Revolutionizing Civilian Remote Sensing: The Launch of Landsat 1

Forty years ago today — July 23, 1972 — the Earth Resources Technology Satellite (ERTS) 1 launched from Vandenberg AFB atop a Delta rocket.

Renamed Landsat 1, the satellite was the first to demonstrate global remote sensing for “agricultural and forestry resources, geology and mineral resources, hydrology and water resources, geography, cartography, environmental pollution, oceanography and marine resources, and meteorological phenomena.”


(Landsat images of Mount St Helens. NASA image.)

According to this Landsat page, the choice of wavelengths for Landsat’s multispectral scanner (MSS) “was primarily based on forestry and geologic applications that had traditionally used Color IR photography.” At the time, multispectral imaging was “secondary and highly experimental,” according to this page, but scientists soon recognized the utility of the multispectral data.

The spacecraft operated until January 1978, five years longer than expected.

Facebooktwittergoogle_pluspinterestlinkedinmailby feather

A New Generation of Environmental Monitoring Capabilities

Thirty years ago today — July 16, 1982 — Landsat 4 launched atop a Delta rocket out of Vandenberg AFB.


(Landsat 4. NASA image.)

Though it was the fourth in the Landsat series of spacecraft, Landsat 4 “was a major step forward in global remote-sensing applications.” According to this NASA page,

In addition to the Multispectral Scanner System (MSS) instrument, Landsat 4 (and Landsat 5) carried a sensor with improved spectral and spatial resolution, i.e., the new satellites could see a wider (and more scientifically-tailored) portion of the electromagnetic spectrum and could see the ground in greater detail. This new instrument was known as the Thematic Mapper (TM).

The Landsat 4 TM instrument had seven spectral bands. Data was collected from the blue, green, red, near-infrared, mid-infrared (2 bands) and thermal infrared portions of the electromagnetic spectrum.

The Thematic Mapper was an important addition to the environmental monitoring instrumentation, and later Landsat spacecraft carried improved versions of it.

Landsat 4 was designed to operate for 3 years. Although some of its components failed, it continued to operate in a limited capacity until 1993. Thereafter, the spacecraft sent telemetry data until 2001, when it was decommissioned.

Facebooktwittergoogle_pluspinterestlinkedinmailby feather

Cometary Mission, Presumed Lost, and a Long-Lasting Solar Explorer

Ten years ago today — July 3, 2002 — a Delta II rocket launched from Cape Canaveral carrying the CONTOUR (Comet Nucleus Tour) spacecraft.


(Artist’s conception of CONTOUR. NASA image.)

CONTOUR operated nominally for six weeks until it started the orbital escape maneuver that would take it away from Earth.

The spacecraft was scheduled to ignite its STAR 30 solid rocket engine on 15 August 2003 at 08:49 UT (4:49 a.m. EDT). This firing was to take CONTOUR out of Earth orbit and put it on a heliocentric trajectory. However, following the scheduled firing time, no further contact was made with the craft. Telescopic surveys were made under the assumption that the firing took place on schedule, and three objects were identified near the expected position of CONTOUR, leading investigators to believe that the firing took place and that these objects were parts of the spacecraft and rocket engine. An investigation board concluded that the most likely cause of the mishap was structural failure of the spacecraft due to plume heating during the solid-rocket motor burn. Alternate possible but less likely causes determined were catastrophic failure of the solid rocket motor, collision with space debris, and loss of dynamic control of the spacecraft.

So CONTOUR was presumed lost. It was supposed to attempt fly-bys of comets Encke and Schwassmann-Wachmann-3, with a possible third flyby of comet d’Arrest.

In more successful space history, on this date in 1992 the Solar, Anomalous and Magnetospheric Particle Explorer (SAMPEX) mission launched from Vandenberg AFB on a Scout rocket. SAMPEX was designed to study cosmic rays, energetic particles emitted by the sun, and the magnetospheric particles for which it was named. The spacecraft was only expected to last about three years, but it continued to send back data until July 2004.

Facebooktwittergoogle_pluspinterestlinkedinmailby feather

Star Wars Day Space History …

… from our little part of this galaxy, not that long ago.

Forty-five years ago today — May 4, 1967 — an Atlas Agena rocket launched from Cape Canaveral carrying the Lunar Orbiter 4 on its mission to the Moon.

Because the previous three Lunar Orbiters had “completed the required needs for Apollo mapping and site selection,” NASA tasked this fourth orbiter to “perform a broad systematic photographic survey of lunar surface features in order to increase the scientific knowledge of their nature, origin, and processes, and to serve as a basis for selecting sites for more detailed scientific study by subsequent orbital and landing missions.”

