EVA #5
Author: Jin Sia, Inga Popovaite
Purpose of EVA:
1.0) Scout and record candidate points of entry to the river delta
south of Robert’s Rock Garden for future EVAs to use (approx. 1.5 h.)
These points will only be explored near the bottom of the escarpment
so that their locations and the regolith structural properties can be
recorded; there will be no attempts to scale the full height of the
escarpment.
2.0) Validate viewshed calculation of MDRS GIS map in southern section
of Cow Dung Road for radio communications, especially in the vicinity
of Robert’s Rock Garden.
2.1) Investigate predicted reception corridor south of Robert’s Rock Garden.
2.2) If time remaining, conduct a similar investigation for the
northern section of Cow Dung Road, up to the intersection with Galileo
Road.
3.0) Film video footage for outreach.
4.0) Inga’s data collection for her dissertation on EVA crew
interaction between themselves and with HabComm.
Start time: 0900
End time: 1230
Narrative:
For the first part of the EVA, Inga and Jin drove to Robert’s Rock
Garden in Spirit and parked on the south side of the formation.
Inga then led the team to the entry of what is now known as Path 1, a
potential entry point to the delta that was previously found by Dave
and Inga on EVA #4. They tested the path and found that it was safely
scalable if done so slowly and with care. They found a summit to the
path, although they did not complete the ascent of the escarpment as
that was outside of the EVA plan. They discovered an alternate path
(which, similarly to Path 1, appears to have been carved by water
flow) that did not have the staircase-like structure of Path 1. This
has been named Path 2. The pair found that it was possible to descend
through Path 2 with slowness and care, especially by stepping over or
detouring around bramble-filled pits. However, it was found to require
detouring through relatively steep inclines.
Both conclude that it is possible to safely ascend the escarpment in
EVA suits, given optimal environmental conditions (good lighting, cool
air temperature), generous time constraints, good physical condition,
proper technique, and experienced hikers. It is a challenging hike
that should not be attempted in non-optimal conditions. Inga and Jin
also recommend using Path 1 over Path 2, as the main detour required
for Path 2 is difficult to negotiate. The GPS locations for the summit
to Path 1 and the entrance to Path 2 have been recorded for
revisiting.
After checking in with HabComm, Jin and Inga proceeded south to
investigate further alternate delta entry points. Visual surveys of
the area did not reveal any paths that were obviously easier than
Paths 1 or 2.
At that location, Inga interviewed Jin in the field about the work the
team was doing and the motivation for it. In addition to documenting
fieldwork, Inga aimed to figure out how to take video interviews
wearing EVA suits. She took additional radio with her and used a voice
recorder to record sound from it while she and Jin were communicating
via headsets. This audio will be overlayed with the video footage.
Following the interview, the team returned to the region immediately
south of Robert’s Rock Garden to check radio reception at multiple
points within it. Jin conducted a total of 14 comms checks with
HabComm every 50-100 m, then graded each check on a 4-level scale
based on the quality of the response. He found that the viewshed
calculation in ArcGIS was very conservative in this area, and that
communications were possible in a much larger region than predicted.
ArcGIS calculated that the reception corridor would fan out at an
angle of 13 degrees. However, the true extent of the fan where
communications are possible exceeds 90 degrees if one is reasonably
far away from the Kissing Camel Ridges. Perhaps this is caused by
reflection, refraction, and/or diffraction of radio waves on the
terrain. In the mean time, Inga shot several short videos for media
outreach purposes.
After characterizing the reception corridor south of Robert’s Rock
Garden, Inga and Jin drove north on Cow Dung Road, during which Jin
collected reception quality data approximately once per minute. He
collected 11 datapoints south of the Hab.
On passing the Hab, approximately 45 minutes were remaining in the
EVA, so the team decided to press on to characterize radio
communications in the northern section of Cow Dung Road. Jin collected
18 datapoints. Then, the team returned to the Hab on time.
Jin discovered that while there were no pockets of complete radio
blackout between the Kissing Camel Ridges and Galileo Road, there were
noticeable decreases in transmission quality in areas where the
viewshed calculation predicted there would be blackouts. The
transition to complete radio blackout north of Galileo road was found
to begin approximately where the viewshed calculation predicted it
would. The thickness of the boundary between reception and blackout is
between 300 and 600 m. Due to the subjective nature of evaluating
reception quality and the low resolution of the data, Jin could not
obtain high precision in his analysis.
Ironically, the team encountered problems not with radio reception,
but with their radio units in the field. Both Inga and Jin brought two
radios each for redundancy, but both of Inga’s radios failed in the
field, and Jin’s primary radio failed. Jin noticed that near failure,
the radio battery indicator drops substantially while transmitting.
Dave and Jin suspect that this due to the age of the batteries,
causing them to hold less charge and to have higher equivalent series
resistances. As a result, when the radio draws current while
transmitting, the battery’s internal voltage drop increases as
predicted by Ohm’s Law, causing the battery indicator to drop. Dave is
in the process of systematically testing the radio batteries while
transmitting.
Crew 228 has made a number of findings in this EVA. Firstly, it
successfully tested hiking trails that permit access to the dried-up
river delta, although these trails are challenging to negotiate and
should only be attempted by experienced EVA personnel. Secondly, it
found that viewshed calculation can be a helpful guide in finding
radio blackout regions, but its precision is low; it is on the order
of hundreds of metres.
Destinations:
1) Robert’s Rock Garden
2) Escarpment ~700 m southwest of Robert’s Rock Garden entering river delta
3) Search region south of Robert’s Rock Garden
4) Cow Dung Road at Galileo Road intersection
Destination coordinates:
DESTINATION TARGET COORDINATES (DD WGS84) TARGET COORDINATES (UTM NAD27)
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1 38.3932857°N -110.7903910°W
zone 12 4249269 N 518369 E
2 38.3880215°N -110.7955099°W
zone 12 4248684 N 517923 E
3 In same region as 2
4 38.4175715°N -110.7814639°W
zone 12 4251966 N 519142 E
Participants: Inga Popovaite, Jin Sia
Road(s) and routes per MDRS Map: Cow Dung Road 0110
Mode of travel: Rover and foot
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