David M. Palmer wrote:
In article , Max Beerbohm
wrote:



Seriously, if you are going to say that there is no reason not to do a
Hubble visit, you need to address the safety issue - as some on this
group have done.

The article above is poorly researched because of this.


The expected risk cost is ~0.1 lives and 0.015 shuttles (assuming a
1/70 chance of disaster with each shuttle mission not to ISS).


Recalculate for 1/50 That is the current safety rating.


It's not a safety issue. It is quite a bit of a project management
issue. The 2007 launch to Hubble would be right in the middle of
ISS flights. They would have to take a shuttle offline and do
a one-off flight to another destination. If they go with a
safety net of a spare shuttle, then you have created a gap of
a couple months when ISS construction and processing is interrupted.

It's also a 40% chance of vehicle loss over the remaining number of
flights, to where no one individual flight is more risky than any
other, it is the aggregate total that is the issue. Without ISS,
shuttle would be permamently grounded already. There is zero push
to get it back into service for anything else.

The deaths are equivalent to ~12 million passenger miles of automotive
travel, or every member of the American Astronomical Society driving
2000 miles, or every U.S. amateur astronomer driving about a dozen
miles, or every person who has ever looked at a Hubble picture and
thought 'wow! that's cool' driving a few hundred meters.

Or to put it another way, it's equivalent to each of the seven
astronauts who decide that they are willing to risk a Shuttle flight to
fix Hubble doing so.

Now that the safety issue has been addressed (although not compared to
that of the dozens of planned trips to the ISS, with only a marginal
increase in safety per flight) let's go and fix it.