 

payload purposes, they are all subject to 

the physical, chemical, and mathematical 

principles understood by NASA discipline 

experts who support the ISS Program. ISS 

hardware, software, and operations are 

organized functionally into systems and 

sub-systems with leading experts that provide support in each of these areas.

NASA’s Pressurized Payloads Interface 

Requirements Document (SSP 57000) is 

the principle source for interface design 

requirements for all NASA-developed payloads operating in the pressurized volume 

of the ISS. Payload developers must verify 

the applicable requirements in this document to ensure the safety of the ISS crew, 

transport vehicles, on-orbit ISS systems 

hardware, and neighboring payloads. This 

document also provides design guidance 

that ensures the basic operation of the 

payload and affects the payload’s mission 

success. It is your responsibility as payload 

developer (PD) to design in accordance 

with the design guidance.

NASA is equipped with laboratories and 

other facilities designed to support payload projects throughout their lifecycles. Although each of these experts fulfills an important role within the ISS Program — such 

as ensuring safety or providing necessities 

for the crew — all of them have something 

to offer you as a (PD) to help you achieve 

payload mission success.

The following content draws from the 

expertise and experience of individuals 

across the organizations mentioned above. 

The sections within this chapter highlight 

specific considerations that should concern 

you while completing the engineering design, development, and verification activities associated with your payloads.

You are encouraged to coordinate closely with your Payload Integration Manager (PIM) and reach out to experts in areas 

relevant to your payload.

CONSIDERATIONS FOR 

PAYLOAD DESIGN

This section describes several aspects of 

space flight that you will need to take into 

account during the payload development 

process.

Payload

Engineering

Building a better mousetrap
Quick Start Guide to Payload Design: Payload Engineering 3

Keep in mind that payloads that use 

less of the station’s limited resources are 

more easily accommodated. Keeping resource usage to only what is absolutely 

required and finding ways of reducing 

the use of resources improves a payload’s opportunities for mission success.

Crew

Pressurized payloads share the ISS environment with the crew, whether they are 

passive/autonomous (not requiring crew 

time) or active (requiring crew time). ISS 

engineering experts are available to assist 

with the design approach and verification 

process to prepare the payload for crew 

interaction. Your PIM will conduct a payload 

Kickoff meeting where these requirements 

are introduced. The PIM is the liaison between you and various ISS experts.

Consider the number of crew absolutely 

required to complete your payload operations.

Thermal

The ISS offers payloads different types of 

thermal control: active, passive, and conditioned stowage.

The Active Thermal Control System (ATCS)

is an internal system (inside the ISS) that 

uses a closed-loop (series of tubes) that 

circulates chilled water and pulls excess 

heat from racks and payloads. In this system, there are two temperatures available: 

a 40C Low Temperature Loop (LTL) and a 

170C Moderate Temperature Loop (MTL).

The Passive Thermal Control System (PTCS)

is also an internal system that removes 

heat using forced cabin airflow across the 

payload.

When designing your payload, consider the thermal requirements and what 

would be ideal: ATCS or the PTCS.

Conditioned Stowage provides for the 

specific temperature needs for scientific 

samples and other temperature-sensitive 

payload items. This resource consists of 

several active devices, such as freezers, 

refrigerators, and incubators as well as 

passive assets like Coldbags and Ice 

Bricks. These options are available on ISS, 

plus during launch and return. Standard 

conditioned stowage temperatures are 

-32°C and +4°C. All other temperatures are 

considered a unique re- quest.

Conditioned stowage is one of the most 

limited resources on ISS. To ensure that 

your payload is accommodated for conditioned stowage, keep sample dimensions as small as possible.

Electrical

The ISS Electrical Power Distribution and 

Control (EPDC) system provides power 

to the ISS and payloads. Your PIM will 

discuss its intricacies during your Kickoff 

meeting and throughout the development 

process and will facilitate interactions with 

the Electromagnetic Effects (EME) and the 

Electrical Power System (EPS) Teams. The 

EME Team provides Power Supply and 

EMI Filter design guidance for compatibility 

with the ISS system and other payloads. 

The Electrical Power System (EPS) Team 

provides guidance on power interface 

requirements.

Engaging the help of the EME team early and often is an important practice to 

ensure success in electrical design. The 

EME team can help you understand the 

EPDC requirements and offer proven 

methods to meet them in addition to 

providing test facilities equipped to support electrical and EMI testing.

When designing your payload, take into 

consideration the following design factors:

Power Interface Design

Two-fault tolerant controls and verifications 
4 Quick Start Guide to Payload Design: Payload Engineering

are required to ensure crew safety through 

the following approaches:

Redundant or Designed for Minimum Risk 

(DFMR) Bonding of all crew accessible 

surfaces (including cables) that can be energized after a failure or electrical fault (i.e., 

test for a minimum of class H bond <0.1 

Ohm or use of double insulation).

Electrical isolation between primary power 

and chassis and secondary power.

EME Team can provide support and guidance on design and verification of all classes of bonding required for your payload.

Power Quality Testing

The EPS combines critical (ISS core systems) and non-critical loads (payloads) in 

the same power feed; therefore, additional 

systems-level requirements are in place to 

protect the system. It is important to involve 

the EME and EPS Teams early in the design of the payload.

Electromagnetic Compatibility (EMC) 

Design

When designing your payload, keep in 

mind that there are electromagnetic standards that must be met. Early communication with you PIM and the EME team will 

help lead to a successful design.

