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Fairing access
Solid-fuel boosters
Delta II rocket
Fairing Jettison
t = 4 min, 42 sec
Alt = 121.3 km (75.4 mi)
VI = 22,377 km/h (13,904 mph)
Stage 2 Ignition
t = 4 min, 36.9 sec
Alt = 118.9 km (73.9 mi)
VI = 22,326 km/h (13,873 mph)
Main Engine Cutoff Stage 2 Cutoff #1
t = 4 min, 23.4 sec t = 9 min, 38.5 sec
Alt = 119.3 km (74.1 mi) Alt = 170.4 km (105.9 mi)
VI = 22,317 km/h (13,867 mph) VI = 28,095 km/h (17,457 mph)
Booster Jettison (3)
t = 2 min, 11.5 sec
Alt = 52.4 km (32.6 mi)
VI = 9,046 km/h (5,621 mph)
Numbers approximate, for
Booster Jettison (3/3) first day of Rover A launch period
t = 1 min, 6 sec and
1 min, 7 sec
Alt = 18.0 km (11.2mi) /
18.3 km (11.4 mi)
VI = 3,668 km/h (2,279 mph) /
3,712 km/h (2,307 mph) Booster Impact Booster Impact
Launch phases
Stage 2 Cutoff #2
29 min, 29.4 sec Mars Exploration Rover
Stage 3 Ignition Spacecraft Separation
162.6 km (101.0 mi) x
30 min, 59.4 sec 37 min, 14.4 sec
4,762.0 km (2,959.0 mi) orbit at
28.48 deg inclination
Stage 2-3 Separation Stage 3 Burnout
30 min, 22.4 sec 32 min, 26.6 sec
Stage 2 Restart
27 min, 23.7 sec
159.8 km (99.3 mi) x
Numbers approximate, for
179.6 km (111.6 mi) orbit at first day of Rover A launch period
28.49 deg inclination
Launch phases
Entry - 6 hours
Mars at 3 or 4 Jan
arrival Maneuver
1/4/04 Entry - 2 days
2 Jan
Earth at
arrival Entry - 8 days
27 Dec
Entry - 58 days
7 Nov
10 Oct
Launch + 10 days
18 Jun
Earth at
1 Aug
6/8/03 17-day launch
20 -day tick marks
Mars at launch
Rover A trajectory
pletion of even one orbit, however, the Delta's second stage will reignite to begin push-
ing the spacecraft out onto its interplanetary trajectory toward Mars. This begins about
14 to 19 minutes after liftoff for Rover A, depending on the date and time of launch,
and about 59 to 67 minutes after liftoff for Rover B. The second burn of the Delta's
second stage will last 2 to 3 minutes.
Small rockets will be fired to spin the Delta's third stage to about 63 rotations per
minute on a turntable attached to the second stage. The third stage will then separate
from the second, firing its engine for about 87 seconds to finish putting the spacecraft
on course for Mars. To reduce the spacecraft's spin rate after the third-stage engine
finishes firing, a set of yo-yo-like weights will reel out on flexible lines. These work like
a twirling ice-skater's arms, slowing the spin as they are extended.
The spacecraft will shed the burned-out Delta third stage about 34 to 39 minutes after
liftoff for Rover A and 78 to 87 minutes after liftoff for Rover B. Springs will push the
third stage away, exposing an antenna on the rover spacecraft's cruise stage. Radio
Mars at Entry - 6 hours
24 or 25 Jan
Entry - 2 days
23 Jan
Earth at Entry - 8 days
17 Jan
1.14 Entry - 65 days
21 Nov
Launch Maneuver
+ 10 days Launch + 75 days
8 Sep
21-day launch
Earth at launch period
Mars at launch
20-day tick marks
Rover B trajectory
transmissions from the Delta II will enable controllers on the ground to monitor critical
events throughout the launch sequence. However, communications with each Mars
Exploration Rover spacecraft cannot begin until after it separates from the Delta's third
stage. NASA's Deep Space Network will begin receiving radio signals from Rover A
about 50 minutes after launch, using the network's Canberra, Australia, antenna com-
plex. For Rover B, initial radio contact with the Deep Space Network is expected at the
Goldstone, Calif., antenna complex one minute or more after third-stage separation.