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National Academy Performance Goals
| SIM Meets National Academy Performance Goals |
| Report Name |
WidepAngle Astrometry
(end of mission) |
Narrow-Angle Astrometry
(single measurement) |
|
| Requirement* |
Goal* |
Requirement* |
Goal* |
Magnitude Limit (V) |
Nulling |
Rotational Synthesis Imaging |
| 1982 Decadal Survey |
Space Optical Interferometer (SOI)
with resolutions of 1 to 10 µas by early part of next century |
| 1991 Decadal Survey ("AIM") |
30 µas |
3 µas |
not specified |
not specified |
20 |
No |
No |
| 2001 Decadal Survey ("SIM") |
10 µas |
4 µas |
3 µas |
1 µas |
20 |
Yes |
Full uv-plane from 1m to 10m |
| 2002 CAA Letter Assessment of SIM |
10 µas |
4 µas |
3 µas |
1 µas |
20 |
No |
10 m baseline |
| SIM-PlanetQuest Performance |
2.4 µas ** |
0.7 µas ** |
20 |
No |
9 m and 6 m baselines |
| Planet Hunter |
none |
1 µas ** |
10 |
No |
6m baseline |
| SIM-Lite |
4 µas ** |
1 µas ** |
19-20 |
No |
6 m baseline |
|
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| * Requirement represents the design accuracy, with margin, to assure a high probability of meeting this value; Goal represents the best performance expected from the design, and is normally quoted without margin. |
| ** Performance is Current Best Estimate (CBE) prediction, without margin, based upon SIM’s completed technology development program and mature flight design. |
SIM Science is Compelling and Uncompromised
- SIM represents an entirely new measurement capability in astronomy and a revolution in astrometry that will exceed all previous measurements by a factor of 100-1,000. For faint stars, SIM's capability will exceed that of upcoming missions such as Gaia by a factor of 25-75 or more.
- SIM science program endorsed by two NRC Decadal committees (Bahcall-1991; McKee/Taylor 2001). Reaffirmed by CAA in 2002 and praised for its dual capability in astrophysics and planet finding. Astrometric performance exceeds, by more than a factor of 2, the objectives established by the NRC/CAA.
- SIM Science Team & Key Projects selected by peer-review in 2000. These remain relevant today can only be accomplished by SIM-PlanetQuest.
- Half of SIM observing time remains to be allocated via future solicitation/competition.
- Importance in definitively measuring planet masses & orbits is not diminished by advances elsewhere. Modeling and inference are not substitutes for actually measuring the most fundamental property of any astronomical body: its mass.
- SIM has the capability to detect large numbers of rocky planets around nearby stars.
- In a survey of the best 120 candidate stars for hosting such planets in the 'habitable zone,' SIM would have the sensitivity to find planets smaller than Earth around six stars, planets smaller than two Earth masses around 24 stars, and planets smaller than ~ three Earth masses around every star in the survey group.
- Kepler and SIM complement one another.
- SIM studies nearby exoplanetary systems, while Kepler studies a large sample of distant stars to obtain a statistical sample of exoplanetary systems that are too distant for follow-up characterization.
- GAIA and SIM complement one another.
- SIM excels at studying bright and faint sources to high accuracy, while GAIA will obtain astrometric measurements of a large number of relatively bright stars.
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