Welcome to the MEOSat Webpage

Purpose of this effort:
"To improve understanding of engineering integration, the class will be involved in a conceptual design study that is concurrent with, and parallel to, an actual ongoing study for a NASA space system."
(Source: Aero 581, Satellite Technology Syllabus)
Presentation Details
- Monday, 8 December 1997
- 9:00 -10:30 am
- 1024 FXB
- Agenda
  
  Introduction and Subject :10
  Orbit and Launch :10
  Spacecraft :20
  Mission Ops, Ground Segment, Cost, and Schedule :15
  Conclusion :05
Latest News
Download the MeoSat Powerpoint Slide Created with Powerpoint 4.0 for the Macintosh. To download the file from a Macintosh, select the link and drag it off onto the desktop. This file can be found in the following directory: ~rohauge/Public/html.
30 Nov 97.
Dry Run
Wed, 3 Dec
6:00 pm
Aero 582 Classroom

24 Nov 97
17 Nov 97. You can access Satellite Tool Kit from a Unix workstation by telnetting to deneb.engin.umich.edu then typing /usr/contrib/stk/STKv4/bin/stk. It takes a minute or so for it to come up. A (lengthy) user's manual resides in the same directory as the program. Let me know if you have any access problems.(Jeanine)

I have set up an e-mail group for us... ae582@umich.edu aero582@umich.edu meosat@umich.edu (Adam)
17 Nov 97 MEOSat Update
- The game plan appears to be to place the satellite in an orbit that will traverse from one region of the inner shell to the 5000 nmi lower level region between the shells. (Likely choice will be elliptical) More to come . . .
- Based on Feedback from Hyland, the users don't seem to care whether the orbit is circular or rectangular. Some wish to see high rads whereas others are more interested in a longer exposure to a lower dose.
- He also mentioned that they are considering placing constellations in orbits that are closer into the earth i.e. not only in the "dip" that we had talked about.
- We are looking to put the spacecraft on a Pegasus (aircraft launched) booster. We should fit within the wt margin at this point, but we still need to contact the vendor OSC to get more data. I'll try to do that before Wednesday.
14 Nov 97. As a recap, we intend to meet at 8:30 (one hour before class) from here on out with a dry run on 1 December at 6pm.
For Monday's meeting: The Subject team will present what they have gleaned on the Van Allen (notto be confused with Van Halen) environment. I was looking at the original slides that Hyland gave to us a the beginning of the class and there are some decent charts on the MEO. There are crappy in black and white, but the references are listed. Just a start: http://www.spaceelectronics.com/SpaceProd/RadTest.html http://www.und.edu/instruct/sharper/lesson7/sld008.htm (a bit too basic perhaps)
The approach I believe we were leaning to was to evaluate putting a s/c into a circular orbit towards the high end of the MEO to see what size booster was required. In addition, we would attempt to identify the booster decision points based on altitude and the wt of the s/c. I think we'll try to have some numbers for Monday as well.
Mission Statement
In order to remain competitive in a global communications marketplace, the United States needs a more efficient satellite constellation. The use of the mid-earth orbit (MEO) promises tremendous cost savings by requiring fewer satellites than a low earth orbit and less time delay than a geosynchronous orbit. However, the MEO is characterized by the severe radiation of the Van Allen Belts. This has prevented its previous exploitation for communication satellite orbits. Ultimately, the government must work with industry to provide a low cost platform for testing radiation hardened electronic components in this hard environment.
MEOsat Mission Objectives

Primary
- Low cost space platform to test radiation hardened electronics and satellite subsystems
- Need to sample and provide information on Mid Earth Orbit radiation environment likely to be experienced by future constellations
- Transmit performance of tested equipment
Secondary
- Form an alliance between NASA and industry in order to enhance US competitiveness in communications and demonstrate to public that government is striving to reduce the cost of space development
Questions
- Where to we want to put the spacecraft? [Mission Ops/Ground Segment/Subject/C3]
  Based on paremeters of APEX, but with apogee capped at 10,000 which represents the end of MEO region. We aren't yet sure why APEX was inclined 70 degrees, perhaps for SCN access. We are also attempting to verify why the 350 km perigee appears to be common for this type of orbit. First cut is shown in Paremeters section below.
- What's the size and weight thus far? [Spacecraft Bus Design]
  See Parameters.
- When does NASA want to get results? (i.e. it may be a 5 yr satellite but do they want feedback in 3 yrs?)
  Based on APEX with a 1 yr design life and the JPL slides we selected a 2 yr design life.
- Where's the ground station?[Mission Ops/Ground Segment/Subject/C3]
  Currently the options are a dedicated ground station, TDRSS, and the SCN.
Parameters

Spacecraft

Item Power (W) Weight (kg) Size
Payload 30 25 .5m
Spacecraft 85 120 TBD
Design life 2 yrs

