Mission Concept Exploration

A space mission is to

  • Provide a service
  • Enhance sience
    • Space exploration
      • Space environment  (in situ measurement of solar wind, magnetic field, etc.)
      • Astronomy and astrophysics
      • Planetary or lunar research
    • Geodesy
    • Micro-gravity
    • Environmental research (Earth climatology)

thereby exploiting one or more space characteristics (global perspective, above the atmosphere, gravity-free environment, and abundant resources). For a description of some space missions, see our overview pages on space missions.

Space missions are conducted far away from Earth in a difficult to reach and alien environment (vacuum) and hence tend to be of a very complex nature. This complexity is illustrated by the great number of people involved in the development of a space mission, the resources (in terms of hard- and software) needed, the long development time and the high cost. As an illustration, we mention that the cost of a mid-sized car is about 25-50 Euro per kilogram (depending on the type of car), whereas the cost of a typical communications satellite orbiting Earth at about 36,000 km altitude is in the range 50,000-300,000 Euro per kilogram.

Space mission concept exploration deals with how the mission will work - that is how it will satisfy the end user's needs. It will lead to a broad definition of the space mission, and the various elements/segments in the space system that work in unison to realize the mission. 

 

Why mission concept exploration (1) ? 

 

 

 

Why mission concept exploration (2) ? 

 


By performing space mission concept exploration we focus on accomplishing the mission thereby balancing what we want with the cost and the risk we are willing to take.  

Definition of a space system

(From: NASA "Systems Engineering Process for Programs and Projects", 1994)

"The whole of hard- and software, personnel, training, support, etc. required to conduct a space mission". 

And in Dutch

"Het geheel van hard- en software, personeel, training, ondersteuning, enz. nodig voor de uitvoering van een ruimtemissie"

In e.g. "Space Mission Analysis and Design" by Larson and Wertz, the following space mission segments/elements (the building blocks) are distinghuised:

  • Mission subject
  • Launch segment
  • Space segment
  • Orbit segment
  • Operations segment
  • Ground segment
  • Command, control and communication architecture

The result of the concept exploration process is laid down in a mission definition document which usually also includes a system requirements definition.

Required expertise:

Experts required for developing a space system include:

  • Subject (e.g. principal investigators, customers, users)
  • Payload expert(s)
  • Spacecraft bus expert(s)
  • Launch expert(s)
  • Assembly, Integration & Verification expert(s)
  • Operations & logistics expert(s)
  • Command & Control expert(s)
  • Communication expert(s)
  • Orbit expert(s)
  • Ground segment expert(s)
  • International law
  • Software expert(s)
  • Data distribution, storage and archiving
  • Marketing expert(s)
  • Costing, risk expert(s)

Note that 1 person can be expert in more than 1 area.

Steps in mission concept exploration:

 

Step

 

Outputs

 

Comments

 

Define mission needs, requirements and constraints

 

  • Mission statement
  • List of mission objectives
  • List of mission requirements

 

  • Includes a study of the subject that we want to interact with (what information is to be gathered/provided, and at what rate)

 

Develop alternative mission concepts

 

  • Alternative mission architectures
  • List of possible launch sites
  • List of possible launchers
  • List of possible orbits (high or low thrust aplications)
  • List of possible payloads (instruments)
  • Communications architecture
  • Possible operations & logistic concepts
  • Etc.

 

  • Include several concepts that scope out of the possibilities
  • Include past solutions
  • Consider the use of "off-the-shelf" hard- & software
  • Avoid any calculations at this point

 

Assess concepts

 

 

  • Collect data 
  • Perform analysis/calculations
  • Avoid detailed optimization

 

Trades

 

  • Ranking criteria
  • Ranking of feasible options
  • Selection of best system
  • Documentation of reasons

 

  • Ranking criteria essentially determine what parameters need to be assessed (see previous step)

 

Iterate and document design

 

  • Documentation of baseline if no iteration is required
  • Documentation of reason for iteration

 

 

 


Problems and answers

Interesting links

Related courses at TU-Delft/LR

  • Space Engineering & Technology I (AE1-801):  Several lecture hours on context of space missions (space markets, applications), space systems and payloads
  • Space Engineering & Technology II (AE2-S02):  4 lecture hours on mission concept exploration (the process and typical outputs)
  • Space Engineering & Technology III (AE3-803):  Mission examples
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