Designing for electromagnetic compatibility up front will reap dividends later in the 

process by reducing costs and schedule 

impacts from later design changes due to 

EMI issues.

Review this paper, Electromagnetic 

Compatibility Considerations for International Space Station Payload Developers, for specific guidance.

Some PDs prefer to buy Commercial-Off-The Shelf (COTS) products for 

their payloads. If a COTS product is being 

considered, EME experts can help based 

on experience with previous payloads. 

Electromagnetic Interference (EMI) 

Testing

EMI testing occurs near the end of the payload development lifecycle. This testing is a 

requirement for flight.

Be sure to account for EMI early in your 

payload design to ensure it will pass 

testing and move forward to flight.

If stated in the Payload Integration Agreement (PIA), NASA can provide testing services. Otherwise, testing can be performed 

at a commercial facility. Talk to your PIM 

about testing options.

Electrical Power Distribution and 

Control (EPDC) Design

In coordination with your PIM, the EME, 

Safety, and EPS Teams will provide assistance with initial requirements for payload 

development and design. It is important 

to engage with these teams early in the 

design phase.

In a microgravity environment, there is no 

convective cooling: objects and structures 

using electricity that heat up on the ground 

likely will get much hotter on orbit.

Example: Laptop chargers are familiar 

COTS products that tend to heat up while 

charging during ground operations. While 

on-orbit, they can heat up to temperatures 

that exceed touch temperatures, potentially endangering the crew. Additional fans 

provide a solution.

The ISS electrical system has a 32-volt 

shock limit, which is lower than what most 

payload developers expect.

By engaging with the EME Team early 

and not waiting until the Phase I safety 

review, cost and schedule impacts can 

be reduced or eliminated.

Example: If a PD up-converts from the 28 
Quick Start Guide to Payload Design: Payload Engineering 5

volts provided by the ISS, the PD could 

unwittingly introduce a situation requiring 

a two-fault tolerance. If this requirement 

is not taken into account early on, the 

payload’s electrical system will have to be 

modified.

Also consider the materials used in the 

electrical system. Polyvinyl Chloride (PVC) 

insulation is not permitted for use on the 

ISS based on its flammability risk.

Teflon-coated wiring is optimal.

Battery Design and Testing

Your PIM will assist in connecting you with 

the Safety Team for assistance with the 

battery selection process. It is important to 

understand the full implications of what is 

required to implement a design using battery power and the time required to do so.

NASA can build batteries, or COTS batteries can be used after testing.

All batteries, regardless of type, have potential risks:

Lithium ion (Li-ion) produce a lot 

energy by operating a higher capacity, 

but unique circuitry that leads to the 

potential of thermal runaway. Thermal 

runaway propagation-resistant batteries are required if the capacity is over 

80 watt-hours. With Li- ion batteries, 

rigorous safety hazard mitigation and 

safety plan documentation are requirements.

Alkaline and electrolyte batteries can 

leak and have venting issues.

Nickel cadmium batteries are easier to 

work with and do not have thermal runaway issues. The drawback is that they 

may not be powerful enough for some 

applications.

Capacitor Component Testing/Screening

When using capacitors, it is important to 

understand the hazards associated with 

wet electrolytic capacitors — particularly 

aluminum electrolytic and wet tantalum 

types — since they present the possibility 

for toxic material to reach the crew. Engage 

the Safety team early in the design phase.

Avoid aluminum electrolytic capacitors. 

Electrolytes tend to react with the dielectric material, creating a short. When 

activated after being off for some time, 

the capacitor may fail quickly. Similarly, tantalum capacitors can have unexpected failure modes. Treating them 

for moisture problems via sealing them 

or baking them out tends to help avoid 

shorts. Ask your PIM for recommendations on appropriate capacitors for your 

payload.

EEE Parts and Ionizing Radiation

The EEE part selection and the effects of 

ionizing radiation are closely monitored for 

ISS hardware.

Select parts from known manufacturers 

with an emphasis on quality and reliability.

Your PIM can help you navigate interactions with the experts on what EEE parts 

may work for your payload.

For COTS parts, it is good practice to ask 

about qualification testing and their current 

Failure-in-Time (FIT) rate when considering 

manufactures.

A FIT rate of approximately 20 is a good 

rule of thumb when selecting parts.

Ionizing radiation for internal payloads is a 

recognized but minor concern. If your payload is sensitive to radiation, the options 

for parts should include redundancy and 

proton testing.
6 Quick Start Guide to Payload Design: Payload Engineering

Consider performing a “burn- in” on the 

payload or a particular electronics assembly by simply letting it run, perhaps 

for a few weeks. This is a cost-effective 

method to identify longevity problems 

in the design.

STRUCTURES AND 

MECHANISMS

When developing your payload, it is important to engage NASA’s Structures and 

Mechanisms (S&M) experts early in the 

design phase. These experts will help you 

deter- mine how your payload and structural loads will play a factor in moving forward 

with the ISS Safety and Review Panel 

(ISRP). When designing your payload, fault 

tolerance requirements and options should 

be understood to ensure the hardware is 

created with enough flexibility to operate on 

the ISS.

Work with the S&M experts prior to entering the safety review process to determine whether your payload would be 

designated as ‘Safety Critical.’

Structural Loads

Structural loads may arise from mechanical, pressure-related, vibration-related, 

inertial, and thermal forces applied to 

structural elements. All payloads must limit 

their disrupting effects on the microgravity 

environment. Keep the following information in mind during the design phase of 

your payload:

The three categories of disruption are Quasi-Steady, Vibratory, and Transient.

