science requirements flowdown : impacts on the capabilities of small* satellites

NSF Small Satellite Workshop - May 15-17,2007

Science Requirements Flowdown : Impacts on the Capabilities of Small* Satellites

David Klumpar

Montana State UniversitySpace Science and Engineering Laboratory

May 16, 2007

* ~1-30 kg

NSF Small Satellite Workshop - May 15-17, 2007 Klumpar

Three MessagesThree Messages

Impact of Requirements flowdown

Nanosats (1-30 kg) have “taken off”

CubeSats (1-3 kg): An introduction and a potential role in space weather science and in training the next generation workforce


Cost? Complexity?

Mass? Size?

Mission Requirements

Science Requirements

Engineering Requirements

Who, What, Where, When?….Lots of questions

NSF Small Satellite Workshop - May 15-17,2007

Q: What is the appropriate size for a satellite

A: No larger than necessary

This satellite is just small enough to

allow its sensor to see the distant

universe

This satellite is just big enough to allow

its sensor to measure

the radiation belts


This satellite carries a 6 g energetic particle sensor: It

- masses 1 kg- generates 1.5 w O.A.- size is 10 cm- passive magnetic ACS- TM rate 1200 bps

This satellite carries a 1.5 kg energetic particle sensor suite: It

- masses 30 kg- generates 8 w O.A.- size is 47 cm- active magnetic ACS- TM rate 9600 bps


Mission/Science Requirements that drive theMission/Science Requirements that drive the S/C Bus S/C Bus

Power --> are body mount solar arrays sufficient? … articulated extensible arrays are major cost driver

Attitude Control: is active 3-axis pointing required?

Attitude Determination --> Pointing knowledge

Transceiver link margin/Telemetry RateChose the simplest instruments and concept

of operations that close the mission requirement.


Nanosatellites (<20 kg) Launched

0

5

10

15

20

25

30

19901991199219931994199519961997199819992000200120022003200420052006

Four Nanosatellites scheduled for launch 12/06 on STS-116 and Minotaur

2000-2006: 50

1990-1999: 14

Historical Trends: NanosatelliteHistorical Trends: Nanosatellite (<20 kg) Launch Log (<20 kg) Launch Log


Specific Recent Nanosat Sciencecraft -1 Specific Recent Nanosat Sciencecraft -1

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Quakesat 4.5 kg (US) -- ULF Earthquake Precursor signals (2003)

ST-5 3 x 25 kg (US) Technologyvalidation and geospace science (2006) QuickTime™ and a

TIFF (Uncompressed) decompressorare needed to see this picture.



Munin (Sweden) 5.5 kg AuroralPhysics (2000)

FalconSat-2 19.5 kg (US A.F. Academy): Ionospheric plasma (2006-FTO)




Specific Recent Nanosat Sciencecraft -2Specific Recent Nanosat Sciencecraft -2



SNAP-1 (UK) 6.5 kg Surrey Satellite Technologies. Demonstrated rendezvousand formation flying (2000).

GeneSat-1 -- 4 kg NASA-AmesBiological sciences investigation (12/2006)




CubeSat-101 The CubeSat ICDCubeSat-101 The CubeSat ICD


What is a CubeSat?What is a CubeSat?

The basic 1U CubeSat (rules of thumb):– 10x10x10 cm cube– Mass < 1 kg– Power: about 2 w orbit avg– Available payload volume: 300-500 cm3

1U, 2U, 3U constitute present systems with space heritage (P-Pod launch deployer)

“2U”

“3U”

30 cm

“1U”10 cm


Delivery to Launch - 15 Delivery to Launch - 15 daysdays

July 9, 2006

Baikonur Cosmodrome

July 12, 2006

July 26, 2006


July 2006 Cluster Launch: A single rocket carrying 18 satellites July 2006 Cluster Launch: A single rocket carrying 18 satellites (unrelated) was to place payloads in LEO. Fourteen were nanosatellites (unrelated) was to place payloads in LEO. Fourteen were nanosatellites from 1 - from 1 - 22 kg each. Four of these were ScienceCraft nanosatellites built kg each. Four of these were ScienceCraft nanosatellites built by U.S. universities.by U.S. universities.

