Mission Report
Canada's ozone research project launched into space.
ACE/SCISAT-1 Project Report-Radio (French only)
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Recent developments
Before the launch:
After the launch:
ACE-FTS Instrument
SUNDAY, AUGUST 10, 2003
A Canadian science satellite designed to monitor Earth's ozone layer will soar into Earth orbit Tuesday night aboard an air-launched Pegasus XL rocket dropped from a carrier jet off the coast of California.
The day's available launch window extends from 7:04:10 to 8:01:26 p.m. Pacific Time (10:04:10-11:01:26 p.m. EDT; 0204-0301 GMT).
Release of the Orbital Sciences rocket from the modified L-1011 aircraft is targeted to occur a few minutes into the window while flying about 100 miles west of California's central coast.
The mission originates from Vandenberg Air Force Base, the home port for Pegasus rockets.
Air Force weather forecasters predict an 80 percent chance of acceptable conditions for the mission. Turbulence is the only worry.
"A developing low pressure system forming off the Washington-Oregon coast will move eastward today, moving onshore late Monday afternoon," Launch Weather Officer Capt. Scott Lisko said Sunday.
"This low will bring increasing upper-level winds to central California, both over Vandenberg and at the drop point. These increasing winds are causing slight concern for the turbulence constraint in the drop box, as the jet stream may cause occasional turbulence in the drop area.
"For launch time, Vandenberg will have scattered low-level marine layer clouds, with winds out of the northwest. The flight path to the drop point will be clear, with occasional turbulence possible.
"Maximum upper level winds on launch day will be out of the west at 70-80 knots near 40,000 feet
In the event launch is delayed to Wednesday, the forecast calls for a 90 percent chance of meeting the launch weather rules. Turbulence remains the only concern.
"Weather conditions for a 24-hour slip will remain steady. The low pressure system moving onshore to our north will continue to bring moderate jet stream winds to the area, with marine layer stratus clouds lingering over Vandenberg. Weather conditions should remain favorable, with slight concern for turbulence in the drop box. Upper level winds will remain out of the west, reaching a maximum of 60-70 knots near 40,000 feet."
This will mark the 35th flight for Pegasus since debuting in 1990 and the last of fourth launches scheduled in 2003. The small satellite launcher is currently riding a string of 20 consecutive successful flights since 1997.
The SciSat 1 cargo being deployed Tuesday carries two instruments to measure the concentration and distribution of chemicals, including ozone, in the atmosphere. Scientists hope the data gathered by the satellite will help explain the processes that break down Earth's ozone layer.
TUESDAY, AUGUST 12, 2003
2200 GMT (6:00 p.m. EDT)
The countdown activities are beginning at Vandenberg Air Force Base in California for tonight's 7:10 p.m. PDT (10:10 p.m. EDT; 0210 GMT) launch of the SciSat 1 atmospheric science satellite aboard an Orbital Sciences Pegasus XL rocket.
The Pegasus countdown lasts over four hours. It features a series of ground-based events such as final preparations to the payload, performing power tests on the rocket and checking the Range Safety's Flight Termination System.
"With an air-launched syustem you obviously want to make sure you are fully checked out before you take off," NASA Launch Manager Chuck Dovale said. "So the Pegasus will be powered on, the electrical and guidance systems checked, we will do a Flight Termination System check with the Range and make sure all the (communications) are working."
The L-1011 carrier aircraft will taxi to the runway in a couple of hours. Takeoff it expected around 6:12 p.m. PDT (9:12 p.m. EDT; 0112 GMT). The jet will fly a pre-determined "race track" pattern over the Pacific to reach the proper launch point where Pegasus will be released to roar into orbit.
Today's launch window extends from 7:04 to 8:01 p.m. PDT (10:04-11:01 p.m. EDT; 0204-0301 GMT.
0401 GMT (12:01 a.m. EDT)
Canada's SciSat 1 atmospheric research satellite heads into space tonight aboard Orbital Sciences' air-launched Pegasus XL rocket.
Flying over the Pacific Ocean about 50 miles northwest of Monterey, California, the 50,000-pound rocket will be released from the belly of Orbital's L-1011 carrier jet, named Stargazer, at approximately 7:10 p.m. local time (10:10 p.m. EDT; 0210 GMT).
The mission will begin 58 minutes earlier when Stargazer takes off from Vandenberg Air Force Base bound for the preset launch point. The aircraft will follow a "race track" course, which is illustrated on this map.
The track takes Stargazer through the launch area on a northward heading, allowing the aircraft crew to evaluate weather conditions. The plane then makes a U-turn and returns to the drop point on a southerly trajectory to launch the rocket.
The day's available launch window extends from 7:04:10 to 8:01:26 p.m. Pacific Time (10:04-11:01 p.m. EDT; 0204-0301 GMT). Should a problem occur during the countdown, the window is long enough to support one recycle before the launch would have to be scrubbed. A backup launch opportunity Wednesday night is available on the Western Range.
