Re: Does Hubble have to die?

hallerb@xxxxxxx wrote:" Redesigning hubble in orbit for eleptical
operations would almost assuredly cost more than launching a new
hubble."


The whole purpose of the sm-4 mission is to utilize the hubble space
telescope until the next generation (jame webb space telescope jwst) or
a version known as a "rehost" (house science committee), can be
placed into operation with as little interruption in data gathering as
possible between programs. The HST's achievements are unrivaled in
the world of astronomy, it would be logical to utilize the hubbles
instruments and platform as to perform science as long as possible. A
possible reduced hubble platform such as one in the case of a
"rehost", would leave the three Fine Guidance Sensors (FGS), (2
used for telescope orientation along with the gyroscopes and 1 that can
be used to measure stellar distances) to perform astrometric research.
The cost of re-boosting the hst up to a higher more elliptical orbit to
conduct astrometric research and the re-tasking the systems, must be
weighed against other programs such as the jwst, but no science is
produced upon the hst burnup, so allocating some funds for a reduced
re-tasked hst mission might actually be more cost effective,
productive, take less time, less money, with less development and
mission risk than the other options discussed below. The estimated
cost of the jwst is "2.4 billion from now to launch" (see below
jwst newsletter), but the technology for such an observatory has yet to
prove it's reliability, and will not be operational until possibly
years after 2013, and so given the fact the technology for an
autonomous mission would possibly not be fully operational by the time
the current batteries run down on the hst, the sm-4 mission was the
only logical way to provide hubbles continuous data gathering for years
to come. Now given another mission to hubble will be necessary for the
purpose of rehost, (or burnup) in the future past 2013, why not
consider other options that would utilize the hst to a reduced but
important data gathering function such as measuring stellar distances,
a base function of equipment that will not be utilized for the rehost,
but may be replaced (sm-4 for instance) to work for years of additional
service past 2013, such as the Fine guidance sensors.


U.S. HOUSE OF REPRESENTATIVES COMMITTEE ON SCIENCE
HEARING CHARTER Options for Hubble Science February 2, 2005
"Page 2
This hearing will help the Committee prepare for the debate over Hubble
that will come to a head once the budget request is released Feb. 7.
There are basically four options available with regard to the Hubble,
each of which is discussed in greater detail later in this charter and
in Attachment A:
· Do not service the telescope. The telescope will then cease to
function as early as 2007. NASA does have other space telescopes in
orbit and others are planned to be launched in 2011, but none has the
same capabilities as Hubble.
· Send the Shuttle to service the telescope. Like any Shuttle
mission, this would put astronauts at risk. It would also delay
completion of the ISS.
· Send a robotic mission to service the telescope. The studies
mentioned above have raised grave doubts as to whether this mission
could be ready in time. The contractor designing the robot takes issue
with those studies.
· Launch a new "platform" with the equipment that was designed to
be added to the Hubble (this is sometimes called "rehosting") and
perhaps include new equipment as well (the proposed "Hubble Origins
Probe" or HOP). This would leave a gap in Hubble science, as the new
platform would probably not be ready until after the Hubble stopped
operating....

Page 10
The Aerospace Corporation Report:
The Academy panel relied heavily on a study produced by the Aerospace
Corporation that analyzed a variety of alternative methods for
extending the life of Hubble. The report was requested, and paid for,
by NASA as an analysis of alternatives (AoA). Aerospace used a "blank
*** of paper" approach that considered generic options rather than
any specific pending proposal. As a result, it did not review the
specific robotics work underway for the Hubble mission, which was only
in an early stage when the Aerospace study was done in any event. (The
Aerospace Report was completed in August, 2004.) Aerospace also did not
review NASA's cost or schedule estimates for the Shuttle, but simply
accepted them as a baseline. Aerospace was not charged with
recommending a specific alternative, but only with ranking their
relative costs and benefits. Key findings of the Aerospace study
include:

· Robotic servicing alternatives, based on estimated development
schedules, are susceptible to arriving too late when Hubble is no
longer in a serviceable state. Furthermore, they undertake
unprecedented servicing operations and are subject to an aging
observatory that may fail for some other reason following servicing.

· Rehost alternatives are lower risk with similar cost to the robotic
servicing missions, but may result in a two- to seven-year science gap.

· SM-4 has costs in the same range as the rehost and robotic
servicing alternatives, has higher probability of mission success than
the robotic servicing missions, and does not suffer from the gap in
science associated with rehost alternatives.

· Other means to perform astronaut servicing with reduced risk such
as launching a safe
haven or relocating Hubble to the vicinity of the International Space
Station are more
costly and take longer to develop than SM-4.

Aerospace Analysis of Alternatives - Summary of HST Servicing Study
Results
Shuttle Servicing Mission SM-4:
Life Cycle Cost (FY04 $B) $2.2, Nominal Development (years) 2.6 ,
Mission Risk: Medium. Development Risk : Medium

Robotic Servicing Mission:
Life Cycle Cost (FY04 $B) $2.0, Nominal Development (years) 5.4.
Mission Risk: High, Development Risk:High

De-orbit Mission (no life extension):
Life Cycle Cost (FY04 $B) $0.4 , Nominal Development (years) 4.2,
Mission Risk: Low, Development Risk: Low

Rehosting SM-4 on a FreeFlyer
Life Cycle Cost (FY04 $B) $2.0, Nominal Development (years) 8.4,
Mission Risk: Low, Development Risk : Low

(Aerospace Corporation defines "Development Risk" for a servicing
mission as the risk that the mission can be developed in time to reach
the Hubble before irreparable damage occurs. Aerospace defines
"Mission Risk" for a servicing mission as the risk that every
element of the mission will succeed as planned and the telescope will
continue to operate for another 3 years after being serviced.)
6. Recent Developments
NASA continues to work on a robotic servicing mission, for which the
FY05 Omnibus Appropriations bill provided $291 million. Of this amount,
NASA plans to spend $175 million through Preliminary Design Review,
scheduled for late March - the stage at which a decision is normally
made as to whether to carry on with a project."


http://www.jwst.nasa.gov/newsletter1.html
The current planned cost for JWST is $2.4 B from now to launch, and
about $1B for 10 years of operations. The JWST project has been
subjected to exhaustive scrutiny by experts who are not part of the
Project or of Goddard, and are chartered by NASA Headquarters to be
skeptical and complete. The technical review panels concluded that the
project is well-managed and making good progress, and that the basic
designs are sound. The independent cost estimate agreed with the
Project's cost estimate within 5%. Both estimates are made on the basis
of extremely detailed lists of parts and subsystems, with discussions
of technical maturity and heritage. The Chandra observatory, which had
extremely challenging optics as well, was built by the same prime
contractor and had comparable total development costs. JWST's planned
budget peaks in 2008, ramping down rapidly after that. The JWST project
has worked to reduce or eliminate many of the future cost risks to the
project. All the contracts are in place every part of the observatory;
the last international agreement (for NASA to accept the ESA
contribution of an Ariane 5 launch vehicle) has been completed. By
January 2007, the project will show that every technological
development is ready for detailed design and flight production by
flight-like testing. Approximately half of the observatory has now
reached the Preliminary Design Review stage (no showstoppers), while
critical design reviews are now being held for the science instruments.
This level of maturity is important because each of these areas
(contracts, technology, mass, etc.) has caused major overruns on other
missions during the mission construction phase."

Open sharing of information is crucial to improving everybody's
understanding of the universe around us.
Tom

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