In the early 1990s, a group of scientists and engineers at NASA's Jet Propulsion Laboratory made an extraordinary claim: They could develop a space telescope powerful enough to detect Earthlike planets around nearby stars. Now the team has delivered extraordinary proof.
SIM PlanetQuest has successfully completed the last of eight seemingly impossible technology milestones required to prove that the mission can accomplish its ambitious science goals. NASA specified that the rigorous tests of the ultra-precise technologies must be finished by the end of 2005 in order for the mission to move forward.
"By completing these milestones, we've convinced both ourselves and the external reviewers involved in the process that we can really do this mission," said David Gallagher, project manager for SIM PlanetQuest at JPL.
"This is the culmination of over 10 years of dedicated effort. It puts the project in a position where we're ready to go forward into the next stage -- implementation and flight," said Robert Laskin, project technologist.
Daunting feats
Along the road to inventing and testing the mission's revolutionary technologies, team members have chalked up a series of firsts, including:
- Demonstrating the ability to detect the angular position of a laboratory "pseudostar" to an accuracy of one millionth of an arcsecond - the thickness of a nickel, viewed at the distance of the moon.
- Suppressing vibrations at the nanometer level, which enables the instrument to make these incredibly precise measurements.
- Demonstrating the capability to achieve not only the instrument's design specifications, but also a suite of more ambitious goals that will enhance the science return.
Scheduled for launch within the next decade, SIM PlanetQuest will determine the orbits and masses of planets around other stars and detect nearby Earth-size planets. The mission will also determine the distances to stars throughout the galaxy with unprecedented accuracy and perform many other fundamental astrophysics investigations.
 |
| Testbed Lead Renaud Goullioud stands in front of the Microarcsecond Metrology (MAM) testbed. |
"We can now make the long-awaited statement that 'SIM technology is in hand,'" said Steve Unwin, deputy project scientist. "We may still face the traditional hurdles that challenge all space projects -- mass allocations, power allocations, reliability, tight schedules, and limited budgets -- but these are challenges for good engineering, not the invention of new technology."
The process of developing SIM PlanetQuest's technology involved isolating the various challenges into separate testbeds at JPL, and assigning specific teams to each problem. By using this approach, the team was able to complete within a few years a process that otherwise might have taken several decades.
"If you make extraordinary claims, you need extraordinary proof," said Gary Blackwood, the project's external metrology element manager. "It was actually a lot of fun to prove we could do it - to have a job that was almost impossible and then deliver on it."
The SIM PlanetQuest survey of nearby planets will set the stage for NASA's future Terrestrial Planet Finder observatories, which will determine which planets are warm enough for life, and analyze their atmospheres and surfaces for the chemical signatures of life.