With the push of a button in the Stargazer's cockpit, the Pegasus rocket is cast free to fall for five seconds, dropping 300 feet below the aircraft. During the plunge, the onboard flight computer will sense the rocket's separation from the carrier jet and issue a command to release the safety inhibits in preparation for ignition.
The first stage solid-fueled motor of Pegasus is lit at T+5 seconds to begin the powered journey to orbit with the SciSat 1 spacecraft.
At T+1 minute, 15 seconds, the Orion 50S XL first stage motor consumes all of its solid-fuel propellant and burns out. A short ballistic coast period begins before the spent first stage is separated to fall into the Pacific Ocean.
A second later, the Pegasus rocket's Orion 50 XL second stage begins firing to continue the trip to orbit. During the firing, at T+2 minutes, 6 seconds, the payload fairing that protected the SciSat 1 satellite during atmospheric ascent is jettisoned.
Having consumed its supply of solid-fuel propellant, the second stage motor burns out at T+2 minutes, 45 seconds. A longer coast period begins before releasing the spent stage at T+plus 7 minutes, 16 seconds.
The solid-fueled Orion 38 third stage ignites at T+plus 7 minutes, 27 seconds to deliver the SciSat 1 spacecraft into the desired highly-inclined orbit around Earth. That circular orbit of 400 miles inclined 73.9 degrees to the Equator is achieved with cutoff of the third stage at T+8 minutes, 38 seconds.
Release of the 330-pound SciSat 1 from the launcher occurs at T+plus 10 minutes, 38 seconds, completing the Pegasus rocket's 35th launch since debuting in 1990.
NASA is managing the launch for Canada's space program under a cooperative arrangement between the two agencies. The launch costs are $21.6 million. The price tag for the SciSat spacecraft, its instruments and two years of mission operations is $40 million.
SciSat 1 will study the chemical processes that control the distribution of ozone in the Earth's atmosphere, particularly at high latitudes.
The primary onboard science instrument is the Fourier Transform Spectrometer, built by ABB of Quebec City. The second instrument is the Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation, or MAESTRO for short. It was built by EMS Technologies of Ottawa.
AUGUST 13, 2003
Canada's SCISAT satellite successfully launched
Saint-Hubert, August 13, 2003 - The Canadian Space Agency (CSA) today confirmed the successful launch of its SCISAT satellite last night from NASA's launch facilities near Lompoc, California. During its two-year mission, SCISAT will help a team of Canadian and international scientists improve their understanding of the depletion of the ozone layer, with a special emphasis on the changes occurring over Canada and in the Arctic.
"This leading-edge Canadian technology will improve our scientific understanding of the complex chemical changes occurring in the upper atmosphere, particularly in the far north", said Mr. Allan Rock, Minister of Industry." The SCISAT mission illustrates how Canadian universities, government and industry can work together to put innovative technologies at the service of scientific research," added Minister Rock.
SCISAT was launched yesterday at 19:10 PDT, approximately 160 km offshore from the Vandenberg Air Force Base. The 150 kg satellite was packed in the nose of a Pegasus XL rocket dropped at 40,000 feet over the Pacific Ocean from a Lockeed-1011 aircraft. The satellite was successfully brought to its 650 km-high polar orbit by the 3-stage Pegasus rocket.
"SCISAT sets a milestone in Canadian space science," said Marc Garneau, President of the CSA. "Following the MOST space telescope launched in June, SCISAT is the second science satellite successfully placed in orbit by Canada in the last 45 days. This illustrates the growing importance of space science for Canada and for the Canadian Space Program."
A scientific team of researchers from around the world, lead by Professor Peter Bernath of the University of Waterloo, will participate in the Atmospheric Chemistry Experiment (ACE) which aims to measure and understand the chemical processes that control the distribution of ozone in the Earth's atmosphere, particularly at high latitudes. The data, recorded as SCISAT orbits the Earth, will provide scientists with improved measurements relating to global ozone processes. It will also help policy makers assess existing environmental policy and develop protective measures for improving the health of our atmosphere and preventing further ozone depletion.
The primary scientific instrument on board SCISAT is a Fourier Transform Spectrometer (ACE-FTS), built by ABB (formerly ABB-Bomem) of Québec City. A second instrument named MAESTRO (Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation), built by EMS Technologies of Ottawa, will also fly on the satellite. Dr. Tom McElroy of Environment Canada is the principal investigator for MAESTRO, and will be supported by Professor James Drummond of the University of Toronto.
SEPTEMBER 10, 2003
The Launch and Early Orbit Phase (LEOP) of the mission was successfully completed within 2 days of launch. The satellite was successfully oriented so that the solar panel pointed toward the sun within a capture-control angle of 11 degrees. Early telemetry indicated that electric power generation and all temperature sensors were at nominal levels.