Quasi-Steady Launch and Landing 

Loads

Quasi-Steady refers the state that the vehicle experiences when traveling through the 

atmosphere. In this state, the turbulence 

experienced occurs slowly and quickly 

reaches equilibrium therefore creating a 

seemingly steady state. Acceleration loads 

need to be considered for your payload.

Payloads in their launch, on-orbit, or landing configurations must provide positive 

margins of safety when exposed to accelerations.

Vibratory Loads

Your payload should be designed to withstand vibrational loads. If your payload is 

vibration-sensitive, the ISRP will recommend Protoflight Random Vibration Hardmount Testing.

Vibration testing and analysis are recommended to verify the function of any 

payload that includes electronics, close 

tolerance moving devices, or optical 

equipment.

Whenever possible, leave tolerances 

loose to enable on-orbit operations, 

such as payload installation.

Structures can change shape compared 

to their ground measurements when in 

microgravity.

Fracture Vulnerability

All payload equipment is evaluated for 

potential breakage that could cause harm 

to the crew, ISS, or visiting vehicles.

Fracture control analysis should be 

performed concurrently with the stress 

analysis early in the development of the 

payload.

Primary structural elements may be classified as low-risk, non-Fracture Critical as 

long as the working stresses are low, use 

of proper materials, and satisfactory fatigue 

life are demonstrated.

To decrease the potential of payload 

fracture, consider the parts and mate-
Quick Start Guide to Payload Design: Payload Engineering 7

rials used in the design. There should 

be no welds, castings, forgings, or additive manufacturing. Materials prone to 

shattering, such as glass, ceramics, etc., 

must be contained.

The containment of hazardous materials/fluids must be 2-fault tolerant (yielding three levels of containment). Otherwise, the primary container will become 

Fracture Critical.

Mechanisms

If your payload has mechanisms, addressing considerations early in the design process is crucial. Your PIM and S&M experts 

will help you through this process with the 

first step of developing a mechanical fault 

tolerance strategy.

Focus your efforts on incorporating mechanical redundancy wherever possible 

and determining whether to implement 

a Design for Minimum Risk (DFMR) 

strategy. (DFMR is a process that allows 

Safety Critical mechanisms to achieve 

fault tolerance through rigorous design, 

analysis, testing, and inspection practices rather than through true physical redundancy.)

Mechanical fault tolerance is always preferred, either in the form of like or unlike 

redundancy. Some examples of incorporating like mechanical fault tolerance 

include dual rotating surfaces for hinges 

and secondary sliding surfaces.

MATERIALS

The JSC Materials and Processes team 

consists of experts to assist you in the 

selection of materials for your payload. This 

team differentiates payloads into the Simple or Complex categories described below.

Payloads will need to meet the verification 

requirements set by the JSC Materials 

and Processes team. Contact your PIM for 

guidance.

Simple Payloads

Simple Payloads are those that have 

minimal ISS vehicle interfaces and little to 

no structural hardware (i.e. welded seams). 

Examples of a simple payload include 

container kits, syringe kits, consumable 

re-supply kits, and Commercial-Off-TheShelf (COTS) hardware such as cameras, 

syringes, filters, sample container bags 

to name a few. The primary concerns for 

simple payloads are flammability and toxic 

off gassing.

COTS hardware can be accepted 

through the COTS certification process. 

Contact your PIM for assistance with this 

process.

Complex Payloads

Complex Payloads are those that do not 

meet the criteria of a Simple Payload. 

These primarily include structures and will 

need to comply with the Structures and 

Mechanisms requirements.

All materials used for Safety Critical 

structural components require certification as to their composition and properties.

Structural payloads should avoid using 

complex materials processes such as additive manufacturing, welding, brazing, 

structural adhesive bonding, forging, 

casting, and structural soldering in Safety Critical structural components.

Payload Guidance

For Complex Payloads, the Materials and 

Processes Technical Information System 

(MAPTIS) contains a collection of verified 

test data on standard design materials 

that will be crucial when designing your 

payload. MAPTIS provides letter rating 

on flammability, fluid compatibility, stress 

corrosion, toxic off gassing, and vacuum 

outgassing.
8 Quick Start Guide to Payload Design: Payload Engineering

MAPTIS experts are available when you 

request assistance through your PIM.

Materials Flammability

The flammability of materials is an important consideration when designing your payload. The basic requirement for flammability is that the materials be nonflammable. 

The materials that you are envisioning for 

your payload may be tested for acceptability.

Something to keep in mind that some 

flammable materials can be accepted by 

configuration analysis, such as containment or low quantity.

Standard flammability test data typically 

used for ground applications in air environments are not conservative enough 

for the oxygen-enriched ISS pressurized 

environment. Consult your PIM to determine the appropriate expert to assist in 

choosing your material.

Common nonflammable materials are listed 

below. Talk to your PIM about any specific 

material you want to use.

Teflon (Tetrafluoroethylene (TFE), Fluorinated 

ethylene propylene (FEP), and Perfluoroalkoxy (PFA))

Nomex (HT 9040 and some additional grades, 

but not all)

Polycarbonates (Lexan, Macrolon), 1/8 inch 

or thicker

Kapton and other polyimides

Ultem

Painted metal

Common flammable materials are listed 

below. These materials are not expressly 

prohibited and may be acceptable within 

the total payload configuration. Be sure to 

discuss any materials you want to use with 

you PIM and materials experts.