MEROPE -- MEROPE -- 1 kg1 kg Trapped Radiation Variations Trapped Radiation Variations(2006-FTO)(2006-FTO)MONTANA STATE UNIVERSITYMONTANA STATE UNIVERSITY

ION -- ION -- 2 kg2 kg Mesospheric Mesospheric Airglow (2006-FTO) Airglow (2006-FTO)UNIVERSITY OF ILLINOISUNIVERSITY OF ILLINOIS

Ice Cube (-1, -2) Ice Cube (-1, -2) 1 kg ea1 kg ea Ionospheric Ionospheric Scintillations (2006-FTO) Scintillations (2006-FTO)CORNELLCORNELL

Specific Recent CubeSat-class Sciencecraft

Qu

ickTim

e™

and

aTIF

F (

Un

com

pre

sse

d)

de

com

pre

sso

rare

nee

de

d t

o s

ee

th

is p

ictu

re.




CubeSats Rule!!???CubeSats Rule!!???

NO !! Definitely not appropriate for most missions.

Why not?Limited resources

PowerVolumeTelemetry

Yet the concept has legs:- Small carriers for small low-power, simple sensors - Deployed as an array as space weather monitors- Non-intrusive launch as secondary payloads

-And…. It is a model that is scalable


Space Weather System ConceptSpace Weather System Concept

Approach: Large numbers of small low-cost satellites will make simultaneous coordinated multi-point measurements throughout appropriately-sized regions of Geospace carrying thoughtfully selected operational-grade instruments.

Hypothesis: Nanosatellite technologies are sufficiently advanced to enable low-cost, low-mass constellation class satellites carrying operational instruments for space weather.

Enablers: Advances in microelectronics, microthrusters, MEMs sensor devices, low-power electronics, high-efficiency solar cells, & microminiaturization have enabled satellites with mass fractions of 80-90% (payload mass/total mass) leading to the concept of:

The “ScienceCraft”: An instrument(s) containing the satellite rather than a satellite bus carrying instruments.


Characteristics of an Operational Space Characteristics of an Operational Space Wx System-1Wx System-1

The concept model has the following characteristics:– the recognition that operational space weather data will

be provided from a distributed array of autonomous measuring stations many of which will be in space (with the largest number in LEO)

– the stations are designed for, and built in, a production environment

– the unit cost of the hardware is minimized by:– employing relatively simple sensors (sufficient to meet the

measurement requirements with no unnecessary frills)– limiting the sensor complement to those that provide only the

essential measurements– single string, simple support system for the sensors (i.e., the

s/c bus)


Characteristics of an Operational Space Characteristics of an Operational Space Wx System-2Wx System-2

– the lifetime system costs overall are minimized by:• designing the system to be tolerant of unit failures

• using the aforementioned production run philosophy on the hardware component

• automating data flow from sensor-to-enduser (minimizing operations manpower)

– launch costs for the LEO assets are minimumized by launching large numbers of stations on two or three single small launch vehicles (cluster launches)

Robust system design: Acceptance of risk that some fraction of the individual stations will fail at no impact to system performance


Summary – Three MessagesSummary – Three Messages Impact of Requirements flowdown

– The mission goal sets the science requirements– Science requirements drive the engineering implementation

Nanosats (1-20 kg) have “taken off”– 14 launched 1990-1999– 50 launched 2000-2006– Jan-April 2007, setting a new record?

CubeSats (1-3 kg) may have a role– Ease of integration (sats --> dispenser --> launcher)– Low-risk as secondaries (containment, inert at launch)– Flexibility to accommodate on virtually any launcher– Standard interface minimizes NRE– Science -- you decide

• IMHO, 70 1 kg nanosats carrying simple sensors deployed simultaneously in LEO make a compelling mission for operational space weather

science requirements flowdown : impacts on the capabilities of small* satellites

Documents

bpsthis satellite

capabilities of small

necessarythis satellite

appropriate size

space weather science

science requirements

g energetic particle

compelling mission