Lunar Orbiter 4 developed problems with the camera door, however: it did not open and close correctly when commanded, and mission controllers feared that it might stick closed so they commanded it to remain open.

This required extra attitude control manuevers on each orbit to prevent light leakage into the camera which would ruin the film. On 13 May it was discovered that light leakage was damaging some of the film, and the door was tested and partially closed. Some fogging of the lens was then suspected due to condensation resulting from the lower temperatures. Changes in the attitude raised the temperature of the camera and generally eliminated the fogging. Continuing problems with the readout drive mechanism starting and stopping beginning on 20 May resulted in a decision to terminate the photographic portion of the mission on 26 May.

Even with those problems, the spacecraft was able to read and transmit “419 high resolution and 127 medium resolution frames were acquired covering 99% of the Moon’s near side at resolutions from 58 meters to 134 meters.”

And in more recent space history …

Just a decade ago, on this date in 2002, the remote sensing spacecraft Aqua was launched from Vandenberg AFB by a Delta-II rocket.


(A depiction of the “A-Train” formation of satellites in similar orbits. Aqua was the first vehicle in the A-Train. NASA image.)

Originally known as Earth Observation System Afternoon One (EOS-PM1) for the time of day it would cross the equator, the mission was renamed Aqua

for the large amount of information that the mission is collecting about the Earth’s water cycle, including evaporation from the oceans, water vapor in the atmosphere, clouds, precipitation, soil moisture, sea ice, land ice, and snow cover on the land and ice. Additional variables also being measured by Aqua include radiative energy fluxes, aerosols, vegetation cover on the land, phytoplankton and dissolved organic matter in the oceans, and air, land, and water temperatures.

If I recall, one of the folks I worked with at the Defense Technology Security Administration came to us from the Aqua program. Pretty cool.

Facebooktwittergoogle_pluspinterestlinkedinmailby feather

Space History: Saturn, Soyuz, Space Tourism, Pegasus, and Clouds

Today’s space history starts a half-century ago — on April 25, 1962 — with a Saturn-1 suborbital test launch out of Cape Canaveral.


(SA-2 launch. NASA image from Wikimedia Commons.)

Mission SA-2, or “Project High Water,” flew water-filled upper stages atop a Saturn-1, which was the Saturn-V first stage. The upper stages were blown up near the apogee of the suborbital flight, creating an “artificial cloud.” According to this NASA history page, “This was used to study the effects on radio transmission and changes in local weather conditions. At an altitude of 150km, explosive devices ruptured the S-IV and S-V tanks and in just five seconds, ground observers saw the formation of a huge ice cloud estimated to be several kilometers in diameter.”

Having nothing to do with clouds, on April 25, 2002, Soyuz TM-34 launched from the Baikonur Cosmodrome on a ferry flight to the International Space Station (ISS). In addition to its working crew of Russian cosmonaut Yuri P. Gidzenko and Italian astronaut Roberto Vittori, it carried South African Mark R. Shuttleworth as the second commercial space tourist.

Finally, on this date 5 years ago, a Pegasus XL rocket launched from its L-1011 carrier aircraft flying out of Vandenberg AFB, carrying the AIM (Aeronomy of Ice in Mesosphere) satellite. The small spacecraft’s mission brings us back to the topic of clouds, as it was built to study “Polar Mesospheric Clouds (PMCs) that form about 50 miles above the Earth’s surface in summer and mostly in the polar regions.”

Facebooktwittergoogle_pluspinterestlinkedinmailby feather

Early European Space Observatory

Forty years ago today — March 11, 1972 — the European TD-1A satellite launched from Vandenberg AFB atop a Thor-Delta rocket. The satellite’s “TD” designation was actually taken from the Thor-Delta launch system.


(TD-1A satellite. NASA image.)

TD-1A was Europe’s first three-axis-stabilized spacecraft, designed “to make a systematic sky survey in the ultraviolet and high-energy regions of the spectrum.” Two instruments pointed at the sun and measured its x-ray and gamma ray output; five other instruments scanned the sky to measure “ultraviolet, x and gamma rays, and heavy nuclei.”

More information on TD-1A is available on its page in the High Energy Astrophysics Science Archive Research Center.

Facebooktwittergoogle_pluspinterestlinkedinmailby feather

Last Titan-IIIB Launch … and the Latest Asimov's

Twenty-five years ago today — February 12, 1987 — a Titan-IIIB launched from Vandenberg AFB carrying a Satellite Data System (SDS) spacecraft.