Paper

Polyethylene

Polypropylene

Acrylonitrile butadiene styrene (ABS)

Nylon

Hook-and-loop fasteners (such as VELCRO® 

or similar products)

Polyvinyl Chloride (PVC)

Polyethylene terephthalate (PET)

Cotton

Polyester

Wool

Complete lists of nonflammable and 

flammable materials are avail- able. 

Please contact your PIM to discuss with 

the material experts.

Off Gassing and Outgassing

When materials release gases into the environment, this is referred to as off gassing. 

Should toxic off gassing occur on the ISS, 

it may create a toxic environment for the 

crew.

Toxic off gassing is frequently confused 

with toxic hazard ratings. The toxic hazard rating pertains to fluids only and the 

hazard that would occur if the entire 

amount of fluid were released into the 

ISS cabin atmosphere.

There are times that “off gassing” and “outgassing” terms are frequently confused. Off 

gassing typically occurs inside the pressurized vehicle whereas outgassing occurs 

outside the vehicle in a vacuum.

When navigating off gassing requirements, keep in mind that unmodified 

COTS hardware that contains less than 

20 pounds (total mass) of polymeric materials need not be tested for off gassing, with some exclusions.

Outgassing may result in contamination 

of the vehicle transporting your payload 

or the ISS. There is potential that your 

payload’s surface or near-by payloads 

could be contaminated. You can find 

an extensive list of outgassing data in 

MAPTIS.
Quick Start Guide to Payload Design: Payload Engineering 9

Fluid Compatibility and Stress 

Corrosion

Your payload materials must be compatible 

with any fluids with which they come into 

contact.

A few of the materials that are permitted 

to come into contact with the Internal 

Thermal Control System (ITCS) coolant 

loops include internal metallic materials 

made of stainless steel, materials with a 

nickel base, or titanium alloys. Aluminum 

alloys containing greater than 5 percent 

copper are not permitted.

Additional requirements to keep in mind 

with respect to materials and the ISS:

Payload materials that provide structural 

support need to meet stress and corrosion 

requirements.

Water-soluble volatile organic compounds 

are strictly controlled within the environment of the ISS. The release of methanol, 

ethanol, isopropyl alcohol, n-propyl alcohol, 

n-butyl alcohol, acetone, ethylene glycol, 

and propylene glycol are restricted in the 

ISS pressurized elements because the 

water recycling system can remove only 

limited quantities of these com- pounds 

from water condensate.

RADIO FREQUENCY AND 

SPECTRUM MANAGEMENT

If you are planning using radio frequencies 

in your payload design, it is important to 

engage the spectrum management team 

early. Your PIM will assist in helping you 

reach the experts.

Your PIM will guide you through the licensing processes (should your payload 

require it). They may seem a bit complex 

but they are necessary to minimize potential technical anomalies, interventions, and risks to mission success.

INFORMATION TECHNOLOGY 

FOR YOUR PAYLOAD

There are several options for telemetry, 

Health & Status monitoring, and commanding for your payload from the ground. Your 

PIM will connect you to the experts that will 

help determine which options will work best 

for your payload.

Separate your ISS interfaces from your 

science software as much as possible to 

facilitate pre-approvals with your software integration.

REQUIREMENTS 

VERIFICATION

Success with requirements verification can 

be achieved by following the best practices 

throughout your payload’s lifecycle:

Stay in close contact with the PIM

Openly communicate preliminary pay- load 

design data

Engage NASA experts early and often

Keep stakeholders apprised of payload 

design changes

You have access to support throughout 

the entire process of building your payload. Working together with experts will 

facilitate your success in meeting your 

scientific objectives while verifying that 

the crew and the ISS remain safe.
National Aeronautics and

Space Administration

Quick Start

Guide to

Payload Design

PAYLOAD

SAFETY

OVERVIEW

March 2, 2022
Safety Reviews are required for all spaceflight hardware going to the ISS, including 

payload, science, equipment and commercial. These reviews span all aspects of the 

payload’s development and performance. 

Reviews consider the design, operations, 

functional capabilities of the payload’s flight 

hardware and the associated ground support equipment a payload needs throughout its entire lifecycle. 

There are four levels, or phases, of Safety 

Reviews aligned to the design maturity of 

the payload.

The payload will need to meet safety requirements associated with each stage. 

Phase 0: Safety Technical Interchange 

Meeting (TIM)

Phase I: Safety Review for payload’s 

Preliminary Design

Phase II: Safety Review for payload’s 

Critical Design

Phase III: Safety Review for payload’s 

Final Acceptance

Documentation of a payload’s potential 

hazards and controls matures over the 

course of these reviews, ending with verifications for all controls. The Safety Review 

phases act as milestones and gates for 

payloads along the path to ISS.

The ISS Safety Team provides safety 

oversight, guidance and review during the 

phased Safety Review process. Much of 

the team’s time is dedicated to ensuring 

Payload

Safety

Overview

Don’t try this at home
Quick Start Guide to Payload Design: Payload Safety Overview 3

successful and active safety engagement 

as part of the payload integration process. 

They work with all payload teams, from first 

time Payload Developers (PDs) to repeat 

PDs.

Your Payload Integration Manager (PIM) 

will connect you with personnel to help 

shepherd you through the multi-staged 

safety process.

