[OZAPRS] Work required to run PCSAT2 on ISS

[Richard Hoskin]

Gday,

 

This is a little off topic but I thought it is of interest to all who used
PCSAT2 or wonder why APRS is not currently on ISS.

 

I would like to thank Bob Bruninga and his crew for all the hard work they
have done to get APRS into space.

 

Cheers

Richard

VK3JFK

 

Message: 8

Date: Fri, 9 Feb 2007 09:31:30 -0500

From: "Robert Bruninga" <bruninga at usna.edu>

Subject: [amsat-bb]  Ham Radio Astronaut procedures.

To: <amsat-bb at amsat.org>

Message-ID: <035401c74c56$ff9e95b0$42577a83 at SGSbb>

Content-Type: text/plain;     charset="us-ascii"

 

> What made the man-safety issues of PCSAT2 costly?

> Didn't you just agree to power PCSAT2 off for long 

> periods of time whenever the need arose?

 

I'll answer this on the AMSAT-BB to share the pain.

 

This should be a real eye-opener as to what the space business

is like from the inside out...

 

A 2W TX on shuttle or ISS is considered a catastrophic safety

hazard due to potential for loss of life due to interference or

reset of the space suit, or shuttle ISS control systems or

anything else.

 

Not only must we then design a system with FOUR independent

ground commandable OFF switches in series (or three that have

positive feedback) they all must be proven to be man safe to

NASA man safe criteria.  This means, not a $2 on/off switch, but

a $5,000 on/off switch that has been built from raw materials

that have a paper work history all the way back to the

manufacturer certifying the materials, assembly procedures, and

all testing, and all handling of -each- such switch.  Now that

is just a switch.  You have to have this for every component

involved in the on/off of a man-safe circuit or that an

astronaut touches.

 

Then you have to present this material and plans 4 times to the

30 or so engineers on the NASA Safety Review board.  Each

meeting involves flying people from all over the country to

participate.  Meetings usually take 2 days to review every

detail of the design.  At $200 per man day plus travel, that is

$6000 times 4 or $24,000 just for the meetings, not counting the

days of preps and reviews of everyone leading up to it.

 

Then the documentation, and reviews, and presentations...  And

testing, and travel to observe testing, and paper work over 3

years, all because a 2W TX is considered to be a catastrophic

hazard.  Then you fly.

 

Now you say, we "simply agree to turn it off".  But this

involves a week of planning for each "turn off".  NASA must have

a plan at least a week in advance, not only showing when we are

going to turn it off, but what backup systems we have in place

to assure that it will be off.    And the exact time is planned,

but is not known for sure,  It changes up to the day of the EVA

or whatever evolution.  Hence we are constantly revising this

plan all week long...  

 

We have to coordinate the schedules of all our ground stations,

find who can be awake at the right time, and still have 2 more

chances to turn it off after that.   Each change of 5 minutes to

the evolution completely changes the ground station we need and

all our planning.  Mean time, NASA has to man the consoles, and

DOD has to provide a 24 hour operator at their console to talk

to NASA to talk to me.  Then we send the commands, and  have to

report it to all concerned.  

 

Meanwhile NASA has to plan contingencies in case we fail to get

the switch turned off from the ground.  They have to include the

plan in their Astronauts procedures to take time out of their

EVA preparations (getting their suits ready) to include then

going over to the HAM radio and going through 74 steps in a 5

page procedure to send the OFF command themselves.  Yes, 74

steps... Just to send the DTMF code 123456, because you have to

have a procedure for the crew to turn on the radio, set the

channels, tune the radio, set the controls, verify operation,

etc, etc...  This requires 15 minutes or more and has to be done

before they get into their space suits.  Which takes 3 hours.

So, this means we had to have exhausted all three of our ground

opportunities prior to that 3 hours, so, we have to attempt to

send the command 6 hours prior to EVA.

 

Many times that is in the middle of the night over the ground

station of choice, and since we had to do this for every EVA,

every Docking, and Every use of the robot arm, you can see why

no-one is going to let us do that again.  It wore everyone out.

 

DOD had at least 6 people probably 1/4 time on this project over

3 years, that is about $500,000.   And that had nothing to do

with actually building the hardware.  That is just "oversight

and management" overhead.  Presumably if we didn't have all the

man-safety issues due to the 2W TX, this effort would have been

much less involved.

 

But it all makes sense.  NASA must assure the safety of the

Shuttle ISS system, and these procedures all make sure that the

material, plans, procedures and operations are thoroughly

reviewed and are as safe as possible.

 

Hope that helps.

 

Bob, WB4APR

 

 

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