(Undated Titan-IIIB [34B] launch. Image from Lee Brandon-Cremer via Wikimedia Commons. Almost certainly this was originally a USAF photograph.)

According to the National Space Science Data Cnter, SDS satellites operated in highly elliptical orbits and

served as a communications link between the Air Force Satellite Control Facility at Sunnyvale, CA, and 7 remote tracking stations located at Vandenberg AFB, Hawaii, Guam, Nahe Island, Greenland, the UK, and Boston.

This is significant to me because I know the tracking station in Greenland well. Many years later I commanded it: callsign POGO, the Thule Tracking Station.

According to this Wikipedia page, this was the last launch of the Titan-IIIB series. This particular vehicle was one of the -34B variants.

At the time of that launch, I was stationed at the AF Rocket Propulsion Laboratory at Edwards AFB, helping prepare for a static test of a full-scale solid rocket motor in support of the Titan-34D “recovery” program. But that’s another story.

And speaking of stories: yesterday my contributor’s copies of the April/May issue of Asimov’s Science Fiction arrived, and there on page 72 is my story, “Sensitive, Compartmented.”

So … space history that relates in part to my own USAF experience, and a new short story. That makes for a pretty good weekend.

Facebooktwittergoogle_pluspinterestlinkedinmailby feather

Last Launches from Algeria, Plus Two Weather Satellites

Forty-five years ago today — February 8, 1967 — France launched the Diademe-1 satellite atop a Diamant-A rocket from their Hammaguir, Algeria, launch site. Exactly a week later they launched Diademe-2. These appear to be the last launch campaigns conducted at the Hammaguir site.


(Diamant launch vehicle static display. Photo by “I, Captainm,” licensed under Creative Commons, from Wikimedia Commons.)

Diademe-1 and its sister satellite were “designed for experimental geodetic studies using Doppler effect and laser telemetry techniques,” and were tracked by French and other ground stations around the world. According to this Wikipedia page on the Diamant launch vehicle, Diademe-1 was placed in a lower-than-expected orbit; however, the National Space Science Data Center did not mention that fact.

On the same 1967 date as the Diademe-1 launch, the U.S. launched a Defense Meteorological Satellite Program Block 4 satellite from Vandenberg AFB on a Thor rocket. And on this date 5 years earlier — i.e., 50 years ago — a Thor-Delta launched from Cape Canaveral put the Television and InfraRed Observation Satellite TIROS-4, also a weather satellite, into orbit.

Facebooktwittergoogle_pluspinterestlinkedinmailby feather

Last Thor-Delta Launch

Forty years ago today — January 31, 1972 — the HEOS (Highly Elliptical Orbit Satellite) A-2 launched from the Western Space and Missile Center at Vandenberg AFB.

HEOS A-2 was built by the European Space Research Organization, the precursor to today’s European Space Agency, to study “interplanetary space and the high-latitude magnetosphere.”

HEOS 2 provided new data on the sources and acceleration mechanisms of particles found in the trapped radiation belts and in the polar precipitation regions and auroral zones. It also monitored solar activity and cosmic radiation.

According to this Wikipedia page on 1972 spaceflight, this was also the last launch of the Thor-Delta rocket configuration, which itself was part of the family of Delta rockets that are still launching satellites today.


(An early Thor-Delta, from 1961. USAF image from Wikimedia Commons.)

Facebooktwittergoogle_pluspinterestlinkedinmailby feather

Dual Launch on a Delta-II, and an Old Test Satellite

Ten years ago today — December 7, 2001 — a Delta-II launch vehicle carried two satellites into orbit from Vandenberg AFB.


(Artist’s conception of the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics [TIMED] satellite. NASA image.)

Jason-1 was a joint mission between the U.S. and France: an oceanographic satellite intended to monitor the level and wave heights of the ocean surface. The Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics, or TIMED, satellite was designed to study “the physical and chemical processes acting within and upon the coupled mesosphere,” i.e., that portion of the atmosphere between 60-180 km altitude. This region of the atmosphere “is difficult to study because it is too high for even the largest research balloons and still dense enough to quickly cause a satellite to decay from orbit.”

In earlier space history, on this date 45 years ago, Applications Technology Satellite 1 (ATS-1) launched from Cape Canaveral atop an Atlas Agena rocket. ATS-1 was a test platform for new spacecraft design concepts, particularly propulsion and attitude control, as well as a remote sensing satellite that collected meterological data and cloud cover images. ATS-1 also tested improved satellite communications.

Facebooktwittergoogle_pluspinterestlinkedinmailby feather