At the payload Kickoff meeting, you are 

introduced to the Safety Review Process 

and are provided preliminary information 

on important safety concepts such as the 

meaning of a payload being designated 

“Safety Critical.” The Kickoff’s safety presentation provides insight into how safety 

requirements, issues and concerns are 

managed throughout the payload development and integration process.

You will receive a large amount of information at the Kickoff, including an explanation 

of the Safety Process. However, it is not 

necessary to understand fully the entire 

process and elements at this early stage. 

PIMs and safety personnel will guide you 

on how best to prepare for each Safety 

Review Phase and associated milestone 

review meeting.

Your PIM can provide clarification regarding safety requirements and receive 

recommendations for avenues to get 

help. If anything seems unclear, ask! In 

addition, specific requirements vary for 

individual payloads. Understanding fundamental safety requirements up front 

will help you lay a solid foundation for 

upcoming ISS Safety Review Panel (ISRP) 

Reviews.

During the Kickoff meeting, be sure to take 

time to discuss safety with your team as 

well as with NASA experts who can provide valuable guidance up front, saving 

disappointing setbacks. This interaction is 

especially important if you are new to ISS 

or if you were PD for a different payload. 

Note that the Safety Review Process can 

be taxing, and you may require extra or 

more personalized and intensive guidance/

assistance. Receiving assistance is especially important when approaching a formal 

Safety Phase Review to mitigate schedule 

risks and stay on track for mission success.

Payloads can have many safety requirements, and information overload can result 

in inefficient and incomplete data for a 

phase review.

To keep safety in perspective, two Space Station Program (SSP) documents are key:

SSP 30599 Safety Review Process: 

Contains process description and data 

requirements

SSP 51721 ISS Safety Requirements: 

Contains top-level NASA technical 

requirements for experiment and 

non-experiment hardware.

Your PIM can provide clarification on important aspects of safety requirements 

documents as they relate to your payload.

THE SAFETY REVIEW 

PROCESS

The Safety Review Process is a joint 

responsibility of the PD, NASA ISRP, and 

visiting vehicle (VV) owners. ISS Program 

and VV owners manage requirements. 

The ISRP and technical support evaluate 

payload compliance throughout the phased 

process. You likely will interact mostly with 

the ISRP.

To succeed at Safety Reviews, begin 

early to establish safety as an integral 

part of hardware design/development 

process. A best practice is to assess payload hardware for all potential hazards 

throughout all mission phases and maintain good documentation on configurations, materials and parts. These documents may be key evidence for meeting 

a safety requirement.
4 Quick Start Guide to Payload Design: Payload Safety Overview

Make sure safety is

part of your design.

Expectations grow at each phased Safety Review:

Phase 0 TIM: seeks images, diagrams 

and other informal documentation to 

inform the ISRP of payload objectives 

and concepts for design and operations 

and to enable provide recommendations.

Phase I: This phase corresponds to the 

Preliminary Design Review and delves 

deeper into evolving payload needs 

and hazards. Initial Hazard Reports, 

which define causes and controls, are 

due. Preliminary verification methods 

may be presented, but full development 

is not yet required.

Phase II: This phase corresponds to 

the Critical Design Review. Design 

iterates to ~60 percent completion, and 

final planned verification methods are 

identified.

Note: Payloads that undergo major 

change or have incomplete products 

entering advanced safety reviews may 

need to return to earlier phases.

Phase III: With the design finalized, 

the status of verifications that were 

successfully performed/completed are 

reported. All analysis is completed with 

only nominal open work remaining; 

e.g., late inspections, late filling operations, etc. Special TIMs can be held 

to address any problems or necessary 

changes to previously agreed-upon 

designs or hazard control/verification 

approaches.

The types of reviews and the relative 

depth of detail required depend on payload hardware complexity, technical maturity, and hazard potential and may be 

modified by the ISRP chairperson in conjunction with you as PD. Additionally, the 

Safety Review Process may be tailored 

as appropriate and agreed to between 

the PD and ISRP. By the end of the process, there may be some residual safety 

risk the ISS Program could consider to 

help you achieve the requested science 

objectives.

As part of the ISS Safety Review Process, 

payloads are required to demonstrate compliance with applicable ISS requirements. 

Assigned ISRP members and technical 

support staff perform independent reviews 

of each payload’s safety assessments and 

provide input to the ISRP.

Many PDs think they can complete all 

the safety documentation to the satisfaction of the ISRP singlehandedly. However, experienced safety engineers are 

able to more easily and thoroughly identify potential hazards and develop controls that instill confidence among safety 

representatives. Best practice suggests 

that including a safety expert on your 

team to help you through these phases 

is optimal. This additional support allows 

you to focus your attention on managing 

the process, consulting with the Safety 

Payload Engineer (SPE) and Client Safety Engineer (CSE) (described in the next 

section) and engaging other members 

of your team as needed.

Even if you do not have a dedicated 

safety engineer on your team, it is recommended that you designate an individual as an ISS representative (such as 

a systems engineer or safety expert) as 

a liaison who attends the formal Safety Reviews for each phase in person. 

Other experts should be on call during 

these meetings to answer questions in 

real-time.

Ultimately, the purpose of the Safety Review Process is to ensure that payloads do 

not compromise the safety and health of 

the crew nor the capabilities of the ISS.

RESOURCES FOR SAFETY 

ADVICE

The Safety Payload Engineer (SPE) 
Quick Start Guide to Payload Design: Payload Safety Overview 5

assigned to each payload executes the 

Safety Review process and helps assure 

payload safety on behalf of the ISRP. While 

their primary duty is independent safety 

review and evaluation of the PD-provided 

safety analysis, they are committed to helping the payload succeed.

