A variety of HST times will be available to augment observations provided by ground based astronomers. A group of planetary scientists, Peter Smith and Robert Reid of the Lunar & Planetary Laboratory, and Matthew Golombek and Ken Herkenhoff of the Jet Propulsion Laboratory, have been granted some HST observing time through Cycle 6 (12 months beginning July, 1996) to determine climatic conditions, dust opacity, and dust storm activity at the Mars Pathfinder primary and secondary landing sites during cruise. Since the Pathfinder spacecraft does not go into orbit around Mars prior to landing, careful monitoring of all landing sites must be made well in advance in order to make necessary course corrections. This is especially true if the primary landing site is experiencing local dust storm activity and Pathfinder must be redirected to a secondary landing site. HST observations have been scheduled for all landing sites prior to trajectory course maneuvers (TCMs).
Dave Crisp of the Jet Propulsion Laboratory, as a member of the Wide Field/Planetary Camera 2 (WFPC2) Science Team, also has some observing time from HST as part of the Guaranteed Time Observing (GTO) program.
In addition, a team of planetary astronomers lead by Phil James of
the
University
of Toledo will continue its long-term program of HST Mars
observations during the 1996-97 apparition. These observations,
begun in 1990 in HST Cycle 0, are designed to monitor the evolution
of clouds, hazes, surface ices, and atmospheric ozone during the
Martian seasonal cycle. As well, they will be used to search for
long-term variations in Mars surface albedo features, to map the
distribution of various minerals on the Martian surface, and to
provide cruise-phase support information for the Mars Pathfinder and
Mars Global Surveyor
spacecraft missions.
The 1996-97 observations during HST Cycle 6 will occur at 8 points
in the Mars seasonal cycle between September 1996 and June 1997.
Planned observation windows are indicated in Table 1 below. Because
of scheduling limitations, it is not possible to know the precise
time that the observations will occur until only a few weeks before
the observation window. The observations will be made with the Faint
Object Spectrograph (FOS) and the WFPC2 instruments. WFPC2 images
will be obtained using up to 10 filters, designed to optimize the
detection and discrimination of clouds, ozone, ices, and surface
minerals, during each orbit.
HST Cycle 6 ends at the end of June 1997. We are planning to
propose to continue these and other observations during the beginning
of HST Cycle 7 starting in July 1997, so as to provide synoptic HST
Mars imaging coverage for the duration of the Mars Pathfinder Lander
primary mission and for the remainder of the Mars Global Surveyor
Orbiter cruise phase.
Other team members include
James Bell (Cornell
University), Todd Clancy (Space Sciences Institute),
Steve Lee (University of
Colorado), Leonard Martin (Lowell
Observatory), and Mike Wolff (Space Sciences Institute).
|
Date |
Observations |
|
16-20 September 1996 |
Imaging at CML=165; FOS Scans |
|
06-10 October 1996 |
Global Imaging at CML=045,165,285 (1st Pathfinder observation) |
|
18-22 November 1996 |
Imaging at CML=165 |
|
02-06 January 1997 |
Global Imaging at CML=045,165,285; FOS Scans |
|
25-31 March 1997 |
Global Imaging at CML=015,105,195,285 |
|
14-18 April 1997 |
Imaging at CML=045 (Pathfinder monitoring intensifies) |
|
17-21 May 1997 |
Global Imaging at CML=045,165,285 |
|
26-30 June 1997 |
Global Imaging at CML=030,075,345 (Daily weather) |
CML=Central Meridian Longitude
FOS=Faint Object Spectrograph
All Imaging will be performed with WFPC2 using up to 10 filters
between 218 and 1042 nm