Zurbuchen Taking One Last Look at JWST Servicing Compatiblity

Zurbuchen Taking One Last Look at JWST Servicing Compatiblity

Thomas Zurbuchen, the head of NASA’s science program, said today that he has created an independent team to take one last look at the servicing compatibility of the James Webb Space Telescope (JWST).  Unlike Hubble, JWST is not designed to be serviced either by humans or robots, but satellite servicing advocates have lobbied for years for NASA to take relatively simple measures to keep the possibility open.

At a meeting of the NASA Advisory Council (NAC) today, Zurbuchen was asked by NAC member Mike Gold if NASA was ensuring some degree of JWST compatibility for servicing.  Gold works for Maxar Technologies.  Its Space Systems Loral business unit is one of the leading companies in developing satellite servicing technologies.

The very popular Hubble Space Telescope is in Earth orbit and was serviced five times by astronaut crews.  The first servicing flight in 1993 saved the mission by fixing Hubble’s defective optics.  Subsequent servicing flights installed many new components and instruments so even though it was launched 28 years ago, Hubble still has many years of productive life ahead.

Artist’s illustration of the James Webb Space Telescope with the telescope on top and its multi-layered sunshield on the bottom.  Credit: NASA

By contrast, JWST will not be in Earth orbit.  It is being sent a million miles away to the Sun-Earth L2 Lagrange point where it will have a better view of the universe.  Even if the space shuttle was still flying, it could not travel that far.  For that and other reasons, including its size and complexity, JWST was not designed to be serviceable.

Once it is launched, JWST will go through an automated deployment sequence that is highly complex.  Northrop Grumman, the telescope’s prime contractor, produced a video demonstrating how it will transpire.  JWST is designed to operate for at least 5 years once it arrives at L2.

JWST was supposed to launch two months from now in October 2018, but significant problems emerged in Integration and Testing (INT) at Northrop Grumman and the launch was delayed to 2019, to 2020 and most recently to 2021.  The cost rose accordingly.  Congress set a cost cap in law of $8 billion for development, but now it will breach that cap by 10 percent and NASA must obtain congressional approval to continue the program.  The new development cost estimate is $8.803 billion, with a life cycle cost (adding operations, but not launch, which is being provided to NASA at no cost by the European Space Agency as part of a cooperative program) of $9.663 billion.  Congress is expected to reauthorize the program.  The oft-used mantra is that it will be “worth the wait” because of the revolutionary science it will produce.

With all that money and scientific discoveries on the line, the fact there is no way to fix it once it is launched is a sobering reality.

Satellite servicing advocates have pointed out for years that although systems do not exist today that could robotically service JWST at L2, they might in the future.  They urged NASA to at least put stickers on the telescope to allow a future robotic system to locate it.

Zurbuchen confirmed today that NASA already has taken some steps and now is looking to see if there is anything else that can be done.

“We have put on stickers, and we are aware of places where we could grapple it related to launch system interfaces … and I actually have tasked an independent team to look at things that we could do that would enhance the ability for us to even do more.”  — Thomas Zurbuchen

He did not provide any further details such as a timeline.

Zurbuchen added ruefully that “I’m paid to worry,” and that while the worst place to find a mistake is in orbit, the second worst place is in INT.

Update:  the word “compatibility” was added to the title for clarification.


User Comments

SpacePolicyOnline.com has the right (but not the obligation) to monitor the comments and to remove any materials it deems inappropriate.  We do not post comments that include links to other websites since we have no control over that content nor can we verify the security of such links.