The SPE is your primary safety resource 

and helps communicate safety expectations and their intent so you can design 

hardware/software to an acceptable level of risk to the crew and vehicle. More 

generally, the SPE will advise you on 

reaching and passing each of the Safety 

Review gates. Like the PIM, the SPE can 

leverage the help of various discipline 

experts who can take on issues and be 

instrumental in helping you succeed 

while preserving safety.

While these experts are available to assist you through the process, you are 

responsible for completing the safety documentation. You have the most 

knowledge about and are ultimately 

responsible for the payload and related 

documents.

For some PDs, an additional level of 

support may also be available. The Client Safety Engineer (CSE) is a senior 

SPE authorized to provide additional 

tailored services to PDs in safety analysis 

and safety product development. The 

CSE serves independently from the SPE 

during ISRP reviews. CSEs are assigned 

in response to authorization/agreement 

from the ISS Program.

For integrated help with a multi-discipline challenge, you can work with 

the assigned SPE and request informal 

working group meetings prior to phased 

Safety Reviews to receive support resolving an issue. Making use of these groups 

is an excellent way to engage expertise 

within NASA. Experts can assist you by 

providing their understanding of any 

technical safety constraints that could 

affect a project.

Working group experts can suggest potential means to control hazards based 

on previously successful implementation 

approaches. They can help guide you 

through the safety process and steer 

your team to develop practical hardware 

designs and proven methods of operation, avoiding payload characteristics 

and thresholds that necessitate additional tests, controls, redundancy, and 

complication.

Bottom line: Safety experts are here to help 

get your payload through the integration 

process while assuring your payload meets 

all safety requirements. Be sure to ask for 

safety contacts by discipline and reach out 

to them early in the project lifecycle.

HAZARD ANALYSES AND 

HAZARD REPORTS

Performing Hazard Analyses and preparing Hazard Reports (HRs) are two crucial 

tasks for any PD. Hazard Analyses involve 

systematically identifying hazards, causes, controls, and associated verification 

methods. Hazard Reports summarize how 

payload design and operations demonstrate compliance with requirements and 

prevent hazards.

Payload hardware and software are assessed for all potential hazards throughout 

all mission phases. If a hazard cannot be 

eliminated in design, the hazard will be 

controlled to mitigate the likelihood and the 

consequences of the risk to an acceptable 

level.

HRs can be time- consuming to complete, and the standard templates are 

written to address many different types 

of hardware and cases in one document. 

Your Hazard Report will never use all 

the possible cases, so you will need to 

delete all the irrelevant cases from your 

payload-specific HRs.

Since the HR template is a guideline intended to be tailored or customized to 
6 Quick Start Guide to Payload Design: Payload Safety Overview

the needs of the specific payload, using 

HR templates without customizing them 

may raise concerns with the Safety Panel. Since each payload is unique, you 

will demonstrate to the panel you and 

your team understand the logic and approaches defined within the generic HR 

templates by modifying them as appropriate for your specific design and operations.

Controlling hazards by design

In the event it is impossible to remove a 

hazard completely, there are two options 

for controlling hazards during payload 

hardware development/ design. Each of 

these terms carries specific meanings and 

ramifications. 

Design to Tolerate Failures indicates 

hazard controls are required.

Design for Minimum Risk requires only 

minimum supporting data and relies on 

design robustness.

Hazard severity classifications are defined as 

follows:

Marginal - Any condition that may (a) 

cause damage to an ISS end item, the 

loss of which itself does not constitute 

a critical or catastrophic hazard, and/

or (b) an injury that does not require 

medical intervention from another 

crewmember nor consultation with a 

Flight Surgeon.

Critical - Any condition that may cause 

(a) a non-disabling personnel injury 

or illness, (b) loss of a major ISS end 

item, (c) loss of redundancy (i.e., with 

only a single hazard control left) for 

on-orbit life sustaining function, or 

(d) loss of use of systems needed for 

essential logistics.

Catastrophic - Any condition that may 

(a) cause a disabling or fatal personnel 

injury or illness, (b) loss of ISS, (c) loss 

of a crew-carrying vehicle, or (d) loss of 

a major ground facility.

For additional rationale, explanation 

and examples for each of these severity definitions, see SSP 51721, ISS Safety 

Requirements.

During a safety review, the ISRP may 

deem an item to be “Safety Critical.” 

This designation indicates the item has a 

feature/aspect whose failure may result 

in a critical or catastrophic hazard. Safety 

experts are familiar with this designation 

and can provide guidance on typical 

hazard controls and verification methods 

to consider should the hardware contain 

Safety Critical elements.

THE SAFETY DATA PACKAGE

To meet ISS Program safety and interface 

requirements and guidelines, you must provide evidence that the payload meets the 

requirements described in program documents. You will demonstrate this evidence 

by providing information through the Safety 

Data Package (SDP), which ISRP technical 

reviewers evaluate. Updated and refined 

by the PD team throughout Safety Review 

Process, the SDP typically includes details 

for the payload, including hardware design 

information and the Concept of Operations. The ISRP expects you to provide an 

assessment of potential hazards, detailing 

your approach towards hazard control and 

associated verification activities.

The SDP defines hazards, hazard controls, 

and verification of hazard controls. The 

PD identifies all hazards and ensures that 

proper hazard controls have been developed and implemented for each hazard.