Orbit

Perigee 600 km
Apogee 10,000 km
Period 3:26?
Inclination 1 deg

Pegasus Payload Parameters

Diameter 1.2 m
Length 1.9 m
Useful Bookmarks

Orbital Pegasus Information
ISPEC: VLC - VAN ALLEN BELTS
PM: TECH UPDATE: Pegasus Puts One In Van Allen Belts : DECEMBER 94
Orbital's APEX Satellite
APEX - Overview Page
The Space Test Program APEX Mission Satellite
The Space Test Program APEX Mission - Flight Results
Radiation Hardened Electronics
Space Environment Effects Branch
Space Environments and Effects Program
Space Radiation in the Literature
Radiation Effects & Analysis Home Page
Kennedy Space Center Home Page
Odyssey Spacecraft (TRW)
Ellipso (Mobile Communications)
Archimedes (ESA)
TDRSS
Air Force SCN
Cincinnati Electronics (Makes SGLS compatible equipment)
NASA's version of the SCN, STDN
STRV-1B, an ESA project. It's weight and orbital parameters are very close to MEOSat.
More on Pegasus
Scout Launch Vehicle 1
Scout Launch Vehicle 2
And more on Van Allen
And more on Pegasus
A nd even more on the Van Allen Belt

We are constrained to work only with the data provided below: (Source: NASA/JPL brief)
The NASA/JPL MEO Satellite Technology Experiment Platforms Program

MEOSat Programmatic Background
- NASA is interested in forming an alliance with the Commercial Communication Industry to facilitate the development and validation of necessary technologies in order to enhance US competitiveness in the global communications marketplace.
- MEOSat is being considered as a key element in the Strategic Plan of this NASA/Industry Alliance.
- Schedule of first MEOsat launch (FY2000/FY2001) will be determined by the needs.
MEO
- MEO is considered from 1,000 to 10,000 km altitude and is primarily characterized by the severe radiation environments of the Van Allen belts.
MEO Dilemma of Commercial Communication
- Would like to explore MEO as placement for constellation
  - less number of satellites needed than LEO
  - less time latency than GEO
- Concerns with radiation in MEO
  - due to their unique business approach
    - low-cost simplified receiving ground station (i.e. cellular phone)
    - more complex and more compact satellite packaging implies more susceptibility to radiation damage
  - Cost/availability of rad/hard parts
Notes
- The purpose of MEOsat is not to design a MEO communications constellation.
- Rather the aim is to develop a low cost platform for the testing of rad-hard electronics in a MEO environment.
- This testing would validate specific electronics components for eventual use in a MEO communications satellite constellation.

Our class email addresses

If you would like to have your phone number listed here, send me an email.

Robert O. Hauge	936-3729	rohauge@engin.umich.edu	Launch/Orb ital Dynamics
Mark Crow	998-0932	miramar@engin.umich.edu	Launch/Orbital Dynamics
Ryan Tyler		tylerr@engin.umich.edu	Launch/Orbital Dynamics
Linda Johnson		lejohnso@engin.umich.edu	Spacecraft Bus Design: Communications
Pete Kyriacou		pkyri@engin.umich.edu	Spacecraft Bus Design: Structure,ADCS
Wendy		wawanner@engin.umich.edu	Spacecraft Bus Design:Thermal,Power
Jeanine Murphy		jeanmurp@engin.umich.edu	Spacecraft Bus Design:Propulsion
Tim Kennedy		xkennedy@engin.umich.edu	Mission Ops/Ground Segment/Subject/C3
Joe Baker	763-8868	bakerjb@zasu.sprl.umich.edu	Missio n Ops/Ground Segment/Subject/C3
Oliver Haas	930-2757	ohaas@engin.umich.edu	Mission Ops/Ground Segment/Subject/C3
Adam Thodey		athodey@engin.umich.edu	Mission Ops/Ground Segment/Subject/C3
David Hyland		dhiland@engin.umich.edu	Grand Poobah

Put together by Robert Hauge
Go to Adam's homepage

Introduction and Subject	:10
Orbit and Launch	:10
Spacecraft	:20
Mission Ops, Ground Segment, Cost, and Schedule	:15
Conclusion	:05

Item	Power (W)	Weight (kg)	Size
Payload	30	25	.5m
Spacecraft	85	120	TBD
Design life	2 yrs

Perigee	600 km
Apogee	10,000 km
Period	3:26?
Inclination	1 deg

Diameter	1.2 m
Length	1.9 m

Welcome to the MEOSat Webpage

Purpose of this effort:

Presentation Details

Latest News

17 Nov 97 MEOSat Update

Mission Statement

MEOsat Mission Objectives

Primary

Secondary

Questions

Parameters

Spacecraft

Orbit

Pegasus Payload Parameters

Useful Bookmarks

The NASA/JPL MEO Satellite Technology Experiment Platforms Program

MEOSat Programmatic Background

MEO

MEO Dilemma of Commercial Communication

Notes

Our class email addresses