An early concern was a slightly noisier command receiver (for data uplink) than expected, although sufficiently minor that it has no impact on the communications function. A technical review of the receiver design, as well as flight data since launch, indicates that the source of the slight noisiness is benign and the noise level is not expected to increase with time.
The power to the two scientific instruments has been switched on, and heaters for temperature control of the instruments are maintaining temperatures within operational limits. The instruments remain in standby mode pending the completion of additional commissioning activities.
The satellite fine pointing control was successfully commissioned last week. This now maintains pointing of the solar panel toward the center of the sun within an angle of approximately 1 degree. Finer pointing of the instrument look direction, to an accuracy of a few seconds of arc, will be accomplished with an instrument-mounted suntracker (not yet commissioned). Although sun-facing, there is no control yet of the satellite roll.
This week and next week the detectors of the Fourier transform spectrometer (FTS) will be decontaminated using heaters. The locking pin on the FTS rotary arm will also be pulled.
Commissioning of the satellite bus is also continuing with the imminent activation of the momentum wheel for roll control. By the end of September, roll control will be achieved allowing the FTS detectors to cool properly, and the first spectra to be recorded.
It is anticipated that "first light" data from the instruments will become available as part of the instrument commissioning activities. If all continues nominally, this is expected by early October for the FTS and by late October for MAESTRO.
SEPTEMBER 23, 2003
The outgassing/decontamination of the ACE-FTS infrared detectors was successfully completed Monday morning (total duration 7 days).
The pin-puller was activated Saturday morning, and everything went as planned. The pin-puller was used to lock the interferometer mechanism during launch. We saw laser fringes appearing right after the activation of the pin-puller: very good sign !
OCTOBER 3, 2003
The roll control and earth avoidance maneuvre of the spacecraft was successfully implemented this week. This control is very critical to maintain the FTS cryocooler oriented toward deep space for cooling infrared detectors to cryogenic temperatures.
The FTS detectors are presently near 80K and cooling down is still in progress at a rate of 0.5K/hour. We have good indications that the cooling performance will be slightly better than initially expected. We also can see significant variations of the DC level of the detectors when the Sun appears (the FTS acting as a radiometer in this configuration), which is a good sign. First interferograms should be acquired in 2-3 weeks.
OCTOBER 23, 2003
The FTS inteferometer mechanism power-on went successfully early morning.
The first step consisted in operating the interferometer in open-loop mode (i.e., not using the laser as feedback for the servo control). We compared the modulated laser signals with the ones measured at Vandenberg and they are nearly identical. Voltage levels and other parameters are also nominal.
Step 2 will be performed Friday, and Step 3 (which includes the acquisition of the first spectra in closed-loop control on Monday).
OCTOBER 27, 2003
The acquisition of the first ACE-FTS spectra was successfully achieved last night. Since the spacecraft orbit was then on night-side, spectra consists of instrument self-emission and possibly some earth emission as well.
The goal of this first acquisition was to start-up the interferometer mechanism in close-loop control, and to calibrate the Zero Path Difference (ZPD) position. The acquisition of the first Sun and atmospheric spectra at full spectral resolution is scheduled for Thursday !
OCTOBER 30, 2003
The acquisition of the first ACE-FTS solar spectra as well as images from the auxiliary imagers was successfully achieved on Thursday 20h45 UTC !
The interferometer was then sweeping at its full spectral resolution (0.02 cm-1). Since the suntracker is not yet activated, the IR spectrometer/FTS was then looking just on the edge of the Sun, but sufficiently to obtain some reasonable level of infrared signals. As for the imagers, interesting Sun images were acquired, showing the two famous spots that are presently causing the solar and geomagnetic storms.
Up to now, the satellite does not seem to be severly affected by the solar storm, but the situation remains critical due to the very high intensity of these storms. Images from the Sun, acquired by the auxiliary two imagers, are showed below (note the two Sun spots).
The IR spectra of the ACE-FTS, the main science product of the SciSat-1 mission, require mathematical processing but at first glance, everything looks as expected.
Sun two spots - Picture not available for now....
OCTOBER 31, 2003
Click Here to see the first spectra acquired with the ACE-FTS.
Although the performance is modest considering the detectors will need decontamination (using outgassing heaters) and that the suntracker is not yet activated, these preliminary measurements indicate that the spectrometer is fully functional as well as the auxilairy imagers.
The first atmospheric measurements are planned in early December !
NOVEMBER 20, 2003
As part of the suntracker commissioning activities the first atmospheric spectra were recorded and a few "first-light" spectra are attached.
ABB-Bomem also converted on of the imager channels into a movie so you can watch the corresponding sunset. (The threshold for the suntracker is set at 10 % of the maximum radiance so at the end of the sequence the suntracker locks its position and thus the image appears to move on the imager.)
As you can see, the spectra are of very high quality!
Click Here to watch the Sunset seen by ACE-FTS NIR imager.
Click Here to get the FIrst ACE-FTS spectra presentation.