The SDP encompasses all safety-related 

information pertaining to a payload, including hazard identification, classification, 

issue(s) resolution, if applicable, and a 

record of all failures/anomalies with special 

emphasis on those pertaining to safety.

Note: The ISRP has available supplemental information on assessing hardware for 

safety, performing a Hazard Analyses, and 

constructing an SDP. These resources can 
Quick Start Guide to Payload Design: Payload Safety Overview 7

be provided by the assigned SPE/CSE.

A good SDP follows a logical, structured 

format, using a common application 

with a reader-friendly platform; e.g., 

Word, PowerPoint, PDF, but not Excel. 

Charts, diagrams and other helpful elements are recommended for conveying 

information as clearly as possible to the 

ISRP.

Through developing the SDP and HRs, you 

communicate with NASA that your team 

has addressed safety throughout the development of the payload. 

Upon completion of each phased Safety 

Review, the Safety Data Package with 

approved Hazard Reports serves as formal 

documentation that a payload has been 

evaluated for any potential safety risks and 

that the mitigation of these risks has been 

thoroughly considered and adequately 

controlled.

The SDP should evolve with additional details added to it throughout the 

phased Safety Review process. See Figure 1, Schematic process flow for SDP.

By working together, you and the NASA 

safety representatives can find ways to 

mutually succeed in fulfilling the obligation 

to fly safely.

SAFETY REVIEW OVERVIEW – 

PHASE 0 EXAMPLE

The ISRP Chair is responsible for determining whether a payload is safe for flight 

based on the recommendations of panel 

members. The Chair’s focus is on HRs and 

safety Non-Compliance Reports generated 

throughout the Safety Review. The Chair 

aims to approve the payload; however, it 

is your responsibility to provide enough 

rationale to enable them to do so.

Although the Phase 0 TIM is not required 

for PD teams, having this standalone TIM 

early in the process is an excellent way 

for you and the ISRP to begin to reach 

a common understanding regarding the 

payload. For PD teams that opt for a 

Phase 0 TIM, this is the first opportunity 

for the ISRP Chair and PD team to meet.

Phase 0 is an opportunity to convey your research objectives as well as the design and 

operations concepts to the ISRP. Sketches 

figure 1

A schematic process flow for 

the Safety Data Package.

Supporting Data

Controls

Supporting DATA

Verifications

Payload Schematic & Function

Hazard Reports & Causes

Safety Data Package Content

Progress Towards Certifications of Flight Readiness (COFR)

ISRP Safety

Review

Process

Phase I

Safety 

Review

Meeting

Phase II

Safety

Review

Meeting

Phase III

Safety

Review

Meeting
8 Quick Start Guide to Payload Design: Payload Safety Overview

and preliminary payload design information 

are acceptable at this phase; plan to include 

as much detail as possible.

Since your field of expertise is likely very 

different from those of the panel members, articulate information thoroughly 

but in layperson-level terms. Since the 

ISRP is more familiar with the ISS and 

its capabilities, the ISRP may be able 

to advise you on design or operational 

concepts that will facilitate easier flight 

certification, and the panel is expected 

to convey their information in understandable language to you.

Approximately two weeks prior to the Phase 

0 review, provide presentation material to the 

ISRP that covers:

What you want to achieve with your 

experiment/ demonstration.

What you think the hardware will do.

How the payload could potentially 

cause harm to the crew, the ISS or VV if 

it did not operate correctly.

What the sources of the hazards are in 

the payload.

What data are available to support the 

details?

What major components your payload 

will include, such as lasers, sources 

of high temperature, toxic chemicals, 

biological samples, etc.

This information helps the panel envision 

the payload in context.

When needed, you may be referred to 

specific technical experts to receive the 

best assistance/resources to resolve any 

anticipated safety challenges as you 

progress through the phases of the Safety Review Process.

Unless the payload has flown routinely 

and no design or operational changes or 

anomalies that would require more extensive in-panel discussions have been 

identified since the previous flight, it is 

recommended that you attend all formal 

Safety Phase Reviews, either in person 

or remotely. Alternately, a safety representative on your PD Team can fulfill this 

function.

There are phase-level checklists (available from the SPE/CSE) to assist the 

PD to help clarify expectations of the 

SDP, accompanying Hazard Reports and 

other supporting data and to ensure all 

necessary technical data are included. 

It is your responsibility to ensure quality control of the data and to know how 

and when this information needs to be 

provided.

When preparing presentation materials 

for Safety Reviews, your objective is to 

explain how the payload works and why 

the payload is safe to fly. You will provide evidence that you have consistently 

prioritized safety throughout the design 

process, providing grounds to establish 

the desired rapport of trust. Aim to make 

your presentation comprehensible and 

succinct and include an orientation overview and illustrations.

The SPE/CSE will clarify what to expect 

at these reviews. Have experts on call 

during the review to help answer technical 

questions during the meeting. Unanswered 

questions are tracked, and you will be 

asked to respond to them at the next review 

if an answer is unavailable when asked 

during the review meeting.

The job of the ISRP is to ensure the safety of the crew and vehicles, so the ISRP 

Chair will ask questions and provide 

feedback in order to gather ample evidence to approve the payload to fly. A 

PD who listens carefully at reviews and 

takes the advice of the panel — particularly regarding appropriate hazard definitions and controls — will be able to 

successfully navigate the safety review 

process.

