Errors in Hubble report

Title of the report:

"Assessment of Options for Extending the Life of
the Hubble Space Telescope: Final Report (2005)"

URL: http://www.nap.edu/books/0309095301/html/

Excerpt from the report, page 6:

"The shuttle crew safety risks of a single mission to ISS
and a single HST mission are similar and the relative
risks are extremely small."

This is not objective risk assessment. NASA
Administrator Sean O'Keefe canceled a scheduled shuttle
servicing mission in January 2004 because of the risks
to the astronauts.

Excerpt from the report, page 63:

"Use of the grapple system to perform the final capture
of HST (Hubble Space Telescope) is a significant
challenge, and this is one of the key technical aspects
of the mission that has never been accomplished in
the history of the space program. Some of the required
technologies are expected to be demonstrated by an
experimental system called the XSS-11 (a DARPA program),
but given its timing (late 2006) the opportunity for
feedback and incorporation of lessons learned into the
HTS robotic servicing mission may not occur.

Risks - The capture of HST by the HRV (Hubble Rescue
Vehicle) is one of the highest risk portions of the
mission. The sequence involves having the two vehicles
fly close enough together to enable the GA (grappling
arm) (which cannot be safely teleoperated, due to the
two-second communications delay), to place its end
effector over the pin of the HST grapple fixture,
engage the snares and stiffen the connection."

If the capture takes place above North America, the
two second delay can be greatly reduced. The report
does not mention any tools that can reduce the risk.
NASA engineers are too dumb to invent such tools,
but their Dextre project is receiving lots of free
help from outside of NASA.

Excerpt from the report, page 65:

"The particular axial doors that the first shuttle
servicing mission crew had difficulty with are
not candidates for the robotic mission."

Excerpt from the report, page 66:

"Taking snapshot data readings of the old instrument
upon removal can be helpful in ensuring that the new
instrument is properly installed, but this is not
an absolute foolproof approach unless the position
accuracy of the integrated grapple/dexterous robotic
system is kept within very fine tolerance constraints
based on allowable misalignment for the respective
instrument."

Dextre can blindly follow its own movements with
one millimeter accuracy. Each of its two "hands" has
a lamp and a monochrome camera which has sufficient
resolution to achieve accuracy of a fraction of a
millimeter.

Excerpt from the report, page 68:

"In 1970 the Soviet Union space program performed
rendezvous and capture with a non-cooperative target
with a human operator in control and with no communication
time delays. (A non-cooperative target is one without
transponders or active sensors to provide other space
vehicles with its location, identification, and/or
relative position) In 1998, collaboration between
ESA and NASDA produced a moderately successful
demonstration using the Japanese Engineering Test
Satellite (ETS) VII."

Excerpt from the report, page 74:

"There is some human intervention in the proposed
robotic plan through teleoperation, and there may
even be the potential for some reprogramming of
robotic systems during flight as has been carried
out with Mars landers and rovers. However, in general
the robotic mission will of necessity be rigid in its
design and in its ability to cope with unplanned
anomalies such as those that have been encountered
during each of the four previous shuttle servicing
missions."

The opposite is true. The shuttle missions are rigid
because the shuttles cannot remain in orbit for a long
time. Dextre may remain in space for years and it may
continuously upgrade the HST while small rocket launchers
(e.g., Pegasus) provide it with new replacement parts
and new tools.

__________________________________________________ ___

The report was made by a panel made of 21 members.
Only 3 of them are robotic experts:
Rodney A. Brooks, Vijay Kumar, and Stephen M. Rock.

According to the report the earliest possible launch
of the Space Shuttle rescue mission is July 2006. NASA
claims that it can prepare the Dextre mission in 39
months, but the report claims that it will take 65
months, so February 2010 is the earliest realistic
launch date for the Dextre telerobot.

I can hardly resist the impression that the report is
political propaganda masquerading as science. The
first version of the report, published July 13, 2004
was more objective.

President George W. Bush nominated the panel's chair,
Louis J. Lanzerotti to serve on the National Science
Board (NSB), the 24-member governing body of the
National Science Foundation (NSF) in September of 2004.
This nomination may have persuaded Lanzerotti that
the foreign telerobot should not dominate the U.S.
space program.

Sean O'Keefe was enthusiastic about the Dextre's
mission, but he was under enormous political pressure
to use the shuttle instead. He choose to resign rather
than to yield to the pressure.