A successful review demonstrates that the 

PD is thorough, has thought things through, 

knows the payload design well, understands 

the requirements, and has anticipated questions and prepared answers.
Quick Start Guide to Payload Design: Payload Safety Overview 9

PAYLOAD SAFETY SUMMARY

Over the years of ISS research utilization, 

safety representatives have learned many 

lessons to apply to future development activities. PDs who approach the review process with a willingness to invest time early, 

demonstrate a thorough understanding of 

potential safety hazards and who display 

a willingness to have candid discussions 

will reap rewards in the later Safety Review 

phases. As is the case with each phase of 

the payload project lifecycle, communication and collaboration are key.

If a requirement is unclear, ask for clarification. When possible, ask to connect 

with experts or specialists and get their 

feedback before design decisions are 

made. If only preliminary information is 

available, identify it as such and share it. 

Test prototypes and always keep complete records on materials, parts, and 

configuration.

Since it is the responsibility of ISS safety 

personnel to ensure the safety of the crew 

and the vehicle, be prepared when safety 

personnel ask questions to highlight missing information. Incomplete data can lead to 

rework and reconvening of phase meetings.

The Safety Review Process can be facilitated by having a dedicated safety 

expert on the PD team, by designating 

an ISS representative (such as the team’s 

project systems engineer) to attend each 

phase review. These highly recommended best practices are worthwhile investments for every PD to consider as part of 

their budget/resource planning.

Seasoned ISS safety personnel may be 

able to assist with simpler or more reliable design/operational considerations. 

At a minimum, they will be able to help 

identify areas to improve efficiency, including solutions for reducing paperwork while continuing to meet ISS safety 

requirements.

While it is always the goal to eliminate or 

fully control hazards whenever possible, 

safety personnel understand that in some 

cases, an easy design solution is neither 

practical nor possible. In such cases, understand that the ISRP will continue to work 

jointly with you on the problem and explore 

options to determine the best solution — 

together. 

A payload may be able to receive an Exception/Waiver for a particular requirement 

if the safety community understands the 

hazard, the environment, and the controls 

to the point that the ISS Program is willing 

to accept the residual risk.

The goal of everyone involved is to fly the 

payload safely in space. The PIM is your 

main source of support through the integration process, and there are multiple people 

available — Research Portfolio Managers 

(RPMs), SPEs/CSEs, and ISRP representatives with a variety of discipline experts 

— to support achieving this goal and the 

desired mission success.
National Aeronautics and

Space Administration

Quick Start

Guide to

Payload Design

ACRONYMS

March 2, 2022
ACRONYM MEANING REFERENCED IN 

GUIDE SECTION(S)

ABS Acrylonitrile butadiene styrene Payload Engineering

ATCS Active Thermal Control System Payload Engineering

C Centigrade Payload Engineering

CoFR Certification of Flight Readiness Payload Safety

COTS Commercial-Off-The-Shelf Payload Engineering

CSE Client Payload Engineer Payload Safety

CSS Client Service+Satisfaction (Team) FAQs

DFMR Redundant or Designed for Minimum Risk Payload Engineering

EDMS Electronic Document Management System FAQs

EEE Electrical, Electronic, and

Electromechanical

Payload Engineering

EMC Electromagnetic Compatibility Payload Engineering

EMI Electromagnetic Interference Payload Engineering

EPDC Electrical Power Distribution and

Control

Payload Engineering

EPS Electrical Power System Payload Engineering

FAQs Frequently Asked Questions Getting Started / FAQs

FEP Fluorinated ethylene propylene Payload Engineering

FIT Failure-in-Time Payload Engineering

IPL Integrated Payload List Getting Started

ISRP ISS Safety and Review Panel Payload Engineering / 

Payload Safety

ISS International Space Station Getting Started / FAQs 

/ Payload Engineering / 

Payload Safety

Acronyms

What does that mean again?
Quick Start Guide to Payload Design: Acronyms 3

IT Information Technology FAQs

ITCS Internal Thermal Control System Payload Engineering

JSC Johnson Space Center Payload Engineering

Li-ion Lithium ion Payload Engineering

LTL Low Temperature Loop Payload Engineering

MAPTIS Materials and Processes Technical Information SystemPayload Engineering

MTL Moderate Temperature Loop Payload Engineering

NASA National Aeronautics and

Space Administration

Getting Started / FAQs 

/ Payload Engineering / 

Payload Safety

NDC NASA Domain Credential FAQs

ORBIT OZ Requirements Baselining and

Integration Tool

FAQs

OZ ISS Research Integration Office’s Mail Code 

OZ at NASA/Johnson Space Center

FAQs

PD Payload Developer FAQs / Payload Engineering / Payload 

Safety

PDI Payload Data Integrator FAQs

PET Polyethylene terephthalate Payload Engineering

PFA Perfluoroalkoxy Payload Engineering

PIA Payload Integration Agreement Getting Started / Payload Engineering

PIM Payload Integration Manager Getting Started / FAQs 

/ Payload Engineering / 

Payload Safety

PSE Safety Payload Engineer Payload Safety

PTCS Passive Thermal Control System Payload Engineering

PVC Polyvinyl Chloride Payload Engineering

RPM Research Portfolio Manager FAQs / Payload Safety

RSA

SecurID

A two-factor authentication technology used 

to protect network resources

FAQs

S&M Structures and Mechanisms Payload Engineering

SDP Safety Data Package Payload Safety

SSP Space Station Program Payload Safety

TFE Tetrafluoroethylene Payload Engineering

TIM Technical Interchange Meeting Payload Safety

VV Visiting vehicle Payload Safety